The risk of death from prostate cancer in men with Gleason score 3+4 prostate cancer treated using brachytherapy with or without a short course of androgen deprivation therapy.

Abstract

We evaluated whether intermediate-risk factors, in addition to age, were associated with risk of prostate cancer-specific mortality (PCSM) among men with Gleason 3+4 prostate cancer. We conducted a prospective cohort study of 1,920 men with Gleason 3+4 adenocarcinoma of the prostate who received brachytherapy (BT) or BT and a median of 4 months of androgen deprivation therapy (ADT). Separate multivariable Fine and Gray competing risks regression models among men treated with BT or BT and ADT were used to assess whether percentage of positive biopsies (PPB), cT2b-T2c stage, prostate-specific antigen (PSA) of 10.1-20.0 ng/ml, and age >70 years (median) were associated with risk of PCSM after adjustment for comorbidity. After median follow-up of 7.8 years, 284 men (14.8%) had died (31 from prostate cancer). For BT alone, increasing PPB, PSA of 10.1-20.0 vs. 4.0-10.0 ng/mL, and age >70 vs. ≤70 were significantly associated with increased risk of PCSM (adjusted hazard ratio 1.015, 95% confidence interval 1.000-1.031, P = 0.048; 5.55, 2.01-15.29, P<0.001; and 3.66, 1.16-11.56, P = 0.03, respectively). The respective results for BT and ADT were 1.009, 0.987-1.031, P = 0.44; 4.17, 1.29-13.50, P = 0.02; and 3.74, 0.87-16.05, P = 0.08. Among men with Gleason score 3+4 prostate cancer treated with BT, the risk of PCSM was elevated in those with PSA of 10.1-20.0 ng/mL and possibly age >70 years, despite the addition of ADT. Should these findings be validated in future studies, then advanced imaging and targeted biopsy of suspicious areas should be investigated in an effort to personalize treatment and minimize the risk of PCSM in these men.