Abstract 3635: Interim results of the BEFIT exercise intervention pilot study to assess the microbiome and immune function in a high-risk cohort for lung cancer

Abstract Background/Objective: Modifiable lifestyle risk factors, such as diet and exercise, have shown to be associated with reduced lung cancer risk. We recently launched a randomized controlled pilot trial, the BEFIT exercise intervention study, whose overall objectives are to: a) confirm the feasibility of an exercise intervention in high-risk smokers, and b) assess the intervention impact on the microbiome and inflammatory biomarkers. This report will describe interim study results, including participant characteristics, recruitment challenges and adherence in this ongoing study. Methods: Participants from The Ohio State University Lung Cancer Screening Clinic (OSULCSC) and social media were randomized into one of two arms: (a) Exercise/Behavioral Support Intervention - an ACSM-approved 12-week virtual resistance training plus aerobic program, or (b) Standard of Care - an information-only, control condition (e.g. light walking). Eligibility criteria included: ages 40-80 years, exercise<150 minutes/week, 20 pack-year smoking history and computer/internet access. Blood draws, stool samples, physical activity measures and behavior change predictors will be evaluated at baseline and intervention completion, with 1-year follow-up to assess adherence. Results: Individuals were primarily recruited through the OSULCSC and social media ads. Our goal was to recruit 40 participants (20 per arm), but due to dropout we had 20 in the intervention group and 16 in the control group. Common reasons for withdrawal include too busy, changed mind and no longer interested. Participant characteristics include mean age 63 years, 64% female, 89% white, 52% current smokers and mean BMI of 35 (obese) and 39% body fat. The intervention group showed significantly greater weight loss and increased lean muscle mass after the intervention. Adherence to the intervention was high with almost 90% of sessions attended with no adverse events reported. Biospecimen analyses and social cognitive intermediates are currently underway. Discussion: We successfully launched the BEFIT exercise intervention study for long-time smokers at high risk for lung cancer with high adherence and no adverse events reported. Despite recruiting challenges and dropout, we successfully recruited and conducted the intervention, with significant improvements in weight loss and lean muscle mass after the intervention. We continue to analyze biospecimen data for changes in the gut microbiome and inflammation, and look forward to reporting these when completed. Citation Format: Marisa Bittoni, Zachary Chaplow, Daniel Spakowicz. Interim results of the BEFIT exercise intervention pilot study to assess the microbiome and immune function in a high-risk cohort for lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 3635.