The predictive value of HGPIN and ASAP for the subsequent diagnosis of prostate cancer in the Reduction by Dutasteride of Cancer Events (REDUCE) study.
4561 Background: REDUCE was a 4-year, randomized placebo (pbo) controlled study of prostate cancer (PCa) risk reduction with once daily dutasteride 0.5 mg (dut). This analysis examines the effect of dut on initial detection of high-grade prostatic intraepithelial neoplasia (HGPIN) and/or atypical small acinar proliferation (ASAP) and the incidence of PCa on subsequent biopsy. Methods: Eligible men were aged 50–75 years, had a serum PSA 2.5–10.0 ng/ml, and a single, negative (no PCa, HGPIN or ASAP) biopsy of 6–12 cores in the 6 months prior to enrollment (4126 subjects randomized to pbo, 4105 dut). Ten-core prostate biopsies were taken at 2 and 4 years and examined for evidence of PCa. For subjects with 2-year biopsies and no PCa (2866 pbo, 2867 dut), the initial incidence of ASAP, HGPIN (without ASAP), and ASAP or HGPIN was compared between treatment groups using Fisher's exact test. PCa incidence in a subsequent biopsy was also compared between treatment groups with Fisher's exact test. Results: PCa inci...