Cancer cell. What causes cancer in humans

Cancer is a disease that begins with cell damage. There are many different types of cells in the body and many different types of cancer that arise from these cells.

What all types of cancer have in common is that cancer cells are abnormal and multiply out of control. Some cancers are more serious than others, some are easier to treat (especially if diagnosed early), some have better prospects (prognosis) than others. So, cancer is not just one disease. In each case, it is important to know exactly what type of cancer has developed, how big it has become, whether it has spread to other organs, and how well it usually responds to treatment.

What are cells?

normal body cells

The body is made up of millions of tiny cells. Different parts of the body such as organs like bones, muscles, skin and blood are made up of different specialized cells. Most of them have a center called the nucleus. The nucleus in each cell contains thousands of genes that make up DNA. Genes are a kind of codes that control the functions of cells. For example, various genes control the proteins or hormones or other chemicals produced by the cell. Specialized genes determine when cells should multiply, and some genes even determine cell death.

Most cell types in the body divide and multiply. When old cells wear out or become damaged, new cells are formed to replace them. Some cells usually multiply rapidly. For example, your body produces millions of red blood cells daily as old ones wear out and break down. Some cells, when they reach maturity, do not multiply at all - for example, brain cells. As a rule, your body produces only the required number of cells.

Abnormal (atypical) cells

Sometimes a cell becomes abnormal. This happens because one (or more) genes in it are changed or damaged. An atypical cell can further divide into two, then four, then eight, and so on. Thus, a large number of atypical cells can develop from the primary abnormal cell. These cells are unable to stop their reproduction. Subsequently, a group of atypical cells may form. If this group of cells becomes larger, it forms a large collection of abnormal cells called a tumor.

What are tumors?

A tumor is a growth of tissue from abnormal cells. Tumors are divided into two types: benign and malignant.

Noncancerous (benign) tumors

Noncancerous (benign) tumors can form in various parts of the body.

They grow slowly, without spreading or penetrating into other tissues. They are not cancerous and are not usually life-threatening. As a rule, they do not cause any harm to the body. However, benign tumors can cause some problems. For example, they can grow quite large and cause symptoms of local pressure or look unsightly. In addition, some benign tumors that originate from cells in glandular hormones can overproduce hormones, which in turn can cause unwanted effects.

Cancerous (malignant) tumors

Malignant tumors tend to grow quite quickly and penetrate into nearby tissues and organs, which can lead to their damage. Tumors usually develop in one place - the primary tumor. Malignant tumors can also spread to other parts of the body and form secondary tumors (metastases). This happens when a few cells break off from the primary tumor and are carried in the bloodstream or through the lymphatics to other parts of the body. These secondary tumors can grow and damage nearby tissues and spread further.

Note: Not all cancers are solid (solid) tumors. For example, in blood cell cancer (leukemia), many of the abnormal blood cells are produced in the bone marrow and circulate in the bloodstream.

What is the cause of cancer?

It is believed that cancer begins with a single atypical cell. What seems to be happening is that some of the vital genes that control cell division and reproduction are damaged or altered. This makes the cells abnormal. Surviving abnormal cells can grow uncontrollably into a cancerous (malignant) tumor.

We all have a risk of developing cancer. Many types of cancer seem to develop for no apparent reason. However, certain risk factors are known to increase the chance that one or more of your cells will become abnormal (atypical) and lead to cancer. Risk factors include the following:

Chemical carcinogens

Carcinogens are environmental factors (chemicals, radiation, etc.) that can damage a cell and turn it into a cancer cell. Generally, the greater the exposure to carcinogens, the greater the risk of developing cancer. Well-known examples of carcinogens include:

Tobacco smoke. Smokers are more likely to develop lung cancer, oral cancer, throat cancer, esophageal cancer, bladder cancer, and pancreatic cancer. Smoking is considered the cause of about a quarter of all cancers. Approximately 1 in 10 smokers die from lung cancer. The heavier tobacco you smoke, the higher your risk of developing cancer. If you stop smoking, this risk will be significantly reduced.
Occupational chemicals such as asbestos, benzene, formaldehyde, etc. If you have worked with them without protection, you have an increased risk of developing certain types of cancer. For example, a cancer called mesothelioma is linked to past exposure to asbestos.
Age. The older you get, the more likely you are to develop cancer. This is most likely due to the accumulation of damage in the cells of the body over time. In addition, with age, the body's defenses can no longer cope with atypical cells. For example, the ability to repair damaged cells and the immune system, which can destroy abnormal cells, becomes less effective with age. So, eventually, one damaged cell can survive and multiply uncontrollably, turning into cancer. Most cancers develop in older people.

lifestyle factors

Diet and other lifestyle factors can affect your risk of getting cancer.

For example:

If you eat plenty of fruits and vegetables, your risk of developing certain types of cancer is reduced. How they protect against cancer is not yet fully understood. These foods, rich in vitamins and minerals, also contain chemicals called antioxidants. They are able to protect against harmful substances entering the body. We should all be eating at least five servings of fruits and vegetables a day (some experts recommend even more).
By eating too much fatty foods, we increase the risk of certain types of cancer.
An increased risk of developing certain types of cancer is associated with obesity, lack of regular exercise and alcohol abuse.

