Clinical benefit of second EGFR-TKI retreatment on overall survival in patients with advanced non-small-cell lung cancer harboring EGFR-mutation positive after failure of the initial EGFR-TKI treatment: A retrospective analysis.

Abstract

e19164 Background: The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) bring the best result to EGFR-mutation positive non-small cell lung cancer patients, but most lead to drug resistance. These acquired resistances are associated with T790M mutation or Met amplification, HGF expression. To assess whether affects overall survival in these patients, we did a retrospective study comparing survival outcomes in 2nd EGFR-TKI treated patients with controls without 2nd EGFR-TKI screened during the same time period. Methods: We examined overall survival in thirty-two of 52 patients with advanced, EGFR-mutation-positive NSCLC who treated 1st EGFR-TKI (gefitinib) from January 2009 to December 2012. We identified 16 patients who were given 2nd EGFR-TKI (erlotinib) after failure of the initial gefitinib treatment (retreatment group) with 16 patients who were not given 2nd EGFR-TKI but given only chemotherapy (control group), 20 patients who might treat with 2nd EGFR-TKI or chemotherapy at that time were excluded in progress after failure of the initial gefitinib treatment. To assess differences in overall survival, we assessed subsets of clinically comparable 2nd EGFR-TKI retreatment group. Results: Among 16 patients who were given 2nd EGFR-TKI, retreatment group who were given one or two cytotoxic chemotherapy from 1st EGFR-TKI to 2nd EGFR-TKI, median overall survival from initiation of the diagnosis with advanced IIIB/IV stage or surgical recurrent NSCLC was 24.2 months. 16 patients of control group who were given from second to seven line cytotoxic chemotherapy, overall survival was 15.8 months (p=0.021). Retreatment group who were given 2nd EGFR-TKI was significantly longer than control group in EGFR mutation positive patients. Response rate and disease control rate with 2nd EGFR-TKI retreatment are 12.5% and 31.3%. Conclusions: In patients with advanced, EGFR mutation positive NSCLC, retreatment group who were given 2nd EGFR-TKI therapy was associated with improved survival compared with control group who were given only cytotoxic chemotherapy.