Abstract 4950: Exploring the impact of neighborhood-level conditions: Geographic disparities in breast cancer mortality in Maryland, 2000-2019

Purpose: To observe the geographic distribution of breast cancer (BC) mortality in Maryland by differences in neighborhood-level social determinants of health Background: Cancer surveillance efforts indicate that BC mortality is unevenly distributed geographically in Maryland; however, it is unknown how area-level socioenvironmental disadvantages might be driving these neighborhood-level disparities. Methods: Utilizing data from the Maryland Cancer Registry (MPCR), we identified women aged 18+ diagnosed with first primary, invasive BC between 2000-2019. We used census tract-level Social Vulnerability Index (SVI) as a proxy measure for neighborhood-level built and social environments. We calculated the 20-year average SVI percentile ranking and categorized each census tract as having low (least disadvantaged), low-medium, medium-high, or high (most disadvantaged) SVI. We computed age-adjusted (<50, 50+) standardized mortality ratios (SMRs) for each SVI level using the 2000 standard female population and BC-specific referent mortality rates for Maryland from 2018-2022 (age <50: 4.4 deaths/100k; age 50+ 60.8 deaths/100k). We used spatial epidemiology methods to estimate age-adjusted SMRs by census tracts among women of all ages (referent mortality rate: 20 deaths/100k). We mapped this data to visualize the geographic distribution of SVI and BC mortality. Results: Our study population included 79,145 women (n=17,027 [2.5%] aged <50; n=62,118 [78.5%] aged 50+), of which 13,005 (16%) died from their BC diagnosis. We observed the largest differences in SMRs by age at diagnosis. Across all SVI categories, BC mortality among women diagnosed at ages 50+ was higher than expected relative to older women in the general female population (SMR range: 19.1-22.1). Results were similar for women diagnosed at ages <50 (SMR range: 48.2-53.3). Census tracts with low-medium/medium-high SVI had higher SMRs (low-med: 50.2, med-high: 53.3) than low/high SVI areas. After calculating the SMRs by census tract for all ages, we observed that census tracts in the Eastern Shore and western Maryland showed a strong spatial correlation between higher SVI and higher SMRs. Similarly, most of the Capital region and central Maryland experienced low SVI and correspondingly lower SMRs, but there was considerable spatial variation in the distribution of SVI and BC mortality around Baltimore City/County and Greater Washington region. Conclusion: The uneven geographic distribution of BC mortality in Maryland may be due to the underlying heterogenic spatial distribution social vulnerability. Younger women diagnosed in census tracts with low-medium or medium-high SVI disproportionately experienced the highest SMRs. Our findings suggest a differential mortality impact of neighborhood-level conditions and socioenvironmental factors among younger vs. older women. Citation Format: Katherine L. Ho, Kassandra Alcaraz, Avonne Connor, Michael Desjardins. Exploring the impact of neighborhood-level conditions: Geographic disparities in breast cancer mortality in Maryland, 2000-2019 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4950.