[Role of 5 alpha-reductase inhibitors in the chemoprevention of prostate cancer].

Prostate cancer is one of the most common visceral malignancies in human. In recent years, its incidence has dramatically increased in China. 5 alpha-reductase inhibitors can block the biological effects of dihydrotestosterone by restraining the transformation from testosterone to dihydrotestosterone, and therefore can be used for the chemoprevention of prostate cancer. Two large clinical trials on the chemoprevention of prostate cancer (the Prostate Cancer Prevention Trial and the Reduction by Dutasteride of Prostate Cancer Events) were completed in 2003 and 2008, respectively, bringing the global interests on this topic. However, the interpretations of these two trials and the possible recommendations on clinical applications remain controversial.