Feasibility of an amplicon based liquid biopsy for ALK and ROS1 fusions in advanced non small cell lung cancer (NSCLC) patients

INTRODUCTION Circulating tumor DNA (ctDNA) is a surrogate material for somatic mutation detection, such as EGFR, BRAF or KRAS mutations in NSCLC patients, however the applicability of this technique for ALK and ROS1 fusion detection is poorly described. The aim of this combined analysis was to evaluate an amplicon-based ctDNA technology in a cohort of ALK and ROS1 positive NSCLC patients. METHODS ALK and ROS1 positive NSCLC patients were prospectively enrolled or retrospective specimens selected, to be included across 6 international centres. ALK/ROS1 positive status was determined by standard of care (FISH/IHC or NGS). The analysis of EML4-ALK fusions (variant 1,2,3) and ROS1 fusions (with partner genes CD74, SLC34A2, SDC4 and EZR) was performed using the InVision™ platform. RESULTS Patients included (n=65; 59 ALK, 6 ROS1): 35 (55%) females, 40 (63%) non-smokers …