Racial Disparities in Receipt of Guideline-Concordant Care in Older Adults With Early Breast Cancer.

Importance: Racial disparities in receipt of guideline-concordant care (GCC) among older patients with potentially curable breast cancer are understudied. Objective: To determine whether rates of GCC, time to treatment initiation, and all-cause mortality in stage I to III breast cancer differ by race among older adults. Design, Setting, and Participants: This cohort study used data from the National Cancer Database and included patients aged 65 years and older with stage I to III breast cancer, diagnosed between 2010 and 2019. Data analysis was conducted between July 2022 to July 2023. Exposures: Race, defined as non-Hispanic Black or non-Hispanic White. Main Outcomes and Measures: The primary outcome was nonreceipt of GCC, defined using the National Comprehensive Cancer Network guidelines, and all-cause mortality. The secondary outcome was time to treatment initiation. Univariate and multivariate regression analysis were used to determine association between exposure and outcomes. Models for GCC and all-cause mortality included age, stage, receptor status, year of diagnosis, Charlson-Deyo comorbidity index, insurance, health care setting, and neighborhood-level educational attainment and median income. Results: The analytic cohort included 258 531 participants (mean [SD] age, 72.5 [6.0] years), with 25 174 participants who identified as non-Hispanic Black (9.7%) and 233 357 participants who identified as non-Hispanic White (90.3%), diagnosed between 2010 and 2017. A total of 4563 non-Hispanic Black participants (18.1%) and 35 374 non-Hispanic White participants (15.2%) did not receive GCC. Non-Hispanic Black race, compared with non-Hispanic White race, was associated with increased odds of not receiving GCC in the multivariate analysis (adjusted odds ratio [aOR], 1.13; 95% CI, 1.08-1.17; P < .001). Non-Hispanic Black race was associated with 26.1% increased risk of all-cause mortality in the univariate analysis, which decreased to 4.7%, after adjusting for GCC and clinical and sociodemographic factors (adjusted hazard ratio, 1.05; 95% CI, 1.01-1.08; P = .006). Non-Hispanic White race, compared with non-Hispanic Black race, was associated with increased odds of initiating treatment within 30 (OR, 1.65; 95% CI, 1.6-1.69), 60 (OR, 2.11; 95% CI, 2.04-2.18), and 90 (OR, 2.39; 95% CI, 2.27-2.51) days of diagnosis. Conclusions and Relevance: In this cohort study, non-Hispanic Black race was associated with increased odds of not receiving GCC and less timely treatment initiation. Non-Hispanic Black race was associated with increased all-cause mortality, which was reduced after adjusting for GCC and clinical and sociodemographic factors. These findings suggest that optimizing timely receipt of GCC may represent a modifiable pathway to improving inferior survival outcomes among older non-Hispanic Black patients with breast cancer.