Tumor growth is caused by various etiological agents. According to experimental studies, the tumor develops under the influence of ionizing and ultraviolet radiation, various chemicals, some classes of DNA viruses with horizontal transmission; the tumor may be due to superinfection of certain RNA viruses, etc.
In medical practice, smoking women and men, workers of certain professions associated with potentially carcinogenic substances (aniline dyes, radioactive radiation, asbestos, etc.) can attract special attention of a doctor. The exclusion or reduction of the concentration of etiological factors is a real way to reduce the incidence of malignant tumors.
Cancer pathogenesis. Tumors can be benign and malignant. The former consist mainly of the same type of cells that do not differ significantly in morphology from normal cells, with little potential for growth, without the ability to invade and metastasize. Many benign tumors retain these features throughout a person's life, rarely degenerating into corresponding malignant tumors. For example, subcutaneous tissue lipoma, uterine fibroids are extremely rarely transformed into sarcoma. However, benign tumors can be a stage in the development of cancer and sarcoma. So, diffuse intestinal polyposis throughout life in almost 100% of cases turns into cancer. In many cases, the stage of preservation by the tumor of the characteristics of benign tissue growth (precancer) may not be as obvious as in polyposis, but one way or another, such a stage, which takes a different period of time, exists. Malignancy is associated with repeated changes in the genetic apparatus of tumor cells, which are prone to mutations much more than normal cells. As a result, new cell clones arise, characterized by sharp cellular polymorphism, atypia, germination in adjacent organs and the ability to grow in the form of metastatic foci in other organs and tissues. rational methods of diagnosis and treatment of these diseases. We emphasize that the diagnosis - a tumor benign or malignant - should be immediate and clear. When establishing a primary diagnosis, the method of observation, which takes into account the growth rate of the tumor, is a path to error. Genetic factors play an important role in the pathogenesis of some tumors. In animals, the role of genetic predisposition is obvious (on the example of high- and low-cancer lines of mice). In humans, a tumor can be either the only manifestation of a genome defect or a part of various disorders in the genome leading to multiple malformations and tumors. The doctor should conduct special monitoring of members of such families, discuss with them their professional activities (it is necessary to exclude contact with potential carcinogens) and choose a system of medical control (early detection of a tumor). Known genetic tumors include retinoblastoma, nevus basal cell carcinoma, trichoepithelioma, multiple endocrine adenomatosis, pheochromocytoma, medullary thyroid cancer, paraganglioma, and colon polyposis. The development of malignant tumors increases with violations of immunological control (immunodeficiency syndromes - agammaglobulinemia, ataxia-telangiectasia, etc.; prolonged use of immunosuppressive agents in case of organ transplantation and in certain diseases). Such patients also need more frequent medical supervision for timely detection of the tumor.
Invasion and metastasis of a malignant tumor determine the course of the disease. Tumor cells grow into neighboring organs and tissues, damage blood vessels and nerves. Invasion often, for example, in skin melanoma, also determines the time of development of metastases. Metastasis is one of the main properties of malignant tumors. Although there are isolated examples of metastasis and morphologically benign tumors (for example, adenomas of the thyroid, pancreas, destructive hydatidiform mole); this is a rare exception. Benign tumors usually do not metastasize.
Metastases of malignant tumors are found in regional lymph nodes, as well as in various organs and tissues. Knowing the ways of outflow of lymph is important when examining patients and planning treatment. In some cases, it is considered mandatory to perform an operation on the regional lymph nodes simultaneously with the removal of the primary tumor. The same approach is used with radiation therapy if it is the main method of treatment (irradiation of regional lymph nodes is also planned). Various tumors have features of metastasis to distant organs and tissues. For example, breast cancer more often metastasizes to the bones, testicular cancer, kidney cancer - to the lungs, colon cancer - to the liver, etc. In most cases, multiple metastases of various sizes occur, preserving the morphological structures and biological characteristics of the primary tumor. The lungs, liver, bones, and brain are most commonly affected.
It is important to know the features of distant metastasis of each tumor when drawing up a conclusion that the tumor is localized. This is necessary when planning surgery and radiation therapy, as well as for dynamic monitoring.
The development of metastases can be different. For example, kidney cancer metastases mainly appear within the first year after diagnosis and surgery, and in breast cancer - within 2-5 years, sometimes even after a year.
Recurrence of tumor growth appears in the same area in the coming months if the operation was non-radical or radiation therapy and / or chemotherapy did not lead to a true complete regression of the tumor. Relapses are similar in morphological structure to the primary tumor, but may have significant differences from it in biological characteristics.
Diagnosis of tumors. A conversation between a doctor and a patient. The doctor draws attention to the change in clinical symptoms in chronic diseases, asks some specific questions. A doctor's examination can also be a precautionary one - for the active detection of symptoms and examination. Significant assistance is provided in some cases by regular self-examination of people (palpation of the mammary gland, examination of pigmented nevi, etc.). The conversation and examination of the doctor contribute initial information to the formulation of the diagnosis.
cytological method. The diagnosis of a malignant tumor should always be established using cytological and/or histological examination. Materials obtained by tumor puncture, prints, washings, liquid centrifuges, etc. are subject to cytological examination. After puncture, cytological preparations are immediately fixed and then the necessary stains are used. The role of cytological analysis in breast cancer (preoperative puncture of the tumor), lung cancer (sputum, materials of bronchoscopy, transthoracic puncture), early stages of cancer of the stomach, esophagus, oral cavity, vagina and other tumors is important. The exceptional importance of the cytological method in cancer in situ should be emphasized, when the possibilities of this method are higher than those of the histological one. The role of cytological examination for early diagnosis is obvious in cervical cancer. If every woman regularly undergoes a cytological examination of smears, cervical cancer can be diagnosed at an early stage and cured in 100% of patients.
LECTURE No. 30. Fundamentals of surgical oncology
1. General Provisions
Oncology is a science that studies the problems of carcinogenesis (causes and mechanisms of development), diagnosis and treatment, and prevention of tumor diseases. Oncology pays close attention to malignant neoplasms due to their great social and medical significance. Oncological diseases are the second leading cause of death (immediately after diseases of the cardiovascular system). Every year, about 10 million people fall ill with oncological diseases, half as many die from these diseases every year. At the present stage, lung cancer occupies the first place in terms of morbidity and mortality, which has overtaken stomach cancer in men, and breast cancer in women. In third place is colon cancer. Of all malignant neoplasms, the vast majority are epithelial tumors.
Benign tumors, as the name implies, are not as dangerous as malignant ones. There is no atypia in the tumor tissue. The development of a benign tumor is based on the processes of simple hyperplasia of cellular and tissue elements. The growth of such a tumor is slow, the mass of the tumor does not grow into the surrounding tissues, but only pushes them back. In this case, a pseudocapsule is often formed. A benign tumor never metastasizes, there are no decay processes in it, therefore, with this pathology, intoxication does not develop. In connection with all the above features, a benign tumor (with rare exceptions) does not lead to death. There is such a thing as a relatively benign tumor. This is a neoplasm that grows in the volume of a limited cavity, such as the cranial cavity. Naturally, tumor growth leads to an increase in intracranial pressure, compression of vital structures and, accordingly, death.
A malignant neoplasm is characterized by the following features:
1) cellular and tissue atypia. Tumor cells lose their former properties and acquire new ones;
2) the ability to autonomous, i.e., uncontrolled by organismal processes of regulation, growth;
3) rapid infiltrating growth, i.e. germination of surrounding tissues by a tumor;
4) the ability to metastasize.
There are also a number of diseases that are precursors and harbingers of tumor diseases. These are the so-called obligate (a tumor necessarily develops in the outcome of the disease) and facultative (a tumor develops in a large percentage of cases, but not necessarily) precancers. These are chronic inflammatory diseases (chronic atrophic gastritis, sinusitis, fistulas, osteomyelitis), conditions accompanied by tissue proliferation (mastopathy, polyps, papillomas, nevi), cervical erosion, as well as a number of specific diseases.
2. Classification of tumors
Classification by tissue - the source of tumor growth.
2. Malignant (cancer):
2. Malignant (sarcomas):
1. Benign (fibroids):
1) leiomyomas (from smooth muscle tissue);
2) rhabdomyomas (from striated muscles).
2. Malignant (myosarcomas).
1. Benign (hemangiomas):
2. Malignant (angioblastomas).
1) acute and chronic;
2) myeloid and lymphoblastic.
2) dermoid cysts;
2. Malignant (teratoblastomas).
Tumors from pigment cells.
1. Benign (pigmented nevi).
2. Malignant (melanoma).
International Clinical Classification for TNM
Letter T (tumor) denotes in this classification the size and prevalence of the primary focus. For each localization of the tumor, its own criteria have been developed, but in any case tis(from lat. tumor in situ- "cancer in situ") - not germinating the basement membrane, T1 - the smallest size of the tumor, T4 - a tumor of significant size with the germination of surrounding tissues and decay.
Letter N (nodulus) reflects the state of the lymphatic apparatus. Nx - the state of regional lymph nodes is unknown, there are no distant metastases. N0 - the absence of metastases in the lymph nodes was verified. N1 - single metastases in regional lymph nodes. N2 - multiple lesions of regional lymph nodes. N3 - metastases to distant lymph nodes.
Letter M (metastasis) reflects the presence of distant metastases. Index 0 - no distant metastases. Index 1 indicates the presence of metastases.
There are also special letter designations that are placed after a pathohistological examination (it is impossible to set them clinically).
Letter R (penetration) reflects the depth of tumor germination of the wall of a hollow organ.
Letter G (generation) in this classification reflects the degree of differentiation of tumor cells. The higher the index, the less differentiated the tumor and the worse the prognosis.
Clinical staging of cancer according to Trapeznikov
I stage. Tumor within the organ, no metastases to regional lymph nodes.
II stage. The tumor does not grow into surrounding tissues, but there are single metastases to regional lymph nodes.
III stage. The tumor grows into the surrounding tissues, there are metastases in the lymph nodes. The resectability of the tumor at this stage is already questionable. It is not possible to completely remove tumor cells surgically.
IV stage. There are distant metastases of the tumor. Although it is believed that only symptomatic treatment is possible at this stage, resection of the primary focus of tumor growth and solitary metastases can be performed.
3. Etiology, pathogenesis of tumors. Diagnosis of a tumor disease
A large number of theories (chemical and viral carcinogenesis, disembryogenesis) have been put forward to explain the etiology of tumors. According to modern concepts, a malignant neoplasm occurs as a result of the action of numerous factors, both external and internal environment of the body. Of the environmental factors, the most important are chemicals - carcinogens that enter the human body with food, air and water. In any case, the carcinogen causes damage to the genetic apparatus of the cell and its mutation. The cell becomes potentially immortal. With the failure of the immune defense of the body, further reproduction of the damaged cell and a change in its properties occur (with each new generation, the cells become more and more malignant and autonomous). Violation of cytotoxic immune reactions plays a very important role in the development of a tumor disease. Every day, about 10 thousand potentially tumor cells appear in the body, which are destroyed by killer lymphocytes.
After about 800 divisions of the original cell, the tumor acquires a clinically detectable size (about 1 cm in diameter). The entire period of the preclinical course of a tumor disease takes 10-15 years. 1.5-2 years remain from the moment when a tumor can be detected to death (without treatment).
Atypical cells are characterized not only by morphological but also by metabolic atypia. In connection with the perversion of metabolic processes, the tumor tissue becomes a trap for the energy and plastic substrates of the body, releases a large amount of under-oxidized metabolic products and quickly leads to exhaustion of the patient and the development of intoxication. In the tissue of a malignant tumor, due to its rapid growth, an adequate microcirculatory bed does not have time to form (the vessels do not have time to grow behind the tumor), as a result, the processes of metabolism and tissue respiration are disturbed, necrobiotic processes develop, which leads to the appearance of foci of tumor decay, which form and maintain state of intoxication.
In order to detect an oncological disease in time, the doctor must have oncological alertness, that is, it is necessary to suspect the presence of a tumor during the examination, based only on small signs. Establishing a diagnosis based on obvious clinical signs (bleeding, sharp pains, tumor disintegration, perforation into the abdominal cavity, etc.) is already belated, since the tumor manifests itself clinically at stages II-III. For the patient, it is important that the neoplasm be detected as early as possible, at stage I, then the probability that the patient will live after the treatment for 5 years is 80-90%. In this regard, screening examinations, which can be carried out during preventive examinations, acquire an important role. In our conditions, the available screening methods are fluorographic examination and visual detection of cancer of external localizations (skin, oral cavity, rectum, breast, external genital organs).
Examination of an oncological patient must be completed with a histopathological examination of a suspicious formation. The diagnosis of a malignant neoplasm is untenable without morphological confirmation. This must always be remembered.
4. Cancer treatment
Treatment should be comprehensive and include both conservative measures and surgical treatment. The decision on the scope of the forthcoming treatment of an oncological patient is made by a council, which includes an oncologist, a surgeon, a chemotherapist, a radiologist, and an immunologist.
Surgical treatment may precede conservative measures, follow them, but a complete cure for a malignant neoplasm without removal of the primary focus is doubtful (excluding blood tumors that are treated conservatively).
