Black, Asian women at highest risk for locoregional breast cancer recurrence
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Key takeaways:
- Rates of 8-year locoregional recurrence exceeded 3% among Black women and Asian women vs. less than 2% among white women.
- Locoregional recurrence appeared associated with increased breast cancer mortality.
Black and Asian women with early-stage, hormone-receptor positive, HER2-negative, node-negative breast cancer appeared about twice as likely as their white counterparts to experience locoregional recurrence.
Results of the unplanned post hoc analysis of the TAILORx trial, published in JAMA Surgery, suggest further study is needed to better understand whether failure to rescue after locoregional recurrence contributes to racial disparities in breast cancer mortality, researchers wrote.
Rationale and methodology
“We wanted to provide a better understanding of why racial differences in breast cancer mortality are prevalent and not fully explained by known factors,” Olga Kantor, MD, MS, researcher in the division of breast surgery at Brigham and Women’s Hospital and Dana-Farber Brigham Cancer Center, told Healio. “Patterns of locoregional recurrence by race and ethnicity are not well defined, and we were interested in exploring if locoregional recurrence differences exist in the context of a clinical trial population with similar access to care and treatment.”
Kantor and colleagues retrospectively examined 9,369 women (78.8% white; 9.4% Hispanic, 7.2% Black, 4.6% Asian) with T1-2N0 hormone receptor-positive, HER2-negative, node-negative breast cancer enrolled in TAILORx between 2006 and 2010. Based on their Oncotype DX (Exact Sciences) recurrence score, women in the trial had been randomly assigned to receive endocrine therapy alone, endocrine therapy vs. chemotherapy followed by endocrine therapy or chemotherapy followed by endocrine therapy.
Researchers defined locoregional recurrence as ipsilateral in breast, skin, chest wall or regional nodal recurrence without concurrent distant recurrence, stratified by race and ethnicity. They used unadjusted Kaplan-Meier and adjusted Cox proportional hazards regression models for survival analyses.
Median follow-up was 94.8 months.
Findings
Overall, 6,474 patients underwent radiation after breast-conserving surgery and 344 after mastectomy.
Results showed 8-year locoregional recurrence rates of 3.6% (95% CI, 1.6-5.6) among Asian women, 3.9% (95% CI, 2.2-5.4) among Black women, 3.1% (95% CI, 1.7-4.5) among Hispanic women and 1.8% (95% CI, 1.5-2.3) among white women (P < .001).
Survival analyses adjusted for patient, tumor and treatment characteristics revealed independent associations between locoregional recurrence and Asian (HR = 1.91; 95% CI, 1.12-3.29) and Black race (HR = 1.78; 95% CI, 1.15-2.77). Moreover, adjusted survival analyses for breast cancer mortality showed independent associations of locoregional recurrence with increased breast cancer mortality (HR = 5.71; 95% CI, 3.5-9.31).
Implications
The findings suggest factors beyond access to care or treatments received impact locoregional recurrence risk and that differing underlying tumor biology may be at play, Kantor told Healio.
“Further, outside of a clinical trial population, these differences in locoregional recurrence may be quite wider than what we report in this study,” she said. “Next steps include analysis of other populations of patients with breast cancer, including triple-negative and HER2-positive breast cancer, as well as larger population-based work to validate these findings and further define differences in locoregional recurrence across breast cancer subtypes. Hopefully, defining these differences will lead to future interventions or optimizations in care to narrow these disparities in breast cancer locoregional recurrences.”
The inherent value of the data in documenting racial and ethnic disparities makes the findings groundbreaking, Lisa A. Newman, MD, MPH, chief of the breast surgery section at New York-Presbyterian and Weill Cornell Medicine in New York, wrote in an editorial that accompanied the study.
“Of at least equal importance, they also represent a practice-changing approach to breast cancer research, where clinical trialists incorporate tumor genomics into the study of breast cancer disparities,” Newman wrote.
References:
- Kantor O, et al. JAMA Surg. 2023;doi:10.1001/jamasurg.2023.0297.
- Newman LA. JAMA Surg. 2023;doi:10.1001/jamasurg.2023.0313.
For more information:
Olga Kantor, MD, MS, can be reached at okantor@bwh.harvard.edu.
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