Prostate cancer seems to be ultimately unavoidable. Autopsies of men who have died of other causes show that around 40 per cent of men over the age of 50 have prostate cancer. The risk rises steadily through the decades so that, by age 80, 70 per cent of men will have it. For men in their 90s, it's a near certainty.
Fortunately, prostate cancer is slow-growing, so most men will die of something else before the cancer becomes a problem. They die with prostate cancer rather than because of it. Surveys show that, for the average 50-year-old with a reasonable life expectancy of another 25 years, there's a 10 per cent chance that he will develop clinically significant prostate cancer, but only a 3 per cent chance that he will die of it (National Cancer Institute Statement, August 2001).
For reasons unknown, black people are at a much higher risk than Asians or whites. Japanese men living in Japan have an extremely low incidence of prostate cancer, but are at normal risk if they live in the USA (National Cancer Institute Statement, August 2001). This strongly suggests the involvement of environmental factors in the disease.