Prostate Specific Antigen Density Velocity (PSADV) on Dutasteride Helps Predict Negative Prostate Biopsy: Analysis of the REDUCE Trial

Abstract

AIM : Prostate specific antigen (PSA) is a widely utilized screening marker for prostate cancer. Its performance in detecting prostate cancer is enhanced with the 5α-reductase inhibitor (5aRI) dutasteride. We evaluated if PSA density velocity (PSADV) further improved the ability to predict prostate cancer risk on repeat biopsy utilizing the REDUCE trial data in order to avoid unnecessary biopsies. MATERIALS AND METHODS : The REDUCE study randomized 8 231 men aged 50 to 75 years with a PSA between 2.5 and 10 ng/mL and a previously benign prostate biopsy. Prostate volume, PSA and biopsy results at 24 months were available for 1 074 subjects. PSADV, defined as the change in PSA density divided by the number of days between PSA measurements (ng/mL/cc/day), was calculated and compared between the placebo and treatment groups and further stratified by prostate biopsy results. Statistical significance was calculated using the Wilcoxon rank sum test. RESULTS : Median PSA, PSA velocity, and PSADV are shown for the placebo and dutasteride treatment cohorts at 24 months in Table 1. Median PSA velocity in both the placebo and treatment groups were positive independent of a prostate cancer diagnosis. Results of PSADV stratified by treatment and biopsy results are seen in the boxplots in Figure 1. There was a significantly more robust reduction in PSADV in those without cancer on biopsy compared to those with prostate cancer in the treatment arm (P = 0.0019). CONCLUSIONS : The magnitude of change in PSADV after dutasteride therapy may be an additional diagnostic adjunct to aid in the identification of those at lower risk for prostate cancer on repeat biopsy. This measurement may reduce unnecessary prostate biopsies and the increasingly prevalent associated risks of the procedure.