What are neoplastic processes?

Many people are afraid of cancer, and quite rightly. This ailment is dangerous and ruthless. Lethal outcome due to cancer is in second place, second only to deaths from heart diseases. Sometimes doctors diagnose a "neoplastic process." What this means is understandable not to all patients. Some even think that this is something good or at least not dangerous. In fact, such a diagnosis means the same tumor processes that are observed in cancer. They affect people of all ages, including infants, can develop in any organ and in any tissue of the body, for a long time do not make themselves felt, which makes the treatment very difficult and worsens the prognosis. This article examines the causes of cancer, its development and methods of treatment.

Etiology of tumors

Neoplastic processes in another way are called neoplasia, which in translation means "new growth". The more familiar term for this phenomenon is a tumor, which means abnormal, excessive, uncontrolled growth of atypical cells, capable of damaging any tissues of the body. The neoplastic process can begin with a mutation in one cell, but according to the accepted international system it is differentiated only when 1/3 of all the cells of an organ lose its previous characteristics and go into a new state. Thus, the onset of the formation of cancer cells is only a prerequisite for the development of the disease, but it is not considered as such. In the overwhelming majority of cases, the neoplastic process starts in one place. The tumor developing there is called primary. Further pathological changes affect the work of all human organs, and the disease becomes systemic. Consider the characteristics of cancer cells.

Division

Our body consists of millions of cells. They have characteristic differences in structure, which depends on the functions of the organ or tissue in which they are located. But they are all subject to a single law - to ensure the viability of the system as a whole. Throughout the life of each cell, there are consistent cellular changes that are not related to the neoplastic process and are the response to the commands that the body gives it. Thus, the multiplication (division) of a normal cell begins only when it receives from the outside the corresponding signal. It is the presence in the nutrient medium of up to 20% of serum and growth factors. These factors, using specific receptors, transmit to the cell an "order" for replication (the synthesis of a daughter molecule) of DNA, that is, to fission. Cancer cage orders are not required. She shares, as she pleases, unpredictably and uncontrollably.

The second immutable law for a normal cell is that it can begin to be divided only if it is attached to a certain extracellular matrix, for example, for fibroblasts it is fibronectin. If there is no attachment, even if there are orders from the outside, division does not occur. A cancer cell does not need a matrix. After the transformations that have taken place in it, it generates its own "commands" to the beginning of the division, which it strictly observes.

Number of divisions

Normal cells live, let's say, in a friendly community of their own kind. This means that the division, growth and development of one of them does not infringe on the existence of another. Interacting with each other and obeying the "orders" of cytokines (information molecules), they stop multiplying, when this disappears for the body need. For example, the same fibroblasts are divided until they form a dense monolayer and establish intercellular contacts. A specific neoplastic process is characterized by the fact that atypical cells, even if they have already formed too much, continue to multiply, creep into each other, squeeze neighboring cells, destroy them and kill them. Cancer cells do not react to "orders" of inhibitors of cytokine growth to stop division, and in addition, their reproduction does not stop arising due to their activity unfavorable conditions, such as hypoxia, lack of nucleotides. In addition, they behave very aggressively - they begin to interfere with the normal synthesis of healthy cells, force them to produce substances not necessary for them and necessary for themselves, thereby disrupting metabolic processes. In addition, cancer cells are able to penetrate the blood, move in its current through the body and settle in other tissues far from the primary focus, that is, metastasize.

Immortality

In the world there is nothing eternal. Healthy cells also have their own lifespan, during which they exercise the number of divisions laid by them, gradually age and die. This phenomenon is called apoptosis. With his help, the body maintains the desired number of each type of cells. Neoplastic processes are characterized by the fact that mutated cells "forget" the number of divisions that they are prescribed by nature, therefore, having reached the final figure, continue to multiply further. That is, they acquire the ability not to grow old and die. Simultaneously with this unique property, cancer cells acquire one more - a violation of differentiation, that is, tumors may not form specific cells that synthesize the necessary proteins, and they begin to multiply, not reaching maturity.

