High-dose radiation employing external beam radiotherapy and high-dose rate brachytherapy with and without neoadjuvant androgen deprivation for prostate cancer patients with intermediate- and high-risk features

Abstract

The role of neoadjuvant androgen deprivation (NAD) in high-risk prostate cancer patients receiving high-dose radiotherapy (RT) remains unstudied. To evaluate the effect of a course of NAD, we reviewed the experiences of three institutions treating these patients with combined RT and high-dose rate brachytherapy (HDR). Of 1260 prostate cancer patients with high-risk features (pretreatment prostate-specific antigen (PSA) > or =10, Gleason Score (GS) > or =7, or T stage > or =T2b), 560 received no NAD (n=308) or NAD for < or =6 months (n=252). Median dose to the prostate from RT and HDR was 42 and 23 Gy, respectively. Average total biologic equivalent prostate dose was >100 Gy (alpha/beta=1.2). Median follow-up was 4.3 years. Pretreatment characteristics were similar on chi(2) tables for all 560 patients treated with or without NAD including pretreatment PSA (P=0.11), GS (P=0.4), and clinical T stage (P=0.2). Outcomes worsened for patients receiving NAD (5-year distant metastasis (DM) 10 vs 5% (P=0.04); cause-specific survival (CSS), 93 vs 98% (P=0.005)). Higher 5-year DM rates and lower CSS occurred in NAD patients with a GS between 8 and 10 (n=112 (P=0.03, P=0.02)), pretreatment PSA> or =15 (n=136 (P=0.03, P=0.008)), and palpable disease > or =T2a (n=434 (P=0.04, P=0.02)). The only two significant risk factors for DM on Cox multivariate analysis were GS (P=0.003, HR 2.8) and NAD (P=0.03, HR 2.7). AD given before definitive high-dose RT did not benefit prostate cancer patients with intermediate- and high-risk features. We favor the use of concurrent/adjuvant AD over prolonged NAD for prostate cancer patients for whom AD is clinically indicated.