For example, one large study followed over 55,000 people over 10 years. It took into account lifestyle factors and cancer incidence. The study concluded that by following recommendations for being physically active, controlling your weight, not smoking, drinking moderately and eating healthy, you can reduce your risk of bowel cancer by as much as 23%. But the study found that even improving some of these lifestyle factors contributes to some reduction in cancer risk.

radioactive radiation

Radioactive radiation is a carcinogen. For example, exposure to radioactive materials and radiation can increase the risk of developing leukemia and other cancers. Excessive sun exposure and sunburn (UVA and UVB radiation) increase the risk of developing skin cancer. The higher the dose of radiation, the higher the risk of developing cancer. But note that the risk from small doses, such as from a single x-ray, is very small.

infections

Some viruses are associated with certain types of cancer.

For example, people with chronic infection with the hepatitis B virus or hepatitis C virus have an increased risk of developing liver cancer. Another example is the link between human papillomavirus (HPV) and cervical cancer. Most (perhaps all) women who develop cervical cancer have been infected with a strain (subtype) of HPV. However, most viruses and viral infections are not associated with cancer.

The immune system

People with weakened immune systems have an increased risk of developing certain types of cancer. For example, people with AIDS or people taking immunosuppressive therapy.

Heredity

Some cancers are hereditary. For example, in some cancers in children, an abnormal gene or genes that can reprogram a cell to be malignant are inherited. Other cancers may have some genetic factor that is less clear cut. It is possible that in some people their genetic makeup (genotype) suggests that they are less resistant to exposure to carcinogens and other factors such as diet.

Most cancers are likely due to a combination of these factors.

Not all people who come into contact with a carcinogen or lead an unhealthy lifestyle develop cancer. For example, not all smokers get lung cancer. Indeed, we are all likely to be exposed to low doses of carcinogens over a long period of time.

The body has certain mechanisms that can protect us from developing cancer. For example, it is believed that many cells that have been damaged by carcinogens can repair themselves. In addition, the body's immune system may be able to destroy certain types of abnormal cells before they multiply into a tumor. Perhaps one carcinogen can damage only one gene, and in order for cellular atypia to occur, two or more factors must act on the cell.

In many cases, it is likely that a combination of factors such as genotype, exposure to carcinogens, age, diet, immune system status, etc., are involved in the malignancy ("malignancy") of cells.

Cancer is not in vain called the scourge of the 21st century, because the cases of patient death are in second place after heart disease. What a tumor looks like, as well as what its types are, are the two main questions that interest almost everyone. Sometimes this information is extremely useful, because skin cancer can be detected by external manifestations.

As you know, neoplasms are benign and malignant. And if the former do not pose a real threat to the body, then the latter most often lead to death.

General characteristics of cancer

What is cancer? This is a disease that is expressed in the uncontrolled division of body cells and is characterized by their degeneration. Tumor foci are expressed in atypia, otherwise - the inability of cells to carry out the program genetically embedded in them. In this case, the structure of the tissue from which the cancer is formed changes. In other words, cancer is a disease in which once healthy cells begin to harm the body. Degenerate cells release harmful substances, causing powerful intoxication. Various cancerous foci differ from benign ones in that they actively metastasize - they grow and move to other organs. What does a cancerous tumor look like?

Usually, during the examination, a specialist can see a dense structure that grows from the tissue of a damaged organ and quickly increases in size.

Types of cancer

Carcinoma is formed from the epithelium of internal organs.

Depending on the cells from which this type of cancer is formed, it is divided into squamous, formed from squamous epithelium, into adenocarcinoma, formed from glandular epithelium. In the first case, it is cancer of the intestine or esophagus. In the second - the prostate gland or chest.

Sarcoma is a cancer of the connective tissue.

Although it appears quite rarely, a fatal outcome can occur from it at any stage. This tumor cyst has a distinctive feature: in the photo you can see a large number of vessels, thanks to which it receives a good blood supply.

Melanoma affects skin cells that contain melanin. A malignant tumor is very aggressive, you can see it yourself when examining your skin. It will look like an asymmetric mole.
Leukemia is a malfunction of the bone marrow when it stops producing red blood cells. With leukemia, blasts accumulate in the bone marrow and interfere with its normal functioning, so the blood changes in its chemical properties. Leukemia can be chronic or acute. In the latter case, the chance of a successful cure is extremely small. Leukemia is diagnosed quite simply: first, apathy and fatigue appear in the patient, then the specialist can see an enlarged spleen, liver and lymph nodes.
In lymphoma, malignant neoplasms appear in the lymph nodes.

Lymphoma disrupts the functioning of the entire lymphatic system and prevents the normal movement of lymph. In this case, the lymph glands are enlarged. Surgery to remove lymphoma is usually not done. If the doctor makes this diagnosis, then the treatment will be chemotherapy. How does this type of cancer manifest itself externally and internally? With lymphoma, you can see how a person becomes covered with red spots, begins to lose weight dramatically, sweats profusely and often vomits.

Glioma is a neoplasm of nerve cells.

When a tumor cyst appears in the brain, doctors make a diagnosis of glioma. It occurs in glial cells responsible for the functioning of neurons. It is poorly diagnosed in the early stages.

Stages of cancer in the body

As you know, there are four stages of a malignant disease. The higher the stage, the lower the likelihood of a positive outcome of treatment, but the greater the chance of making a correct diagnosis.

At the first stage, it is rather problematic to see a malignant neoplasm and make an accurate diagnosis. However, it is at this time that it can be completely cured. In the second stage, the tumor noticeably increases in size, and therefore it is more difficult to cope with it. The third stage is similar to the second, except that the treatment of the body is almost useless. The fourth stage of the disease can be called terminal. Cases of cure for malignant tumors around the world are rare.

