The Impact of Race and Sex on Metastatic Bladder Cancer Survival

Abstract

Objective: To characterize the epidemiological profile of metastatic bladder cancer (BC) and assess mortality rate with respect to race and gender across the three most common histologies of bladder cancer-Transitional Cell Carcinoma, Adenocarcinoma, and SCC (Squamous Cell Carcinoma).

Materials and methods: The Surveillance, Epidemiology, and End Results Program database (2000-2017) was queried for all metastatic bladder cancer patients at presentation. Our primary exposure consists of four race/gender combinations. One-way ANOVA and Chi-square tests compared categorical and continuous variables across the exposure variable, respectively. Univariable and multivariable Cox proportional hazards regression analyses were used to examine the association between race/gender combinations and the overall and cancer specific survival adjusting for the other variables.

Results: A total of 312,846 bladder cancer patients, 6337 with distant metastases and 11,446 with regional metastases were evaluated. Black female cancer specific survival in metastatic disease was disproportionally lower compared to all race/gender for Transitional Cell Carcinoma 4.3% (95% CI: 1.6-8.9), SCC 2.6% (95% CI: 0.2-11.8), and Adenocarcinoma 6.4% (0.4%-25%). In regional metastastatic disease, worse cancer specific mortality was associated with identifying as a Black Female (aHR 1.17, P = .023), SCC (aHR 1.8, P <.001), increasing age (aHR 1.3, P <.001), and poorly differentiated grade (aHR 2.01, P <.001).

Conclusion: Black females experience excess mortality in overall and cancer oncologic outcomes in metastatic BC. Our findings contribute to the body of research warranting examination of the impact of social determinants of health and provider decisions on BC survivorship and contribute to physician decision making in the treatment and surveillance of bladder cancer.