Race reporting and disparities regarding clinical trials in bladder cancer: a systematic review

Purpose: To systematically review the literature to investigate racial disparities among bladder cancer clinical trial enrollees. Methods: A systematic review was conducted using Ovid, MEDLINE® to identify clinical trials between 1970 and 2020. Articles were reviewed and were included if they assessed race in their outcomes reporting among bladder cancer patients enrolled in clinical trials. The review was conducted in accordance with the PRISMA statement. Results: We identified 544 clinical trials meeting our initial search criteria, with only 24 (4.4%) studies reporting racial demographic data. Enrollees were largely Caucasian (81–98%), with a strikingly small proportion of enrolled patients consisting of African-Americans (2–8%) and Hispanics (2–5%). Only one of the studies reported results on the efficacy and safety/tolerability of the tested treatment separately for racial groups and performed analyses stratified by race. Conclusion: Race is poorly studied in bladder cancer clinical trials. Trial cohorts may not reflect multicultural populations. The potential association between race and efficacy, safety or tolerability of the tested interventions is unknown. Given the up to twofold increase in bladder cancer-specific death among African-Americans, further research is needed to address the impact of race in clinical trials, while encompassing socioeconomic factors and disease risk factor exposures.