REDUCE: Dutasteride reduced risk for prostate cancer in men at high risk

The use of the 5-alpha-reductase inhibitor dutasteride in men at high risk for prostate cancer reduced the number of cancers detected on biopsy, according to the full results of the Reduction by Dutasteride of Prostate Cancer Events, or REDUCE, trial.

Preliminary results of the trial were presented last year at the American Urological Association Annual Meeting.

REDUCE was a four-year, multicenter, double blind trial. It included 9,729 men aged 50 to 75 years who were randomly assigned to 0.5-mg dutasteride daily or placebo. All men had a PSA of 2.5 ng/mL to 10 ng/mL and had at least one negative prostate biopsy in the past six months.

On biopsy, 659 of the 3,305 men assigned dutasteride had cancer (19.9%) and 858 of the 3,424 men in the placebo group had cancer (25.1%). During the four years of the study, this was a relative risk reduction for prostate cancer of 22.8% (P<.001).

The reduced risk for prostate cancer was mostly in men with a Gleason score of 5 to 6 (437 tumors in the dutasteride group vs. 617 tumors in the placebo group; P<.001). There was no significant difference in tumors with Gleason scores of 7 to 10 for the dutasteride group vs. the placebo group.

Men assigned dutasteride also had a reduced acute urinary retention, urinary tract infection and benign prostatic hyperplasia requiring surgery.

Seventy men in the dutasteride group died during the study vs. 77 in the placebo group (P=.65).

Andriole GL. N Engl J Med. 2010;362:1192-1202.

It's a trial that parallels the Prostate Cancer Prevention Trial that was done by SWOG with National Cancer Institute sponsorship. That trial used a different 5-alpha-reductase inhibitor and had similar outcomes. Findings of the two trials are consistent indicating that the use the 5-alpha-reductase inhibitor reduces the frequency with which prostate is diagnosed.

These results, quite like the results of the tamoxifen and raloxifene prevention trials in breast cancer, do indicate that modest hormonal manipulation does reduce the clinical frequency of these tumors occurring. From my perspective, given the risks of these agents, I believe that these are important results and men should know that this in an option.

– Donald L. Trump, MD
HemOnc Today Editorial Board member