Surgery for cancer can be:
Radical operations imply the complete removal of the pathological focus from the body. This is possible due to the implementation of the following principles:
1) ablastics. During the operation, it is necessary to strictly observe ablastics, as well as asepsis. The ablasticity of the operation is a prevention of the spread of tumor cells in healthy tissues. For this purpose, the tumor is resected within healthy tissues, without affecting the tumor. In order to check the ablasticity after resection, an emergency cytological examination of the imprint smear from the surface remaining after resection is performed. If tumor cells are found, the resection volume is increased;
2) zoning. This is the removal of nearby tissue and regional lymph nodes. The volume of lymph node dissection is determined depending on the prevalence of the process, but it must always be remembered that the radical removal of lymph nodes leads to the occurrence of lymphostasis after surgery;
3) antiblasts. This is the destruction of locally advanced tumor cells, which in any case dissipate during surgery. This is achieved by chipping the circumference of the pathological focus with antitumor drugs, regional perfusion with them.
Palliative surgery is performed if it is impossible to carry out a radical operation in full. In this case, a part of the tumor tissue array is removed.
Symptomatic operations are performed to correct emerging disorders in the activity of organs and systems associated with the presence of a tumor node, for example, the imposition of an enterostomy or a bypass anastomosis in a tumor that obstructs the outlet section of the stomach. Palliative and symptomatic operations cannot save the patient.
Surgical treatment of tumors is usually combined with other methods of treatment, such as radiation therapy, chemotherapy, hormonal and immunotherapy. But these types of treatment can also be used independently (in hematology, radiation treatment of skin cancer). Radiation therapy and chemotherapy can be applied in the preoperative period in order to reduce tumor volume, remove perifocal inflammation and infiltration of surrounding tissues. As a rule, the course of preoperative treatment is not long, since these methods have many side effects and can lead to complications in the postoperative period. The bulk of these therapeutic measures is carried out in the postoperative period. If the patient has stages II-III of the process, surgical treatment must necessarily be supplemented with a systemic effect on the body (chemotherapy) in order to suppress possible micrometastases. Special schemes have been developed to achieve the maximum possible removal of tumor cells from the body, without exerting a toxic effect on the body. Hormone therapy is used for some tumors of the reproductive sphere.
Etiology of cancer
Precancerous diseases of the red border of the lips and oral mucosa. Classification. Etiology, pathogenesis, clinic, diagnostics.
Currently, more than 10 million people in the world fall ill with cancer every year, and about 7 million people die (WHO data - 2003). Cancer is a disease of the genes.
Etiology of oncological diseases:
1. The theory of embryonic dystopia (Yu. Kongeim, 1882)
2. Theory of chronic nonspecific irritation (R. Vikhrov, 1885)
3. Theory of chemical carcinogenesis (P. Pott, 1775.; L. Shabad, 1981)
4. Theory of infectious-viral carcinogenesis (L. Zilber, 1946)
Exogenous factors: smoking (79%) - t°, toxins; chronic diseases; exposure to carcinogens; radioactive substances, destruction of immunomediators; chronic injuries (9%); PR hygiene (47%): theory of immune surveillance, associated with the endocrine and nervous system (herpes-candidiasis-poor hygiene > distracted immunity > precancer); galvanosis - the damaging effect of various metals on epithelial cells (the same charge of Ni, Co, W and other metal ions - the occurrence of repulsive forces), the first manifestations are redness, burning, dryness; then a state of precancer is possible.
Cell division: healthy (:50) and cancerous (: an infinite number of times). Apoptosis.
carcinogens. Currently, more than 1200 are known. Sources of carcinogens. Oncoviruses - about 60 of them are known, they easily start the cancer process.
In most patients, cancer is preceded by certain diseases of the oral mucosa and the red border of the lips, which are called precancerous. The state of precancer is a microscopic multicentrically emerging multiple foci of non-inflammatory atypical growth of immature epithelium with a tendency to infiltrative growth - "dormant cells". Contribute to their occurrence in the first place injuries, especially chronic ones, including smoking and chewing tobacco, betel, drinking nas, alcohol. Injuries are considered as external factors of carcinogenesis. Cancer is often preceded by proliferative processes, benign tumors, chronic inflammatory diseases, accompanied by erosions and ulcers. A precancerous disease exists for a long time (from several months to tens of years), then it can turn (but not necessarily) into cancer. Timely detection and treatment of precancerous diseases eliminates the threat of cancer or allows for timely, more effective and harmless treatment.
The pathogenesis of tumor growth:
- initiation - transformation of normal cells into tumor cells (due to a virus or a carcinogen);
Characteristic states of the immune system for phases.
Every cancer has a precancer, but not every precancer has a cancer.
Directions of precancer: progression; growth without progress, regression, without change.
Depending on the degree of probability of malignancy, obligate and facultative precancerous processes are distinguished. Obligate precancers without treatment necessarily lead to the development of cancer after various periods. In most cases, they are already cancer in situ from the very beginning. Facultative precancers do not always lead to cancer. We have adopted the classification of precancers proposed by A. L. Mashkilleison in 1970 and approved with minor amendments in 1976 by the Committee for the Study of Head and Neck Tumors of the All-Union Scientific Medical Society of Oncologists.
Classification of precancerous processes of the oral mucosa
A. With a high frequency of malignancy (obligate): 1) Bowen's disease.
B. With a low frequency of malignancy (optional): 1) verrucous and erosive leukoplakia; 2) papillomatosis; 3) erosive-ulcerative and hyperkeratotic forms of lupus erythematosus and lichen planus; 4) post-radiation stomatitis.
Classification of precancerous processes of the red border of the lips
A. With a high frequency of malignancy (obligate):
1) warty precancer; 2) limited precancerous hyperkeratosis; 3) abrasive pre-cancer cheilitis of Manganotti.
B. With a low frequency of malignancy (optional): 1) leukoplakia; 2) keratoacanthoma; 3) skin horn; 4) papilloma with keratinization; 5) erosive-ulcerative and hyperkeratotic forms of lupus erythematosus and lichen planus; 6) postradiation cheilitis.
Observations - Cancer loves the right side.
Below is information about obligate and some facultative precancers of the mucous membrane and the red border of the lips.
Bowen's disease (morbus Bowen)
Bowen first described this disease in 1912. It is cancer in situ from the very beginning. Etiology: chronic trauma of the oral mucosa.
Clinical picture. The posterior part of the oral cavity (palate, arches) is more often affected. The lesion is usually single, most often looks like a hyperemic bright red spot, smooth or with a velvety surface due to small papillary growths. The central area is similar to leukoplakia with a small bumpy surface or to lichen planus with keratinization foci on a hyperemic background. Due to atrophy of the mucous membrane, the focus sinks somewhat in comparison with the surrounding areas, in some places easily bleeding erosion occurs on it. The size of the lesion is from 1-2 mm to 5-6 cm, its outlines are uneven, quite clear. The seal at the base is not defined. When localized on the tongue, the papillae of the tongue at the site of the lesion disappear. Regional lymph nodes are usually not palpable. Subjective sensations are insignificant, but pain can be expressed with erosion. The clinical picture of Bowen's disease on the oral mucosa is not always clearly expressed. The disease can manifest itself only with a small area of hyperemia or resemble leukoplakia without severe inflammation.
The disease continues indefinitely, in some cases invasive growth quickly sets in, and traumatization accelerates this process, in others it remains in the cancer in situ stage for years. The diagnosis must be confirmed by histological examination.
Histologically, in Bowen's disease, a picture of intraepithelial spinocellular cancer is detected: polymorphism of cells of the spinous layer up to atypia, an increase in the number of mitoses, their irregularity, giant cells, multinucleated cells, acanthosis, in some cases hyperkeratosis and parakeratosis. Basement membrane and basal layer are preserved. In the upper part of the stroma there is a small infiltrate of lymphocytes and plasma cells.
Differential diagnosis is carried out with leukoplakia, lichen planus, chronic traumatic injury, lupus erythematosus, syphilis.
Treatment. Excision of the focus within healthy tissues with mandatory histological examination, consultation with an oncologist.
Warty precancer (praecancer verrucosus)
Described by A.L. Mashkilleyson in 1965. Etiology: trauma, increased insolation.
Occurs almost exclusively on the lower lip and looks like a painless hemispherical nodule with a warty surface with a diameter of mm. The color of the focus is from almost normal color of the red border to stagnant red. From above, the nodule is covered with gray scales that are difficult to remove and is located on an unchanged red border or against a background of slight hyperemia.
At histological the study reveals a pronounced limited proliferation of the epithelium due to the expansion of the styloid layer, in some cases hyperkeratosis and parakeratosis, polymorphism of the cells of the spiky layer of varying severity, up to a sharp one. The basement membrane is preserved. The transition to an invasive form of cancer occurs quickly - after 1-2 months from the onset of the disease.
Differential diagnosis should be carried out primarily with papillomas and warts. But the papilloma has a stalk, and the wart has a hypertrophic stratum corneum along the periphery. Malignancy can occur in 1-2 months. The diagnosis is specified after histological examination.
Treatment: only surgical (excision of the focus with subsequent histological examination) together with an oncologist.
Limited precancerous hyperkeratosis of the red border of the lips (hyperkeratosis praecancrosa circumscripta)
Etiology: trauma, increased insolation.
Clinical picture: men are more often ill after 30 years. On the lateral surface of the red border of the lower lip, a polygonal keratinization area larger than 2 mm appears. The lesion in most patients is, as it were, immersed in the mucous membrane, more often slightly sinks, but may be somewhat elevated, with a flat surface covered with thin, tightly-fitting scales. When scraped, it cannot be removed. Palpation reveals a superficial lamellar seal. There are no background changes, less often this form of precancer occurs against the background of nonspecific inflammation.
At histological the study determined a limited area of acanthosis, often the phenomenon of discompletion and polymorphism of cells, hyperkeratosis on the surface.
Differential diagnosis carried out with lupus erythematosus, leukoplakia and lichen planus. Malignancy occurs after a few months or years.
Treatment: together with an oncologist, surgical excision of the focus with subsequent histological examination.
Abrasive pre-cancer cheilitis Manganotti (cheilitis abra - siva praecancrosa Manganotti)
This form is isolated and described by Manganotti in 1933. It occurs mainly in men over 50 years of age. Herpetic infection, increased insolation, mechanical trauma, glandular and meteorological cheilitis, hypovitaminosis, diseases of the gastrointestinal tract contribute to the occurrence of this disease.
clinical picture. Against the background of mild limited or diffuse chronic catarrhal inflammation of the lower lip, one, less often several, red erosions with a smooth surface appear, which is sometimes covered with a tightly seated bloody or serous crust. It is removed with difficulty, with little bleeding. Erosion, not covered with a crust, has no tendency to bleed. There is no seal in the base. Erosions are characterized by a sluggish course, resistant to any kind of treatment with ointments and applications. Long existing, they can epithelialize, but then reappear in the same or in other places.
At histological examination a defect in the epithelium is detected, in the underlying connective tissue - inflammatory infiltration. The epithelium at the edges of erosion is in a state of acanthosis or atrophic. Epithelial strands extend from it deep into the stroma. Spiny cells in places are in varying degrees of discompletion and atypia. A cytological examination can detect the phenomena of dyskaryosis of epithelial cells, elements of inflammation, but more often only inflammation.
The process lasts from 1-2 months to many years, without treatment leads to malignancy. Clinically, this is manifested by compaction at the base and around the erosion, the appearance of papillary growths on the surface of the erosion, its slight bleeding, and keratinization around the erosion. The diagnosis is specified by finding atypical cells in scrapings from the lesion or by the results of a histological examination.
Differential diagnosis should be carried out with erosive forms of leukoplakia, lichen planus, lupus erythematosus, pemphigus, erythema multiforme exudative, actinic cheilitis, secondary syphilis, herpetic erosions.
Treatment. It is necessary to carefully remove local irritants, then carry out sanitation of the oral cavity, including full-fledged prosthetics, categorically prohibit smoking and eating irritating food, and recommend the elimination of insolation. It is necessary to identify and treat concomitant diseases of other organs and systems. Vitamin A is prescribed inside (a solution of retinol acetate in oil 3.44% or a solution of retinol palmitate in oil 5.5%), 10 drops 2-3 times a day, multivitamins. Applications are locally prescribed with an oily solution of vitamin A, with background inflammation - ointments with corticosteroids and antibiotics. Conservative therapy should not be carried out for more than 1 month. The best results are obtained by surgical removal of the focus in. within healthy tissues.
Only with Manganotti's cheilitis is an attempt at conservative treatment acceptable. Treatment of all types of obligate precancer is surgical - complete excision of the lesion within healthy tissues, followed by urgent histological examination. Excised tissue is examined by preparing serial sections. Operations should be preceded by sanitation of the oral cavity and elimination of irritants. If surgery is not possible, radiation therapy is indicated.
Prevention: improvement of the body, proper nutrition, elimination of adverse effects and bad habits.
Cutaneous horn (cornu cutaneum)
Cutaneous horn - limited hyperplasia of the epithelium with powerful hyperkeratosis, resembling a horn in appearance and density. Etiology unknown.
Occurs on the red border of the lips, often the lower one, in people over 60 years old, painless. A slowly growing, painless, limited focus with a diameter of up to 1 cm appears, from the base of which a cone-shaped, dirty-gray horn extends, dense, soldered to the base. Cutaneous horn is a long-term (years) existing disease. Its malignancy is indicated by the appearance of inflammation and compaction around the base of the horn, increased keratinization. The diagnosis is specified after the removal of the focus and its histological examination. Treatment surgical with subsequent histological examination.
