Hospital-specific probability of cystectomy affects survival from muscle-invasive bladder cancer.

Objectives: Radical cystectomies (RCs) are increasingly centralized, but bladder cancer can be diagnosed in every hospital The aim of this study is to assess the variation between hospitals of diagnosis in a patient's chance to undergo a RC before and after the volume criteria for RCs, to identify factors associated with this variation and to assess its effect on survival.

Methods And Materials: Patients diagnosed with muscle-invasive bladder cancer (cT2-4a,N0/X,M0/X) without nodal or distant metastases between 2008 and 2016 were identified through the Netherlands Cancer Registry. Multilevel logistic regression analysis was used to investigate the hospital specific probability of undergoing a cystectomy. Cox proportional hazard regression analysis was used to assess the case-mix adjusted effect of hospital-specific probabilities on survival.

Results: Of the 9,215 included patients, 4,513 (49%) underwent a RC. The percentage of RCs varied between 7% and 83% by hospital of diagnosis before the introduction of the first volume criteria (i.e., 2008-2009; minimum of 10 RCs). This variation decreased slightly to 17%-77% after establishment of the second volume criteria (i.e., 2015-2016; minimum of 20 RCs). Age, cT-stage and comorbidity were inversely and socioeconomic status was positively associated with RC. Both being diagnosed in a community hospital and/or being diagnosed in a hospital fulfilling the RC volume criteria were associated with increased use of RC compared to academic hospitals and hospitals not fulfilling the volume criteria. For each 10% increase in the percentage of RC in the hospital of diagnosis, 2-year case-mix adjusted survival increased 4% (hazard ratio 0.96, 95% confidence interval 0.94-0.98).

Conclusion: Probability of RC varied between hospitals of diagnosis and affected 2-year overall survival. Undergoing a RC was associated with age, cT-stage, socioeconomic status, type of hospital, and whether the hospital of diagnosis fulfilled the RC volume criteria. Future research is needed to identify patient, tumor, and hospital characteristics affecting utilization of curative treatment as this may benefit overall survival.