Purpose/objective(s):

Breast cancer (BC) is one of few malignancies in which improved locoregional control has been shown to improve overall survival. Contemporary redlining, or mortgage lending bias on the basis of home location, is a form of structural racism which has been demonstrated to impact BC survival in older patients. Self-reported race has been thought to serve as a surrogate for interpersonal racism and has similarly been shown to have associations with survival, redlining, and access to care. We aim to examine the relationship between race, redlining, and the receipt of guideline compliant locoregional therapy (LRT) in older women with BC.

Materials/methods:

Women aged 66-90 years with an initial Stage I-III BC diagnosis in 2010-2017 and known metropolitan statistical area (MSA) were identified in SEER-Medicare. Redlining was estimated using Home Mortgage Disclosure Act data (2010-2017). Guideline compliant LRT was assessed based on whether patients underwent surgery (lumpectomy or mastectomy), and if surgery was performed, whether they received adjuvant radiation treatment per the National Quality Forum and National Comprehensive Cancer Network guidelines in effect during the study period. A multiple logistic regression model was fitted to estimate ORs for the relationship between redlining and receipt of guideline compliant LRT, accounting for covariates (age, race/ethnicity, comorbidities, dual enrollment, tumor stage, hormone receptor status, census region, and year of diagnosis). Cluster bootstrap at the MSA-level was used to obtain P-values and confidence intervals.

Results:

The cohort included 64,987 women: 31% aged 66-70, 82% Non-Hispanic (NH) White, 7.4% NH Black, 24% with 2+ comorbidities, 12% with dual Medicaid/Medicare enrollment, 60% stage I, 31% stage II, and 77% HR+/HER2-. Overall, 6.4% did not undergo surgery; 84% received guideline compliant LRT. Women in the highest redlining areas had 81% guideline compliant LRT compared to 84-85% in the least, low and moderate redlined areas (p<0.001). However, model results revealed that contemporary redlining was not a predictor of guideline compliant LRT. NH Black women were less likely than NH White women to receive guideline-compliant LRT (OR 0.77, 95% CI 0.71-0.84, p<0.001). No significant differences were noted between NH White and NH Asian or Hispanic women.

Conclusion:

In this population-based cohort of older women with breast cancer, NH Black race, even after adjusting for several important clinical and demographic factors, was associated with a lower likelihood of receiving guideline-compliant LRT. This finding demonstrates the profound impact of interpersonal racism on receipt of cancer-directed therapies. Though contemporary redlining did not significantly impact guideline-compliant LRT, further work is needed to identify systematic factors explaining known associations between contemporary redlining and BC survival.