Keratoacanthoma is a benign epidermal tumor that develops rapidly and spontaneously regresses. The etiology is unknown, suggest that immune disorders and a hereditary factor contribute to the occurrence of keratoacanthoma.
The disease is localized on the red border of the lips, very rarely on the tongue. Keratoacanthoma occurs as a dense grayish-red nodule with a funnel-shaped depression in the center, filled with rather easily removed horny masses. The tumor grows rapidly and in a month reaches its maximum size (2.5X1 cm). Keratoacanthoma is painless, mobile, not soldered to the surrounding tissues. After 6-8 months, the tumor either spontaneously regresses and disappears, leaving a scar, or becomes malignant, turning into cancer. Keratoacanthoma should be distinguished from warty precancer and cancer. Cancer has a denser consistency, a dense base, after removal of the horny masses, bleeding appears with it. Keratoacanthoma differentiate with skin horn, basalioma, squamous cell carcinoma.
Treatment: carried out jointly with an oncologist, surgical excision of the lesion or its diathermocoagulation, cryotherapy, close-focus X-ray therapy.
Papillomatosis is an accumulation of many papillomas on the skin and mucous membranes.
Etiology: trauma, chronic inflammation.
Clinical picture: Borovsky E. V. (1984) distinguishes the following types of papillomatosis:
Reactive papillomatosis of various nature:
inflammatory papillary hyperplasia of the mucous membrane of the hard palate and alveolar processes;
traumatic papillomatosis of the buccal mucosa, lips, tongue;
rhomboid papillomatosis of the tongue.
Papillomatosis of non-plastic nature.
Papillomas are round or mushroom-shaped, located on a stalk or on a wide base, their consistency is soft, sizes are from 1-2 mm to 1-2 cm, palpation is painless. Reactive papillomas stop growing after the stimulus stops.
Papillomatosis of a non-plastic nature is often malignant. The appearance of increased keratinization, bleeding, dense infiltrate at the base, ulceration, rapid growth indicates malignancy.
Treatment: surgical with subsequent histological examination.
Lichen planus
Assume the autoimmune nature of the disease with a violation of local immune mechanisms that develop against the background of estrogen deficiency, there is always a psycho-emotional factor.
Prevalence: women are more often ill.
Forms: typical, exudative-hyperemic, erosive-ulcerative, hyperkeratotic, bullous, atypical, infiltrative.
Factors contributing to the aggravation of the clinical picture: trauma, galvanism, candidiasis, diabetes mellitus, hypertension, dietary errors.
Localization: in the oral cavity - the mucous membrane of the cheeks, tongue, lips; on the skin - forearms, lower legs.
Symptoms: the course is often asymptomatic, sometimes there is a roughness of the mucous membrane; sometimes sensitivity, burning, soreness.
Clinical picture: in the oral cavity - a white lacy pattern consisting of individual small papules, sometimes merging into a solid white spot that rises above the surface of the mucous membrane. On the skin - bluish-red, with a waxy sheen, flat, itchy papules from 0.2 to 1 cm in diameter.
Diagnostics: based on clinical data and examination of the oral mucosa.
Histological picture: the epithelium is keratinized, diffuse lymphocytic infiltrate is determined in the papillary layer, the basement membrane is edematous.
antihistamines (suprastin, diazolin, bikarfen, fenkarol)
psychotropic therapy (valerian, peony, motherwort, seduxen, phenazepam)
vitamin therapy (vit.A, provitamin A-vetoron-T, vit.RR)
glucocorticoids (prednisone, dexamethasone, triamcion)
histoglobulin - as a histamine release blocker
painkillers (1% pyromecaine solution, 5% pyromecaine solution methyluracil ointment, 10% lidocaine aerosol, panthenol)
antiseptics (solution of hydrogen peroxide, potassium permanganate solution, furatsilin)
epithelializing agents (solcoseryl, oil solutions vit.A and E)
corticosteroid ointments (celistoderm, advantan)
Principles of patient management :
elimination of traumatic factors
sanitation of the oral cavity
blood test for sugar and estrogen
Lichen planus (erosive-ulcerative form)
Symptoms: painful, long-term non-healing erosions on the oral mucosa.
Clinical picture: irregularly shaped erosions covered with fibrinous plaque with papular elements.
epithelializing and regenerating agents
long-term treatment and drug changes are required
Forecast: Favorable, but erosion is not prone to epithelialization for a long time.
Erosive-ulcerative and hyperkeratotic forms of lichen planus are optional precancer; the likelihood of malignancy increases in the elderly, who have multiple risk factors.
An autoimmune disease, blood neutrophils and the basement membrane of the skin become alien to one's own body.
Prevalence: women are more often ill.
Localization: skin and red border of the lips, oral mucosa.
Forms: on the red border of the lips - a typical, erosive-ulcerative, deep form of Irgang-Kaposi. On the mucous membrane - typical, exudative-hyperemic, erosive-ulcerative.
Symptoms: dryness and tightening of the red border of the lips, asymptomatic course (with a deep form), soreness when eating in all forms on the oral mucosa.
Diagnostics: rashes on the mucous membrane of the mouth are always combined with characteristic changes on the skin of the face.
Histological picture: parakeratosis intermittent with hyperkeratosis, vacuolar degeneration of cells of the basal layer of the epithelium, dense infiltrate in the connective tissue from lymphocytes, degeneration of collagen fibers.
synthetic antimalarials: delagil, plaquenil, hingamin
Long-term lesions of lupus erythematosus, if left untreated, may become malignant.
Leukoplakia ("white plaque")
It develops as a response of the mucous membrane to a long-term injury, often chemical (smoking), mechanical.
Prevalence: more common in men.
Forms: flat, verrucous, erosive; a combination of different forms is possible.
Symptoms: asymptomatic, sometimes a feeling of roughness of the mucous membrane.
Clinical picture: a limited area of white color, irregular in shape, not rising or elevated above the surface of the mucosa, may have cracks and erosions. The surface of the lesion is rough or smooth.
Localization: mucous membrane of the lips, cheeks, corners of the mouth, along the line of closing of the teeth.
Diagnostics: area of the mucous membrane that is not removed by scraping.
with vercous and erosive forms: total excision over a wide range.
with flat forms: inside - aevit, pyridoxine; locally - applications of oily solution vit.A, 10% dibunol linimet.
Principles of patient management:
tobacco smoking ban
sanitation of the oral cavity
elimination of traumatic agents
protection of the red border of the lips from direct sunlight (photoprotective ointments)
endocrinological examination (appointment of testosterone blockers)
The occurrence is associated with the activation of the Epstein-Barr virus.
Prevalence: occurs only in AIDS patients.
Localization: lateral surfaces of the tongue.
Symptoms: asymptomatic.
Clinic: a limited area of thickening of the mucous membrane of opal-white color with indistinct boundaries.
Diagnostics: based on serological studies confirming HIV infection. Treatment: underlying disease.
Forecast: bad (malignant).
Verrucous and erosive forms of leukoplakia are optional precancers with a high degree of malignancy.
Chronic fissure of the lip
lip soreness aggravated by smiling, eating
The long-term existence of a chronic lip fissure is considered as a background disease capable of malignancy (6%), with thickening of the edges and base, keratinization in the circumference, and small papillomatous growths in the depth of the crack are possible.
severe headaches
paroxysmal pain radiating along the trunk of the affected nerve
burning and paresthesia of the innervated area
Clinical picture: on the oral mucosa and skin strictly in the zone of innervation of the 2nd or 3rd branches of the trigeminal nerve, erosions appear, covered with a fibrinous coating, sharply painful. Intraepidermal vesicles on the skin are filled with transparent serous contents, the staging of the appearance of vesicles is characteristic.
cytological data
analgesics and non-steroidal anti-inflammatory drugs
anti-inflammatory and pain medications
Relapses of herpes zoster indicate a significant decrease in immunity - it is necessary to exclude HIV infection, malignant neoplasm, leukemia.
The autoimmune mechanism of the disease has been proven.
Clinical picture: blisters on the skin from 0.5-5 cm with a flaccid tire_bright red erosion; on the mucous membrane of erosion with scraps of the bladder cover at the edges. On the red border of the lips: erosions are covered with yellowish-brown or hemorrhagic crusts
Treatment: performed by a dermatologist. Corticosteroids and cytostatics are prescribed.
Forecast: relatively favorable for early diagnosis and timely treatment; poor without treatment (before the era of corticosteroids, more than 50% were fatal).
Malignant epithelial neoplasm (cancer)
asymptomatic or mild pain
enlargement of regional lymph nodes
cytological results
radical surgery on cervical lymph nodes affected by tumor metastases
Forecast: depends on the location, size, type of tumor, age and health of the patient.
keratinizing squamous cell carcinoma
Prevalence: more common in older men.
Localization: mucous membrane of the lips, tongue, floor of the mouth, cheeks.
Clinical picture: white spot, flat or raised above the mucous membrane; cracks, erosion; in the future, a dense infiltrate, enlarged cervical lymph nodes are determined.
Diagnostics: is based on a histological examination of the lesion after its wide surgical excision.
Treatment: wide excision, possibly radiation therapy.
Forecast: favorable with lesions of the lips; bad with damage to the bottom of the mouth, the base of the tongue.
Dentists, like doctors of any other profile, should be oncologically vigilant when examining a patient. No matter what complaints the patient has, an examination of the entire oral cavity and the red border of the lips is the law for the doctor. Any deviation from the norm should attract his close attention. Early manifestations of cancer may go unnoticed by patients, and it is the doctor's duty to detect them in a timely manner, as early as possible. The concept of "oncological alertness" is, first of all, the sum of specific knowledge of oncology, which allows the doctor to conduct an early or timely diagnosis of cancer. This concept also includes knowledge of precancerous diseases and their treatment, knowledge of the organization of oncological care, the network of oncological medical institutions, and the rapid referral of the patient to the destination. In difficult cases of diagnosis, one should think about the possibility of growth of a malignant tumor and make a diagnosis as soon as possible. Treatment without a diagnosis should not be carried out for more than 7 days. It is necessary to eliminate local irritants, do not use agents that promote tumor growth (cauterization, physiotherapy, etc.). In difficult cases, the doctor is obliged to involve more experienced specialists in the examination of the patient.
Treatment is carried out by oncologists. After treatment of cancer or precancerous diseases, patients should be under dispensary observation. The clinic of expressed forms of cancer of various localization is described in the course of surgical dentistry.
Cancer of the oral mucosa and red border of the lips
On the red border of the lips and in the oral mucosa, in most cases, keratinizing squamous cell carcinoma develops, less often non-keratinizing. This is almost always a spinocellular carcinoma arising from the cells of the styloid layer, and very rarely a basal cell carcinoma (usually on the red border of the lower lip).
The clinical course of early forms of cancer depends on previous precancerous diseases, on the nature of growth (exophytic, endophytic, mixed forms). Cancer at first can proceed painlessly, but on the tongue, as a rule, it is accompanied by pain, often severe, radiating. In appearance at the beginning of the disease, papillary, infiltrative and ulcerative forms are distinguished.
papillary form. At the beginning, a limited seal appears in the form of a warty outgrowth on a wide base or on a stalk. Its surface is covered with papillary growths and often horny masses. On palpation, a shallow infiltration around and at the base is determined. The tumor grows in breadth and depth, rather quickly disintegrates in the center and turns into an ulcerative form.
The infiltrative form of cancer is the most unfavorable. At the beginning of the disease, a painless seal appears, often located under the mucous membrane. The infiltrate grows, disintegrates in the center, a typical cancerous ulcer appears.
The ulcerative form is the most common, since in most cases the tumor begins to disintegrate early and looks like an erosion, and then like an ulcer. With the onset of invasive growth, it is typical for cancer to compact around the ulcer in the form of a roller and at the base, which is determined by palpation. In the initial stage, the compaction is insignificant or not clinically determined at all, then, due to the rapid growth of the tumor, it increases, sometimes reaching a stony density. In the later stages, the difference in forms is not determined, the picture of ulcerative-infiltrative growth prevails. The ulcer usually has raised, inverted dense edges, an uneven granular bottom, covered with a gray-yellow coating or gray necrotic coating in the oral cavity; on the red border of the lip, the ulcer is covered with a dense gray coating or, with bleeding, with bloody-gray crusts. Inflammatory phenomena in the tissues surrounding the cancer are pronounced or clinically absent.
Accelerate the growth of the tumor injury sharp edges of teeth, prostheses, eating hot food, smoking, cauterization, etc. Cauterizing agents can not be used for ulcers of any etiology, but it is especially dangerous for malignant tumors. After metastasis of cancer to the lymph nodes, the latter become denser, enlarge, and then solder with the surrounding tissues. Cancer of the tongue metastasizes especially early, apparently due to its greater mobility.
Cancer of the oral cavity and the red border of the lips refers to cancers of visual localization, which facilitates its diagnosis, allows for examination and palpation of the lesion without special equipment. With the help of a stomatoscope, earlier morphological changes can be seen. Clinical diagnosis must be confirmed by morphological studies - cytological or histological method.
The cytological method of research allows to make the correct diagnosis in 90-95% of cases. The material in such cases is taken by scraping or puncture.
