Finasteride.

IMPORTANCE OF THE FIELD: Prostate cancer is the most common non-cutaneous malignancy in males in the US. Prostate cancer chemoprevention entails the use of agents which retard or inhibit the progression to invasive disease. Chemoprevention is an attractive option for patients with prostate cancer given the hormonally responsive nature of cancer, long latency period and high prevalence of the disease. AREAS COVERED IN THIS REVIEW: This review outlines a detailed background on the development of finasteride as a chemopreventive agent for prostate cancer. It discusses the Prostate Cancer Prevention Trial, a large randomized clinical trial that showed reduction in prostate cancer prevalence through the use of finasteride. In addition, an in-depth discussion involving theories on a higher incidence of high-grade cancer in the finasteride arm is presented. Other notable recently completed randomized trials and novel chemopreventive agents for prostate cancer are discussed as well. WHAT THE READER WILL GAIN: Readers will get an in-depth understanding of the balance of risks and benefits of finasteride for prevention of prostate cancer. TAKE HOME MESSAGE: Finasteride was the first 5alpha-reductase inhibitor to show a benefit in reducing prevalence of prostate cancer. It is well tolerated but a higher incidence of high-grade prostate cancer in men taking finasteride has hindered its use in clinical practice. It may temporarily shrink tumors that have a low potential for being lethal and is not approved as a chemopreventive agent.