Abstract C069: The relationship of demographics, exposome, and outcomes among patients with breast cancer brain metastasis

Abstract

Breast cancer brain metastases (BCBM) presage a rapid decline in functional status and mortality; endpoints with known associations to race and socioeconomic status. The contribution of the neighborhood exposome, particularly as patients progress with metastatic disease, is not well characterized. Polycyclic aromatic hydrocarbons (PAH) are pollutants emitted during many industrial processes and have been linked to breast cancer progression, underscoring their relevance as an exposure in neighborhoods located near industrial point source emissions. This study compared and analyzed associations in women with BCBM for demographics, features of the neighborhood exposome, and disease outcomes. Annotated clinical MBC database (N=2,108; 1999 - present) of all MBC patients at UPMC Magee Women’s Hospital.Demographics: Age, Race (White, Black). Exposome: Area Deprivation Index (ADI), state (0-10) and national (0-100), where higher scores indicate greater deprivation; Distressed Communities Index (DCI) - economic neighborhood well-being (0-100) where higher scores indicate greater distress. Euclidean distance (miles) from home address to nearest industrial site emitting PAH as measured by the EPA website, Enviromapper. BCBM Outcomes (years) – Time to BCBM from MBC diagnosis; Time from MBC diagnosis to death. Descriptive statistics were used to characterize age, race, distance from industrial point-source emissions, and MBC outcomes. Tests of association were conducted using Spearman's rank correlation. n = 561 with BCBM (of 2,108 patients). Median age at BCBM diagnosis was 52.5 years; 87.3% of patients were White, 10.4% Black. Age (younger) comparisons for all outcomes were significantly different only for time to metastatic disease from diagnosis. Race: Black patients lived closer to point-source emission sources (median 4.6 vs. 7.0 miles, p < 0.001), experienced higher ADI (p < 0.001), and had a significantly shorter time to metastatic diagnosis (median 1.4 vs. 2.2 years, p < 0.001). Distance to the nearest emission source showed a weak positive correlation with time to metastatic diagnosis overall (Spearman's ρ = 0.14, p = 0.002). Race, not distance to PAH emission site or ADI, was the most consistent correlate of time to metastatic progression. Distance to emission site and ADI were tightly confounded with race, which limits conclusions about an independent environmental exposure effect. Findings should be interpreted as hypothesis-generating, given modest sample sizes, particularly among Black patients. Future directions include identifying which neighborhood-level exposome factors are most strongly associated with survival in this cohort to plan targeted, equitable interventions that improve quality of life for patients with MBC. Claude AI was used to help focus the conclusion. Cameron S. Herbst, Deilyla O. Rue, Margaret Q. Rosenzweig. The relationship of demographics, exposome, and outcomes among patients with breast cancer brain metastasis [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 C069.