Social determinants of appropriate treatment for muscle-invasive bladder cancer

Background: Racial disparities in guideline-based, appropriate treatment (ApT) may be a significant driving force for differences in survival for people with nonmetastatic muscle-invasive bladder cancer (MIBC). We hypothesize that receipt of ApT is influenced by factors such as race and socioeconomic status, irrespective of neighborhood-level differences in healthcare, variations in practice patterns, and clinical characteristics of patients with nonmetastatic MIBC. Methods: Within the National Cancer Database, we identified individuals diagnosed with MIBC between 2004 and 2013. Multivariable logistic regression and mixed effects modelling was used to examine predictors of ApT, clustered within institutions. Results: A total of 51,350 individuals had clinically staged nonmetastatic, lymph node-negative MIBC. Black individuals comprised 6.4% of the cohort. Mean age was 72.6 years (SD 11.6) with a male predominance (71.4%). Less than half received ApT (42.6%). Fewer black individuals received ApT compared with white individuals (37% vs. 43%, P < 0.001). When clustered by institution, the odds of ApT were 21% lower for black individuals [odds ratio (OR), 0.79; 95% confidence interval (CI), 0.73-0.87] compared with white individuals with nonmetastatic MIBC. When restricted to higher volume centers with more diverse populations, black individuals had 25% lower odds of ApT (OR, 0.75; 95% CI, 0.61-0.91; P < 0.01), compared with white counterparts. Conclusions: Racial disparities in treatment persisted after accounting for various clinical factors and social determinants of health. Future efforts should focus on addressing racial bias to improve disparities in bladder cancer treatment. Impact: If we are not delivering evidence-based care due to these biases (after accounting for access and biology), then it is expected that patients will experience inferior outcomes.