MP06-12 CHEMORADIATION VERSUS RADICAL CYSTECTOMY FOR MUSCLE INVASIVE BLADDER CANCER: COMPARATIVE ANALYSIS OF NATIONAL CANCER DATABASE WITH PROPENSITY SCORE WEIGHTING

Abstract

INTRODUCTION AND OBJECTIVES: There is growing interest in the bladder preservation approach (Chemoradiation therapy: CMT) for muscle invasive bladder cancer (MIBC). The current overarching question is whether CMT offers similar overall survival (OS) when compared with radical cystectomy (RC) which is currently the gold standard treatment for MIBC. METHODS: The NCDB (National Cancer Database) is a hospital- based registry that represents 70% of all cancer cases in the United States and draws data from more than 1500 accredited cancer programs. We reviewed the NCDB for patients diagnosed with MIBC between 2004 and 2014 who subsequently underwent either RC with or without perioperative chemotherapy or primary CMT. RC and CMT patients were propensity score weighted based on demographic, clinical and pathologic variables. Subsequently, a weighted univariate proportional Cox regression model was used to contrast RC and CMT with OS. Weighted Kaplan-Meier curves were used to describe the two survival distributions. As an alternative to the propensity score weighing, multivariate Cox-regression analysis was performed for patients treated with RC and CMT to account for the same variables used in the propensity score weighing. RESULTS: We identified 16,180 (RC: 14,282; CMT: 1,898) patients who met the inclusion criteria and had complete dataset. After performing propensity score weighting, we determined that RC and CMT differed significantly with regard OS, with CMT experiencing decreased OS relative to RC [Figure 1, Hazard Ratio 1.57 (CI: 1.52- 1.62); p<0.0001]. The median 5-year OS was higher for RC (40.51 months) compared to CMT (20.24 months); 95% confidence bands are shaded. In addition, OS was inferior with CMT compared to RC on multivariate analysis (HR, 1.47; 95% CI: 1.42-1.52; P<0.0001). CONCLUSIONS: This large analysis compared survival outcomes between RC and CMT for MIBC using a nationally representative database. RC was associated with 47% - 57% improved OS compared to CMT. Further studies are required to identify optimal treatment for specific patients.