The main features that distinguish a cancerous cell from a non-cancerous one are as follows: 1) the vicious structure of the cell membrane and intracellular membranes, as a result of which cancer cells are more easily separated from the main tissue, lose their cytoplasm, and "bare" nuclei appear; 2) morphological and chemical anaplasia of nuclei, their sizes are different (usually larger than normal), polychromatophilia, irregularity in the arrangement of chromatin, giant cells, multinucleated cells, tuberosity of nuclei, mitoses, etc.; 3) anaplasia of nucleolus, an increase in their number; 4) additional inclusions in the cytoplasm and nucleus, signs of dystrophy, phagocytosis. Material for cytological examination is not always possible to obtain in sufficient quantities. "Soft", poorly differentiated cancers give abundant scrapings, and from "dense", scirrhous, cancers, scanty scrapings are obtained, which is not always sufficient.
Differential diagnosis of cancer should be carried out with leukoplakia, benign tumors, traumatic and trophic ulcers, specific lesions (tuberculosis, syphilis, leprosy), ulcers with lichen planus and other chronic inflammatory processes.
General characteristics of tumor growth
Tumor - (lat. tumor; synonyms: neoplasm, Greek neoplasma; blastoma, lat. blastoma) - “there is an excessive, continuing after the cessation of the causes that caused it, uncoordinated with the body, pathological tissue growth, consisting of cells that have become atypical in relation to differentiation and growth and transmitting these properties to their derivatives” (L.M. Shabad). This definition reflects the fundamental features of growth that are different from other forms of tissue growth pathology (hypertrophy, hyperplasia, regeneration).
Rice. 1."Stairs" of growth: A- cancer mortality in the USA (according to R. Suess et al., 1977); B- incidence of cancer in Poland (according to WHO, 1992)
The number of malignant neoplasms worldwide is steadily increasing (Fig. 1). In the first half of the 20th century, they moved from 7th place in 1900 to 2nd and today they firmly hold this position, yielding the leading position only to cardiovascular diseases. Among the most important reasons for this are the following.
Improvement in diagnostics due to a significant expansion of diagnostic capabilities; the introduction of new examination methods in the 20th century (fibrogastroscopy, colonoscopy, bronchoscopy, a number of methods of isotope research - scanning, ultrasound, computer diagnostic methods, etc.);
More careful registration of oncological patients.
Increasing the average life expectancy of a person. Malignant neoplasms, especially cancer, are the destiny of elderly and senile people. Cancer at the age of 70 is 100 times more common in men and 70 times more common in women than at age 30.
Pollution of the environment with carcinogenic agents due to the development of industry, transport, with the ever more intensive use of atomic energy, with the testing of atomic weapons, with the use in the national economy, medicine, scientific research of various kinds of isotopes, with their not always sufficiently competent use, etc. d.;
Significant advances in medicine in the treatment and prevention of many, primarily infectious forms of pathology (plague, smallpox, cholera, tuberculosis, etc.). As a result, the share of diseases, in the treatment and prevention of which our successes are much more modest, is noticeably increasing.
The prevalence of tumors in general and their individual forms in different countries of the world among different ethnic groups of the same country is different. Data on the epidemiology of cancer suggests that not one, but many factors play an important role in its occurrence and development. Climatic conditions, genetic characteristics of the population of people living in a particular area of the planet, bad habits that are different in different parts of the world, nutritional habits, gender, age, etc., are of some importance.
Distribution of tumors in phylogenesis
Tumors are not limited to humans. Tumor-like growths are found in plants (on roots, stems, fruits), true tumors are widely represented in the animal kingdom (Fig. 2).
Rice. 2. Spontaneous lymphosarcoma of the skin in pike (A) and mammary fibroadenoma in an old female rat (B)
As a result of the analysis of data on the spread of tumors in phylogenesis, the following patterns of tumor growth were revealed.
Neoplasms are found in all types of animal organisms. Apparently, any multicellular animal organism is capable of giving rise to a tumor germ.
As the body becomes more complex:
the frequency of spontaneously arising tumors increases;
the number of tumors of epithelial-tissue origin is growing;
an increasing proportion of malignant neoplasms;
the variety of forms of tumor growth increases;
The course of a tumor disease with similar forms of tumors becomes more and more malignant.
3. Each species of animal organisms has its own tumor spectrum. Between 70 and 90% of all tumors in cattle, for example, are leukemias. In mice, adenocarcinoma is most common, in rats - breast fibroadenoma, in humans - cancer of the stomach, lungs, breast, and uterus.
So, tumor growth is a general biological phenomenon and, therefore, the disclosure of the mechanisms of tumor transformation is associated with the knowledge of general biological patterns: reproduction, genetics, differentiation, growth, aging.
Main biological features of tumors
All tumors are usually divided into benign and malignant. The main criteria for differentiating a malignant tumor from a benign one are considered to be: the nature of growth (a benign tumor grows expansively, pushing back, squeezing, but not destroying healthy tissues; malignant tumors are characterized by infiltrating, invasive and destructive growth, i.e. they germinate healthy tissues and at the same time they are destroyed), a tendency to metastasize and develop exhaustion - cachexia. A more complete picture of the distinctive features of malignant and benign tumors can be obtained by considering the following biological properties of the tumor.
1. Relative autonomy and uncontrollability of tumor growth is an obligatory universal sign of any neoplasm, both malignant and benign, a fundamental sign of any neoplasm.
Uncontrolled excessive proliferation of tumor cells does not mean that tumor cells are dividing at a rate that exceeds the maximum rate of division of homologous healthy tissue cells. Many healthy tissues (fetal tissue, regenerating liver) grow much faster than any of the most malignant tumors. Independence of the tumor growth rate from the integrative effects of ceabdominal organism, "functional deafness"(A.S. Salyamon, 1974) - this is what is characteristic of a tumor.
Some of the known causes of uncontrolled and unlimited proliferation in tumor growth are:
Significant decrease in tumor cells contact brakezheniya. Cells of normal tissue in a culture medium grow in a monolayer - upon reaching a certain population density, division stops upon contact with neighboring cells. Cancer cells, multiplying, form, as a rule, multilayered cultures;
No Hayflick cell division limit;
Decrease in the intensity of synthesis in the tumor tissue of chalons (substances produced by mature cells; specifically inhibit the mitotic activity of proliferating cells) and a decrease in the sensitivity of tumor cells to their action;
Difference in microreliefs of normal and tumor cells (Fig. 3). The multiplicity of microvilli of a malignant tumor cell significantly increases its surface, allowing it to capture large amounts of metabolites and ions necessary for vital activity, and weakens intercellular contacts.
Rice. 3.Manifestations of morphological (cellular) atypism:
top: micrographs of normal (a - mouse embryonic fibroblast) and tumor (b - transformed fibroblast) cells obtained using a scanning electron microscope (according to Yu.A. Rovensky, 1979);
at the bottom: V- giant multinucleated gastric cancer cell (Cave culture); atypical forms of division of tumor cells in Cave culture (G- the formation of chromosome bridges, d- 3-pole mitosis, according to B IO. Ieretyatko, 1980).
2. Simplification of the structural-chemical organization (atypism, anaplasia), those. a decrease in the level of differentiation of tumor tissue, bringing it closer in a number of signs and properties to embryonic tissue ("embryonicization") - a characteristic feature of a tumor in general and a malignant tumor in particular. There are several types of atypism: morphological, biochemical, energetic, functional, immunological.
Morphological atypism, in turn, is divided into tissue And cellular. Tissue atypism is expressed in an abnormal, disturbed ratio in the tumor tissue of the stroma and parenchyma, cellular - refers to deviations in the structure of the cell and its components (Fig. 3).
One of the most characteristic manifestations of biochemical atypism is unification of the isozyme spectrum of enzymes tumors, regardless of its histogenesis (Fig. 4). At the same time, the isoenzyme rearrangement in various tumors of humans and animals goes in the direction of the spectrum of isoenzymes characteristic of homologous tissues of embryonic development. In tumor cells, the processes of protein synthesis prevail over the processes of catabolism. The intensity of protein synthesis of the mitotic apparatus increases especially. The processes of transamination and deamination of amino acids, etc. are disturbed.
Rice.4. Manifestation of biochemical atypism - LDH isoenzyme spectrum(ByB. C. Shapotu, 1975):A - normal leukocytes (/- lymphocytes, //- granulocytes; 1-5 - serial numbers of isoenzymes); B- power cells in acute human leukemia (/, // - lymphoblastic and myeloblastic leukemia, respectively)
Energy atypism is characterized by the transition of the tumor to a phylogenetically more ancient, uneconomical, wasteful way of obtaining energy due to the glycolytic breakdown of carbohydrates. As a result, the tumor becomes a "glucose trap", initiating a cascade of phenomena, the final consequence of which is the development of cachexia and increasing immunosuppression. Due to the accumulation of underoxidized metabolic products (primarily lactic acid) inherent in glycolysis, acidosis develops.
Functional atypism manifests itself in the loss, perversion or (most often) inconsistency, insubordination of the function performed by the tumor tissue, and the regulatory influences of the whole organism. Sometimes certain functions drop out altogether. In the hepatoma, for example, bile pigments cease to be synthesized. In some cases, tumor cells begin to perform a function that is not inherent in them under normal conditions. For example, tumor cells of the lungs, bronchi can synthesize hormone-like substances.
Immune (antigenic) atypism is usually understood as a change in the antigenic properties of the tumor tissue:
antigenic simplification- decrease in the production of organ-specific antigens by the tumor cell (Fig. 7, b);
antigenic divergence- synthesis by tumor cells of antigens that are not inherent in homologous cells of healthy tissue, but produced by other tissues (for example, synthesis in the hepatoma of organ-specific antigens of the spleen, kidney or other organs);
antigenic reversion(Fig. 7, A)- synthesis of embryonic antigens by tumor cells (for example, fetal protein - a-fetoprotein, embryonic prealbumin in the hepatoma).
Heritability of changes- biological feature of tumor cells, which is as follows. A cell that has undergone tumor transformation, during reproduction, transfers the properties acquired by it during the transformation to its derivatives, i.e. a clone of cells is formed, which gives rise to a tumor node.
Invasive (infiltrative) and destructive growth- the main criterion of malignancy, allowing with a sufficient degree of confidence to distinguish a malignant tumor from a benign one (Fig. 5).
Rice. 5.The nature of tumor growth:A- Invasive and destructive growth of a malignant tumor (cervical cancer; according to I.V. Davydovsky, 1969); B- expansive growth of benign bladder papilloma (according to G.A. Berlosh, 1970)
Rice. 6. Metastatic cascade (according to Carton R.S., Kumak V., Rubins S.L. 1989): bm- basement membrane; ECM- extracellular matrix
5. metastasis, or the appearance of new foci of tumor growth in various organs and tissues distant from the primary tumor node. There are the following stages of hematogenous and lymphogenous metastasis (Fig. 6):1)separation one or a group of tumor cells from the primary tumor and their penetration into the blood or lymphatic vessels;
2) transportation tumor cells through the vessels;
3) implantation tumor cells in a particular organ; carried out in stages:
a) fixation of the tumor cell to the vessel wall;
b) penetration of tumor cells outside the vascular wall;
c) proliferation of tumor cells.
6. Tumor progression- the ability of a tumor to change its characteristics (morphological structure, biochemical characteristics, antigenic spectrum and other properties) in the process of development (Fig. 7). At the same time, different properties of a tumor cell (phenomena of anaplasia, invasiveness, ability to metastasize, sensitivity or resistance to chemotherapeutic effects, radiation therapy, etc.) change in different ways, at different rates, independently of each other, but in general during profession, the malignancy of the tumor increases. It is believed (B.C. Shapot, 1975, L.M. Shabad, 1979) that a benign tumor is the initial stage of progression, the first step towards malignancy.
7. Tendency to relapse- the reappearance of the tumor in its original place after its removal. It may be due to incomplete removal of tumor cells that far infiltrate healthy tissue, or their introduction into healthy tissue during a traumatic surgical intervention.
8. The systemic effect of the tumor on the body(see the teaching aid "Pathogenesis of tumors").
Rice.7. The phenomena of antigenic reversion, antigenic simplificationand tumor progression L.S. Lemeshonok, 1980): dynamics of changes in the content of embryonic prealbumin (A) and organ-specific antigens (b) liver of mice in extracts of ascitic hepatoma I during passage of tumors in animals.
The doctrine of true tumors occupies a significant place among the problems of cognition of pathological processes and has long been singled out as a special discipline - oncology(gr. oncos- a tumor logos- the science). However, familiarity with the basic principles of diagnosis and treatment of tumors is necessary for every doctor. Oncology studies only true tumors, in contrast to false ones (an increase in tissue volume due to edema, inflammation, hyperfunction and working hypertrophy, hormonal changes, limited fluid accumulation).
General provisions
Tumor(syn.: neoplasm, neoplasm, blastoma) - a pathological formation that independently develops in organs and tissues, characterized by autonomous growth, polymorphism and cell atypia. A characteristic feature of a tumor is the isolated development and growth within the tissues of the body.