Diagnosis of malignant neoplasms in women

Recently, cases of cancer of the female organs, namely the ovaries, the body of the uterus or the cervix, have become more frequent.

Ovarian cancer is dangerous because already at the third stage of development, the survival rate is small - this is how the development of the disease looks like. In the last stage, only 5% of women with ovarian cancer can survive.

Such a malignant neoplasm can be of five types. For example, dysgerminomas are formed from the rudimentary tissues of the ovaries, and chorionepithelioma - from the cells of the fetal egg.

What does an ovarian tumor look like? In the process of diagnosing this disease from a photo, the doctor can see how the female organ has increased many times in size. It looks like a normal cyst, so it can be confused and given the wrong treatment. A feature of ovarian cancer is cell growth, but a malignant formation is diagnosed only by a good specialist in photo transvaginal ultrasound, MRI, laparoscopy, and also during manual examination.

Medical studies show that ovarian cancer most often develops after the age of 50, although it is not uncommon for it to be diagnosed in 30-year-olds. This disease is dangerous because it is completely asymptomatic in the first stages, and does not look at all like something suspicious, and only a doctor can see changes in the body. The subsequent treatment is extremely difficult.

As the cells divide uncontrollably, the woman begins to feel pain in the lower abdomen, which radiates to the lower back. Her menstrual cycle is disturbed, and the stomach itself increases in size. With a malignant neoplasm of the ovaries, most women experience discomfort with intimacy. Since the ovarian tumor presses on the internal organs, a woman may often feel the urge to go to the toilet.

It is especially worth noting that the ovarian tumor can twist, as a result of which its nutrition is stopped. This is fraught with the occurrence of tumor necrosis and acute pain. This condition is removed exclusively promptly.

As a complication of ovarian cancer, experts note ascites - the accumulation of fluid in the abdomen, due to which it can also increase in size. In some cases, fluid may accumulate in the chest and cause shortness of breath.

Uterine cancer is less common in women. In this case, there may be cancer of the body of the uterus or a neoplasm of the cervix. However, the mortality from this disease among women is small, since cancer of the body of the uterus and cervix is quite easy to see in the diagnostic process. What does a cancerous tumor of this organ look like? This is an exophytic neoplasm in the form of a mushroom or cap. Often such a tumor occupies the entire body of the uterus. The danger of the disease lies in the fact that it is able to grow inside the body and affect the appendages in the form of ovaries or fallopian tubes. Often metastases affect the kidneys, liver, lungs and mammary glands.

Uterine cancer most often occurs in postmenopausal women, that is, 12 months after menstruation completely disappears. The first symptoms are profuse bleeding, as the tumor suppresses the endometrium.

Symptoms of cervical cancer are expressed in the fact that a woman feels a dense formation, intimacy becomes painful, blood and pus are released.

In this case, timely diagnosis is required. In addition to ultrasound and manual examination, specialists practice diagnostic curettage for histological examination.

A large number of young women suffer from malignant neoplasms in the cervix. Currently, medical studies among the main causes of cervical disease note the human papillomavirus. It is believed that erosion and dysplasia also precede the disease, but if they respond well to treatment, then cervical cancer does not.

Kidney cancer is a disease that affects the body equally, both women and men. Its diagnosis, however, can be quite difficult.

Tumor cysts can grow inside the kidney to large sizes without symptoms. And yet, to diagnose a malignant neoplasm of the kidney, doctors ask you to pay attention to the presence of blood in the urine, pain concentrated in the lower back, weight loss, swelling of the ankles or fever. All of these may indicate kidney cancer.

What does a skin cancer look like?

Each type of cancer looks different. But if a tumor of the internal organs can only be seen by a doctor thanks to special equipment, then skin cancer can be diagnosed independently. In appearance, it is divided into three varieties: squamous cell, basal cell and melanoma.

Squamous cell carcinoma is ulcerative, nodular and plaque.

In the first case, the skin is covered with ulcers that look like small craters. In addition, such neoplasms have an unpleasant odor and bleed. Ulcerative tumors grow extremely fast. With the nodular variety, bumpy red-brown nodules form on the skin. If the variety is plaque, the skin is covered with red sores.

Basiloma, or basal cell carcinoma, in the early stages looks like a small white pimple.

Melanoma is the most common and aggressive skin cancer. It quickly grows through the skin layers and destroys them. Further, it affects the lymphatic glands and blood vessels, its metastases often penetrate the brain or lungs.

You should contact your doctor immediately if you notice asymmetrical growths on the skin and if they have jagged edges.

Where does it all start

If you think about it, “the immune system missed the cancer cells, and then a tumor developed from them” is not at all the answer to the question of why cancer begins. After all, it is not clear why the cell becomes cancerous at all. Unfortunately, scientists do not have an unequivocal answer to this question. Describing the behavior of existing tumors is much easier than fixing the moment when a normal healthy cell "turns into a crooked path."

Strictly speaking, there is no such moment: many chemical processes go on continuously in every living cell (a fascinating thought, if you think about it). Some of them, under the influence of chemical or physical factors, can go wrong - and then mutations occur in the cell. However, mutations can also be inherited. Not all of them cause the cell to become cancerous - most often the mutant cell simply dies - by committing suicide called "apoptosis" or by waiting for the killers who are in the service of the immune system. But in a number of cases, a tumor grows out of just such abnormal cells.

