Prostate-specific antigen density during dutasteride treatment for 1year predicts the presence of prostate cancer in benign prostatic hyperplasia after the first negative biopsy (PREDICT study).

Abstract

To prospectively evaluate the detection rate of prostate cancer, and to identify the risk factors of prostate cancer detection after a 1-year administration of dutasteride and first negative prostate biopsy. Patients with benign prostatic hyperplasia who presented high prostate-specific antigen levels after the first negative prostate biopsy were administered 0.5mg dutasteride daily for 1year. They underwent a repeat prostate biopsy after 1year. The primary end-point was the detection rate of prostate cancer. The secondary end-point was the ability of prostate-specific antigen kinetics to predict prostate cancer detection. Prostate-specific antigen was measured before the initial prostate biopsy and at 6, 9 and 12months after starting dutasteride. Patients were classified into a prostate cancer and a non-prostate cancer group. Prostate cancer was detected in 15 of 149 participants (10.1%). The total prostate-specific antigen change between the prostate cancer and non-prostate cancer group at 1year was significantly different (P=0.002). Although prostate-specific antigen levels at baseline did not significantly differ between study groups (P=0.102), prostate-specific antigen levels at 6, 9 and 12months were significantly different (P=0.002, P=0.001 and P<0.001, respectively). The mean reduction rate of prostate-specific antigen density between the prostate cancer and non-prostate cancer group at 1year was significantly different (-4.25±76.5% vs -38.0±28.7%, P=0.001). Using a multivariate analysis, a >10% increase of prostate-specific antigen density at 1year post-dutasteride treatment was the only predictive risk factor for prostate cancer after the first negative prostate biopsy (odds ratio 11.238, 95% confidence interval 3.112-40.577, P<0.001). In the present study cohort, >10% increase in prostate-specific antigen density represented the only significant predictive risk factor for prostate cancer diagnosis in patients with elevated prostate-specific antigen after the first negative prostate biopsy.