Liquid biopsy is a promising method for the management of lung cancer, but previous studies focused mainly on patients with advanced-stage disease. As the methodology has progressed for the detection of circulating tumor DNA (ctDNA) and its aberrant methylation, researchers are gradually investigating the utility of liquid biopsy in early-stage patients. As a result, liquid biopsy has shown its potential for the application in patients with early- and locally advanced-stage non-small cell lung cancer (NSCLC). Areas covered: This review summarizes the utility of liquid biopsy in NSCLC and provide an outlook for future development. We focus on the role of ctDNA and its aberrant methylation in patients with stage IA to stageⅢA NSCLC, in the field of early detection and screening, perioperative management, and postoperative surveillance. Expert opinion: Liquid biopsy has shown the potential for clinical application of early-stage patients but has not been routinely applied yet. The utilization of liquid biopsy will be promoted by improved detection methods and data from well-designed clinical trials. With the development of precision medicine, liquid biopsy will likely play an increasingly important clinical role.
Keywords: Lung cancer; circulating tumor DNA; liquid biopsy; minimal residual disease.