The tumor has a number of differences from the healthy tissue surrounding it. Healthy tissues in the human body appear and grow, obeying certain laws. The tumor grows simply because it can. The second key feature, perhaps even more impressive, is that tumor cells are virtually immortal. Healthy cells divide a certain number of times, after which they "commit suicide" - this principle is called the Hayflick limit. It is different for different types of cells, but this genetic mechanism works for almost all healthy cells. But for tumor cells, it does not work, and therefore they are able to divide an infinite number of times. There is even a rather Jesuitical theory that by understanding the mechanisms of tumor growth, one can find the key to immortality.

Good and Evil

It should be noted that not all tumors are equally terrible - they are usually divided into benign and malignant. The former are called so because they live in their "ghetto" - a kind of capsule forms around the tumor tissues, and as its size grows, it simply pushes the surrounding healthy tissues apart. That is why it does not have a particularly adverse effect on the body (excluding brain tumors that can compress the nerve centers in it). Unlike them, malignant tumors behave like true invaders. They grow rapidly and tend to somehow spread throughout the body. Malignant tumors penetrate into neighboring tissues, grow and destroy them - this phenomenon is called "infiltrative growth", they tend to recur - that is, grow again after removal, chemotherapy or radiation therapy in the same place, they can cause weakness and exhaustion. And, of course, one of their key features (largely related to the previous ones) is the ability to metastasize.

Internal Invaders

Metastasis is the transfer of tumor cells outside the "historical homeland" to various organs and tissues. There they form new tumors, called secondary and similar in structure to the primary tumor. As the number of cells in the new "colony" increases, they begin to secrete substances that stimulate the formation and development of a network of vessels and capillaries around it - this gives the tumor the opportunity to "feed", and since, due to the extremely rapid growth of nutrition, it also needs more than other tissues, cancer patients may experience depletion - nutrients pass by the rest of the body.

Unfortunately, cancer cells have quite a few different ways to move around the human body. They can penetrate into the lymphatic vessels of the body, reaching first to the nearest lymph nodes, and from there, migrating further and reaching other organs and tissues. Cancer cells move through the blood vessels - in the presence of a malignant tumor, they are always present in the blood, but most of them are hunted down and killed by the immune system. However, those that go unnoticed will reach other organs and tissues and form a new tumor there. Sometimes, however, cancer cells consider long-distance travel unnecessary and form a new tumor right next to the old one.

Travel destinations depend primarily on the type of cancer - lung cancer, for example, metastasizes to the brain, bones and adrenal glands, while kidney cancer forms intravascular tumors and bone tumors. Earlier and more extensive metastases are observed in young people, in addition, metastasis becomes more frequent with tumor growth. On average, as a rule, metastases appear 1-2 years after the onset of cancer development.

Metastases, like the main tumor, significantly disrupt the functioning of the body - they release toxins and biologically active substances that interfere with the regulatory systems of organs and tissues, destroy healthy tissue around them, decay, dying, and also poison the body. Chemotherapy and radiation therapy are carried out, among other things, in order to prevent the appearance of metastases. But if they do appear, the death of oncological patients, as a rule, occurs precisely because of them.

Every day, thousands of abnormal cellular structures appear in the human body, which can later acquire a malignant status. Thanks to immunity, these cells are destroyed in a timely manner.

But if the immune defense for certain reasons misses these cells, then they multiply freely, forming into a tumor.

What are cancer metastases?

Malignant cells from the foci of primary localization spread through the blood and lymph flow to other organic structures, forming metastatic foci, which are actually secondary localizations of cancer.

So, metastases are cancer cells that spread throughout the body from the main focus of the tumor process.

When cancer spreads to neighboring tissues, they speak of regional metastasis. If malignant cellular structures with blood flow or lymphatic fluid have penetrated into peripheral tissues, then distant metastasis occurs.

Reasons for the spread

In general, metastasis is caused by certain factors of oncological growth, which stimulate the formation of capillary and vascular networks around the tumor formation.

As a result, a favorable environment is created for malignant structures, which provides them with the necessary nutrition. According to this scenario, metastasis occurs throughout the body.

In general, the spread of malignant cells can occur in various ways:

With blood flow - malignant cells hematogenously spread through the veins, capillary structures and vessels throughout the body;
with lymph flow. Lymph nodes act as a protective barrier for malignant structures and they are partially destroyed. But when there are too many changed cells, macrophages cannot cope with them;
Implantation or on the shell of serous tissue.

Metastases of lymphogenous origin are most characteristic of and, and, and.

Hematogenous pathways of metastasis are usually observed in the late stages of chorionepithelioma and, pelvic and abdominal tumors, hypernephromas, etc.

At what stage do they appear and how quickly do they spread?

If the cancer patient does not receive the necessary treatment, then metastases will eventually occur in any cancer process, but the timing of appearance is not always clear.

In some oncopathologies, metastasis occurs within a few months after the formation of the primary tumor focus, while in others, they are detected only after several years. Therefore, it is impossible to even presumably establish the timing of metastasis.

Considering metastasis in the lymphatic system, we can say that metastases are a sign of the transition of cancer to the second stage of development.

If a hematogenous spread of malignant cells has appeared, then we are talking about the transition of oncopathology to stage 4. On average, metastases form at stages 3-4 of cancer. That is, in fact, the appearance of metastatic processes determines the stage of a cancerous tumor.

Video about how cancerous tumors metastasize:

How do different types of cancer metastasize?

Usually metastases are detected in the lung structures, liver and lymph nodes. Much less often, metastatic foci are found in the heart and skeletal muscles, spleen and pancreas.

