Radical cystectomy versus trimodal therapy for muscle-invasive bladder cancer: Analysis of an other-cause mortality matched cohort.

ABSTRACT

OBJECTIVE: Comparative effectiveness studies comparing trimodal therapy (TMT) to radical cystectomy (RC) are typically hindered by selection bias where TMT is usually reserved to patients with poor overall health status. We developed a novel approach by matching patients based on their calculated other-cause mortality (OCM) risk. Using this homogeneous cohort, we tested the impact of TMT vs RC on cancer-specific mortality (CSM). MATERIALS AND METHODS: The Surveillance, Epidemiology and End Results (SEER) 2004-2018 database was queried to identify patients diagnosed with cT2-4N0M0 muscle-invasive bladder cancer (MIBC). A Fine-Gray competing-risk regression model calculating the 5-year OCM risk was used to create a 11 propensity-score matched-cohort of patients treated with RC or TMT. Cumulative incidence and competing-risk regression analyses tested the impact of treatment type (RC vs TMT) on CSM. Patients were further stratified according to clinical T stage (cT2 vs cT3-4) in sensitivity analyses. RESULTS: We identified 6,587 patients (76%) treated with RC and 2,057 (24%) with TMT. The median follow-up was 3.0 years. In the unmatched-cohort, 5-year OCM and CSM rates were 14% and 40% for RC vs 23% and 47% in TMT group, respectively (all P < 0.001). Our matched-cohort included 4,074 patients, equally distributed for treatment type, with no difference in 5-year OCM (HR 0.98, 95% CI 0.86-1.11, P = 0.714). In clinical-stage specific sensitivity analyses, 5-year CSM rate was significantly worse for cT2N0M0 patients treated with TMT (HR 1.52, 95% CI 1.21-1.91, P < 0.001) than those treated with RC. For cT3-4N0M0 patients, there was no difference in CSM among the 2 approaches (HR 0.98, 95% CI 0.63-1.52, P = 0.900). CONCLUSIONS: Our findings demonstrate an oncologic advantage of RC over TMT for cT2 MIBC patients. Conversely, we did not find a cancer-specific survival difference for cT3-T4 MIBC patients, regardless of treatment.