The geography of prostate cancer and its treatment in Japan.

The age adjusted death rate from prostate cancer in Japan is one of the lowest in the world but is rising steadily. The vast majority of cases of prostate cancer remain undetected during life, the prevalence of prostate cancer detected at autopsy being 2800 times that of lethal cancer in Japanese in Japan, 570 times in whites in the USA and 470 times in blacks in the USA. A case-control study of prostate cancer carried out in Japan and the Netherlands revealed a number of statistically significant risk factors, including rural residence, more brothers, colon neoplasms in relatives, no morning erections, frequent sexual intercourse in 30s, episodes of sexually transmitted disease, lower plasma testosterone and dihydrotestosterone concentrations and lower beta-carotene intake.