Epidemiology of prostate cancer chemoprevention.

In absolute terms, prostate cancer is a public health problem of major and increasing importance particularly as the population ages. Prostate cancer control comprises a series of actions ranging from primary prevention, through screening to improvements in therapy for prostate cancer. An exciting approach lies in the possibility of chemoprevention to reverse the process of carcinogenicity and prevent prostate cancer by this route. Indeed, there are several very interesting ideas being tested at this moment. One major difficulty is the long length of time which can elapse between exposure and the time at which clinical cancer can be found and diagnosed. In cases where delays are long, then preventative treatment should be initiated at an early age. This, and many other issues, current in prostate cancer, are rendered problematic by the age distribution of prostate cancer in the population. Although it is decreasing now, around the early 1990s, the median age of diagnosis of prostate cancer was around 75 in some European countries although considerably lower in population groups in the United States. The median age at death is between 77 and 80 in most countries. These special circumstances must be taken into account when discussing clinical trials of chemoprevention of prostate cancer. The importance of developing reliable intermediate endpoints which can be used in such studies in highlighted.