The disease is characterized by high prevalence. In developed countries, it occurs in 10% of women. The countries of Europe are in the lead. The lowest prevalence of breast cancer is in Japan.
Some epidemiological data on breast cancer:
- most cases are registered after the age of 45;
- after 65 years, the risk of developing breast carcinoma increases 5.8 times, and in comparison with the young age (under 30 years) increases 150 times;
- most often the lesion is localized in the upper external part of the breast, closer to the axilla;
- 99% of all patients with breast carcinoma are women, 1% are men;
- single cases of the disease in children;
- mortality for a given neoplasm is 19-25% of all other malignant tumors;
- today breast cancer is one of the most common tumors in women.
At the moment there is an increase in the incidence worldwide. At the same time, a number of developed countries tend to decline due to well-organized screening (mass survey of women) and early detection.
Causes of Breast Cancer
There are many factors that contribute to the development of breast carcinoma. But almost all of them are associated with two types of disorders: increased activity of female sex hormones (estrogens) or genetic disorders.
Factors that increase the risk of developing breast cancer:
- adverse heredity (the presence of cases in close relatives);
- the onset of menstruation earlier than 12 years or their termination after 55 years, their presence for more than 40 years (this indicates an increased activity of estrogens);
- absence of pregnancy or its onset for the first time after 35 years;
- Malignant tumors in other organs (in the uterus, ovaries, salivary glands);
- various mutations in the genes;
- the effect of ionizing radiation (radiation): radiation therapy for various diseases, living in areas with an increased radiation background, frequent fluorographs for tuberculosis, occupational hazards, etc .;
- other diseases of mammary glands: benign tumors, nodal forms of mastopathy;
- the effect of carcinogens (chemicals that are capable of provoking malignant tumors), some viruses (for the time being these moments have been poorly studied);
- high growth of a woman;
- low physical activity;
- alcohol abuse, smoking;
- hormone therapy in large doses and for a long time;
- constant use of hormonal means for contraception;
- obesity after menopause.
Different factors increase the risk of developing breast carcinoma to varying degrees. For example, if a woman has a high body height and excess body weight, this does not mean that the probability of the disease is greatly increased. The general risk is formed due to summation of different reasons.
Usually malignant tumors of mammary glands differ heterogeneity. They consist of different types of cells that multiply at different rates, respond differently to treatment. In this regard, it is often difficult to predict how the disease will develop. Sometimes all the symptoms grow rapidly, and sometimes the tumor grows slowly, without causing noticeable disturbances for a long time.