Effectiveness of tyrosine kinase inhibitors against non-small cell lung cancer patients with postoperative recurrence harboring uncommon EGFR mutations

Abstract

Objective: To investigate the efficacy of tyrosine kinase inhibitor (TKI) treatment on non-small cell lung cancer (NSCLC) patients with postoperative recurrence who harbored uncommon EGFR mutations, and discuss the relationship between TKI treatment and prognosis. Methods: A total of 39 relapsed NSCLC patients after surgery with EGFR uncommon mutations who were detected at Cancer Hospital, Chinese Academy of Medical Sciences between January 1999 and December 2013 were retrospectively analyzed in this study. Twenty patients were treated with EGFR-TKI after recurrence and 19 cases were not. The clinical characteristics of patients with EGFR uncommon mutations were evaluated, and the prognosis of TKI-treatment group and non-TKI treatment group was compared. Results: In 39 relapsed NSCLC patients with EGFR uncommon mutations, insertion mutations and point mutations were included. The highest frequency of EGFR uncommon mutation happened in exon 20 (20/39, 51.3%). A total of 13 uncommon point mutations were detected in exon 18, 20 and 21. The most frequent rare point mutations located in exon 21, and there were 7 different point mutation sites in exon 21. G719S/C/A mutation in exon 18 was the most common type of point mutation (14/25, 56.0%). Survival after postoperative recurrence in TKI treatment group was obviously better than that in non-TKI treatment group, the median time after recurrence were 44 months and 23 months, respectively (P=0.044). However, the postoperative overall survival showed no differences between two groups (48 months vs 43 months, P=0.129). Conclusion: NSCLC patients with postoperative recurrence who harbored rare EGFR mutations should be treated with TKI agent.