The main properties of the tumor
There are two main differences between a tumor and other cellular structures of the body: autonomous growth, polymorphism, and cell atypia.
autonomous growth
By acquiring tumor properties due to one reason or another, cells convert the resulting changes into their internal properties, which are then passed on to the next direct progeny of cells. This phenomenon is called "tumor transformation". Cells that have undergone tumor transformation begin to grow and divide without stopping even after the elimination of the factor that initiated the process. At the same time, the growth of tumor cells is not subject to the influence of any regulatory mechanisms.
mov (nervous and endocrine regulation, immune system, etc.), i.e. not controlled by the body. The tumor, having appeared, grows as if by itself, using only nutrients and energy resources of the body. These features of tumors are called automatic, and their growth is characterized as autonomous.
Polymorphism and atypia of cells
The cells undergoing tumor transformation begin to multiply faster than the cells of the tissue from which they originated, which determines the faster growth of the tumor. The speed of proliferation can be different. At the same time, to varying degrees, there is a violation of cell differentiation, which leads to their atypia - a morphological difference from the cells of the tissue from which the tumor developed, and polymorphism - the possible presence in the tumor structure of cells that are heterogeneous in morphological characteristics. The degree of impairment of differentiation and, accordingly, the severity of atypia may be different. While maintaining a sufficiently high differentiation, the structure and function of tumor cells are close to normal. In this case, the tumor usually grows slowly. Poorly differentiated and generally undifferentiated (it is impossible to determine the tissue - the source of tumor growth) tumors consist of unspecialized cells, they are distinguished by rapid, aggressive growth.
The structure of morbidity, mortality
Cancer is the third most common cancer after cardiovascular diseases and injuries. According to WHO, more than 6 million newly ill with oncological diseases are registered annually. Men get sick more often than women. Distinguish the main localization of tumors. In men, the most common cancers are of the lung, stomach, prostate, colon and rectum, and skin. In women, breast cancer ranks first, followed by cancer of the stomach, uterus, lung, rectum and colon, and skin. Recently, attention has been drawn to an increase in the incidence of lung cancer with a slight decrease in the incidence of gastric cancer. Among the causes of death in developed countries, oncological diseases take the second place (after diseases of the cardiovascular system) - 20% of the total mortality rate. At the same time, the 5-year survival rate after
The diagnosis of a malignant tumor averages about 40%.
Etiology and pathogenesis of tumors
At present, it cannot be said that all questions of the etiology of tumors have been resolved. There are five main theories of their origin.
The main theories of the origin of tumors Theory of irritation by R. Virchow
More than 100 years ago, it was found that malignant tumors often occur in those parts of organs where tissues are more susceptible to trauma (cardia, stomach outlet, rectum, cervix). This allowed R. Virchow to formulate a theory according to which constant (or frequent) traumatization of tissues accelerates the processes of cell division, which at a certain stage can transform into tumor growth.
Theory of germinal rudiments by D. Congeim
According to D. Konheim's theory, in the early stages of embryonic development, more cells may appear in different areas than is necessary to build the corresponding part of the body. Some cells that remain unclaimed can form dormant primordia, potentially possessing high growth energy, which is characteristic of all embryonic tissues. These rudiments are in a latent state, but under the influence of certain factors they can grow, acquiring tumor properties. At present, this mechanism of development is valid for a narrow category of neoplasms called "disembryonic" tumors.
Regeneration-mutation theory of Fisher-Wazels
As a result of exposure to various factors, including chemical carcinogens, degenerative-dystrophic processes occur in the body, accompanied by regeneration. According to Fischer-Wazels, regeneration is a “sensitive” period in the life of cells, when tumor transformation can occur. The very transformation of normal regenerating cells into tumor-
virus theory
The viral theory of the onset of tumors was developed by L.A. Zilber. The virus, invading the cell, acts at the gene level, disrupting the regulation of cell division. The influence of the virus is enhanced by various physical and chemical factors. At present, the role of viruses (oncoviruses) in the development of certain tumors has been clearly proven.
immunological theory
The youngest theory of the origin of tumors. According to this theory, various mutations constantly occur in the body, including tumor transformation of cells. But the immune system quickly identifies the "wrong" cells and destroys them. Violation in the immune system leads to the fact that one of the transformed cells is not destroyed and is the cause of the development of neoplasms.
None of the presented theories reflects a single scheme of oncogenesis. The mechanisms described in them are important at a certain stage of the onset of a tumor, and their significance for each type of neoplasm can vary within very significant limits.
Modern polyetiological theory of the origin of tumors
In accordance with modern views, during the development of different types of neoplasms, the following causes of tumor cell transformation are distinguished:
Mechanical factors: frequent, repeated traumatization of tissues with subsequent regeneration.
Chemical carcinogens: local and general exposure to chemicals (for example, scrotum cancer in chimney sweeps when exposed to soot, squamous cell lung cancer when smoking - exposure to polycyclic aromatic hydrocarbons, pleural mesothelioma when working with asbestos, etc.).
Physical carcinogens: UV (especially for skin cancer), ionizing radiation (tumors of bones, thyroid, leukemia).
Oncogenic viruses: Epstein-Barr virus (role in the development of Burkitt's lymphoma), T-cell leukemia virus (role in the genesis of the disease of the same name).
A feature of the polyetiological theory is that the very impact of external carcinogenic factors does not cause the development of a neoplasm. For the appearance of a tumor, the presence of internal causes is also necessary: a genetic predisposition and a certain state of the immune and neurohumoral systems.
Classification, clinic and diagnostics
The classification of all tumors is based on their division into benign and malignant. When naming all benign tumors, the suffix -oma is added to the characteristic of the tissue from which they originated: lipoma, fibroma, myoma, chondroma, osteoma, adenoma, angioma, neurinoma, etc. If there is a combination of cells of different tissues in the neoplasm, their names also sound accordingly: lipofibroma, neurofibroma, etc. All malignant neoplasms are divided into two groups: tumors of epithelial origin - cancer and connective tissue origin - sarcoma.
Differences between benign and malignant tumors
Malignant tumors are distinguished from benign ones not only by their names. It is the division of tumors into malignant and benign that determines the prognosis and tactics of treating the disease. The main fundamental differences between benign and malignant tumors are presented in Table. 16-1.
Table 16-1.Differences between benign and malignant tumors
Atypia and polymorphism
Atypia and polymorphism are characteristic of malignant tumors. In benign tumors, cells exactly repeat the structure of tissue cells from which they originated, or have minimal differences. Cells of malignant tumors are significantly different in structure and function from their predecessors. At the same time, the changes can be so serious that it is morphologically difficult or even impossible to determine from which tissue, which organ the neoplasm originated (the so-called undifferentiated tumors).
growth pattern
Benign tumors are characterized by expansive growth: the tumor grows as if by itself, increases and pushes the surrounding organs and tissues apart. In malignant tumors, growth is infiltrating in nature: the tumor captures, penetrates, infiltrates the surrounding tissues like claws of cancer, sprouting at the same time blood vessels, nerves, etc. The growth rate is significant, high mitotic activity is observed in the tumor.
Metastasis
As a result of tumor growth, some of its cells can break off, enter other organs and tissues and cause the growth of a secondary, daughter tumor there. This process is called metastasis, and the daughter tumor is called metastasis. Only malignant neoplasms are prone to metastasis. At the same time, metastases usually do not differ in their structure from the primary tumor. Very rarely they have even lower differentiation, and therefore are more malignant. There are three main ways of metastasis: lymphogenous, hematogenous, implantation.
The lymphogenic route of metastasis is the most common. Depending on the ratio of metastases to the lymphatic drainage pathway, antegrade and retrograde lymphogenous metastases are distinguished. The most striking example of antegrade lymphogenous metastasis is metastasis to the lymph nodes of the left supraclavicular region in gastric cancer (Virchow's metastasis).
The hematogenous pathway of metastasis is associated with the entry of tumor cells into the blood capillaries and veins. With bone sarcomas, hematogenous metastases often occur in the lungs, with intestinal cancer - in the liver, etc.
The implantation path of metastasis is usually associated with the entry of malignant cells into the serous cavity (with the germination of all layers of the organ wall) and from there to neighboring organs. For example, implantation metastasis in gastric cancer in the space of Douglas - the lowest region of the abdominal cavity.
The fate of a malignant cell that has entered the circulatory or lymphatic system, as well as the serous cavity, is not completely predetermined: it can give rise to a daughter tumor, or it can be destroyed by macrophages.
Recurrence
Recurrence refers to the re-development of a tumor in the same area after surgical removal or destruction with radiation therapy and/or chemotherapy. The possibility of recurrence is a characteristic feature of malignant neoplasms. Even after a seemingly macroscopically complete removal of the tumor, individual malignant cells can be detected in the area of operation, capable of re-growth of the neoplasm. After complete removal of benign tumors, relapses are not observed. The exceptions are intermuscular lipomas and benign neoplasms of the retroperitoneal space. This is due to the presence of a kind of legs in such tumors. When the neoplasm is removed, the leg is isolated, bandaged and cut off, but re-growth is possible from its remains. Tumor growth after incomplete removal is not considered a relapse - this is a manifestation of the progression of the pathological process.
Influence on the general condition of the patient
With benign tumors, the entire clinical picture is associated with their local manifestations. Formations can cause inconvenience, compress nerves, blood vessels, disrupt the function of neighboring organs. At the same time, they do not affect the general condition of the patient. The exception is some tumors, which, despite their "histological goodness", cause serious changes in the patient's condition, and sometimes lead to his death. In such cases, they speak of a benign tumor with a malignant clinical course, for example:
Tumors of the endocrine organs. Their development increases the level of production of the corresponding hormone, which causes characteristic
general symptoms. Pheochromocytoma, for example, releasing a large amount of catecholamines into the blood, causes arterial hypertension, tachycardia, autonomic reactions.
Tumors of vital organs significantly disrupt the state of the body due to the disorder of their functions. For example, a benign brain tumor during growth compresses brain areas with vital centers, which poses a threat to the life of the patient. A malignant tumor leads to a number of changes in the general condition of the body, called cancer intoxication, up to the development of cancer cachexia (exhaustion). This is due to the rapid growth of the tumor, its consumption of a large amount of nutrients, energy reserves, plastic material, which naturally impoverishes the supply of other organs and systems. In addition, the rapid growth of the formation often accompanies necrosis in its center (tissue mass increases faster than the number of vessels). Absorption of cell decay products occurs, perifocal inflammation occurs.
Classification of benign tumors
The classification of benign tumors is simple. There are types depending on the tissue from which they originated. Fibroma is a tumor of the connective tissue. Lipoma is a tumor of adipose tissue. Myoma - a tumor of muscle tissue (rhabdomyoma - striated, leiomyoma - smooth), etc. If two types of tissues or more are present in the tumor, they bear the corresponding names: fibrolipoma, fibroadenoma, fibromyoma, etc.
Classification of malignant tumors
The classification of malignant neoplasms, as well as benign ones, is primarily related to the type of tissue from which the tumor originated. Epithelial tumors are called cancer (carcinoma, carcinoma). Depending on the origin, in highly differentiated neoplasms, this name is specified: keratinizing squamous cell carcinoma, adenocarcinoma, follicular and papillary cancer, etc. In low-differentiated tumors, it is possible to specify the tumor cell form: small cell carcinoma, cricoid cell carcinoma, etc. Connective tissue tumors are called sarcomas. With relatively high differentiation, the name of the tumor repeats the name
tissue from which it developed: liposarcoma, myosarcoma, etc. Of great importance in the prognosis of malignant neoplasms is the degree of tumor differentiation - the lower it is, the faster its growth, the greater the frequency of metastases and relapses. Currently, the international classification of TNM and the clinical classification of malignant tumors are considered generally accepted.
TNM classification
The TNM classification is accepted worldwide. In accordance with it, in a malignant tumor, the following parameters are distinguished:
T (tumor)- the size and local spread of the tumor;
N (node)- presence and characteristics of metastases in regional lymph nodes;
M (metastasis)- the presence of distant metastases.
In addition to its original form, the classification was later expanded with two more characteristics:
G (grade)- the degree of malignancy;
R (penetration) the degree of germination of the wall of a hollow organ (only for tumors of the gastrointestinal tract).
T (tumor) characterizes the size of the formation, the prevalence of the departments of the affected organ, the germination of surrounding tissues.
Each organ has its own specific gradations of these features. For colon cancer, for example, the following options are possible:
T o- there are no signs of a primary tumor;
T is (in situ)- intraepithelial tumor;
T1- the tumor occupies a small part of the intestinal wall;
T 2- the tumor occupies half the circumference of the intestine;
T 3- the tumor occupies more than 2/3 or the entire circumference of the intestine, narrowing the lumen;
T 4- the tumor occupies the entire lumen of the intestine, causing intestinal obstruction and (or) grows into neighboring organs.
For a breast tumor, gradation is carried out according to the size of the tumor (in cm); for stomach cancer - according to the degree of germination of the wall and spread to its sections (cardia, body, output section), etc. Cancer stage requires a special reservation "in situ"(cancer in situ). At this stage, the tumor is located only in the epithelium (intraepithelial cancer), does not grow into the basement membrane, and therefore does not grow into the blood and lymphatic vessels. Thus, on
At this stage, the malignant tumor is devoid of the infiltrating nature of growth and, in principle, cannot give hematogenous or lymphogenous metastasis. Listed features of cancer in situ determine more favorable results of treatment of such malignant neoplasms.
