Zhang B, et al. - Given circulating tumor DNA (ctDNA) testing in plasma in patients with non-small-cell lung cancer (NSCLC) might potentially serve as a supplemental or surrogate tool for tissue biopsy, researchers intended to clarify identification of genomic abnormalities in ctDNA as well as their relation to clinical features in early-stage NSCLC. They used a targeted 546 genes capture-based next generation sequencing (NGS) assay and comprehensively assessed gene variations of 48 tumor tissues and 48 matched preoperative (pre-op) plasma and 25 postoperative (post-op) plasma from early-stage NSCLC patients. According to findings, ctDNA detection in early-stage NSCLC could be influenced by histology subtype and gene mutations. A much higher tissue- pre-op plasma concordant ctDNA mutation detection ratio was found in lung squamous cell carcinoma (LUSC) as compared to that in lung adenocarcinoma (LUAD). In LUSC-LUAD classification, the potential usefulness of NGS-based ctDNA profile was suggested.