Long-term oncological and functional outcomes support use of low-dose-rate brachytherapy with or without external beam radiation in young men (≤60 years) with localized prostate cancer

Abstract

PURPOSETo evaluate the oncological and functional outcomes of young men treated with low-dose-rate brachytherapy (BT) for prostate cancer (PCa). MATERIALS AND METHODS423 men aged ≤60 years with clinically localized PCa were treated with BT ± external beam radiation. Biochemical failure was defined by Phoenix criteria. Freedom from biochemical failure (FFbF) and cancer-specific survival (CSS) at 10 and 15 years were estimated by the Kaplan–Meier method with the log-rank test to compare outcomes between National Comprehensive Cancer Network risk groups. The Cox proportional hazards model was used to determine significant predictors for FFbF and CSS. RESULTSMedian followup was 9.9 years (range, 5.1–21.7). Median age was 57 years (range, 39–60), and median prostate-specific antigen was 6.1 ng/mL (range, 0.8–71). Overall, 10- and 15-year FFbF rates were 89% and 88%; 10- and 15-year CSS rates were 99% and 98%. Increasing disease risk was associated with lower FFbF and CSS (p < 0.0001). Biologically effective dose (p < 0.0001) and use of external beam radiation (p = 0.005) were significantly associated with higher FFbF. In men potent before BT, 64% (151/237) had preserved erectile function at a median 10.2 years. There was no significant difference between treatment groups with respect to long-term urinary function (p = 0.56). CONCLUSIONSYounger men treated with BT experience excellent long-term PCa control with low rates of treatment-related toxicity.