Our findings shed light on the clinical efficacy of osimertinib as a form of sequential therapy after progressive disease under first- and second-generation EGFR-TKI in advanced and recurrence EGFR-mutant NSCLC patients with acquired T790M mutation as well as the impact of the different lines of sequential osimertinb used. This evidence concerns the gene EGFR and non-small cell lung carcinoma.