Experts have identified some pattern of cancer metastasis of various localizations:

Melanoma usually metastasizes to the muscles or skin;
- in a healthy lung, liver and adrenal tissues;
A malignant tumor in the uterus, stomach and pancreas usually metastasizes to the lungs, liver and abdominal cavity;
It is mammary glandular, and spreads mainly to, hepatic and lung tissues.

What are dangerous?

The lethal outcome in oncopathologies often occurs precisely because of active metastasis, rather than because of the presence of a primary tumor. Therefore, metastases are very dangerous.

They disrupt the activity of vital systems and organs;
If metastases have appeared, then the body can no longer independently resist oncology;
Metastasis negatively affects the course of the oncological process and the patient's condition, worsening it.

Varieties

Metastasis has many variants and varieties that differ significantly from each other.

Virchowski

Virchow's metastasis is localized in the supraclavicular region on the neck and occurs against the background of gastric cancer. Such an arrangement of the secondary oncocenter is determined by the direction of the lymph flow from the abdominal cavity.

Malignant cell structures rise along the lymphatic pathways precisely to the cervical lymph node, they cannot go further, therefore they begin to form into a secondary tumor. Virchow metastasis can occur due to, and other abdominal structures.

Krukenberg

Such metastases are also characterized by lymphogenous origin and are localized in the ovaries. The share of such secondary tumors accounts for about 35-40% of the total number of ovarian metastases.

Krukenberg metastases are observed in malignant gastric, mammary gland, intestinal or bile duct lesions, bladder or cervical cancer.

Schnitzlerovsky

Schnitzler metastases are called the spread of a malignant process into the tissue of the perirectal localization and pararectal lymph nodes.

Such metastatic formations are palpable during rectal digital examination and are painless seals.

Most often occurs against the background of stomach cancer.

osteoblastic

Metastatic tumors that form in bone tissues and contribute to the activity of osteoblasts are called osteoblastic. Against the background of increased osteoblastic activity, there is an increased deposition of calcium in bone tissues, which contributes to their rapid growth.

Such metastatic foci arise against the background of mammary gland, or prostatic cancer, sarcomas and. Forecasts are predominantly unfavorable.

Solitary

Metastases of the solitary type are large-nodular solitary formations localized in the lung, brain and other tissues.

osteolytic

Osteolytic secondary formations are also localized in bone structures, however, their effect on bones is somewhat different. They destroy bone tissue and activate osteoclasts, which leads to destructive changes in bones.

Symptoms and signs

The clinical picture of metastasis depends on its location and the type of primary tumor. Usually, metastases lead to severe dysfunctional changes in the structures of the body.

With liver metastasis patients have itchy skin, jaundice and liver failure;
Cerebral metastatic processes lead to rapid;
Lung metastasis causes bronchopulmonary inflammation, respiratory disorders, etc.;
Bone metastases are characterized by severe soreness throughout the body.

On the skin

Skin metastases occur mainly against the background of malignant lesions of the ovaries, lungs and kidneys. Metastatic processes on the skin are of lymphatic or hematogenous origin. In men, such metastases are localized on the abdomen and neck, chest and head, and in women on the chest and abdomen.

Signs of skin metastases:

The appearance of formations similar to moles;
Change in skin color at the site of metastases;
Rapid increase in skin formation;
Asthenia;
Weakness;
Drowsiness and weakness;
Lack of performance;
Pain in the area of the tumor;
Weight loss and hyperthermia.

The photo shows what stage 4 cancer looks like with metastases on the skin

If the metastasis has formed on the scalp, then it usually looks like a sebaceous cystic formation.

in the ribs

The first signs of costal metastases are intense pain, leading to limited mobility. At later stages, secondary tumor foci can lead to rib fractures that occur even with minor loads.

Cancer tumors of the thyroid gland, breast, prostate and cervix, liver and lungs, etc. most often metastasize to the ribs. To detect them, it is necessary to carry out.

Heart

Secondary cardiac tumors usually occur due to pleural, carcinoma, melanoma or esophageal squamous cell carcinoma, renal and thyroid oncology or.

Signs of cardiac metastases are:

pericardial effusion;
Obstruction of veins in the myocardium;
Inhibition of cardiac activity;
Arrhythmia, myocardial insufficiency.

Peritoneum

Cancer cells can penetrate into any part of the body, in particular into the abdominal cavity. Malignant structures settle on the surface of the internal organs and peritoneal walls. For quite a long time they accumulate, gradually forming a secondary tumor.

Similar processes in the body are usually accompanied by an increase in the abdomen. If the tumor began to disintegrate, then general signs of intoxication appear.

For breast cancer

Metastatic foci in the mammary gland are manifested by the appearance of seals in the chest, which are easily palpable on palpation.

Malignant cells penetrate into the mammary gland with the bloodstream or lymphogenously. The patient feels intense pain in the chest and other uncomfortable sensations.

Distant metastases

The greater the parameters of the primary formation, the earlier metastatic processes will begin. Usually, the real threat of metastasis occurs when the tumor exceeds 3 cm in diameter.

Together with the blood flow, malignant cells spread to distant tissues and organs, which indicates the late stages of the tumor process.

If metastases have arisen in the skeletal system, then patients experience bone pain, which can seriously reduce the quality of life.
If breast cancer has metastasized to the lungs, then the patient is worried about shortness of breath, cough and chest pain.
With neurological metastasis dizziness and headaches, convulsions and hallucinations, auditory and visual disturbances, coordination disorders, etc.

Regional

Already in the early stages, metastases may occur in regional lymph nodes. Usually these are axillary lymph nodes.

But if the primary tumor was formed closer to the center of the chest, then the sternal lymph nodes undergo metastasis.

