Propensity matched comparative analysis of survival following chemoradiation or radical cystectomy for muscle-invasive bladder cancer.

Abstract

To compare survival outcome between chemoradiation therapy (CRT) and radical cystectomy (RC) for muscle-invasive bladder cancer (MIBC). We conducted a retrospective analysis of patients with MIBC (≥cT2, N0, M0) in the National Cancer Database (2004-2013). CRT was defined as a radiation dose of ≥40 Gy and chemotherapy within 90 days of radiation. Descriptive statistics were used to compare groups. RC and CRT patients were propensity matched. Kaplan-Meier analysis was used to compare overall survival (OS). Multivariable Cox regression was used to determine predictors of survival. In all, 8 379 (6 606 RC and 1 773 CRT) patients met the inclusion criteria and 1 683 patients in each group were propensity matched. On multivariable extended Cox analysis, significant predictors of decreased OS were age, Charlson-Deyo Comorbidity score of 1, Charlson-Deyo Comorbidity score of 2, stage cT3-4, and urothelial histology. CRT was associated with decreased mortality at year 1 (hazard ratio [HR] 0.84, 95% confidence interval [CI] 0.74-0.96; P = 0.01), but at 2 years (HR 1.4, 95% CI 1.2-1.6; P < 0.001) and 3 years onward (HR 1.5, 95% CI 1.2-1.8; P < 0.001) CRT was associated with increased mortality. The 5-year OS was greater for RC than for CRT (38% vs 30%, P = 0.004). Initially after treatment for MIBC the risk of mortality is lower with CRT compared to RC. However, at ≥2 years after treatment the mortality risk favours RC. Patients who are suitable surgical candidates, with a low risk of morbidity, may be better served by RC.