Assessing racial disparities in disease outcomes of patients with high-risk, triple-negative breast cancer and residual disease after neoadjuvant therapy: a post-hoc analysis of the ECOG-ACRIN 1131 clinical trial.

Purpose: Although triple-negative breast cancer (TNBC) is associated with increased risk for early locoregional (LRR) and distant recurrence (DR), it is unclear if there are racial differences in clinical outcomes. This study examines patterns of recurrence and breast cancer mortality (BCM) between Black and White women with high-risk TNBC treated on the Eastern Cooperative Oncology Group-American College of Radiology Imaging Network (ECOG-ACRIN) EA1311 randomized clinical trial.

Methods: From 2015 to 2021, 415 patients with clinical stage II-III TNBC and residual disease after neoadjuvant chemotherapy (NAC) were randomized to adjuvant capecitabine or platinum chemotherapy. Overall, 363 patients with self-reported Black or White race were included in this analysis. LRR, DR, and BCM were analyzed by race using Kaplan-Meier curves for unadjusted estimates and Cox modeling for adjusted analyses.

Results: Racial distribution included 66 (18.2%) Black and 297 (81.8%) White patients. Disease presentation, response to chemotherapy, and treatment arm were similar by race. Two-year estimated LRR was 27.1% in Black and 17.3% in White patients (p = 0.378), and 2-year estimated DR and BCM were similar by race. Models adjusted for race, age, stage, grade, treatment arm, and locoregional therapy did not identify race as an independent predictor of LRR, DR, or BCM.

Conclusion: Among women with residual TNBC after NAC treated on this trial, there were no significant differences in LRR, DR, or BCM between Black and White patients at 2 years of follow-up. Despite the small cohort and short-term follow-up, our results suggest that treatment on a clinical trial may mitigate disparities in disease outcomes in TNBC.