Detection of EGFR-Activating and T790M Mutations Using Liquid Biopsy in Patients With EGFR-Mutated Non–Small-Cell Lung Cancer Whose Disease Has Progressed During Treatment With First- and Second-Generation Tyrosine Kinase Inhibitors: A Multicenter Real-Life Retrospective Study

Epidermal growth factor receptor T790M detection using liquid biopsy was evaluated in a real-life setting in 120 advanced non–small-cell lung cancer patients whose disease had progressed during first- or second-generation tyrosine kinase inhibitors. The T790M detection rate was 25.8% using liquid biopsy and 49.2% after tissue rebiopsy. Liquid biopsies performed before disease progression according to Response Evaluation Criteria In Solid Tumors were all negative for T790M and T790M positivity was higher in cases of extrathoracic metastatic sites.