Characteristics Contributing to Survival Differences Between Black and White Patients Following Cystectomy

Examine patient, tumor, and treatment characteristics effect on the disparity between black and white patients with muscle-invasive bladder cancer (MIBC) who undergo radical cystectomy (RC).

1,286 black patients in the 2004 to 2016 National Cancer Database fit inclusion criteria. A tapered match was performed from 17,374 white patients sequentially matched to the black cohort on demographics (age, gender, insurance, income, education, county, diagnosis year), presentation (demographic variables, stage, grade, tumor size, Charlson score), and treatment (demographic and presentation variables, lymph node count, hospital volume, neoadjuvant chemotherapy [NAC], treatment delay), creating 3 matched cohorts. Chi-square and Kruskal-Wallis tests were used to compare cohorts. Kaplan-Meier analysis was used to compare 5-year overall survival (OS).

5-year OS rate was 40.4% and 35.6% for unmatched white and black cohorts (P < 0.001), respectively. Following demographics and presentation match, 5-year OS rate for white patients decreased to 39.2% (P = 0.003) and 39.10% (P = 0.019), respectively. After treatment match, 5-year OS rate decreased to 36.7% for white patient (P = 0.32). Following presentation match, 7.2% of black patients vs. 5.8% of white patients had treatment delay, and 10.1% of black patients vs. 11.2% of white patients received NAC. The treatment match resulted in a 0.3% difference between groups for treatment delay and NAC.

Our analysis demonstrates that disparity between black and white patients with muscle-invasive bladder cancer exists in demographic-, presentation-, and treatment-related variables. Treatment variables may be a large contributing factor to survival disparities. Further research is needed to identify social, biological, and organizational inputs that contribute to these disparities.