Effect of dutasteride on prostate cancer progression and cancer diagnosis on rebiopsy in the REDEEM active surveillance study.

2 Background: The REDEEM (Reduction by Dutasteride of Clinical Progression Events in Expectant Management of Prostate Cancer) study tested whether dutasteride controlled growth of existing low risk, localized prostate cancer (PCa) and hence reduced the need for aggressive therapy in men followed with active surveillance. METHODS 302 men, aged 48-82, with PSA <11 ng/ml, and Gleason score ≤6 PCa (≤3 cores positive, <50% of any core positive) were randomized to dutasteride or placebo for 3 years. Repeat 12-core biopsies were performed at 18 and 36 months, or for-cause at other times during the study. The primary endpoint was time to progression, defined as the earliest of either pathological progression (Gleason score >6, ≥4 cores positive, or >50% of any core positive) or therapeutic progression (radical prostatectomy, radiation therapy, or hormonal ablation). RESULTS 96% of subjects reached the primary endpoint or had a post-baseline biopsy. Dutasteride reduced time to PCa progression (relative risk reduction 38.9%, 95% CI: 12.4-57.4%, P=0.007). The table presents incidence of progression and Gleason score on final biopsy. 23% of men (N=31) in the placebo group and 36% of men (N=50) in the dutasteride group had no cancer detected on their final biopsy. PCa-related anxiety was reduced in the dutasteride arm compared to the placebo arm (P=0.036), based on the Memorial Anxiety Scale for PCa (MAX-PC). Drug-related adverse events were similar to those previously reported for dutasteride. CONCLUSIONS In men followed with active surveillance, dutasteride delayed the time to PCa progression, increased the percent of men with no detectable PCa, and improved PCa-related anxiety. There was no evidence of increased Gleason score upgrading with dutasteride. Dutasteride may provide a useful adjunct to active surveillance for management of PCa. [Table: see text] [Table: see text].