Abstract A095: Neighborhood multi-modal spatial access to primary care is associated with improved colorectal cancer screening in NCI-designated cancer center catchment areas

Abstract Introduction: The National Cancer Institute (NCI) requires each designated cancer center to describe their identified geographic catchment areas to better address cancer burden, mortality, and disparities, and planning of community outreach and engagement. Colorectal cancer (CRC) mortality remains burdensome in the U.S. and little is known about whether improving travel-related access to primary care could increase CRC screening to reduce mortality in NCI catchment areas. To examine relationships and geographic disparities between spatial access to primary care and neighborhood CRC screening, we performed a novel geospatial analysis for 74,000 census tracts within the 66 NCI catchment areas in the 48 contiguous U.S. states. Methods: An enhanced two-step floating catchment area (E2SFCA) method that accounts for multi-modal transportation (i.e., driving, walking, and public transit) was used to compute spatial access to primary care physicians which was interpreted as the number of primary care physicians per 100,000 population. Primary care physicians were geocoded from the 2024 CMS Doctors and Clinicians National Downloadable File. The study outcome, CRC screening prevalence, was obtained from 2024 CDC PLACES. Due to spatial autocorrelation, we performed an unadjusted Lee’s L statistic bivariate cluster analysis between spatial access to primary care and CRC screening to identify clustering of double burden (low access and low screening). We then fit a negative binomial spatial lag model to examine the relationship between CRC screening and spatial access to primary care, adjusting for the most recent area deprivation index (ADI=1-100) data (derived from 2023 American Community Survey) and 2020 U.S. urban-rural status. Results: Significant clusters of low spatial access and low CRC screening were found in 54 of the 66 NCI catchment areas studied, including larger clusters in California, Texas, Oklahoma, Tennessee, Southeastern Georgia and Florida, Chicago, and Ohio catchment areas. In spatial modeling, we found that for every 100 primary care physicians increase per 100,000 population in catchment area tracts, CRC screening prevalence significantly increased by 0.23% (p0.001; deviance R2=0.74). Conclusions: 82% of NCI catchment areas had at least one cluster of double burden of low access and low CRC screening. Improving multi-modal spatial access to primary care may potentially increase CRC screening prevalence. Cancer centers should consider prioritizing resources towards locales in their catchment areas with poorer primary care access in order to address CRC mortality disparities by improving screening rates. Citation Format: R. Blake. Buchalter, Changzhen Wang, Paul R. Gunsalus, Jarrod E. Dalton, Johnie Rose, Stephanie L. Schmit. Neighborhood multi-modal spatial access to primary care is associated with improved colorectal cancer screening in NCI-designated cancer center catchment areas 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 A095.