The epidemiology of prostate cancer: clues for chemoprevention.

Prostate cancer exists as two different clinical entities; a "latent" or "histologic" form and a clinically evident form. While the prevalence of histologic prostate cancer is similar around the world, the prevalence of clinical cancer varies dramatically from country to country. This suggests that promotional events which contribute in the transformation of histologic cancer to clinically important cancer vary from country to country and population to population. The ultimate goal of epidemiologic studies is to identify risk factors, i.e., promotional agents, for prostate cancer and to use this knowledge for disease prevention strategies.