N (nodes) characterizes changes in regional lymph nodes. For gastric cancer, for example, the following types of designations are accepted:
N x- there is no data on the presence (absence) of metastases in regional lymph nodes (the patient was underexamined, not operated on);
No- there are no metastases in regional lymph nodes;
N 1 - metastases to the lymph nodes along the greater and lesser curvature of the stomach (collector of the 1st order);
N 2 - metastases in prepyloric, paracardial lymph nodes, in the nodes of the greater omentum - removed during surgery (collector of the 2nd order);
N 3- para-aortic lymph nodes are affected by metastases - they cannot be removed during surgery (collector of the 3rd order).
Gradations No And N x- common to almost all tumor localizations. Characteristics N 1 -N 3- different (so they can indicate the defeat of different groups of lymph nodes, the size and nature of metastases, their single or multiple nature).
It should be noted that at present it is possible to give a clear definition of the presence of a certain type of regional metastases only on the basis of a histological examination of postoperative (or autopsy) material.
M (metastasis) indicates the presence or absence of distant metastases:
M 0- there are no distant metastases;
M. i- there are distant metastases (at least one).
G (grade) characterizes the degree of malignancy. In this case, the determining factor is a histological indicator - the degree of cell differentiation. There are three groups of neoplasms:
G1- tumors of a low degree of malignancy (highly differentiated);
G2- tumors of an average degree of malignancy (poorly differentiated);
G3- tumors of a high degree of malignancy (undifferentiated).
R (penetration) the parameter is introduced only for tumors of hollow organs and shows the degree of germination of their walls:
P1- tumor within the mucous membrane;
R 2 - the tumor grows into the submucosa;
R 3 - the tumor grows into the muscle layer (to the serous layer);
R 4 The tumor invades the serous membrane and extends beyond the organ.
In accordance with the presented classification, the diagnosis may sound, for example, as follows: cancer of the caecum - T 2 N 1 M 0 P 2 The classification is very convenient, since it characterizes in detail all aspects of the malignant process. At the same time, it does not provide generalized data on the severity of the process, the possibility of curing the disease. To do this, apply the clinical classification of tumors.
Clinical classification
In the clinical classification, all the main parameters of a malignant neoplasm (the size of the primary tumor, germination into surrounding organs, the presence of regional and distant metastases) are considered together. There are four stages of the disease:
Stage I - the tumor is localized, occupies a limited area, does not germinate the wall of the organ, there are no metastases.
Stage II - a tumor of moderate size, does not spread outside the organ, single metastases to regional lymph nodes are possible.
Stage III - a large tumor, with decay, germinates the entire wall of the organ or a smaller tumor with multiple metastases to regional lymph nodes.
Stage IV - tumor growth into surrounding organs, including non-removable ones (aorta, vena cava, etc.), or any tumor with distant metastases.
Clinic and diagnosis of tumors
The clinic and diagnosis of benign and malignant neoplasms are different, which is associated with their effect on the surrounding organs and tissues, and the patient's body as a whole.
Features of the diagnosis of benign tumors
Diagnosis of benign formations is based on local symptoms, signs of the presence of the tumor itself. Often sick
pay attention to the appearance of some kind of education themselves. In this case, tumors usually slowly increase in size, do not cause pain, have a rounded shape, a clear border with surrounding tissues, and a smooth surface. The main concern is the education itself. Only sometimes there are signs of dysfunction of the organ (an intestinal polyp leads to obstructive intestinal obstruction; a benign brain tumor, squeezing the surrounding sections, leads to the appearance of neurological symptoms; adrenal adenoma due to the release of hormones into the blood leads to arterial hypertension, etc.). It should be noted that the diagnosis of benign tumors is not particularly difficult. By themselves, they cannot threaten the life of the patient. A possible danger is only a violation of the function of organs, but this, in turn, quite clearly manifests the disease.
Diagnosis of malignant tumors
Diagnosis of malignant neoplasms is quite difficult, which is associated with a variety of clinical manifestations of these diseases. In the clinic of malignant tumors, four main syndromes can be distinguished:
Syndrome "plus-tissue";
Pathological discharge syndrome;
Organ dysfunction syndrome;
Syndrome of small signs.
Plus tissue syndrome
A neoplasm can be detected directly in the location area as a new additional tissue - "plus-tissue". This symptom is easy to identify with superficial localization of the tumor (in the skin, subcutaneous tissue or muscles), as well as on the extremities. Sometimes you can feel the tumor in the abdominal cavity. In addition, the “plus-tissue” sign can be determined using special research methods: endoscopy (laparoscopy, gastroscopy, colonoscopy, bronchoscopy, cystoscopy, etc.), x-ray or ultrasound, etc. In this case, it is possible to detect the tumor itself or to determine the symptoms characteristic of the “plus tissue” (filling defect in an X-ray examination of the stomach with barium sulfate contrast, etc.).
Syndrome of pathological discharge
In the presence of a malignant tumor due to the germination of blood vessels by it, spotting or bleeding often occurs. Thus, gastric cancer can cause gastric bleeding, a tumor of the uterus - uterine bleeding or spotting from the vagina, for breast cancer, a characteristic sign is a serous-hemorrhagic discharge from the nipple, for lung cancer, hemoptysis is characteristic, and with germination of the pleura, the appearance of hemorrhagic effusion in the pleural cavity, with rectal cancer, rectal bleeding is possible, with a kidney tumor - hematuria. With the development of inflammation around the tumor, as well as with a mucus-forming form of cancer, mucous or mucopurulent discharge occurs (for example, with colon cancer). These symptoms are collectively referred to as the pathological discharge syndrome. In some cases, these signs help to differentiate a malignant tumor from a benign one. For example, if there is bloody discharge from the nipple during a neoplasm of the mammary gland, the tumor is malignant.
Organ dysfunction syndrome
The very name of the syndrome suggests that its manifestations are very diverse and are determined by the localization of the tumor and the function of the organ in which it is located. For malignant tumors of the intestine, signs of intestinal obstruction are characteristic. For a tumor of the stomach - dyspeptic disorders (nausea, heartburn, vomiting, etc.). In patients with esophageal cancer, the leading symptom is a violation of the act of swallowing food - dysphagia, etc. These symptoms are not specific, but often occur in patients with malignant neoplasms.
Syndrome of small signs
Patients with malignant neoplasms often present seemingly inexplicable complaints. Note: weakness, fatigue, fever, weight loss, poor appetite (aversion to meat food, especially in stomach cancer), anemia, increased ESR. The listed symptoms are combined into a syndrome of small signs (described for the first time by A.I. Savitsky). In some cases, this syndrome occurs on quite
early stages of the disease and may even be its only manifestation. Sometimes it can be later, being essentially a manifestation of a clear cancerous intoxication. At the same time, patients have a characteristic, “oncological” appearance: they are undernourished, tissue turgor is reduced, the skin is pale with an icteric tint, sunken eyes. Usually, this appearance of patients indicates that they have a running oncological process.
Clinical differences between benign and malignant tumors
When defining plus-tissue syndrome, the question arises whether this extra tissue is formed due to the development of a benign or malignant tumor. There are a number of differences in local variations (status localis), which are primarily important for palpable formations (tumor of the breast, thyroid gland, rectum). Differences in local manifestations of malignant and benign tumors are presented in Table. 16-2.
General principles for diagnosing malignant neoplasms
Considering the pronounced dependence of the results of treatment of malignant tumors on the stage of the disease, as well as the rather high
Table 16-2.Local differences between malignant and benign tumors
the risk of recurrence and progression of the process, in the diagnosis of these processes, attention should be paid to the following principles:
Early diagnosis;
Oncological predisposition;
Hyperdiagnosis.
Early diagnosis
Elucidation of the clinical symptoms of a tumor and the use of special diagnostic methods are important for making a diagnosis of a malignant neoplasm as soon as possible and choosing the optimal path of treatment. In oncology, there is a concept of the timeliness of diagnosis. In this regard, the following types of it are distinguished:
early;
timely;
Late.
Early diagnosis is said in cases where the diagnosis of a malignant neoplasm is established at the stage of cancer. in situ or at the first clinical stage of the disease. This implies that adequate treatment should lead to recovery of the patient.
The diagnosis made at the II and in some cases at the III stages of the process is considered timely. At the same time, the treatment undertaken allows the patient to be completely cured of cancer, but this is possible only in some patients, while others will die from the progression of the process in the coming months or years.
Late diagnosis (establishment of a diagnosis at stage III-IV of an oncological disease) indicates a low probability or fundamental impossibility of curing a patient and essentially predetermines his future fate.
From what has been said, it is clear that one should try to diagnose a malignant tumor as quickly as possible, since early diagnosis makes it possible to achieve much better treatment results. Targeted cancer treatment should be started within two weeks of diagnosis. The importance of early diagnosis is clearly shown by the following figures: the five-year survival rate in the surgical treatment of gastric cancer at the stage in situ is 90-97%, and in stage III cancer - 25-30%.
Cancer alertness
When examining a patient and finding out any clinical symptoms, a doctor of any specialty should ask himself the question:
Could these symptoms be a manifestation of a malignant tumor? Having asked this question, the doctor should make every effort to either confirm or exclude the suspicions that have arisen. When examining and treating any patient, the doctor should have oncological alertness.
The principle of overdiagnosis
When diagnosing malignant neoplasms, in all doubtful cases, it is customary to make a more formidable diagnosis and take more radical methods of treatment. This approach is called overdiagnosis. So, for example, if the examination revealed a large ulcerative defect in the gastric mucosa and the use of all available research methods does not allow answering the question of whether it is a chronic ulcer or an ulcerative form of cancer, it is considered that the patient has cancer and is treated as an oncological patient.
The principle of overdiagnosis, of course, must be applied within reasonable limits. But if there is a possibility of error, it is always more correct to think about a more malignant tumor, a greater stage of the disease and, on the basis of this, use more radical means of treatment than to look at the cancer or prescribe inadequate treatment, as a result of which the process will progress and inevitably lead to death.
Precancerous diseases
For early diagnosis of malignant diseases, it is necessary to conduct a preventive examination, since the diagnosis of cancer in situ for example, on the basis of clinical symptoms is extremely difficult. And at later stages, an atypical picture of the course of the disease can prevent its timely detection. Preventive examinations are subject to people from two risk groups:
Persons who, by occupation, are associated with exposure to carcinogenic factors (work with asbestos, ionizing radiation, etc.);
Persons with so-called precancerous diseases that require special attention.
Precancerouscalled chronic diseases, against the background of which the frequency of development of malignant tumors increases sharply. So, for the mammary gland, a precancerous disease is dishormonal mastopathy; for the stomach - chronic ulcers, polyps, chronic
chesky atrophic gastritis; for the uterus - erosion and leukoplakia of the cervix, etc. Patients with precancerous diseases are subject to dispensary observation with an annual examination by an oncologist and special studies (mammography, fibrogastroduodenoscopy).
Special diagnostic methods
In the diagnosis of malignant neoplasms, along with conventional methods (endoscopy, radiography, ultrasound), various types of biopsy, followed by histological and cytological examination, are of particular, sometimes decisive importance. At the same time, the detection of malignant cells in the preparation reliably confirms the diagnosis, while a negative answer does not allow it to be removed - in such cases, they are guided by clinical data and the results of other research methods.
Tumor markers
As is known, at present there are no changes in clinical and biochemical blood parameters specific for oncological processes. Recently, however, tumor markers (TM) have become increasingly important in the diagnosis of malignant tumors. OM in most cases are complex proteins with a carbohydrate or lipid component synthesized in tumor cells in high concentrations. These proteins can be associated with cellular structures and then they are found in immunohistochemical studies. A large group of OM is secreted by tumor cells and accumulates in the biological fluids of cancer patients. In this case, they can be used for serological diagnosis. The concentration of OM (primarily in the blood) can, to a certain extent, correlate with the onset and dynamics of the malignant process. In the clinic, about 15-20 OM are widely used. The main methods for determining the level of OM in the blood serum are radioimmunological and enzyme immunoassay. The following tumor markers are most common in clinical practice: osphetoprotein (for liver cancer), carcinoembryonic antigen (for adenocarcinoma of the stomach, colon, etc.), prostate-specific antigen (for prostate cancer), etc.
Currently known OMs, with a few exceptions, are of limited use for the diagnosis or screening of tumors, since
as an increase in their level is observed in 10-30% of patients with benign and inflammatory processes. Nevertheless, OM have found wide application in the dynamic monitoring of cancer patients, for the early detection of subclinical relapses and monitoring the effectiveness of antitumor therapy. The only exception is the prostate-specific antigen used for direct diagnosis of prostate cancer.
General principles of treatment
The therapeutic tactics of benign and malignant tumors is different, which primarily depends on the infiltrating growth, the tendency to recurrence and metastasis of the latter.
Treatment of benign tumors
The main and in the vast majority of cases the only way to treat benign neoplasms is surgical. Only in the treatment of tumors of hormone-dependent organs, instead of or together with the surgical method, hormone therapy is used.
Indications for surgery
In the treatment of benign neoplasms, the issue of indications for surgery is important, since these tumors, which do not pose a threat to the patient's life, do not always have to be removed. If a patient has a benign tumor that does not cause him any harm for a long time, and at the same time there are contraindications for surgical treatment (severe concomitant diseases), then it is hardly advisable to operate the patient. In benign neoplasms, surgery is necessary if there are certain indications:
Permanent traumatization of the tumor. For example, a tumor of the scalp, damaged by scratching; formation on the neck in the area of the collar; swelling in the waist area, especially in men (rubbing with a trouser belt).
