Oncologic diseases come second according to death rate after cardiovascular diseases i.e. its rate is 18-22 per cent of total fatal outcome depending on region. Its causes and tumorogenesis mechanisms are not defined. But there is a great experience on risk factors. It makes a basis of effective preventive measures.

The risk factors of adult cancer include irrational diet, smoking, virus infections, insalubrity of work in some industry, alcohol addiction, solar radiation, and negative state of mind, power line closeness, genetic cancer susceptibility, age and other factors. Special attention is focused on the role of immune system in child and adult cancer development. The majority of scientists think that immune impairment is a determining factor of tumor development and growth.

In general, genetic cancer susceptibility and environmental conditions are very important. For example, it was found out that in Japan breast cancer is rare but stomach cancer is very frequent. But Japanese who lives in the USA suffers from stomach cancer more seldom than Japanese who lives in Japan but more frequently than other American citizens. Moreover, this type of cancer is adult cancer.

English citizens who have moved to Australia, the United States or South Africa suffer from cancer of lung more seldom than the citizens of Great Britain. England comes first according to adult lung cancer statistics.

Today there is no unified theory of cancer genesis and its development. The scientists began their investigation and researchers in this field only at the end of the 19th century. Before it other diseases were more actual, e.g. plague, cholera, smallpox, typhus, malaria and other infectious diseases. Even today when we have vaccination and antibiotics these diseases are called dangerous.

For many years they were fatal. For example, in the 17th century the average lifetime was 35-40. So, many people just did not live till his tumor as in general senior suffers from it. At the end of the 19th century, natural sciences' achievements (i.e. microbiology, epidemiology and hygiene) resulted in the fact that infections as a cause of death receded into the background and cardiovascular disorders and adult cancer took their place.

Leukosis is the child most common cancer. Its risk factors include ionizing radiation, weak immune system, genetic disorders, viruses and chemicals.

Breast cancer is the female most common cancer. The risk factors include age, genetic susceptibility, pregnancy absence, premature menstruation and late menopause. The five-year survival rate i.e. complete recovery rate is 79 per cent. Today ovary cancer and cancer of lung is becoming more frequent. The risk factors of ovary cancer are the same as the risk factor of the breast cancer. Smoking, asbestos, radiation, radon and other chemical agents cause the cancer of lung. The five-year survival rate is lower. It is 39 per cent and 13 per cent correspondently.

Rectal cancer, large intestine cancer and prostate cancer are the male most common cancer. They are caused by genetic susceptibility and excess fat and oil in the diet. The five-year survival rates are 58 per cent and 77 per cent correspondently.

So, as we see eutrophy is an important part of cancer treatment and prevention. But the most effective method of cancer prevention is regular examination and check-ups.