T790M correlates with longer progression-free survival in non-small cell lung carcinomas harboring EGFR mutations

Background/Aim: The aim of this study was to evaluate the relationship between T790M status and the characteristics of non-small cell lung cancer (NSCLC) patients undergoing rebiopsy after initial epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) therapy and whether the site of rebiopsy has an effect on the detection rate for T790M in these patients. Materials and Methods: We retrospectively reviewed the clinical data from stage IV or recurrent NSCLC patients who harbored EGFR mutations and who had initially received EGFR-TKI at our Center from January 2009 to December 2016. Results: Overall, 129 patients were included. The median age at EGFR-TKI therapy initiation was 73 years and 110 showed progressive disease. The presence of T790M mutation was associated with significantly longer progression-free survival (PFS) and EGFR mutation status. The participants' characteristics and rebiopsy site did not affect the T790M detection rate. Conclusion: It is highly recommended that patients with exon 19 deletions and long PFS undergo screening for T790M.