[Objective]

The primary objective of the PCPT is to test the difference in the histologically proven prevalence of carcinoma of the prostate between these two groups of randomized participants. Other objectives include assessment of the effect of finasteride on the stage and grade of carcinoma at the time of diagnosis, and estimations of the difference between the two groups in (1) total and prostate cancer-specific mortality and (2) the incidence and severity of benign prostatic hyperplasia (BPH). The toxicity and side effects of long-term administration of finasteride will be assessed, as well as the effect of finasteride treatment on various quality of life dimensions. The standard screening parameters for prostate cancer (DRE, PSA) will be evaluated for their sensitivity, specificity and predictive value; the effect of long-term finasteride treatment on these parameters will be estimated. The association of dietary fat with increased risk of prostate cancer will also be investigated.