Decision Analysis of Dutasteride Use for Patients With Negative Prostate Biopsy

Abstract

To determine whether the additional benefits of improved prostate cancer detection associated with 5α-reductase inhibitors are sufficient to warrant chemoprevention in the case where the degree of prostate cancer risk reduction is deemed inadequate. We reanalyzed data from REDUCE, a randomized trial of dutasteride for prostate cancer chemoprevention in men with prior negative biopsy. We evaluated whether statistical models using prostate-specific antigen (PSA) and PSA velocity could help predict the result of repeat prostate biopsy separately for dutasteride and placebo groups. Area under the curve was evaluated by 10-fold cross-validation. PSA velocity improved discrimination at 4 years in the dutasteride group but not at 2 years nor in the placebo group. At 2 years, dutasteride improved discrimination of PSA slightly (0.616 vs. 0.603 for any grade cancer; 0.681 vs. 0.676 for high-grade disease). Between-group differences in cancer rates at 4 years were small. Clinicians who are willing to treat at least 23 patients with dutasteride for 2 years to avoid 1 prostate cancer diagnosis should offer dutasteride after initial negative biopsy. Clinicians not willing to do so might consider dutasteride for its additional benefit of reducing unnecessary biopsy, although this benefit is apparent only under very restrictive conditions. It is difficult to justify extending treatment with dutasteride for >2 years.