Abstract C164: Disparities in sociodemographic characteristics and cancer burden in census tracts without access to lung cancer screening facilities

Abstract Background: Recent efforts have sought to identify gaps in access to lung cancer screening facilities using geospatial analysis, but little has been done to describe the populations affected. Methods: Census tract sociodemographic data were obtained from 2019 5-year ACS. Location of lung cancer screening facilities (LCSF) as of summer 2024 were obtained using the American College of Radiologists’ Lung Cancer Screening Locator Tool. County-level 2016-2020 age-adjusted incidence, mortality, and percent late-stage data were obtained from the CDC State Cancer Profiles and state health departments. We follow a method by Sahar et al. (2021) to identify census tracts (CT) across the contiguous United States without access to an LCSF—CTs with no LCSF within a 40-mile radius of their centroid are considered without access. We then compare the sociodemographic characteristics between CTs with or without access using descriptive statistics and Wilcoxon rank-sum test. We correlate measures of cancer burden with the proportion of population aged 50-80 living in a CT without access to an LCSF in each county using the Spearman’s rank correlation coefficients. We analyze separately by metro and non-metro areas (National Center for Health Statistics’ 2013 Rural-Urban Classification Scheme). Results: There were 60,383 tracts in metropolitan areas and 11,950 in non-metropolitan areas. Among CTs in metro areas, 2.8% had no access at the 40-mile range. CTs without access had higher median uninsured rates (11% vs 7%), median poverty rates (10% vs 7%), and median % Hispanic (25% vs 9%). Tracts without access had lower median % non-white(16% vs 23%), median % aged 50-80 years old (28% vs 31%) and median incomes ($54,444 vs $63,626). Median % aged 25+ with a high school diploma (or equivalent) and unemployment rate were not significantly different. In the non-metro CTs, 21% had no access at the 40-mile range. As with the metro tracts, CTs without acces had higher median uninsured rates (11% vs 7%), poverty rates (11% vs 10%), and % non-white (11% vs 6%). Median population aged 50-80 and median income were lower in CTs without access (35% vs 36%, $47,159 vs $49,405). Unlike in metro areas, high school attainment was significantly lower among CTs without access (34% vs 37%). Aggregating tracts to the county level, incidence and mortality are negatively correlated with the proportion without access in metro areas (rho: -0.23, -0.17, <0.001), while percent late-stage was not significantly correlated. The same is true for non-metro areas (rho: -0.30, -0.22, -0.08). Conclusion: These findings suggest that gaps in access disproportionately impact communities with lower access to health insurance, greater poverty rates, and larger Hispanic populations, regardless of whether the gaps occur within metropolitan areas or rural regions. The trend of incidence and mortality decreasing as the population without access increases is unexpected and could suggest the presence of unmeasured confounding. Citation Format: Alex C. Watts, Wei-Ting Hwang. Disparities in sociodemographic characteristics and cancer burden in census tracts without access to lung cancer screening facilities [abstract]. In: Proceedings of the 18th AACR Conference on the Science of Cancer Health Disparities; 2025 Sep 18-21; Baltimore, MD. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2025;34(9 Suppl):Abstract nr C164.