Impact of race on biochemical disease recurrence after prostate brachytherapy

Understanding racial differences in disease presentation and response to therapy is necessary for the effective treatment and control of prostate cancer. In this study, the authors examined the influence of race on biochemical disease-free survival (BDFS) among men who received prostate brachytherapy.

In total, 2301 men were identified who had a minimum follow-up of 24 months and had received low-dose-rate brachytherapy for prostate cancer at the Mount Sinai Medical Center from June 1990 to October 2008. Patient factors, with specific emphasis on patient race, were analyzed with respect to freedom from biochemical failure (FFbF). Kaplan-Meier analyses, life-tables, and log-rank tests were used to identify variables that were predictive of 10-year FFbF.

In this series, a total of 2268 patients included 81% Caucasians, 12% African Americans, 6% Hispanics, and 1% Asians. The 10-year actuarial FFbF rate was 70% for AA men and 84% for all others (P = .002). Between Caucasian men and AA men, the 10-year FFbF rate was 83% versus 70%, respectively (P = .001).There was no significant difference in 10-year FFbF between Caucasian men and Hispanic men (83% vs 86%, respectively; P = .6). The 10-year FFbF rate for Hispanic men and AA men was 86% versus 70%, respectively (P = .062). A greater percentage of AA men presented with higher prostate-specific antigen levels (PSA) (>10 ng/mL; 44% vs 21%; P < .001) and, thus, with higher risk disease (24% vs 15%; P < .001) compared with Caucasian men. Among the men with low-risk disease, the 10-year FFbF rate was 90% for Caucasian men and 76% for AA men (P = .041). The 10-year BDFS rate for patients who received brachytherapy alone was 86% for Caucasian men and 61% for AA men (P = .001); however, this difference was not observed when brachytherapy was combined with androgen-deprivation therapy(ADT) with or without supplemental external-beam radiotherapy (EBRT). Multivariate analysis revealed that PSA (P = .024), Gleason score (P < .001), the biologic effective dose (P < .001), EBRT (P = .002), ADT (P = .03), and AA race (P = .037) were significant predictors of 10-year FFbF. No significant differences was observed in overall survival, cause-specific survival, or distant metastasis-free survival between racial groups.

AA race appeared to be an independent negative predictor of BDFS after prostate brachytherapy, and this result may highlight the need for more aggressive therapy in this patient population.