886 LONG-TERM SURVIVAL AFTER SURGERY VERSUS EXTERNAL BEAM RADIOTHERAPY FOR HIGH-RISK PROSTATE CANCER

Abstract

INTRODUCTION AND OBJECTIVES: The management of patients with high-risk prostate cancer remains in debate, and prospective clinical trials comparing treatment outcomes are lacking. We evaluated the survival of patients with high-risk disease following radical prostatectomy (RP) and external beam radiation therapy (RT) during the PSA era. METHODS: We identified 1,238 men who underwent RP and 609 men treated with RT between 1988–2004 who had a pretreatment prostate specific antigen (PSA) 20 ng/mL, biopsy Gleason score 8–10, or clinical stage T3. The impact of treatment modality on cancer-specific (CSS) and overall survival (OS) was analyzed using Cox proportional hazard regression models controlling for patient age, Charlson comorbidity index (CCI), and clinicopathologic tumor variables. RESULTS: Patients treated with RT were older (p 0.0001), had a greater pretreatment PSA (p 0.02), higher biopsy Gleason score (p 0.0001), and more advanced clinical stage (p 0.0001). In total, 344 (57%) men who underwent RT were treated with adjuvant androgen deprivation therapy (ADT), while 418 (34%) men who underwent RP received adjuvant ADT and 136 (11%) received adjuvant RT. Median follow-up was 10.2, 6.0, and 7.2 years after RP, RT ADT, and RT alone. Estimated 10-year CSS following RP and RT ADT was equivalent (92%), and was modestly better than RT alone (88%; p 0.06). 10-year OS was significantly improved after RP (77%) versus RT ADT (67%) or RT alone (52%; p 0.001). On multivariate analysis (Table), patients who underwent RT alone had a significantly increased risk of death from prostate cancer (p 0.0006) and overall mortality (p 0.0001) compared to patients treated with RP. No significant difference in the risk of cancer death was seen between RT ADT and RP (p 0.90); however, men who received RT ADT had a greater than 50% increased risk of overall mortality versus men who underwent RP (p 0.0005). CONCLUSIONS: RP and RT ADT provide similar long-term cancer control for patients with high-risk disease, although the risk of all-cause mortality was greater after RT ADT. As surgery provides pathologic staging to guide the selected use of secondary therapies, prospective studies evaluating the differing impact of treatments on quality of life and non-cancer mortality are necessary to determine the optimal management approach to these men.