The Impact of Radiotherapy Facility Volume on the Survival and Guideline Concordance of Patients With Muscle-invasive Bladder Cancer Receiving Bladder-preservation Therapy

摘要

Objectives: Higher facility surgical volume predicts for improved outcomes in patients with muscle-invasive bladder cancer (MIBC) who undergo radical cystectomy. We investigated the association between facility radiotherapy (RT) case volume and overall survival (OS) for patients with MIBC who received bladder-preserving RT, and the relationship with adherence to National Comprehensive Cancer Network (NCCN) guidelines for bladder preservation. Methods: The National Cancer Database was used to identify patients diagnosed with nonmetastatic MIBC from 2004 to 2015 and received RT at the reporting center. Facility case volume was defined as the total MIBC patients treated with RT during the period. Facilities were stratified into high-volume facility (HVF) or low-volume facility at the 80th percentile of RT case volume. OS was assessed using Kaplan-Meier analysis. Rates of compliance with NCCN guidelines regarding the use of transurethral resection of the bladder tumor before RT, planned use of concurrent chemotherapy, and total RT dose were compared. Cox proportional hazard model was used to evaluate predictors of OS. Results: There were 7562 patients included. No differences in age, Charlson-Deyo score, T stage, or node-positive rates were observed between groups. HVFs exhibited greater compliance with NCCN guidelines for bladder preservation (P<0.0001). Treatment at an HVF was associated with the improved OS for all patients (P=0.001) and for the subset of patients receiving NCCN-recommended RT doses (P=0.0081). Volume was an independent predictor of OS (P=0.002). Conclusions: Treatment at an HVF is associated with improved OS and greater guideline-concordant management among patients with MIBC.