Abstract B131: Disparities in late-stage breast cancer: The impact of socioeconomic status across racial groups by healthcare utilization and community healthcare access

Abstract BACKGROUND: Late-stage breast cancer (LSBC, defined as stage 3 or 4) significantly contributes to breast cancer (BC) mortality, underscoring the importance of early detection and intervention. Understanding the individual and community factors contributing to LSBC is crucial for improving LSBC diagnoses and outcomes. OBJECTIVE: To evaluate the association between LSBC and individual demographic/socioeconomic status (SES) characteristics by race, and describe differences in individual healthcare utilization (IHU) and community healthcare access (CHA). Methods: This population-based retrospective study used demographic and SES data (age at diagnosis, marital status, years of education, income, poverty status, health insurance, and body mass index) from the Carolina BC Study Phase 3, a population-based cohort of women diagnosed with invasive BC from 2008-13. We analyzed all cases of LSBC (n=545) and stage 1 (n=1,225). Age-adjusted relative frequency differences (RFDs) and 95% confidence intervals (CIs) assessed the relationship between LSBC and SES for Black (n=835, 47.2%) and non-Black (n=935, 52.8%) women. Analyses were stratified by IHU status (High vs Low: High: Had regular pre-diagnostic care and were adherent to BC screening guidelines, >0.5 mammograms per year; Low: Lacked one or both forms of care); and stratified by CHA status (High vs Low), a census tract-level measure of cancer-specific healthcare infrastructure (e.g., oncologist density) and utilization (e.g., insurance rates). High CHA had either high or low infrastructure and high use; Low CHA had low infrastructure and low use. Results: Compared to non-Black women, Black women had more LSBC diagnoses (38.7% vs 23.7%), were more likely to be unmarried (59.1% vs 28.7%), have an income of <$50k (71.8% vs 38.2%), and be impoverished (27.0% vs 6.1%). Age at diagnosis, years of education, and income were significantly, positively associated with LSBC for all women, but the age-adjusted RFDs were greater among Blacks. After stratifying by IHU, income remained significantly associated with LSBC for Blacks with low IHU. For those with high IHU, the effects of SES on LSBC were not statistically significant. After stratifying by CHA, income and poverty status were significantly positively associated with LSBC for all women with high CHA; Marital status was significantly associated with LSBC for Blacks. Among the low CHA group, income and poverty were significantly associated for Blacks; RFDs were not estimable for non-Blacks due to small sample size (n=66). Notably, 36.5% of Blacks lived in low CHA areas compared to 7.1% of non-Blacks. Conclusion: Healthcare access exacerbates the effects of IHU but does not mitigate the impact of demographic/SES characteristics on LSBC diagnoses. Enhancing CHA alone is insufficient. Targeted interventions addressing individual and community factors are crucial to reduce LSBC diagnoses and improve outcomes, especially for Black women. Citation Format: Joel A. Begay, Brittney A. Gedeon, Matthew R. Dunn, Melissa A. Troester, Marc A. Emerson. Disparities in late-stage breast cancer: The impact of socioeconomic status across racial groups by healthcare utilization and community healthcare access [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr B131.