Finasteride as a chemopreventive agent in prostate cancer: impact of the PCPT on urologic practice.

Prostate cancer chemoprevention involves the use of natural and/or synthetic agents that inhibit or reverse the development of precancerous lesions or delay progression of these lesions to invasive disease. The recent completion of the first Phase III trial for prostate cancer prevention, the Prostate Cancer Prevention Trial (PCPT) using the drug finasteride, has provided the urologic community with the first evidence that a chemopreventive agent can reduce the risk of developing prostate cancer. The enthusiasm for the clear relative risk reduction in the finasteride arm of the trial has been tempered by the observation that the incidence of high-grade tumors was higher in men receiving finasteride compared to those on placebo. A question remains about whether the observed higher incidence in high-grade tumors is real or whether it is related to a pathologic or sampling artifact. The PCPT has instigated a great deal of debate, resulting in the larger urologic community being reluctant to recommend the widespread use of finasteride as a chemopreventive agent. This review summarizes the PCPT, analyzes its controversial results, and describes future prostate cancer chemoprevention studies.