Abstract A040: Race and socioeconomic factors associated with decreased survival in breast cancer, assessing for healthcare disparities using the National Cancer Database
Authors: Norman Thomas , Hwang Lindsay , Lei Xiaomeng , Cen Steven , Ye Jason 
Published: January 2023

Purpose: It has widely been shown that lower socioeconomic status (SES) is associated with worse survival in breast cancer patients. Some researchers suggested this disparity is driven by diagnosis at a more advanced stage and in patients with more pre-existing health conditions, while other groups have postulated that this disparity is driven by unequal treatment, including decreased access to systemic and radiation therapy. Our purpose was to determine whether a survival disparity in low SES groups still exists after controlling for these aforementioned factors. Methods: We queried the National Cancer Database (NCDB) for patients with nonmetastatic breast cancer of all stages diagnosed in 2004-2016 who underwent simple mastectomy with or without reconstruction, breast conserving surgery (BCS), or subcutaneous mastectomy (SCM). Hazard ratios (HRs) were calculated, adjusting for age, Charlson Comorbidity Index (CCI), receptor status, grade, laterality, clinical and pathological stage, number of positive nodes, surgery type, margin, systemic therapy, radiation, insurance, income, education level, urban-rural, and race. Results: From 2004 to 2016, 1,851,465 patients diagnosed with nonmetastatic breast cancer were treated with BCS, SCM, or mastectomy. Adjusted HRs revealed that low income remained independently associated with worse survival, at every income level when compared with the highest quartile (lowest vs highest median income quartile: aHR 1.23, 95% CI 1.19-1.27). Other demographic factors were also independently associated with worse survival, including increasing age (aHR 1.49, 95% CI 1.47-1.5), higher CCI (CCI 3+ vs 0: aHR 2.91, 95% CI 2.76-3.07), Black race (vs White: aHR 1.1, 95% CI 1.07-1.13), Medicaid insurance (vs Medicare: aHR 1.19, 95% CI 1.14-1.23), and low education level (second lowest vs highest high school graduation rate quartile: aHR 1.07, 95% CI 1.04-1.1). Many tumor and treatment factors were also independently associated with worse survival, with the strongest factors being triple-negative receptor cancer (vs ER+/PR+/Her2-: aHR 2.01, 95% CI 1.99-2.09), and pathologic stage 3 (vs stage I: aHR 2.04, 95% CI 1.95-2.13). Interestingly, there was a greater survival benefit observed in patients receiving mastectomy with reconstruction (vs BCS: aHR 0.63, 95% CI 0.61-0.65) versus those without reconstruction (vs BCS: aHR 0.98, 95% CI 0.95-1). Conclusion: In patients diagnosed with nonmetastatic breast cancer in the NCDB from 2004 to 2016, lower income, in addition to black race, Medicaid insurance, and lower educational level were all independently associated with worse survival. However, older age, higher CCI, and tumor factors were stronger predictors of decreased survival. The apparent survival advantage of mastectomy with reconstruction over that with no reconstruction was a surprising finding that could suggest the influence of unincluded demographic factors limiting access to reconstructive surgery.

Citation Format: Thomas Norman, Lindsay Hwang, Xiaomeng Lei, Steven Cen, Jason Ye. Race and socioeconomic factors associated with decreased survival in breast cancer, assessing for healthcare disparities using the National Cancer Database [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr A040.