Abstract C145: Baseline participant characteristics from PATHFINDER 2, a prospective interventional study of a multi-cancer early detection test in a population setting

Abstract A blood-based multi-cancer early detection (MCED) test has demonstrated feasibility as a screening tool in large-scale clinical trials. The PATHFINDER 2 (PF2) study (NCT05155605) evaluates safety and performance of the MCED test in a diverse intended-use population. To gauge generalizability of study results, we assessed participant (ppt) baseline characteristics vs general US population data from the National Health and Nutrition Examination Survey (NHANES). PF2, a prospective, multicenter, interventional study, enrolled ppts aged ≥50 y from diverse clinical settings in North America. Enrollment targets for sex and race/ethnicity were established from the 2019 American Community Survey (US Census Bureau). Recruitment strategies were implemented to maximize enrollment for groups historically underrepresented in clinical studies. Exclusion criteria included clinical suspicion of cancer or cancer diagnosis/treatment within 3 y. Data on baseline characteristics and key cancer risk factors were collected at enrollment. We compared the PF2 study population to a nationally representative sample of US adults aged ≥50 y from 2017-2020 NHANES data. NHANES data were weighted using complex, multistage probability sampling to generate a nationally representative sample. There were 35,878 ppts enrolled in PF2; 35,307 clinically eligible and evaluable ppts were included in this analysis. Mean age was 64 y for both PF2 and NHANES; 56.2% were females in PF2 vs 53.6% (95% CI 52.0-55.3%) in NHANES. Race/ethnicity distribution for PF2 vs NHANES was 7.4 vs 11.0% (8.9-13.1%) Hispanic, 74.6 vs 69.7% (65.0-74.5%) non-Hispanic (NH) White, 8.6 vs 10.3% (7.6-13.1%) NH Black, and 5.8 vs 5.1% (3.5-6.8%) NH Asian. In terms of lifestyle characteristics for PF2 vs NHANES, 58.9 vs 29.2% (25.8-32.7%) had at least a bachelor’s degree, 74.8 vs 63.8% (60.6-67.0%) were married/living with a partner, 69.3 vs 53.8% (50.9-56.7%) had never smoked, 66.5 vs 70.4% (68.0-72.8%) were overweight/obese, and 24.2 vs 28.4% (26.4-30.3%) reported never using alcohol. PF2 enrolled a diverse ppt population that is reasonably reflective of the demographics of the US population aged ≥50 y. As is typical for clinical trials, a higher percentage of PF2 vs NHANES ppts reported lifestyle characteristics associated with better health. As the study population largely reflects the MCED test intended-use population, safety and performance results from PF2 are expected to reflect real-world clinical experience. Citation Format: Shirish Gadgeel, Nima Nabavizadeh, Dax Kurbegov, Charles McDonnell, III, James W. Lillard, Jr., Marc Matrana, Alan Roth, Andrea Johnston, Sami Tahhan, Rami Owera, Matthew Margolis, Anuraag Kansal, Margarita Lopatin, Margaret McCusker, Karthik V. Giridhar. Baseline participant characteristics from PATHFINDER 2, a prospective interventional study of a multi-cancer early detection test in a population setting 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 C145.