Organ dysfunction. Leiomyoma can interfere with evacuation from the stomach, a benign tumor of the bronchus can completely close its lumen, pheochromocytoma leads to high arterial hypertension due to the release of catecholamines, etc.
Before surgery, there is no absolute certainty that the tumor is malignant. In these cases, the operation, in addition to the therapeutic function, also performs the role of an excisional biopsy. So, for example, with neoplasms of the thyroid or mammary gland, patients in some cases are operated on because with such localization the question of the malignancy of the tumor can be resolved only after an urgent histological examination. The result of the study becomes known to surgeons at a time when the patient is still under anesthesia on the operating table, which helps them choose the right type and volume of surgery.
cosmetic defects. This is primarily characteristic of tumors on the face and neck, especially in women, and does not require special comments.
Surgical treatment of a benign tumor is understood as its complete removal within healthy tissues. In this case, the formation should be removed in its entirety, and not in parts, and together with the capsule, if any. An excised neoplasm is necessarily subject to histological examination (urgent or planned), given that after removal of a benign tumor, relapses and metastases do not occur; after surgery, patients recover completely.
Treatment of malignant tumors
Treatment of malignant tumors is a more difficult task. There are three ways to treat malignant neoplasms: surgery, radiation therapy and chemotherapy. In this case, the main method, of course, is the surgical method.
Principles of surgical treatment
Removal of a malignant neoplasm is the most radical, and in some localizations, the only method of treatment. Unlike operations for benign tumors, it is not enough to simply remove the formation. When removing a malignant neoplasm, it is necessary to observe the so-called oncological principles: ablastic, antiblastic, zoning, sheathing.
Ablastic
Ablasty is a set of measures to prevent the spread of tumor cells during surgery. In this case, it is necessary:
Perform incisions only within known healthy tissues;
Avoid mechanical trauma to the tumor tissue;
As soon as possible, tie up the venous vessels extending from the formation;
Bandage the hollow organ above and below the tumor with a ribbon (prevention of cell migration through the lumen);
Remove the tumor as a single block with fiber and regional lymph nodes;
Before manipulating the tumor, limit the wound with napkins;
After removal of the tumor, change (process) the instruments and gloves, change the restrictive napkins.
antiblast
Antiblastics is a set of measures for the destruction during the operation of individual tumor cells that have come off from its main mass (they can lie on the bottom and walls of the wound, enter the lymphatic or venous vessels and in the future be a source of tumor recurrence or metastases). Distinguish between physical and chemical antiblast.
Physical antiblast:
The use of an electric knife;
Use of a laser;
The use of cryodestruction;
Irradiation of the tumor before surgery and in the early postoperative period.
Chemical antiblast:
Treatment of the wound surface after removal of the tumor 70? alcohol;
Intravenous administration of antitumor chemotherapy drugs on the operating table;
Regional perfusion with anticancer chemotherapeutic drugs.
Zoning
During surgery for a malignant neoplasm, it is necessary not only to remove it, but also to remove the entire area in which there may be
individual cancer cells - the principle of zoning. At the same time, it is taken into account that malignant cells can be located in tissues near the tumor, as well as in the lymphatic vessels and regional lymph nodes extending from it. With exophytic growth (the tumor is on a narrow base, and its large mass is facing the external environment or the internal lumen - a polypoid, mushroom-shaped form), it is necessary to deviate from the visible border of the formation by 5-6 cm. With endophytic growth (spread of the tumor along the wall of the organ) from the visible border should recede at least 8-10 cm. Together with the organ or part of it, it is necessary to remove all the lymphatic vessels and nodes that collect lymph from this zone (in case of stomach cancer, for example, the entire greater and lesser omentum should be removed). Some of these operations are called "lymphodisection". In accordance with the principle of zoning, in most oncological operations, the entire organ or most of it is removed (for gastric cancer, for example, it is possible to perform only subtotal resection of the stomach [leaving 1/7-1/8 of its part] or extirpation of the stomach [complete delete]). Radical surgical interventions performed in compliance with all oncological principles are complex, large in volume and traumatic. Even with a small-sized endophytically growing tumor of the body of the stomach, the stomach is extirpated with the imposition of an esophagoenteroanastomosis. At the same time, the small and large omentum, and in some cases the spleen, are removed as a single block along with the stomach. In breast cancer, the mammary gland, pectoralis major muscle and subcutaneous adipose tissue with axillary, supraclavicular and subclavian lymph nodes are removed in a single block.
The most malignant of all known tumors, melanoma, requires a wide excision of the skin, subcutaneous fat and fascia, as well as the complete removal of regional lymph nodes (if melanoma is localized on the lower extremity, for example, inguinal and iliac). In this case, the size of the primary tumor usually does not exceed 1-2 cm.
Case
Lymphatic vessels and nodes, through which tumor cells can spread, are usually located in cellular spaces separated by fascial septa. In this regard, for greater radicalism, it is necessary to remove the fiber of the entire fascial sheath, preferably together with the fascia. A striking example of
observing the principle of sheathing - surgery for thyroid cancer. The latter is removed extracapsularly (together with the capsule formed by the visceral sheet IV of the fascia of the neck), despite the fact that due to the risk of damage n. laryngeus recurrens and parathyroid glands, removal of thyroid tissue in case of benign lesions is usually performed intracapsularly. In malignant neoplasms, along with radical ones, palliative and symptomatic surgical interventions are used. When they are implemented, oncological principles are either not observed, or they are not performed in full. Such interventions are performed to improve the condition and prolong the life of the patient in cases where radical removal of the tumor is impossible due to the neglect of the process or the serious condition of the patient. For example, in case of a decaying bleeding tumor of the stomach with distant metastases, a palliative resection of the stomach is performed, achieving an improvement in the patient's condition by stopping bleeding and reducing intoxication. In case of pancreatic cancer with obstructive jaundice and liver failure, a bypass biliodigestive anastomosis is applied, which eliminates the violation of the outflow of bile, etc. In some cases, after palliative operations, the remaining mass of tumor cells is treated with radiation or chemotherapy, achieving a cure for the patient.
Fundamentals of Radiation Therapy
The use of radiation energy for the treatment of cancer patients is based on the fact that rapidly multiplying tumor cells with a high intensity of metabolic processes are more sensitive to the effects of ionizing radiation. The task of radiation treatment is the destruction of the tumor focus with the restoration in its place of tissues with normal properties of metabolism and growth. In this case, the action of radiation energy, leading to an irreversible violation of the viability of tumor cells, should not reach the same degree of influence on the surrounding normal tissues and the patient's body as a whole.
The sensitivity of tumors to radiation
Different types of neoplasms are differently sensitive to radiation therapy. The most sensitive to radiation are connective tissue tumors with round cell structures: lymphosarco-
we, myeloma, endothelioma. Certain types of epithelial neoplasms are highly sensitive: seminoma, chorionepithelioma, lymphoepithelial tumors of the pharyngeal ring. Local changes in these types of tumors disappear quite quickly under the influence of radiation therapy, but this, however, does not mean a complete cure, since these neoplasms have a high ability to recur and metastasize.
Tumors with a histological substrate of the integumentary epithelium respond sufficiently to irradiation: cancer of the skin, lips, larynx and bronchi, esophagus, squamous cell carcinoma of the cervix. If irradiation is used for small tumor sizes, then with the destruction of the primary focus, a stable cure of the patient can be achieved. To a lesser extent, various forms of glandular cancer (adenocarcinomas of the stomach, kidneys, pancreas, intestines), highly differentiated sarcomas (fibro-, myo-, osteo-, chondrosarcomas), as well as melanoblastomas are less susceptible to radiation exposure. In such cases, irradiation can only be an auxiliary treatment that complements surgery.
The main methods of radiation therapy
Depending on the location of the radiation source, there are three main types of radiation therapy: external, intracavitary and interstitial irradiation.
With external irradiation, installations for X-ray therapy and telegamma therapy are used (special devices charged with radioactive Co 60, Cs 137). Radiation therapy is applied in courses, choosing the appropriate fields and radiation dose. The method is most effective for superficially located neoplasms (a large dose of tumor irradiation is possible with minimal damage to healthy tissues). Currently, external radiotherapy and telegammatherapy are the most common methods of radiation treatment of malignant neoplasms.
Intracavitary irradiation allows you to bring the radiation source closer to the location of the tumor. The radiation source is injected through natural openings into the bladder, uterine cavity, oral cavity, achieving the maximum dose of irradiation of the tumor tissue.
For interstitial irradiation, special needles and tubes with radioisotope preparations are used, which are surgically installed in the tissues. Sometimes radioactive capsules or needles are left in the surgical wound after removal of the malignant
noah tumor. A peculiar method of interstitial therapy is the treatment of thyroid cancer with drugs I 131: after entering the patient's body, iodine accumulates in the thyroid gland, as well as in the metastases of its tumor (with a high degree of differentiation), thus radiation has a detrimental effect on the cells of the primary tumor and metastases.
Possible Complications of Radiation Therapy
Radiation therapy is far from a harmless method. All its complications can be divided into local and general. Local complications
The development of local complications is associated with the adverse effect of irradiation on healthy tissues around the neoplasm and, above all, on the skin, which is the first barrier to the path of radiation energy. Depending on the degree of skin damage, the following complications are distinguished:
Reactive epidermitis (temporary and reversible damage to epithelial structures - moderate edema, hyperemia, pruritus).
Radiation dermatitis (hyperemia, tissue edema, sometimes with the formation of blisters, hair loss, hyperpigmentation followed by skin atrophy, impaired pigment distribution and telangiectasia - expansion of intradermal vessels).
Radiation indurative edema (specific thickening of tissues associated with damage to the skin and subcutaneous tissue, as well as with the phenomena of obliterating radiation lymphangitis and sclerosis of the lymph nodes).
Radiation necrotic ulcers (skin defects characterized by severe soreness and the absence of any tendency to heal).
Prevention of these complications includes, first of all, the correct choice of fields and doses of radiation. General complications
The use of radiation treatment can cause general disorders (manifestations of radiation sickness). Its clinical symptoms are weakness, loss of appetite, nausea, vomiting, sleep disturbances, tachycardia and shortness of breath. To a greater extent, hematopoietic organs, primarily the bone marrow, are sensitive to radiation methods. In this case, leukopenia, thrombocytopenia and anemia occur in the peripheral blood. Therefore, against the background of radiation therapy, it is necessary to perform a clinical blood test at least once a week. In some cases, uncontrolled leu-
accumulation causes a reduction in the dose of radiation or the cessation of radiation therapy altogether. To reduce these general disorders, leukopoiesis stimulants, blood transfusion and its components, vitamins, and high-calorie nutrition are used.
Fundamentals of Chemotherapy
Chemotherapy - the impact on the tumor by various pharmacological agents. In terms of its effectiveness, it is inferior to the surgical and radiation methods. The exceptions are systemic oncological diseases (leukemia, lymphogranulomatosis) and tumors of hormone-dependent organs (breast, ovary, prostate cancer), in which chemotherapy is highly effective. Chemotherapy is usually given in courses over a long period of time (sometimes for many years). There are the following groups of chemotherapeutic agents:
cytostatics,
antimetabolites,
anticancer antibiotics,
Immunomodulators,
Hormonal preparations.
Cytostatics
Cytostatics inhibit the reproduction of tumor cells, inhibiting their mitotic activity. Main drugs: alkylating agents (cyclophosphamide), herbal preparations (vinblastine, vincristine).
Antimetabolites
Medicinal substances act on metabolic processes in tumor cells. Main drugs: methotrexate (folic acid antagonist), fluorouracil, tegafur (pyrimidine antagonists), mercaptopurine (purine antagonist). Antimetabolites together with cytostatics are widely used in the treatment of leukemia and poorly differentiated tumors of connective tissue origin. In this case, special schemes are used with the use of various drugs. In particular, the Cooper scheme has become widespread in the treatment of breast cancer. Below is the Cooper scheme in the modification of the Research Institute of Oncology. N.N. Petrov - scheme CMFVP (by the first letters of drugs).
On the operating table:
200 mg cyclophosphamide.
In the postoperative period:
On days 1-14, 200 mg of cyclophosphamide daily;
1, 8 and 15 days: methotrexate (25-50 mg); fluorouracil (500 mg); vincristine (1 mg);
On the 1st - 15th day - prednisolone (15-25 mg / day orally with gradual withdrawal by the 26th day).
Courses are repeated 3-4 times with an interval of 4-6 weeks.
Antitumor antibiotics
Some substances produced by microorganisms, primarily actinomycetes, have an antitumor effect. The main antitumor antibiotics are: dactinomycin, sarcolysin, doxorubicin, carubicin, mitomycin. The use of cytostatics, antimetabolites and antitumor antibiotics has a toxic effect on the patient's body. First of all, the hematopoietic organs, liver and kidneys suffer. There are leukopenia, thrombocytopenia and anemia, toxic hepatitis, renal failure. In this regard, during chemotherapy courses, it is necessary to monitor the general condition of the patient, as well as clinical and biochemical blood tests. Due to the high toxicity of drugs in patients over 70 years of age, chemotherapy is usually not prescribed.
Immunomodulators
Immunotherapy began to be used for the treatment of malignant neoplasms only recently. Good results have been obtained in the treatment of kidney cancer, including at the stage of metastasis, with recombinant interleukin-2 in combination with interferons.
