Racial and elderly disparities in receipt of guideline-concordant care in stage I-III breast cancer.

e13688 Background: Elderly and non-Hispanic Black (NHB) patients have worse breast cancer specific survival outcomes. We evaluated whether guideline concordant care (GCC) and all-cause mortality in stage I-III breast cancer differed by race among patients ≥ 65 years old. Methods: We used the National Cancer Database (NCDB), to identify a cohort of 25174 NHB and 233357 non-Hispanic White patients (NHW), ≥65 years old, diagnosed with stage I-III breast cancer between 2010 and 2019. We used the National Comprehensive Cancer Network guidelines to define GCC, including surgery, radiation and systemic therapy. Specific systemic therapies and cause of death were unavailable. We used logistic regression models to assess the association between race and GCC. We used Cox proportional hazards models to estimate associations between race and all-cause mortality after adjusting for GCC. Both models adjusted for disease, demographics, income and educational attainment. We assessed the odds of not receiving timely GCC within 30, 60 and 90 days from diagnosis for NHB vs. NHW patients using logistic regression. Results: Overall, 15% of patients did not receive GCC. Being NHB compared to NHW was associated with increased odds of not receiving GCC in univariate (OR=1.24 95%CI: 1.20-1.28) and multivariate analysis (aOR=1.13, 95%CI: 1.08-1.17). Being NHB was associated with 26% increased risk of all-cause mortality in the univariate analysis (HR=1.26, p<0.001), which decreased to 4% increased risk, after adjusting for GCC, age, clinical and sociodemographic factors (aHR=1.04, p=0.027). Non-receipt of GCC (aHR=1.75, p<0.001) and lower educational attainment (aHR 1.18, p <0.001) were independently associated with higher risk of all-cause mortality. Higher median income (aHR 0.91, p<0.001) was independently associated with a decreased risk of mortality. Being NHW compared to NHB 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 days of breast cancer diagnosis (OR=2.39, 95% CI 2.27-2.51). Conclusions: Among elderly patients with stage I-III BC, being NHB was associated with increased odds of not receiving GCC and less timely treatment initiation. Being NHB was associated with increased all-cause mortality, which was attenuated after adjusting for GCC. Optimizing timely receipt of GCC may reduce inferior survival outcomes among elderly NHB breast cancer patients. Identifying area-level determinants may help design targeted interventions. Limitations include lack of granular systemic therapy data, likely overestimating GCC receipt, biasing the analysis towards the null, and lack of cause-specific death among elderly patients with competing risks of death.