Abstract C142: Regional availability of lung cancer screening facilities in the year prior to diagnosis among non-Hispanic American Indians and White patients

Abstract Introduction: Lung cancer is the leading cause of cancer mortality among American Indian (AI) people. Lung cancer screening through low-dose computed tomography (LDCT) imaging detects cancer at earlier stages and reduces lung cancer mortality by 20%. However, LDCT has low uptake among eligible individuals, and access to LDCT screening facilities presents a challenge. Our objective was to examine the association between geographic availability of LDCT (measured using distance to nearest screening facility) and stage at diagnosis among non-Hispanic AI and non-Hispanic White (NHW) individuals. Methods: We used state cancer registry data and health insurance claims from the North Carolina Cancer Information and Population Health Resource (CIPHR), to identify incident lung cancer cases among NHW and AI individuals who were age-eligible (56-81 years of age) for lung cancer screening between 2015 and 2020. We identified LDCT facilities that existed in the year prior to each lung cancer case and calculated the minimum ZIP code centroid to centroid distance to all LDCT facilities. We estimated odds ratios (OR) and 95% confidence limits (CL) for the association between distance to the nearest available LDCT facility in the year prior to diagnosis and stage of lung cancer at diagnosis for both localized and distant SEER summary stage. Logistic regression models adjusted for age, race/ethnicity, and insurance coverage at diagnosis. Results: We identified 314 non-Hispanic AI and 21,508 NHW incident lung cancer cases that would have been age-eligible for lung cancer screening between 2015 and 2020. Compared to NHW individuals, the median age at diagnosis for AI individuals was 3 years younger. AI individuals were more frequently insured by Medicaid and less frequently covered by private insurance than NHW individuals. The median ZIP code centroid-to-centroid distance to the nearest LDCT facility in the year prior to diagnosis was 7.5 miles for AI individuals compared with 3.4 miles for NHW individuals. Approximately half of AI individuals (52%) and NHW individuals (50%) presented with distant stage at diagnosis, whereas fewer AI individuals presented with localized stage (AI:18% vs NHW: 25%). In our multivariable models, further distance (≥10 miles from available LDCT facilities) was associated with lower adjusted odds of being diagnosed with localized stage disease (aOR=0.90; 95%CL: 0.83, 0.99). Conclusions: Distance to care may act as a barrier to lung cancer screening. These results suggest that accessible targeted interventions, such as mobile lung cancer screening units, may increase access to screening services, especially since AI patients are more likely to be living in rural areas. Limitations of these data include lack of smoking pack year history to accurately identify all individuals who should have received LDCT screening. Citation Format: Marc A. Emerson, Bradford E. Jackson, Lisa Spees, Madison T. Uhrin, Joel Begay, Erica M. Fennimore, Christopher Baggett, Ronny A. Bell, Stephanie B. Wheeler. Regional availability of lung cancer screening facilities in the year prior to diagnosis among non-Hispanic American Indians and White patients [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 C142.