REDUCE randomized high-risk men to the 5-alpha-reductase inhibitor (5-ARI) dutasteride (Avodart) or placebo. Men in the treatment arm showed a 23% reduction in the risk of developing prostate cancer versus the placebo arm (see, "Dutasteride shown to reduce prostate Ca in high-risk men"). 

REDUCE was well designed, and its findings validate those of the landmark Prostate Cancer Prevention Trial, or PCPT (

 2003; 349:215-24). The PCPT showed a similar (24.8%) reduction in prostate cancer in men receiving the 5-ARI finasteride (Proscar). Sexual side effects were more common in both trials' treatment arms. 

The rate of Gleason 7 to 10 cancers proved to be a striking difference between the studies, occurring in 37% versus 22.2% of the treatment versus placebo arms of PCPT and 6.7% versus 6.8% of the treatment versus placebo arms of REDUCE. This finding raises multiple questions: 

Collectively, these data provide strong evidence that hormonal manipulation with 5-ARIs reduces the relative risk of prostate cancer, but multiple questions remain. Further analysis of the REDUCE trial with longer follow-up and pathologic analysis will help us answer these questions and direct therapy. 

Editorial Council, is professor and chair of urology, University of Kansas Medical Center, Kansas City. 

News

Further analysis of the REDUCE (Reduction by Dutasteride of Prostate Cancer Events) trial will help answer important questions and direct therapy.