Abstract B109: Beyond persistent poverty: A population-based study of social vulnerability and gastrointestinal cancer survival

Abstract

Abstract Introduction: Areas experiencing persistent poverty (PP) and areas experiencing current poverty face higher mortality from gastrointestinal cancers than non-poverty areas. Evidence suggests that areas in poverty experience higher levels of social and environmental vulnerability, are often rural, and lack access to cancer care. No studies examine the mechanism underlying this disparity, which is essential for identifying intervention targets. Thus, we evaluate how social vulnerability, environmental vulnerability, rurality, and access to cancer care affect the association between area-level poverty status and gastrointestinal cancer survival. Methods: Data included all adult (≥18 years), incident cases of gastrointestinal cancers from the Alabama Statewide Cancer Registry diagnosed between September 1, 2017 and September 30, 2021 followed through December 31, 2022. The exposure was census tract-level PP, current, or no poverty. The outcome was overall survival (months from diagnosis to death or end of follow-up). Potential mediators were census tract-level social vulnerability index (SVI) score [excluding poverty], environmental burden module (EBM) score, rurality, and access to cancer care. Covariates were individual-level age, sex, race/ethnicity, cancer type, and cancer stage. A series of Cox proportional hazards models were fit: models with covariates, individual mediators plus covariates, and full model with all covariates and mediators. Models of SVI subthemes and mediation by SVI were also examined. Results: Living in a PP census tract was associated with 15% higher (95% CI: 1.08-1.23) and living in a current poverty census tract with 8% higher risk of death (95% CI: 1.02-1.14) than living in a no poverty tract. Adjusting for SVI, the poverty-survival association lost significance, but increasing SVI was associated with 34% higher risk of death (95% CI: 1.21-1.48). Adjusting for EBM maintained the poverty-survival association and increasing EBM was associated with 14% higher risk of death (95% CI: 1.04-1.25). Full adjustment results were similar to the SVI-only model. SVI was not a mediator; SVI subthemes of socioeconomic status, household composition and disability, and housing type and transportation drove the SVI-survival association. Conclusion: Targeting interventions to socioeconomic, housing, and transportation-related variables may be actionable and effective foci for eliminating poverty-related disparities in gastrointestinal cancer mortality disparities rather than intervening on the distal, multi-generational construct of PP itself. Citation Format: Mackenzie E. Fowler, B. Grey Vandeberg, Hayden D. Reeves, Elizabeth Baker, Gabriela R. Oates, Lucia D. Juarez, Grant R. Williams, R. Blake Buchalter, Kelley Pettee Gabriel. Beyond persistent poverty: A population-based study of social vulnerability and gastrointestinal cancer survival [abstract]. In: Proceedings of the 19th AACR Conference on the Science of Cancer Health Disparities; 2026 Oct 18-21; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2026;35(10 Suppl):Abstract nr B109.