A Randomized, Double-Blind, Placebo-Controlled, Parallel Group Study of the Efficacy and Safety of Dutasteride 0.5 mg Administered Orally Once Daily for Four Years to Reduce the Risk of Biopsy-Detectable Prostate Cancer

This 4-year study will compare how safe and effective an oral investigational medicine is (compared to placebo) in preventing the development of prostate cancer in men that are defined by the study entrance criteria as being at an increased risk for prostate cancer. Study visits to the clinic will occur every 6 months for up to 4 years (10 clinic visits), and a prostate biopsy will be performed at 2 and 4 years of treatment.