Use of cell-free tumor DNA in early detection of lung cancer.

Abstract

e20088 Background: USPSTF recommends annual screening for lung cancer with low-dose computed tomography (LDCT) in adults 50-80 years with 20 pack-year smoking history or current/former smoking in the past 15 years. This prospective study evaluated whether we could detect lung cancer at the time of LDCT screening from cell-free tumor DNA using Guardant Health’s LUNAR-2 assay. Methods: Kaiser Permanente Colorado (KPCO) members with upcoming LDCT screenings were invited via email/phone and recruited into two groups, (1) suspicious lung nodules or (2) no lung nodules. We limited enrollment to patients whose LDCT results were classified under the Lung-RADS (version 1.0) categories of 1-3 (recommended follow-up at 12-month intervals) or category 4 (“suspicious”; recommended follow-up at 3-month intervals). We excluded members with lung nodules > 30mm, those with a history of any hematologic malignancy, history of invasive malignancy within the past 5 years, currently pregnant, or known dementia or cognitive impairment. After informed consent, Guardant Health LUNAR test collection kits were mailed to the participant with sample collection instructions provided. Participants were asked to have their blood drawn on the day of their LDCT visit, or no more than 14 days of the scan. We also collected survey and EHR data on smoking history, LDCT, and other associated factors. The KPCO tumor registry confirmed all reported cancers. Results: The study initiated in September 2020 and ended in 08/2022 with 982 individuals consented and blood samples collected. Participants were on average 68 years old, 56% female, 58% former smokers, and 85% had no personal history of cancer. A total of 15 lung cancer cases and 22 other cancer cases were diagnosed. Data analysis is ongoing and expected to be completed early 2024. Conclusions: This study will demonstrate sensitivity and specificity of the LUNAR-2 assay to detect lung cancer relative to standard of care screening modalities in high-risk populations. We will also evaluate whether factors such as comorbidities, pack year history, or medications affect assay accuracy. The impact of this research can inform blood-based early detection of lung cancer.