The utility of 5-alpha reductase inhibitors in the prevention and diagnosis of prostate cancer

Purpose of review We examine the role of 5-alpha reductase inhibitors in prevention and diagnosis of prostate cancer, highlight the basic science supporting this role, and analyze the phase III clinical trials addressing the association between 5-a reductase inhibitor use and prostate cancer. Recent findings To date, the Prostate Cancer Prevention trial (PCPT) is the only reported phase III randomized clinical trial to evaluate the role of 5-alpha reductase inhibitors in the prevention and treatment of prostate cancer. The original PCPT data revealed that finasteride reduced the risk of prostate cancer by approximately 25% in comparison with placebo. However, patients who received finasteride had a greater incidence of high-grade tumors, which prohibited acceptance of finasteride as a chemopreventive agent by most urologists. Recent updates of the PCPT findings confirmed that finasteride reduces the risk of clinically significant prostate cancer, including high-grade tumors, primarily due to its effects on improving the performance characteristics of prostate-specific antigen and prostate biopsy. There was no increase in high-grade prostate cancer. Rather, there was improved detection of high-grade prostate cancer due to decreased prostate volume. Summary Finasteride is a valuable chemopreventive tool because it reduces the risk of prostate cancer, including high-grade cancer, and enhances our ability to detect high-grade disease.