Oncology - Prostate
Introduction & Objective :
Men with Gleason score 9-10 prostate cancer have significantly worse outcomes compared to those with Gleason score 8 disease. Choice of upfront treatments remain controversial for this patient cohort. Using the Surveillance, Epidemiology, and End Results (SEER) database, we evaluated the impact of initial treatment with external beam radiation therapy (EBRT), external beam radiation therapy with brachytherapy (EBRT+BT), or surgery on prostate cancer-specific mortality (PCSM) and overall mortality in Gleason 9-10 disease.
The SEER database was queried for men diagnosed with Gleason score 9-10 prostate cancer from 2004-2014. Only localized disease with clinical N0 and M0 status was included. Gathered data included demographic, pathologic, therapy received, and survival outcomes. Using JMP v11.0, Kaplan-Meier survival curves and univariate and multivariate analyses were generated for initial therapy with EBRT, EBRT+BT, or surgery.
A total of 11,359 men were included with 5,078 (44.7%) who underwent upfront treatment with EBRT alone, 683 (6.0%) with EBRT+BT, and 5,598 (49.3%) with surgery. 7-year PCSM rates were 26.8%, 14.1%, and 9.4% for EBRT, EBRT+BT, and surgery respectively (p < 0.001) (Figure 1). 7-year overall mortality rates were 41.7%, 26.3%, and 16.0% for EBRT, EBRT+BT, and surgery respectively (p < 0.001) (Figure 2). When controlling for age, Gleason score, clinical tumor stage, and PSA level on multivariate analysis, EBRT had greater PCSM than either surgery or EBRT+BT (HR 0.32, 95% CI 0.23 – 0.44, p < 0.001 and HR 0.57, 95% CI 0.33 – 0.90, p = 0.015 respectively). Comparison of PCSM and overall mortality between surgery and EBRT+BT revealed HR 0.56 (95% CI 0.34 – 1.00, p = 0.052) and HR 0.58 (95% CI 0.42 – 0.81, p < 0.001) respectively.
Among men with localized Gleason 9-10 disease, surgery and EBRT+BT showed significant improvement in survival outcomes compared to EBRT alone. When compared with EBRT+BT, surgery showed improvement in overall mortality but no significant difference in PCSM. Future prospective studies are warranted.