In a post hoc analysis published in JAMA Oncology from the TAILORx trial of adjuvant therapy in early hormone receptor (HR)-positive, HER2-negative, axillary node–negative breast cancer, Sadigh et al found that Black women had a poorer relapse-free interval and overall survival vs White women. This discrepancy did not appear to be fully explained by early discontinuation of endocrine therapy, clinicopathologic characteristics, insurance coverage, or neighborhood deprivation index (NDI).
As stated by the investigators, “Racial disparities in survival outcomes among Black women with HR-positive breast cancer have been reported. However, the association between individual-level and neighborhood-level social determinants of health on such disparities has not been well studied.”
Study Details
The analysis included 9,719 women from the randomized trial conducted between April 2006 and October 2010. A multivariate model evaluated the association between race and relapse-free interval and overall survival with adjustment for insurance status, NDI quartile, age, tumor size, tumor grade, early discontinuation of endocrine therapy, no endocrine therapy, and breast cancer recurrence test score. NDI scores range from 0 to 100, with higher scores representing greater neighborhood deprivation. Median follow-up for clinical outcomes was 96 months.
Key Findings
Among the 9,719 women, 405 (4.2%) were Asian, 693 (7.1%) were Black, 8,189 (84.3%) were White, and 403 (4.4%) were other/not specified; in addition, 889 (9.1%) were Hispanic or Latinx.
In multivariate analyses, Black race vs White race was associated with significantly shorter relapse-free interval (hazard ratio [HR] = 1.39, 95% confidence [CI] = 1.05–1.84, P = .02) and overall survival (HR = 1.49, 95% CI = 1.10–2.99, P = .009) after adjustment for insurance status, NDI quartile, early discontinuation of endocrine therapy, and other factors included in the analysis.
Additional significant factors in multivariate analysis of relapse-free interval were age, tumor size and grade, no receipt of endocrine therapy, and breast cancer recurrence risk score, but not early discontinuation of endocrine therapy, insurance status, or NDI status.
Additional significant factors on multivariate analysis of overall survival were age, insurance status, NDI status, tumor size and grade, early discontinuation of endocrine therapy, no receipt of endocrine therapy, and breast cancer recurrence score. For example, compared with private insurance, Medicare (HR = 1.30, 95% CI = 1.01–1.68, P = .04) and Medicaid (HR = 1.44, 95% CI = 1.01–2.05, P = .05) but not uninsured status were associated with poorer survival. Patients in the highest NDI quartile had poorer survival vs the lowest quartile (HR = 1.34, 95% CI = 1.01–1.77, P = .04) irrespective of race.
The investigators concluded: “The findings of this post hoc analysis of a randomized clinical trial suggest that Black women with breast cancer have significantly shorter relapse-free interval and overall survival compared with White women. Early discontinuation of endocrine therapy, clinicopathologic characteristics, insurance coverage, and NDI do not fully explain the observed disparity.”
Gelareh Sadigh, MD, of the Department of Radiology and Imaging Sciences, Emory University School of Medicine, is the corresponding author for the JAMA Oncology article.
Disclosure: The study was supported by grants from the National Cancer Institute and Canadian Cancer Society. For full disclosures of the study authors, visit jamanetwork.com.
