E57: Poverty's Shadow on Survival: Examining the Impact of Persistent Neighborhood Poverty on Breast Cancer Outcomes

Introduction: Patients with breast cancer residing in economically disadvantaged communities often face poorer outcomes (e.g., mortality) compared to individuals living in more affluent neighborhoods. This study aims to examine the association between persistent neighborhood poverty and breast tumor characteristics, surgical treatment, and mortality.

Methods: Women aged 18+ diagnosed with stage I-III breast cancer between 1/1/2010-12/31/2018 were identified in the Surveillance, Epidemiology, and End Results (SEER) Program. The study cohort was stratified based on residence in areas affected by persistent poverty. Persistent poverty was defined as census tracts (CTs) where ≥20% of the population has lived in poverty since 1980. Sociodemographic, clinical, and treatment variables were evaluated using bivariate analysis. The association between persistent poverty and mortality was summarized using Cox proportional hazards models. 

Results: Of 334,004 patients, 21,750 (6.51%) lived in a CT with persistent poverty. Compared to those living in more affluent areas, patients residing in persistently impoverished CTs were more likely to identify as Black (44.2% vs 10.4%, p< 0.001) or Hispanic (13.3% vs 8.3%, p< 0.001). Further, those in impoverished CTs had more aggressive tumor characteristics including higher grade disease (grade 3: 35.1% vs 28.1%, p< 0.001), triple negative breast cancer (16% vs 10.5%, p< 0.001), and advanced stage (stage III: 14.3% vs 10.3%, p< 0.001) of disease. A higher proportion of patients residing in areas with persistent poverty underwent mastectomy (44.8% vs 39.8%, p< 0.001) and axillary lymph node dissection (21.3% vs 15.2%, p< 0.001), but a lower proportion received breast reconstruction (41.8% vs 53.8%, p< 0.001). On multivariable analysis, living in a persistently impoverished CT was associated with a higher risk of breast cancer-specific (aHR 1.16, 95% CI 1.09-1.23) and all-cause mortality (aHR 1.18, 95% CI 1.13-1.22). Notably, breast cancer-specific (RR 1.79, 95% CI 1.69-1.90) and all-cause (RR 1.64, 95% CI 1.57-1.71) mortality risks diverged between groups as early as three years following diagnosis. 

Conclusions: Living in neighborhoods characterized by persistent poverty can have implications on tumor characteristics, surgical management, and mortality among patients with breast cancer. Future research efforts should aim to clarify the mechanistic pathways through which living in persistent poverty influences oncological outcomes.