Association of Gleason 9-10 prostate cancer with worse outcomes compared to Gleason 8 disease.

Abstract

157 Background: Use of pathological Gleason score for risk stratification of localized prostate cancer is widely accepted. However, data are lacking regarding differences in presentation and outcome among those with Gleason 8-10 disease. Methods: Using the Dana-Farber Cancer Institute Prostate Clinical Research Information Systems database, we identified a cohort of patients with biopsy Gleason 8-10 disease who received definitive radical prostatectomy (RP) or radiation therapy (RT) (external beam or brachytherapy) for curative intent. The study endpoints, time to biochemical recurrence (BCR), time to metastatic disease (MD), and overall survival (OS) were estimated using the Kaplan-Meier method. Cox proportional hazards model was used to investigate the association of the study endpoints and Gleason score groups (8 vs. 9 and 10) adjusted for clinical and pathological factors including age, PSA at diagnosis, type of local therapy, and tumor stage. Results: We identified 848 patients who received either local definitive RT (n=411) or RP (n=437). Median follow-up from diagnosis was 5.3 years. Patient characteristics at diagnosis (race, age, and clinical stage) were similar between the two groups (Gleason 8 vs. Gleason 9-10). Patients with Gleason 9-10 disease were more likely to receive radiotherapy as primary local therapy (58% vs. 46%, p=0.001), and to receive hormonal therapy as a part of their definitive treatment course (64% vs. 48%, p<0.001). Patients with Gleason 9-10 disease had shorter time to BCR, time to MD, and a trend towards worse OS using multivariate analysis adjusted for significant clinical and pathological factors. (Detailed in table below). Conclusions: In our study, we found that patients with localized Gleason 9-10 disease who were treated with definitive therapy with curative intent had worse outcomes compared to patients with Gleason 8 disease. More aggressive, multimodality treatments may be indicated for men diagnosed with the highest Gleason grades. [Table: see text]