Hormonal drugs
Hormone therapy is used to treat hormone-dependent tumors. In the treatment of prostate cancer, synthetic estrogens (hexestrol, diethylstilbestrol, fosfestrol) are successfully used. In breast cancer, especially in young women, androgens (methyltestosterone, testosterone) are used, and in the elderly, drugs with antiestrogenic activity (tamoxifen, toremifene) have recently been used.
Combined and complex treatment
In the process of treating a patient, it is possible to combine the main methods of treating malignant tumors. If two methods are used in one patient, one speaks of combined treatment if all three are o complex. Indications for one or another method of treatment or their combination are established depending on the stage of the tumor, its localization and histological structure. An example is the treatment of different stages of breast cancer:
Stage I (and cancer in situ)- enough adequate surgical treatment;
Stage II - combined treatment: it is necessary to perform a radical surgical operation (radical mastectomy with removal of axillary, supraclavicular and subclavian lymph nodes) and chemotherapy treatment;
Stage III - complex treatment: first, radiation is used, then a radical operation is performed, followed by chemotherapy;
Stage IV - powerful radiation therapy followed by surgery for certain indications.
Organization of care for cancer patients
The use of complex diagnostic and treatment methods, as well as the need for dispensary observation and the duration of treatment, led to the creation of a special oncological service. Assistance to patients with malignant neoplasms is provided in specialized medical institutions: oncological dispensaries, hospitals and institutes. In oncology dispensaries, they carry out preventive examinations, dispensary observation of patients with precancerous diseases, primary examination and examination of patients with suspected tumors, conduct outpatient courses of radiation and chemotherapy, monitor the condition of patients, and keep statistical records. In oncology hospitals, all methods of treating malignant neoplasms are carried out. At the head of the oncological service of Russia is the Russian Cancer Research Center of the Russian Academy of Medical Sciences, the Oncological Institute. P.A. Herzen in Moscow and the Research Institute of Oncology. N.N. Petrov in St. Petersburg. Here they coordinate scientific research in oncology, provide organizational and methodological guidance to other oncological
institutions, develop problems of theoretical and practical oncology, apply the most modern methods of diagnostics and treatment.
Evaluation of the effectiveness of treatment
For many years, the only indicator of the effectiveness of the treatment of malignant neoplasms was a 5-year survival rate. It is believed that if within 5 years after treatment the patient is alive, relapse and metastasis did not occur, the progression of the process in the future is extremely unlikely. Therefore, patients who live 5 years or more after surgery (radiation or chemotherapy) are considered to have recovered from cancer.
Evaluation of results based on 5-year survival remains the main one, but in recent years, due to the widespread introduction of new chemotherapy methods, other indicators of treatment effectiveness have appeared. They reflect the duration of remission, the number of cases of tumor regression, the improvement in the quality of life of the patient and allow us to evaluate the effect of treatment in the near future.
>> Pathogenesis
Tumors are either benign or malignant. The former arise mainly as a result of the division of cells of the same type, which do not differ significantly from normal cells in morphology, although there is a tendency to increased growth. A benign tumor lacks the ability to invade and metastasize. It can retain these characteristics throughout a person's life, but in some cases turns into cancer. For example, subcutaneous tissue lipoma and uterine fibroids in most cases do not transform into sarcoma, and diffuse intestinal polyposis in 100% of cases turns into cancer. Thus, benign tumors may be the initial stage cancer development and sarcomas, that is, precancer. They are able to maintain the characteristics of benign tissue growth for a long time, but there is always a threat of their further transformation and degeneration into cancer.
Such a transformation, or malignancy, is explained by scientists by the fact that there is a repeated change in the genetic apparatus of tumor cells. And since these cells tend to mutate much more than normal cells, new clones of cells with characteristics inherent in cancer arise. This is a sharp cellular polymorphism, atypia, the ability to germinate and adjacent tissues and organs, destroying them and thereby creating metastatic foci of cancer.
Benign and malignant tumors have their own clinical patterns and features of the development of symptomatology. When diagnosing, it is important to immediately make a clear diagnosis, determining the type of tumor. In no case should one be limited to one observation of the development of the tumor (its growth rate, etc.) when establishing the primary diagnosis. It is necessary to resort to the most rational methods of diagnosis in order to prevent the progression of cancer.
Genetic factors play an important role in the pathogenesis of some tumors. In animals, the role of genetic predisposition is more obvious than in humans. Various disorders in the genome lead to multiple malformations, including the development of cancer. Families with multiple cases cancer taken under medical supervision. Physicians develop a certain control system that allows to detect the development of cancer at an early stage. It is recommended to minimize etiological factors, it is especially important to exclude contact with potential carcinogens. The most common "genetic" tumors are as follows: retinoblastoma, pheochromocytoma, nevus basal cell carcinoma, medullary thyroid cancer, trichoepithelioma, multiple endocrine adenomatosis, colon polyposis, paraganglioma.
Tumors are observed even in some plants (sunflower, carrot, turnip, etc.), although they are fundamentally different from true cancer neoplasms in humans or animals. The main reasons for their appearance and development are bacteria and radiation.
Peculiar tissue growths resembling cancer are observed in embryonic forms of insects. For example, Drosophila larvae have both benign and malignant tumors. They occur spontaneously or as a result of exposure to x-rays.
Benign tumors and sarcomas are observed in many fish, especially teleosts. Some get cancer, like gobies in the Caspian Sea. Specific forms of cancer observed in fish common in a particular reservoir. For example, trout found in the waters of Switzerland and New Zealand usually have adenomas or adenocarcinomas.
TO cancer development can lead to violations of immunological control: immunodeficiency syndromes (agammaglobulinemia, ataxia, telangiectasia, etc.), as well as long-term use of immunosuppressive drugs (after organ transplantation, etc.). Such patients also need to be under more vigilant medical supervision so that the development of cancer can be noticed at an early stage.
Development of cancer largely determined by invasion and metastasis. During invasion, cancer cells grow into neighboring organs and tissues, changing blood vessels and nerves. In most cases, invasion leads to the development of cancer metastases (for example, with melanoma of the skin). Altered nerve elements create focal growths of cancer that are woven into other tissues. Blood vessels have thinner walls, are filled with blood, and are often distended. Due to a violation of the blood supply to the tumor tissues, necrosis (tissue death) develops in it. In areas of necrosis, both vessels and nerves disintegrate.
During metastasis, tumor cells are carried by the bloodstream throughout the body. Metastasis is the main sign of cancer. Although in exceptional cases there are examples of metastasis of a morphologically benign tumor (for example, with adenoma of the thyroid, pancreas, destructive hydatidiform mole). But, as a rule, benign tumors do not cause metastases.
In the presence of cancer, metastases occur primarily in the regional lymph nodes, and then appear in other organs and tissues. When examining a patient, it is very important to know the ways of lymph outflow well. Often, simultaneously with the removal of the primary tumor, an operation is performed on the regional lymph nodes. A similar method is used for radiation therapy (if it is the main method cancer treatment). Simultaneously with irradiation of a cancerous tumor, irradiation of regional lymph nodes is also carried out.
Many tumors metastasize to fairly distant organs and tissues. For example, testicular cancer, kidney cancer has the ability to metastasize to the lungs, colon cancer - to the liver, mammary cancer- most often in the bones, etc. Multiple metastases of various sizes may occur. At the same time, they always retain the morphological structure and biological characteristics of the primary tumor. Lungs, bones, liver and brain are affected more often than other organs. During observation, drawing up a conclusion, as well as for further planning of radiation therapy or surgery, it is important to clearly know the localization of the tumor and the features of its distant metastasis.
Metastases develop in different ways, and the period of their development may vary. For example, breast cancer can metastasize within 2-5 years, and sometimes after 10-15 years. Metastases of kidney cancer usually appear within the first year after diagnosis or surgery.
Tumors and cancer occur even in birds, and in a variety of forms. Epithelial tumors in the ovaries and tumors of the hematopoietic apparatus, various types of leukemia and sarcomas are more often observed. It is known that benign and cancerous tumors, as well as sarcomas and other types of tumors, are more common in chickens and budgerigars than in ducks and geese, both wild and domestic.
Tumors and cancer observed in many mammals, including cats and dogs, mice and rats. Tumors increase in size with age, and by the end of life, incidence increases. Each species often has a particular type of tumor. For example, in guinea pigs, lipomas are more often observed, in rats - fibroadenomas of the mammary glands, etc.
Malignant tumors of some organs
As mentioned earlier, the classification of cancer types is made depending on whether the tumor belongs to a particular tissue. There are four types of tissue: epithelial, muscle, nervous and connective. Within each group, a classification is made according to the morphological structure and histogenesis of the tumor. In addition, other tissues that make up the cancerous tumor are also taken into account, since several types of tissue can be part of the tumor parenchyma. Recently, in oncology, the names of some types of cancer on an organ or part of it.
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In 1908-1911, a viral nature of leukemia and chicken sarcomas. In the following decades, the viral etiology of a number of lymphoid and epithelial tumors in birds and mammals was proven. It is now known that under natural conditions, for example, leukemia is caused by viruses in chickens, cats, cattle, mice, gibbons.
Opened in recent years first viral pathogen that causes the development of leukemia in humans is ATLV (adult T-cell leukemia virus - adult T-cell leukemia virus) black people in the Caribbean. Patients with this lymphoma occur sporadically and in other regions, but many of them have been identified in one way or another with endemic areas.
This disease occurs usually in people over 50 years of age, presents with skin lesions, hepatomegaly, splenomegaly, lymphadenopathy, and has a poor prognosis ATLV or HTLV virus is exogenous in humans, differs from other known animal retroviruses, is transmitted by T cells horizontally from mother to child, from husband to wife (but not vice versa), during blood donation, is not found in any other forms of human leukemia or lymphoma. Thus, adult T-cell leukemia is a typical infectious disease (vertical transmission of the virus through germ cells is excluded by special studies). In endemic foci, more than 20% of practically healthy people, mainly relatives of patients, are carriers of the virus.
In other parts the globe antibodies to the virus are rarely found. It is believed that 1 out of 2000 infected people becomes ill. A virus indistinguishable from ATLV has been found in Africa in a monkey. In addition to lymphoma (leukemia), this virus can cause AIDS, in which T-cell immunity is impaired.
Viral etiology suspected in relation to some other human tumors Epstein-Barr virus (EBV), which is part of the group of herpes viruses, is a very likely etiological factor in Burkitt's lymphoma. In the cells of this lymphoma in endemic foci in Africa, EBV DNA is constantly detected. However, Burkitt's lymphoma also occurs outside of Africa, but EBV DNA is found in only a minority of such cases. Common for EBV-positive and EBV-negative tumors are characteristic rearrangements of chromosomes (translocation between chromosomes 8 and 14), which is considered as evidence of a common etiology of these tumors.
DNA of this virus is found in the genome of cells of undifferentiated nasopharyngeal carcinoma, but not in tumors of the nasopharynx of another histogenesis. In patients with these tumors, a high titer of antibodies to various components of EBV is noted, significantly exceeding these figures in the population - EBV is widespread, and antibodies to it are found in 80-90% of healthy people. A high titer of antibodies was found in patients with lymphogranulomatosis. Immune suppression and EBV activation are, according to some authors, the main cause of the development of lymphomas and immunoblastic sarcomas in patients with transplanted kidneys exposed to immunodepressive agents; This is supported by the high titer of antibodies to EBV and the detection of EBV DNA in the genome of tumor cells.
There is evidence to suggest an infectious (viral) etiology cervical cancer the frequency of occurrence of this cancer is higher at an early onset of sexual activity with a frequent change of partners, it is increased in the second wives of men whose first wives also suffered from the same disease. On the basis of seroepidemiological data, one thinks about the role of type II herpes virus as an initiator; condylomavirus is also suspected.
In areas with high frequency occurrence of viral hepatitis B the incidence of hepatocellular cancer is also increased. On the other hand, patients with this tumor are more likely to be seropositive for the hepatitis B virus than healthy individuals; but there are also seronegative cases of cancer. Tumor cell lines containing virus DNA and producing its antigen have been obtained. In general, the role of hepatitis B virus in the induction of hepatocellular carcinoma remains unclear.
From human warts(verrucae vulgaris) isolated several types of papillomaviruses, which are believed to cause only benign tumors that are not prone to malignancy. Only one of these viruses (type 5) was isolated from papillomas developing in hereditary epidermodysplasia warty and tending to malignancy.
Initially tumor viruses were considered as infectious agents that induce cells to unregulated reproduction. In contrast, L. A. Zilber (1945) developed a theory according to which the genome of a tumor virus integrates into the genome of a normal cell, turning it into a tumor cell, i.e., tumor viruses are fundamentally different from infectious ones in their action. In the 1970s, genes necessary for the transformation of a normal cell into a tumor cell were found in tumorigenic RNA-containing viruses - transforming genes or oncogenes (v-onc - viral oncogenes). Subsequently, copies or analogs of oncogenes were found in normal cells of various animals and humans (c-ops - "cellular"-cell oncogenes), then the ability of the oncogene to integrate into the virus genome was proved.
Oncogenes now identified, their chemical structure, localization in chromosomes are determined. Proteins have also been identified - the products of the activity of these genes, each of them synthesizes its own specific protein.