Epidemiology Of Prostate Cancer Risks

The incidence of prostate cancer is increasing steadily, especially in elderly males.

In some countries in the structure of cancer, this tumor is out for 2-3 places after lung cancer and stomach, and in the U.S. - in the first place. Mortality from prostate cancer among cancer ranks second after lung cancer. In the late 80-s been a dramatic increase in the incidence of prostate cancer, which gradually decreased to normal rates, due to the identification of a large number of asymptomatic cancers in relation to the introduction of a routine practice of diagnostic tumor markers - prostate-specific antigen (PSA).

Up to 40% of men aged 60-70 years have microscopic prostate cancer. In connection with the peculiarities of the clinical course of tumors may be many years does not affect the condition of patients. Only 10% of the latent form of prostate cancer becomes clinically significant and leads to death, only 3-5% of the male population.

There are marked differences in the frequency of incidence of the various geographical regions and different ethnic groups. The highest incidence is observed in the U.S., the lowest - in the countries of Asia and Africa. Interestingly, the incidence of the Chinese and Japanese living in the United States, significantly higher than in Japan. In addition, there are significant fluctuations in the frequency of occurrence of prostate cancer within the same country among different ethnic groups. Example and the highest incidence was registered among U.S. black men (102.0 per 100.000 population) compared with whites (60.0 per 100.000 population).

Despite significant differences in the frequency of occurrence of clinical forms of prostate cancer in different countries, the frequency of detection of latent disease process running virtually the same in all regions, as evidenced by the results of autopsies.

The proportion of prostate cancer incidence in the structure of the male population is steadily growing. In 1989 it amounted to 2,8%, and in 1999 - already 5%. Number of newly diagnosed disease increased from 5.5 thousand to 10.7 thousand standardized incidence rate in 1999 amounted to 14.3 (per 100.000 male populations. The average age of patients with prostate cancer is - 69 years, died of this cancer - 70 years. In the U.S. the corresponding figures were 72 and 77 years respectively.

Age is the most important epidemiological factor. The proof is the fact that 70% of men older than 80 years, there are various forms of prostate cancer.

Race. In 1990, Carter et al reported that prostate cancer occurs with equal frequency in Japan and the United States. The difference lies in the fact that Japan dominates the latent cancer, rarely goes into clinically meaningful form. This phenomenon may be due to the presence of a number of factors or inhibiting tumor progression, or contributing to it. Watanabe et al. (1994) have shown that mutations in the p53 gene required for the development of the disease, much less frequently observed among the Japanese. Takahashi et al. (1995) have shown that androgen receptor mutations observed more frequently in the case of latent forms of prostate cancer and a higher frequency found among the Chinese and Japanese, which corresponds to the low occurrence of clinical prostate cancer in this population of men.
Significant differences incidence of prostate cancer in the United States and Asia for a long time explained only by genetic predisposition. However, the fact that the incidence of the Japanese living in the United States, significantly higher than those in Japan, said the impact of environmental factors, diet and lifestyle.

Nutrition. The value of nutrition in the etiology of prostate cancer is discussed for many years. Several studies have found that the risk of developing the disease increases in the use of a large number of animal fats. There is a more frequent occurrence of prostate cancer in obese men.

Vitamin D. Ultraviolet radiation may also affect the risk of developing prostate cancer. Geographic differences in the intensity of solar activity and the incidence of prostate cancer are almost identical and are inversely proportional. A possible explanation for this connection is the induction of vitamin D3. Last inhibits cell growth and may be used for the prevention of tumor progression.

Genetic Factors. The risk of prostate cancer is 2-3 times higher in men with close relatives who have prostate cancer was detected in the relatively young age. The probability of developing the disease increases even more if more than one relative, a patient with prostate cancer. Found that the risk of prostate cancer increased 8-fold in men, blood relatives who suffered from prostate cancer? According to expert estimates, about 9% of cases of prostate cancer due to genetic causes, although the localization of the genetic defect has not been established.