Abstract B10: Feasibility of bronchial washing fluid-based approach to early-stage lung cancer diagnosis

Abstract

Abstract Circulating tumor DNA has few applications for detecting early-stage lung cancers. Bronchial washing (BW) is minimally invasive, and BW fluids can contain tumor DNA. Thus, analysis of BW fluids could be used for precision medicine. Forty-eight paired specimens (primary tumor tissue, normal tissue, BW supernatant, and BW precipitate) from twelve patients with early-stage non-small cell lung cancer were analyzed using ultradeep next-generation sequencing with a custom panel containing 113 genes. In primary tumors, 130 missense mutations/indels (5–16 per patient) and 20 driver mutations (0–3) were found; 105 (80.8%) and 97 (74.6%) of these missense mutations/indels were identified in BW supernatants and precipitates, respectively, and 19 (95.0%) of the driver mutations in both BW supernatants and precipitates. Concordance between EGFR mutations in primary tumors, BW supernatants, and BW precipitates was 100%. The median allele frequencies (AFs) for missense mutations/indels in primary tumors, BW supernatants, and BW precipitates were 13.0%, 0.3%, and 0.1%, respectively. The AFs of missense mutations/indels in BW supernatants correlated with those in primary tumors and in BW precipitates (P<0.001). In conclusion, this study provides evidence that the BW fluids, especially supernatants, can be an alternative to overcome the limitation that clinical utility of ctDNA is often not reliable in early-stage NSCLC. Citation Format: Jeong Seon Ryu, Myoung Kyu Lee, Seung Jae Lee. Feasibility of bronchial washing fluid-based approach to early-stage lung cancer diagnosis [abstract]. In: Proceedings of the AACR Special Conference on Advances in Liquid Biopsies; Jan 13-16, 2020; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(11_Suppl):Abstract nr B10.