Impact of clinical features on the efficacy of osimertinib therapy in patients with T790M-positive non-small cell lung cancer and acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors

Lung cancer is one of the most common malignant diseases in the world. First- (gefitinib and erlotinib) and second-generation (afatinib and dacomitinib) epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) benefit patients with non-small cell lung cancer (NSCLC) harboring sensitive mutations and dramatically improve survival (1-5). However, almost all tumors with sensitive mutations acquire resistance to first- or second-generation EGFR-TKIs in approximately 1 year (6). Several mechanisms of the resistance to EGFR-TKIs were reported in the literature (7), and the most common mechanism of resistance to first- and second-generation EGFR-TKI is the mutation of threonine 790 to methionine (T790M)