Malignization – process of transformation of good-quality cages in malignant. Can occur in any normal fabrics or fabrics of benign tumors. Is followed by decrease in level of a differentiation, change of morphological properties, malfunction and rough reproduction of cages, the progressing growth of a new growth and development of the remote metastasises. Confirm to Malignizatsy on the basis of clinical yielded, results of laboratory and tool researches. In the course of treatment of a tumor usually apply surgical interventions, chemotherapy and radiotheraphy. Use of hormones, immunostimulators and other medicines is possible.
Malignization (ozlokachestvleniye, malignant regeneration) – difficult patomorfologichesky process during which good-quality cages gain properties of malignant. Both the normal cages and which are already changed, but not showing zlokachestvennost signs can be exposed to Malignization. Most often the centers of an ozlokachestvleniye arise in the field of ulcers, polyps and various benign tumors. Genetic predisposition and harmful factors of the environment can become the reason of a malignization.
At initial stages the malignization proceeds asymptomatically therefore early diagnostics of malignant new growths is accompanied by considerable difficulties, however regular routine inspections, use of modern laboratory and tool methods of a research allow to solve a problem of early identification of a malignization partially. Diagnostics and treatment experts in the field of oncology carry out, gastroenterologies, pulmonology, neurology, dermatology, otolaryngology, gynecology, orthopedics and doctors of other specialties (depending on localization of a tumor).
Now malignant tumors are the reason of mortality, the second for prevalence, after cardiovascular diseases. In 2012 died more than 8 million people from cancer. The probability of a malignization increases with age, however, along with people of advanced years, malignant tumors quite often affect children and patients of working-age. The most widespread types of cancer are lung cancer, stomach cancer, a breast cancer, cancer of a liver and cancer of a large intestine.
As a result of a malignization in a human body about 150 types of malignant cages can be formed. About 80% of such cages have an epitelialny origin, 15% - soyedinitelnotkanny, 5% - hematogenic. According to forecasts of experts, prevalence of a malignization in the next decades will grow that is connected with a number of factors, including – with increase in life expectancy, an adverse ecological situation, addictions, use of a large amount of chemicals, increase in level of ionizing radiation etc. All this causes extreme importance of studying of processes of a malignization, and also development of optimum algorithms of identification of such processes when carrying out mass surveys, diagnostics and treatments of not oncological diseases.
The combination of several factors among which experts specify chemical carcinogens, features of the environment, some viruses, conditions of a hormonal imbalance, age, addictions and adverse heredity is the reason of a malignization of cages. When carrying out researches it was established that more than 2000 various chemicals can provoke a malignization, however extent of their influence on processes of malignant regeneration of cages can strongly differ.
The list of the chemical compounds, certainly, causing a malignization of cages includes polycyclic aromatic hydrocarbons (sources transport, the industrial enterprises and heating systems are), nitrosamines (contain in cigarettes, some grades of beer and the amidopirena), hydrazine derivatives (are a part of herbicides and some medicines), asbestos and other mineral fibers (a source industrial productions are), and also some compounds of metals.
The most significant physical factor of a malignization is sunlight on which level the probability of development of cancer of skin directly depends. Than skin and hair are lighter and the longer the person is affected by sunshine – the risk of development of a melanoma, a bazalioma and planocellular cancer of skin is higher. Besides, the ionizing radiation provoking developing of leukoses, bone tumors (radioactive strontium) and cancer of a thyroid gland (radioactive caesium and iodine) can stimulate a malignization.
It is proved that the probability of a malignization increases at impact on cells of certain viruses, in particular – the ATLV virus (causes a leukosis), Epstein-Barre's virus (provokes development of a lymphoma of Berkitt), a virus of papilloma of the person (plays a part in developing of cancer of neck of a uterus) and a virus of herpes of the II type. Malignization is also promoted by violations of hormonal balance. Hormones can provoke directly an ozlokachestvleniye, affect cages indirectly, stimulating their proliferation, to exert negative impact on immunity and to change metabolism of some carcinogens.
An essential role in the course of a malignization is played by genetic predisposition. The set of hereditary diseases with high probability of a malignization, for example, system polyposes of intestines at which at most of patients by 40-50 years the colon cancer, or a Down syndrome at which the risk of development of a leukosis is 11 times higher, than on average on population develops is described. Communication between a malignization and congenital malformations is traced.
Dependence between probability of a malignization of fabrics of certain bodies and a sex of the patient comes to light. Men 2,4 times more often have tumors of eyes, is 2,1 times more often – stomach new growths, is twice more often – malignant damages of a nasopharynx, by 1,7 times – tumors of bones. At women the malignization of tissues of thyroid gland comes to light twice more often. First place on prevalence at men is won by tumors of airways, women have tumors of genitals and a mammary gland. In most cases the probability of a malignization at patients of both floors increases with age, however some types of new growths come to light at children or young people more often.
