Early dutasteride monotherapy in men with detectable serum prostate-specific antigen levels following radical prostatectomy: A prospective trial

PURPOSE To investigate the effects of early administration of dutasteride in patients with detectable serum prostate-specific antigen (PSA) levels after radical prostatectomy (RP). MATERIALS AND METHODS A prospective open-label study, with a cumulative analysis of asymptomatic increase in PSA following RP, was conducted from January 2005 to December 2013. An early increase in PSA level was defined as detectable serum PSA level> 0.04 ng/mL. Patients with PSA level>0.04 ng/mL were treated with dutasteride 0.5 mg daily. Serum PSA level and biochemical recurrence (BCR) were monitored. We divided the patients into 2 groups based on the serum PSA response after dutasteride treatment. RESULTS Eighty patients were included in the study. At the median follow-up of 51.8 months, 56 patients (70.0%) showed a decrease of greater than 10% in serum PSA level, and 24 showed increased PSA levels. Twelve of the 56 patients with PSA response showed subsequently increased PSA. Intergroup differences in preoperative PSA levels, PSA nadir levels, and Gleason score of 6 or less were significant (p=0.028, p=0.030, and p=0.035, respectively). A multivariate analysis revealed that Gleason score of 6 or less (p=0.018) and PSA nadir levels (p=0.011) were predictive factors for PSA response after early dutasteride treatment in men with increased PSA levels following RP. CONCLUSIONS Early monotherapy of dutasteride showed a decline in serum PSA levels in men with lower nadir PSA levels, and a Gleason score 6, when the serum PSA was detected after RP.