Impact of race on treatment outcomes in triple-negative breast cancer at an academic medical center.

Abstract

e12616 Background: Triple negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, and in all but the smallest tumors, neoadjuvant chemotherapy (NACT) is part of the standard of care. Black women (BW) suffer a poorer prognosis than white women (WW) with TNBC, and whether this is due to differences in treatment, disease biology, or socioeconomic variables is not fully known. This study, conducted at a racially diverse academic medical center, aimed to investigate factors associated with unfavorable outcomes in BW with TNBC. Methods: 131 patients with TNBC received NACT from 2008-2017 at Winship Cancer Institute were included in this retrospective study. Descriptive statistics were applied to delineate the relationship with racial disparity. Clinical outcomes include progression free survival (PFS) and distance metastasis free survival (DMFS) and were analysis using Cox proportional hazard model. Results: Among 131 patients with TNBC treated with NACT, 58.5% were BW and median age was 55. BW and WW had similar disease staging at diagnosis and similar pathologic responses to treatment. Yet, BW were less likely to complete NACT compared with WW (80.8% BW completed NACT vs 98.0% WW, p=0.005). BW were more likely to either not complete NACT or to require dose reduction or dose delay (42.5% BW vs. 23.1% WW, p=0.024). Coexisting hypertension (65.8% BW vs. 35.2% WW), elevated BMI (31.7% BW vs. 27.5% WW), or covered by Medicaid (29.3% BW vs. 13.0% WW) were more common among BW. Medicaid insurance was associated with worse progression-free survival (HR 2.49, p=0.015) and distant metastasis free survival (DMFS, HR 2.73, p=0.018). Dose delays were associated with worse DMFS (HR 3.02, p=0.017). Discussion: In this study, we found that BW were less likely to complete NACT than WW, more likely to suffer dose delays, and more likely to require dose reductions. BW were also more likely to have Medicaid insurance, another factor that correlated with inferior outcomes; perhaps because patients with Medicaid insurance are also more likely to suffer from reduced access to transportation, childcare, and other infrastructure critical to maintaining a schedule for NACT. More research is needed to understand the reasons for the dose delays, dose reductions, and failures to complete NACT so that interventions can be designed to address them. Conclusions: As we move into the era of chemoimmunotherapy for TNBC, where drug combinations and treatment schedules are becoming even more complex, a better understanding of the reasons for dose delays, dose reductions, and treatment discontinuations will be key to maintaining optimal outcomes for TNBC patients, regardless of race.