Neoangiogenesis

The unique property of cancerous tumors consists in their ability to very active angiogenesis, that is, to the formation of new blood vessels. In a healthy organism, angiogenesis occurs in an insignificant amount, for example, in the formation of scars or in the healing of foci of inflammation. Neoplastic processes repeatedly increase this function of the body, because if the blood vessels do not appear in the overgrown body of tumors, not all cancer cells will receive nutrients that they also need. In addition, the blood vessels they use to move on through the body (for the formation of metastases).

Genetic instability

When a normal cell is divided, the daughter is obtained by its exact copy. At certain factors, DNA malfunctions, and a "daughter" appears in the division, a mutant with some new qualities. When it comes its turn to share, there are even more transformed cells. Neoplastic processes occur with the gradual accumulation of these mutations. Immortality of such cells and their departure from obedience to the orders of the organism leads to the appearance of ever more malignant variants and to the steady progression of tumor growth.

Causes

The cell begins to behave incorrectly due to changes in its DNA. Why they occur until there is no exact answer, there are only theories according to which neoplastic processes can begin with some degree of probability.

1. Hereditary genetic predisposition. 200 types of malignant neoplasms caused by the hereditary anomaly of the following genes were identified:

-responsive for the restoration of damaged DNA;

-regulating the interaction between cells;

-responsive for suppressing the development of tumors.

2. Chemical substances (carcinogens). According to WHO statistics, they are responsible for 75% of cancers. The most commonly recognized carcinogens are: tobacco smoke, nitrosamines, epoxides, aromatic hydrocarbons - more than 800 elements and their compounds.

3. Physical agents. These include radiation, radiation, exposure to high temperatures, trauma.

4. Endogenous carcinogens. These are substances formed in the body with hormonal disorders, malfunctions in metabolic processes.

5. Onkoviruses. It is believed that there is a special kind of virus that can trigger neoplastic processes. These include the herpes virus, papillomovirus, retrovirus and others.

Bad ecology, poor-quality food, high psychological loads lead to the fact that mutant cells in humans appear constantly, but their immune protection detects them and destroys them in time. If immunity is weakened, atypical cells remain alive and gradually become malignant.

Types of tumors

Often asked, is the neoplastic process, is it cancer or not? There is no unequivocal answer to it. All tumors are divided into two categories:

-high-quality;

-cancerous.

Benign cases are those in which cells can be differentiated and which do not give metastasis.

In malignant tumors, cells often completely lose their resemblance to the tissues from which they developed. These formations have rapid growth, the ability to infiltrate (penetrate into neighboring tissues and organs), metastasize and have a pathological effect on the entire body.

Benign tumors without proper treatment very often develop into malignant tumors. Distinguish their types:

-epithelial (have no specific localization);

Epithelial tumors of the endocrine glands and integuments;

- mesenchymal (soft tissues);

- Muscular tissues;

- shells of the brain;

-organisms of the nervous system;

-products (hemoblasts);

-teratomas.

Stages of development

Answering the question whether the neoplastic process is cancer or not, it should be said that in the pathogenesis of tumor development, a condition such as a precancer is observed. There are two of its types:

-obigious (almost always turning into cancer);

- optional (turning into cancer is not always). An optional precancer is bronchitis of smokers or chronic gastritis.

Any neoplastic process develops not instantaneously, but gradually, often beginning with atypical changes in just one cell. This stage is called initiation. At the same time, oncogenes appear in the cell (any genes that can turn a cell into a malignant one). The most famous oncogene p53, which in the normal state is an anti-oncogene, that is, it fights the development of tumors, and when mutated, it causes them.

At the next stage, called a promotion, such altered cells begin to divide.

The third stage is called pre-invasive. In this case, the tumor grows, but does not penetrate neighboring organs.

The fourth stage is invasive.

The fifth stage is metastasis.

Signs of the neoplastic process

At the first stages, the pathology that started does not manifest itself in any way. Detect it is very difficult even with such studies as ultrasound, x-rays, various tests. In the future, patients develop specific symptoms, the nature of which depends on the location of the primary tumor. So, its development in the skin or in the mammary gland is signaled by tumors and densities, about development in the ear - hearing impairment, in the spine - movement difficulties, in the brain - neurologic symptoms, in the lungs - coughing, in the uterus - blood discharge. When cancer cells begin to penetrate into neighboring tissues, they destroy blood vessels in them. This is what causes the appearance of blood in the secretions, and not only from the genitals. Thus, blood in the urine is observed when the neoplastic process of the kidney, bladder or urinary tract develops, blood in the feces may indicate the onset of cancer in the intestine, blood from the nipple - about the tumor in the mammary gland. Such a symptom must necessarily cause anxiety and spodvigut on immediate contact with a doctor.

