Outcomes for black versus white women with stage IV breast cancer enrolled on investigator-initiated clinical trials at Emory.

Abstract

1086 Background: Black women are 40% more likely to die from their breast cancer compared to White women. Inadequate representation of Blacks in clinical trials may contribute to health care inequity. Emory’s Winship Cancer Institute (WCI) in Atlanta serves a significant Black population and has a unique opportunity to engage these underrepresented patients in clinical trials. We aimed to assess clinical outcomes in Black versus White women with metastatic breast cancer (MBC) enrolled on investigator-initiated clinical trials (IITs) at Emory. Methods: Black and White women with MBC enrolled on IITs conducted at WCI between 1/2009 and 1/2019 were retrospectively evaluated. Descriptive statistics were generated for all patient characteristics. Univariate analyses and a multiple logistic regression model were used to assess the effect of age and race on clinical response, length of time on trial, number of therapy lines prior to trial enrollment, and toxicity on trial. Overall survival was assessed using Kaplan Meier analysis. Results: Sixty-two women with MBC were included [White, n = 41 (66%), and Black, n = 21 (34%), p = 0.55]. Over 90% of women were enrolled on phase II clinical trials and received targeted therapy. Mean age at clinical trial consent was 53.2 and 55.9 years in Black and White women, respectively (p = 0.36). While the majority of women had hormone-receptor positive disease, a higher percentage of Blacks had triple negative breast cancer (29% vs. 17% in Whites, p = 0.39). Black women had fewer lines of systemic therapy prior to trial enrollment (2.86 vs. 4.3, respectively, p = 0.017) and were enrolled on trial for less time than White women (5.67 mo vs. 7.83 mo, respectively, p = 0.22). There were no differences in toxicity rates among patients enrolled on IITs based on race. Black women were more likely to have progressive disease (PD) on trial (45% in Blacks vs. 20% in Whites, p = 0.05). While there was no significant difference in overall survival (p = 0.482), there was a trend towards shorter survival in Black women (51.3 mos vs. 64 mos, respectively). Conclusions: Black women with MBC who enrolled on IIT trials at Emory had worse treatment response and a trend towards poorer survival compared to White women. More research is needed to determine whether this is due to adverse biology. These results reinforce the need for exploration of biomarkers of response by race and ethnicity and improved representation of Blacks in clinical trials to inform real world efficacy.