In the future, the cancerous process spreads to more distant lymph nodes.

In the intestines

Metastasis to the intestine is accompanied by frequent diarrhea or constipation, blood in the stool, abdominal pain and bloating.

In addition, the waste products of cancer formation cause general intoxication of the body, which is manifested by dyspeptic disorders.

Kidney

The main sign of metastasis in the kidneys and adrenal structures is hematuria, which is characterized by the presence of blood in the patient's urine.

An additional sign of kidney metastasis is pain in the lumbar region, constant temperature and weakness, high blood pressure and progressive anemia.

Spleen

Metastases in the spleen are extremely rare, because the organ itself is capable of producing substances that destroy malignant cells.

Among the obvious signs of metastasis, fever, thrombopenia, an increase in the size of the organ, heaviness and soreness are distinguished. With the growth of a secondary tumor, the condition worsens, and the body is depleted.

Pleura

The pleura lines the chest wall and the lungs from the inside. It produces a special lubricant that facilitates lung work during breathing. Metastasis to the pleural tissues is accompanied by cough, subfebrile temperature and soreness in the sternum.

stomach

Metastasis in the stomach is quite rare, with tumors spreading here from the uterus, esophagus, breast, or lung. Metastasis is accompanied by hyperthermia and lack of appetite, anemia and taste changes, pain in the stomach, etc.

ovaries

At the initial stages, ovarian metastases do not manifest themselves in any way. Some cancer patients observe lack of appetite and general weakness, menstrual disorders and hyperthermia. When the metastasis increases, there are painful sensations and a bursting feeling in the lower abdomen.

Adrenal

Many tumors metastasize to the adrenal glands, for example, from the lungs, kidneys, mammary glands, etc.

This spread of the tumor causes adrenal insufficiency.

Large secondary formations are almost always accompanied by necrotic processes.

With uterine cancer

Metastasis begins at stage 3 of the cancer process. The spread of malignant cells occurs in the lymphogenous way, and hematogenous spread is possible in the last stage of cancer.

Patients complain of spotting between periods, lumbar pain and cramps in the lower abdomen, especially during exercise.

Bladder

Metastatic spread of malignant cells to the bladder structures occurs via the lymphogenous route, mainly from the pelvis or ureters.

At first, symptoms that are most characteristic of cystitis appear, frequent urges, lumbar pain, and painful urination are disturbing.

With the development of metastasis, the condition worsens, constant hyperthermia appears, blood in the urine, etc.

Pancreas

Pancreatic metastasis is characterized by such manifestations as sudden weight loss and lack of appetite, nausea and vomiting, epigastric pain and frequent diarrhea.

Sometimes metastases in the pancreas cause some yellowing of the skin and girdle pain in the abdomen.

throat

Metastatic formations in the throat usually appear from tumors of the mouth, respiratory and digestive organs. Most often, such localization of metastases causes such signs:

Wounds and sores in the throat;
Swelling of oral tissues;
Trouble speaking, breathing, swallowing;
Enlargement of lymph nodes, etc.

How to determine in the body?

Detection of metastases requires a thorough diagnosis, including:

Plain radiography;
radioisotope diagnostics.

Such procedures allow you to determine the degree of metastasis, the size of secondary tumors, germination in other tissues and the presence of purulent processes or decay, the nature of growth, etc.

Are they visible on ultrasound?

Ultrasound diagnostics is one of the main methods for detecting the metastatic spread of malignant processes.

Such a study is considered quite informative and is widely used in modern diagnostic practice.

How to cure?

Treatment of oncopathology with metastasis is determined by the location, size and number of secondary foci. Several different techniques are used: surgical removal, and drug therapy.

Surgical treatment

Initially, doctors try to remove the primary formation, which in the future may act as a source of metastases.

Then proceed directly to the removal of the metastatic foci themselves. To do this, remove the lymph nodes and adjacent tissue.

When removing secondary formations, the surgeon also cuts off part of the healthy tissues, which may also contain micrometastases.

RF ablation

Radiofrequency ablation is now successfully used in the treatment of metastatic spread of tumor processes.

This method involves the destruction of the tumor through high temperatures, which are created by special electrodes. Electromagnetic currents heat malignant tissues and destroy them. Then the dead cells shrink, and a scar forms in their place.

Medications

Drug treatment of metastatic tumors involves the use of methods such as, and hormone therapy.

Chemotherapy with anticancer drugs stops the growth and spread of metastases. Often this technique is combined with radiation or radiofrequency ablation.

How many live with metastases: prognosis

Usually, the presence of metastases in the lymph nodes and other organic structures indicates unfavorable prognosis of oncopathology.

Prognosis of metastases in the abdominal cavity. The lethal outcome with such metastasis today is 5%. Timely detection of abdominal metastasis and mandatory chemotherapy with appropriate rehabilitation greatly increases the patient's chances for a favorable outcome of oncology treatment.
In the adrenal glands. Adrenal metastases are usually combined with damage to other organs, so the prognosis depends on the specific clinical situation.
Mediastinum. Such metastasis with early detection can end positively, however, with late detection, the prognosis is unfavorable.
Intestine. With timely access to an oncologist, there is a tendency to a favorable outcome of the disease. Cure with timely surgical intervention in combination with radiotherapy and chemotherapy, on average, occurs in half of patients. In the later stages, the prognosis is disappointing.
Liver. Without treatment for liver metastases, survival is 4 months. Upon receipt of the necessary assistance, the patient's life is extended by a year and a half, additional chemotherapy can give a cancer patient about a year of life.
Lungs. Unfavorable factors in lung metastasis are its appearance earlier than 12 months after removal of the primary tumor focus, as well as the rapid increase in metastatic tumors. Survival for 5 years with a single metastasis and after adequate treatment is about 40%.