Another early symptom is, so-called, small symptom syndrome. Its main feature is a wide variety of manifestations. Common can be called complaints of patients for weakness, fatigue, sudden temperature changes, inexplicable irritation or, conversely, indifference to everything, loss of appetite, and on this soil is emaciation.

In the next stages there are symptoms of intoxication, as well as a discoloration of the jaundice with a pale shade, a decrease in skin turgor, and cancerous cachexia.

With neoplasms in the brain tissues due to the fact that this organ is limited by the skull bones, and for the developing tumor the space is severely limited, and also because of the specificity of the functions of each part of the brain, the symptoms have characteristic features that allow differentiating localization. Thus, the neoplastic process in the occipital part is manifested by the appearance of visions in the patient, a violation of the perception of color. With the process in the temporal region, no vision is observed, but there are auditory hallucinations. A tumor in the frontal lobe is characterized by a patient's mental disorders, a violation of his speech, and in the parietal region a violation of motor functions and sensitivity. Symptoms of cerebellar involvement are frequent vomiting and terrible headaches, and brain stem lesions - difficulty in swallowing, breathing disorders, malfunctioning of many internal organs.

In the last stages, all cancer patients experience painful pains, which can only be stopped by narcotic drugs.

Diagnostics

To establish the diagnosis of "neoplastic process," the patient is subjected to a series of tests and appoints a comprehensive examination. Recently, often make tests for oncomarkers. These are substances that can indicate the presence of the neoplastic process in the body, even in the early stages. In addition, many oncomarkers are specific, their number increases only in the presence of tumor formations in any one organ. For example, the PSA oncomarker indicates that the patient has started a neoplastic prostate process, and the CA-15-3B oncomarker has a neoplastic process in the mammary gland. The downside of the analysis for cancer markers is that they can increase in the blood and other diseases not associated with neoplastic processes.

To clarify the diagnosis, the patient is tested:

-analyses of blood, urine;

-UZI;

-TCT;

-MPT;

- angiography;

- biopsy (this is a very important analysis by which not only determine the presence of a cancerous tumor, but also the stage of its development).

When suspected of bowel cancer perform:

- analysis of feces for the presence of hidden blood in it;

- fibrosigmoscopy;

-Rectonomoscopy.

The neoplastic process of the brain is best detected by MRI. If this type of diagnosis is contraindicated for a patient, a CT scan is performed. Also, when brain tumors are carried out:

-pneumoencephalography;

- Electroencephalogram (EEG);

- Radioisotope scanning;

- spinal puncture.

Treatment

If the disease affects children, their treatment is mainly in chemotherapy and radiotherapy, surgery is rarely performed. For the treatment of adults, all available methods are used that are appropriate for a particular stage of the neoplastic process and depending on the site of its localization:

-chemotherapy (systemic treatment that affects the entire body);

-radiation and radiotherapy (directly affects the tumor, it can affect neighboring healthy areas);

- hormone therapy (designed to produce hormones that hinder tumor growth or its destruction, for example, the neoplastic process of the prostate gland can be stopped by a decrease in testosterone levels);

-immunotherapy (positively affects the whole body);

-genetic therapy (scientists try to replace mutated to the normal gene p53);

Surgical operation (can be performed to remove the tumor or to reduce the patient's suffering by reducing the overgrowing inoperable tumor to adjacent tissues).

Forecast

The neoplastic process is not a verdict. In children, due to the fact that their young organism is able to recover quickly, the prognosis is favorable in 90% of cases, if the development of the tumor is detected in the early stages. But even in the later stages of detection in intensive care, children can be completely cured.

In adults, a favorable prognosis in the first stage of the tumor is 80% or higher. In the third stage, a favorable outcome of treatment is observed in 30% -50% of cases (depending on the localization of education and the characteristics of the organism of each person). In the fourth stage, according to statistics, from 2% to 15% of patients after therapy live 5 years or more. These figures also depend on the location of the tumor. The least favorable prognosis for cancer of the prostate and brain.