Abstract C135: The heterogenous impact of healthcare access factors throughout the breast cancer care continuum
Authors: Dunn Matthew R. , Li Didong , Emerson Marc A , Thompson Caroline A. , Nichols Hazel B , Van Alsten Sarah C , Roberson Mya L. , Carey Lisa A. , Hyslop Terry , Lafata Jennifer Elston , Troester Melissa A. 
Published: September 2024

Abstract
Background: Delays in breast cancer diagnosis and treatment lead to worse survival and quality of life decrements. Racial disparities in care timeliness have been reported, but few studies have examined access at multiple points along the care continuum (diagnosis, treatment initiation, treatment duration, and genomic testing). Methods: The Carolina Breast Cancer Study Phase 3 (CBCS3) is a population-based cohort (n=2998, 50% Black) with invasive breast cancer diagnoses (2008-2013). We used latent class analysis (LCA) to group participants based on patterns of factors within 3 separate domains: “socio-economic status (SES)”, “care barriers”, and “care use.” These classes were evaluated in association with delayed diagnosis (approximated with stage 3 or 4 at diagnosis), delayed treatment initiation (more than 30 days between diagnosis and first treatment), prolonged treatment duration (time between first and last treatment – by treatment modality), and receipt of OncotypeDx genomic testing (evaluated among patients with early stage, ER+, HER2- disease). Associations were evaluated using adjusted linear-risk regression to estimate relative frequency differences (RFDs) with 95% confidence intervals (CIs). Results: Overall, 18% of CBCS participants had late stage/delayed diagnosis, 35% had delayed treatment initiation, 48% had prolonged treatment duration, and 62% did not receive OncotypeDx. Black women had greater frequency of each unfavorable care outcome compared to non-Black women, including diagnostic delay (22% vs 15%, RFD= 6.9, 4.1-9.6), treatment initiation delay (39% vs 31%, RFD=7.9, 4.5-11.3), prolonged treatment (50% vs 46%, RFD= 4.3, 0.5-8.2), and OncotypeDx non-receipt (69% vs 57%, RFD= 12.2, 7.3-16.7). We identified 3 latent classes for SES (“high SES”, “moderate SES,” and “low SES”) 2 classes for care barriers (“few barriers”, “more barriers”), and 5 classes for care use (“short travel/high preventive care”, “short travel/low preventive care,” “medium travel,” “variable travel,” and “high travel”). Low-SES and more barriers to care were associated with greater frequency of delayed diagnosis (RFDadj = 5.5, 2.4-8.5; RFDadj =6.7, 2.8-10.7, respectively) and prolonged treatment (RFDadj = 9.7, 4.8-14.6; RFDadj = 7.3, 2.4-12.2, respectively). Variable travel (short time to diagnosis but long time to surgery) was associated with delayed treatment in the entire study population (RFDadj = 10.7, 2.7-18.8) compared to the short travel, high use referent group. The high travel group (representing long travel to both diagnosis and surgery) was associated with delayed treatment only among Black women relative to the same referent group (RFDadj = 10.0, -3.3-23.2). Conclusions: Black patients face more frequent delays throughout the care continuum, likely stemming from different types of access barriers at key junctures. Improving breast cancer care access will require intervention on multiple aspects of SES and healthcare access.
Citation Format: Matthew R. Dunn, Didong Li, Marc A Emerson, Caroline A. Thompson, Hazel B Nichols, Sarah C Van Alsten, Mya L. Roberson, Lisa A. Carey, Terry Hyslop, Jennifer Elston Lafata, Melissa A. Troester. The heterogenous impact of healthcare access factors throughout the breast cancer care continuum [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 C135.