Almost all cancer patients die within a decade, regardless of the presence of metastatic processes. And if they are, then life expectancy is significantly reduced.

If the patient has a terminal (fourth) stage of oncology and has metastases, then life expectancy is calculated in several weeks, and sometimes even days, depending on the type of tumor.

How are cancer cells formed? What is the environment of cancer cells?

Cancer cells and normal cells: how are they different?

There are many differences between cancer cells and normal cells. Some of the differences are well known, while others have only recently been discovered and are less well understood. You may be interested in learning how cancer cells differ from normal cells as you deal with your own or a loved one's cancer. For researchers, understanding that cancer cells function differently from normal cells lays the foundation for developing treatments to rid the body of cancer cells without damaging normal cells.

The first part of this list discusses the main differences between cancer cells and healthy cells. For those interested in some of the more difficult to understand differences, the second part of this list is more technical.

If you want to first analyze what a cancer cell is, check out the following article:

properties of a cancer cell

A brief explanation of the proteins in the body that regulate cell growth is also helpful in understanding cancer cells. Our DNA carries genes, which in turn are the basis for the proteins produced in the body. Some of these proteins are growth factors, chemicals that allow cells to divide and grow. Other proteins work to suppress growth. Mutations in specific genes (such as those caused by tobacco smoke, radiation, ultraviolet radiation, and other carcinogens) can lead to abnormal protein production. Too much may be produced, or not enough, or it may be that the proteins are abnormal and not functioning as they should.

Cancer is a complex disease and it is usually a combination of these abnormalities resulting in a cancerous cell rather than a single protein mutation or abnormality.

What are cancer cells and normal cells?

The following are some of the main differences between normal cells and cancer cells, which in turn explain how malignant tumors grow and respond to their environment than benign tumors.

Height. Normal cells stop growing (reproducing) when there are enough cells. For example, if cells are produced to repair a cut in , new cells are no longer created when there are enough cells to fill the hole when repairs are made. In contrast, cancer cells do not stop growing when enough cells are available. This continued growth often leads to the formation of a tumor (cluster of cancer cells). Each gene in the body carries a blueprint that codes for a different protein. Some of these proteins are growth factors, chemicals that tell cells to grow and divide. If the gene encoding one of these proteins is stuck in the "on" position by a mutation (oncogene), growth factor proteins continue to be produced. In response, cells continue to grow.
Connection. Cancer cells do not interact with other cells as normal cells do. Normal cells respond to signals sent from other nearby cells that essentially say "you've reached your boundary." When normal cells "hear" these signals, they stop growing. Cancer cells do not respond to these signals.
Cell repair and cell death. Normal cells either repair or die (undergo apoptosis) when they are damaged or age. Cancer cells either do not regenerate or do not undergo apoptosis. For example, one protein, called p53, checks to see if the cell is damaged for repair, and if so, advises the cell to kill itself. If this p53 protein is abnormal or inactive (for example, from a mutation in the p53 gene), then old or damaged cells can reproduce. The p53 gene is a type of tumor suppressor gene that codes for proteins that suppress cell growth.
stickiness Normal cells secrete substances that cause them to stick together in a group. Cancer cells are unable to produce these substances and may "float away" to nearby locations or through the bloodstream or lymphatic system to distant areas of the body.
Ability to metastasize(spread) - normal cells remain in the area of the body to which they belong. For example, lung cells remain in the lungs. Cancer cells, because they lack the adhesion molecules that cause stickiness, are able to travel through the bloodstream and lymphatic system and to other areas of the body - they have the ability to metastasize. Once they arrive in a new region (such as the lymph nodes, lungs, liver, or bones), they begin to grow, often forming tumors that are far removed from the original tumor.
Appearance. Under a microscope, normal cells and cancer cells can look completely different. Unlike normal cells, cancer cells often show much greater variability in size - some larger than normal and some smaller than normal. In addition, cancer cells often have an abnormal shape, both cells and nuclei (the "brain" of the cell). The nucleus appears larger and darker than that of a normal cell. The reason for the darkness is that the nucleus of cancer cells contains an excess of DNA. Cancer cells often have an abnormal number of chromosomes that are misaligned and disorganized.
growth rate. Normal cells reproduce themselves and then stop when enough cells are available. Cancer cells multiply rapidly before the cells have had a chance to mature.
Maturation- Normal cells mature. Cancer cells, because they grow and divide rapidly before the cells are fully mature, remain immature. Doctors use the term undifferentiated to describe immature cells (as opposed to differentiated to describe more mature cells). Another way to explain this is to consider cancer cells as cells that do not "grow" and specialize in adult cells. The degree of cell maturation corresponds to cancer. are rated on a scale of 1 to 3, with 3 being the most aggressive.
Immune system evasion- When normal cells become damaged, the immune system (through cells called lymphocytes) identifies and removes them. Cancer cells are able to evade (trick) the immune system long enough to grow into a tumor, either by escaping detection or by releasing chemicals that inactivate immune cells that appear on the scene. Some of the new immunotherapy drugs address this aspect of cancer cells.
Functioning- Normal cells perform the function for which they are designed, while cancer cells may not be functional. For example, normal white blood cells help fight infections. With leukemia, white blood cell counts can be very high, but because cancerous white blood cells don't function properly, people may be more at risk of infection even with elevated white blood cell counts. The same can be said about the substances produced. For example, normal thyroid cells produce thyroid hormone. Thyroid cancer cells (thyroid cancer) cannot produce thyroid hormone. In this case, the body may not have enough thyroid (hypothyroidism) despite an increase in thyroid tissue.
blood supply Angiogenesis is the process by which cells attract blood vessels to grow and nourish tissue. Normal cells undergo a process called angiogenesis only as part of normal growth and development and when new tissue is needed to repair damaged tissue. Cancer cells undergo angiogenesis even when growth is not necessary. One type of cancer treatment involves the use of angiogenesis inhibitors, drugs that block angiogenesis in the body in order to prevent the growth of tumors.

