MP53-10 SURGICAL MANAGEMENT VERSUS COMBINATION RADIOTHERAPY IN GLEASON SCORE 9-10 PROSTATE CANCER

Abstract

INTRODUCTION AND OBJECTIVE: For men with Gleason score 9-10 prostate cancer, studies have demonstrated conflicting results on the outcomes from combination radiation therapy (ComboRT) with external beam radiation therapy plus brachytherapy boost versus radical prostatectomy (RP), with or without adjuvant radiation therapy (ART). Differences in patient selection and management may explain some of the disparate outcomes of prior reports. METHOD(S): The Surveillance, Epidemiology, and End Results database identified 10,396 men managed with ComboRT versus RP (+/-ART). Competing-risks regression analysis with treatment propensity adjustment defined hazard ratios (aHR) for prostate cancer-specific mortality (PCSM), controlling for patient-specific demographic factors. To explore the possible effect of patient selection, analyses were conducted before and after excluding men from analysis if they had evidence-based indications for ART (adverse pathology, i.e. pT3-T4 or positive margins) but did not receive it. RESULT(S): Median age was 64 years; median follow-up was 69 months. Five-year PCSM was similar between patients treated with RP (with or without ART, regardless of pathologic features, N =8,934) and ComboRT (N=1,462) (6.9% vs 8.1%, aHR=0.94, 95% confidence interval [CI] 0.78-1.13, P=0.51). After excluding RPtreated men with adverse pathology who did not receive ART (N =4,527 excluded), patients treated with RP+/-ART (N=4,407) had improved 5-year PCSM compared with those treated with ComboRT (5.3% vs 8.1%, aHR=0.74, 95% CI 0.60-0.91, P=0.004). CONCLUSION(S): For Gleason 9-10 prostate cancer, ComboRT was associated with similar PCSM compared to RP, but risk-tailored surgical management may be associated with superior PCSM. (Figure Presented).