Abstract 7408: Factors influencing false positive low-dose computed tomography-based lung cancer screening in an urban, safety-net system

Abstract Background: False-positive results from low-dose computed tomography (LDCT)-based lung cancer screening can result in unnecessary follow-up tests, increased patient anxiety, and higher healthcare costs. We evaluated the prevalence of false-positive LDCT results and assessed factors associated with these LDCT results within an integrated, urban safety-net healthcare system serving a diverse and underserved population. Design: Retrospective cohort study. Setting: Electronic health records data from Parkland Health, an integrated safety-net provider in Dallas, Texas (January 1, 2017-May 31, 2022), with a 1-year follow-up period through May 31, 2023. Outcome: False-positive LDCT was defined as positive screen (lung RADS 3, 4A, 4B or 4X) followed by a negative completed work-up or no diagnosis of lung cancer after 12-month follow-up. Analysis: Univariable and multivariable logistic regression models were used to assess the associations between patient characteristics (patient age, sex, race/ethnicity, preferred language, insurance status, comorbidity score, smoking status and smoking pack-years) and a false-positive LDCT. Results: A total of 2525 LDCTs were included from 2029 patients. Of these, lung cancer was diagnosed in 12 patients (0.6%), and 394 (19.4%) were classified as false-positive. Median age was 62 years, 59% were men, 49% were non-Hispanic Black, 16% were Hispanic, and the median pack-years were 40. In both univariable and multivariable analyses, age was significantly associated with false positive LDCT results. Patients aged 65-70 years (OR=1.81, 95% CI: 1.06-3.10) and >70 years (OR=2.02, 95% CI: 1.15-3.54) had higher odds of false-positive results compared to those aged 50-54 years. Conclusion: In our integrated safety-net healthcare system, approximately one in 5 patients had a false-positive LDCT result, and age was a significant contributor. Patients aged 65 years and older were more likely to experience false-positive findings, suggesting that age-related factors may influence the diagnostic accuracy of LDCT. Future studies are needed to replicate these findings and further minimize unnecessary follow-up interventions, particularly in older populations. Citation Format: Rutu Rathod, Urooj Wahid, Asha Kandathil, Mary Gwin, Sheena Bhalla, Song Zhang, Andrea Semlow, Vijaya Natchimuthu, Sarah Malone, George Oliver, David H. Johnson, Megan A. Mullins, David Gerber, Rasmi Nair. Factors influencing false positive low-dose computed tomography-based lung cancer screening in an urban, safety-net system [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 7408.