Even More Differences Between Cancer Cells and Normal Cells

This list contains additional differences between healthy cells and cancer cells. For those who wish to skip these technical points, please skip the following subheading to mark the differences.

Avoiding Growth Suppressors. Normal cells are controlled by growth suppressors (tumors). There are three main types of tumor suppressor genes that code for proteins that suppress growth. One type tells cells to slow down and stop dividing. Another type is responsible for fixing changes in damaged cells. The third type is responsible for the apoptosis described above. Mutations that result in the inactivation of any of these tumor suppressor genes allow cancer cells to grow unhindered.
Invasiveness- normal cells listen to signals from neighboring cells and stop growing when they invade nearby tissues (called contact inhibition). Cancer cells ignore these signals from normal cells and invade nearby tissues. Benign (not cancerous) tumors have a fibrous capsule. They may adhere to nearby tissues, but they do not invade/mix with other tissues. Cancer cells, on the other hand, do not respect boundaries and invade tissues. This leads to finger-like projections, which are often noted on x-ray scans of cancerous tumors. The word cancer, in fact, comes from the Latin word crab and is used to describe crabs as an invasion of cancer into nearby tissues.
Energy source. Normal cells get most of their energy (in the form of a molecule called ATP) through a process called the Krebs cycle and only a small amount of their energy through another process called glycolysis. While normal cells produce most of their energy in the presence of oxygen, cancer cells produce most of their energy in the absence of oxygen. These are the arguments for hyperbaric oxygen treatment that have been experimentally used (with disappointing results so far) in some people with cancer.
Mortality / Immortality. Normal cells are mortal, that is, they have a lifespan. Cells are not designed to live forever, and like the people in whom they are present, cells age. Researchers today are starting to look at something called telomeres, the structures that hold DNA together at the end of chromosomes, for their role in cancer. One of the limitations of growth in normal cells is telomere length. Every time a cell divides, the telomeres get shorter. When telomeres become too short, the cell can no longer divide and dies. Cancer cells have figured out a way to renew their telomeres so they can keep dividing. An enzyme called telomerase works to lengthen the telomeres so that the cell can divide indefinitely, essentially becoming immortal.
The ability to "hide"- many people wonder why cancer can recur for years and sometimes decades after it has disappeared (especially with tumors such as estrogen receptor breast cancer). There are several theories as to why cancers can recur. In general, it is believed that there is a hierarchy of cancer cells, with some cells (cancer stem cells) having the ability to resist treatment and are in a dormant state. This is an active area of research and it is extremely important.
Genomic instability. Normal cells have normal DNA and a normal number of chromosomes. Cancer cells often have an abnormal number of chromosomes, and the DNA becomes more and more abnormal as it develops many mutations. Some of these are driver mutations, which means they cause the cell to transform to be cancerous. Many of the mutations are passenger mutations, which means that they do not have the direct function of becoming a cancer cell. For some cancers, determining the presence of driver mutations (molecular profiling or gene testing) allows doctors to use targeted drugs that specifically target cancer growth. The development of targeted therapies, such as EGFR inhibitors for cancers with EGFR mutations, is one of the fastest growing and progressive areas of cancer treatment.

The multiple changes it takes for a cell to become cancerous

As noted above, there are many differences between normal cells and cancer cells. Also noteworthy is the number of "checkpoints" that must be bypassed for a cell to become cancerous.
The cell must have growth factors that encourage it to grow, even when growth is not needed.
It must evade proteins that direct cells to stop growing and die when they become abnormal.
The cell must bypass signals from other cells.

Cells must lose the normal "stickiness" (adhesion molecules) that normal cells produce.

In general, a normal cell becomes cancerous through mutations, which may not be surprising. This is explained by the fact that in a normal body, approximately three billion cells divide every day. "Accidents" in cell reproduction, caused by heredity or environmental carcinogens during any of these divisions, can create a cell that, after further mutations, can develop into a cancer cell.

Benign and malignant tumors

As noted above, there are many differences between cancer cells and normal cells that make up either benign or malignant tumors. In addition, there are ways in which tumors containing cancer cells or abnormal cells are detected, they behave differently in the body.

Cancer stem cell concept

Having discussed these many differences between cancer cells and normal cells, you may be surprised that there are differences between cancer cells themselves. That there may be a hierarchy of cancer cells - some of which have different functions than the rest - is the basis of discussions regarding cancer stem cells, as discussed above.

We still don't understand how cancer cells can hide for years or decades and then reappear. Some believe that the "generals" in the cancer cell hierarchy, called cancer stem cells, may be more resistant to treatment and have the ability to lie dormant when other cancer soldier cells are eliminated through treatments such as chemotherapy. Although we currently treat all cancer cells in a tumor as identical, it is likely that some differences in cancer cells in an individual tumor will be further accounted for in the future.