Not immune to inequity: minority under-representation in immunotherapy trials for breast and gynecologic cancers

Abstract

Objective To describe the participation of minority women in clinical trials using immunologic agents for breast and gynecologic cancers. Methods A retrospective review of completed clinical trials involving immunotherapy for breast and gynecologic cancers was performed. Completed trials were examined for data on race, tumor type, and start year. Minority enrollment was stratified by tumor site. Based on Center for Disease Control and Prevention age-adjusted incidence for race, expected and observed ratios of racial participation were calculated and compared using Χ2 testing, p≤0.05. Results A total of 53 completed immunotherapy clinical trials involving 8820 patients were reviewed. Breast cancer trials were most common (n=24) and involved the most patients (n=6248, 71%). Racial breakdown was provided in 41 studies (77%) for a total of 7201 patients. Race reporting was lowest in uterine (n=4, 67%) and cervical cancer trials (n=6, 67%), and highest in ovarian cancer trials (n=12, 86%). White patients comprised 70% (n=5022) of all the patients included. Only 5% of patients involved were black (n=339), and 83% of these patients (n=282) were enrolled in breast cancer trials. Observed enrollment of black women was 32-fold lower for ovarian, 19-fold lower for cervical, 15-fold lower for uterine, and 11-fold lower for breast cancer than expected. While all trials reported race between 2013 and 2015, no consistent trend was seen towards increasing race reporting or in enrollment of black patients over time. Conclusion Racial disparities exist in clinical trials evaluating immunologic agents for breast and gynecologic cancers. Recruitment of black women is particularly low. In order to address inequity in outcomes for these cancers, it is crucial that significant attention be directed towards minority representation in immuno-oncologic clinical trials.