Clinical Utility of Liquid Biopsy (Cell-free DNA) Based EGFR Mutation Detection Post treatment Initiation as a Disease Monitoring Tool in Patients With Advanced EGFR-mutant NSCLC

•It is essential to monitor the response to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors in non-small cell lung cancer (NSCLC).•Circulating tumor DNA (ctDNA) analysis has emerged as a valuable tool for this purpose.•ctDNA clearance from plasma post treatment initiation prolongs the progression-free survival and overall survival.•It can be used as a predictive marker for outcomes in patients with EGFR-mutant NSCLC.