The contribution of demographic, access and treatment-related factors on racial disparities in bladder cancer
Cole AP, Krimphove MJ, Fletcher SA, Lipsitz S, Gild P, Preston M, Menon M, Kibel A, and Trinh QD. The contribution of demographic, access and treatment-related factors on racial disparities in bladder cancer. Eur Urol Suppl 2019; 18(1):e2101-e2102.
Eur Urol Suppl
Introduction & Objectives: There are race-based differences in bladder cancer survival. To better understand the factors contributing to this phenomenon, we designed a study to assess the statistical contribution of tumor, treatment and access to care on race-based differences in survival. Materials & Methods: Using the National Cancer Database, we extracted data on Black or White adults diagnosed with muscle invasive bladder cancer from 2004-2015. The impact of tumor, access and treatment on differences in survival was inferred by performing sequential propensity score-weighted analyses wherein Black and White patients were balanced with respect to (A)demographics and comorbidities (B)tumor characteristics (C)treatment and (D)access-related variables. To estimate the relative contribution of each group of variables, we calculated the propensity score-weighted hazard of death (Black v. White)after each iteration. The change in the hazard ratios were used to infer the relative contribution of each group of variables on the excess risk of death among Blacks. Results: We identified 44,577 patients with T1-4N0M0 bladder cancer, with a median follow up of 77 months. After balancing demographics and comorbidities, Black race was associated with 18% worse hazard of all-cause mortality (HR 1.18, 95% CI 1.12–1.25; p < 0.001). Balancing by tumor characteristics reduced this to 16%, balancing by treatment reduced this to 10%, and balancing by access-related variables yielded no statistically significant difference in survival. In summary, access-related variables explained 40% (95% CI 22.9-57.0%)of the excess risk of death in Blacks, whereas treatment factors explained 35% (95% CI 22.2 – 46.9). The contribution of tumor characteristics was not significant. The results of each balancing procedure are shown in the attached Table. [Table Presented]Conclusions: In our models, differences in survival for Black and White patients with bladder cancer are best explained by disparities in access and treatment, not tumor characteristics. Initiatives to improve access to care (e.g. through improved insurance coverage and reduced barriers to urological care)may represent a key step in reducing racial disparities in bladder cancer outcomes.