The number of the habits exerting the strongest impact on a malignization of cages includes smoking, improper feeding and alcohol intake. At smokers lung cancer develops 11 times more often; tumors of an oral cavity, a throat and a throat – are 7 times more often; bladder new growths – are 2,2 times more often; pancreas tumors – 1,7 times more often than at non-smoking. The main eating habits increasing probability of a malignization are reception of a large number of meat, greasy, spicy and spicy food, tendency to a peresalivaniye and the use of insufficient amount of vegetable cellulose. Alcohol in itself does not cause a malignization, but acts as the activator, strengthening influence of other factors.
Stages and stages of a malignization
Initial stage of a malignization is initiation – mutation of cells under the influence of internal or external harmful factors. In a genome of a cage there are cellular or virus oncogenes – the changed genes causing growth and reproduction of defective cages. In a human body defective cages are constantly formed, but normal process of a malignization is interrupted at an initiation stage as such cages are exposed to apoptosis – adjustable process of cellular death. At simultaneous switching off of the genes causing apoptosis and activation of the genes interfering apoptosis, defective cages do not perish, and continue to develop.
At repeated impact on cages of the same or other harmful factor there comes the second stage of a malignization – a promotion. Oncogenes become more active, stimulating proliferation of defective cages. However, even it is not enough for development of a malignant tumor. Growth of a new growth becomes possible only after passing of the third stage of a malignization – evasion of defective cages from process of a differentiation. Evasion usually happens under the influence of certain microrNA.
Besides, transition to the third stage of a malignization can be caused by a lack of the tsitokinin promoting transition of a cage to higher level of a differentiation. Over time the quantity of the low-differentiated cages increases, there is a microscopic site of the changed fabric. Cages with the prevailing set of chromosomes form the so-called stem line – a tumor basis. One of features of a malignization is genetic instability of cages because of which the cellular players of a new growth are constantly changed, instead of one stem line others appear.
The changed cages which lost ability to react to external influences (influence of a microenvironment, immune supervision) continue to share actively. There comes the fourth stage of development of a malignant new growth – a tumoral progression. The fabric which changed in the course of a malignization sprouts the next bodies, destroys walls of blood and lymphatic vessels. Cages of a new growth get to blood and a lymph, and then are carried on an organism, "settling" in lymph nodes and the remote bodies. The new centers of tumoral growth – secondary new growths (metastasises) are formed of the "settled" cages.
From the point of view of properties of fabric it is possible to allocate the following stages of a malignization: a fabric giperplaziya, emergence of sites of focal proliferation, developing of a benign tumor, formation of sites of a dysplasia, in situ cancer (the malignant tumor which is not sprouting surrounding fabrics), an invasive malignant new growth. In some cases the stage of a benign tumor can be absent. Stages of focal proliferation, a benign tumor and dysplasia are considered as precancer states.
Properties of a tumor after a malignization
Malignant new growths have a number of the properties which are absent at any normal cages and body tissues:
- As a result of a malignization the tumor becomes capable to the rapid growth which is followed by a sdavleniye or destruction of surrounding fabrics.
- At an ozlokachestvleniye the new growth has an ability to infiltration (introduction) in surrounding fabrics.
- After a malignization the tumor has an ability to distribution by metastasis. Cages of a malignant new growth migrate with current of blood and a lymph, and then "settle" in various bodies and fabrics, giving rise to secondary tumors (metastasises). It is established that there is certain "tropnost" - tendency to metastasis in these or those bodies and fabrics depending on a type of primary new growth.
- At a malignization the tumor has an ability to produce the toxins exerting the expressed negative impact on the patient's organism. Development of a malignant new growth is followed by the general intoxication, fatigue, a loss of appetite and loss of weight up to a kakheksiya.
- After an ozlokachestvleniye the changed cages appear behind The Limits of Control of immune system of an organism.
- Malignization is accompanied by high tendency to mutations as a result of which cages find unusual abilities (ability to uncontrollable growth, to lack of reaction to immune influences, to metastasis etc.).
- Low level of a differentiation of cages is characteristic of a malignization. The level of a maturity of cages, the zlokachestvenny a tumor is lower, the quicker it progresses and resistance to chemotherapy and radiotheraphy gives metastasises, the higher it.
- The malignant new growth possesses the expressed cellular and fabric atipizm.
- In the course of a malignization the changed cages and fabrics have an ability to stimulate growth of blood vessels. Fabric of a malignant tumor well of a vaskulyarizovan, in it often there are hemorrhages.