The mutation profile of genes related to primary resistance to EGFR-TKI in early NSCLC.

Abstract

e21014 Background: In targeted therapy for patients with advanced non-small cell lung cancer (NSCLC), approximately 30% of NSCLC patients with EGFR mutations develop primary resistance at the beginning of treatment with TKIs. However, the knowledge of primary resistance in early-stage NSCLC patients with EGFR positve remains poorly understood. Methods: Mutations of nine genes that may be related to primary resistance EGFR TKIs in advanced non-small cell lung cancer were chosen through pubmed and other databases including EGFR T790M, EGFR 20ins, PIK3CA, KRAS, BRAF, ERBB2 amplification, MET amplification, PTEN deletion and BCL2L11 deletion. Gene mutations related to primary resistance in patients with early-stage lung cancer (I-IIIA) from the TCGA database were analyzed. Results: According to TCGA database, there were 1089 patients with NSCLC of which 585 were lung adenocarcinoma and 504 lung were squamous cell carcinoma. A number of 46 EGFR-sensitive (19del / L858R) mutations were observed in adenocarcinoma, of which the clinical information of which 44 cases harbored competed clinical information including 39 patients with early stage could be identified as follows,1 patient in stage I, 11 patients in stage IA, 8 patients in stage IB, 7 patients in stage IIA, 4 patients in stage IIB, 8 patients in stage IIIA, 1 patient in stage IIIB and 4 patients in stage IV, respectively. Among the 39 cases of early non-small cell lung cancer with EGFR-sensitive mutations, 2 case of EGFR T790M mutations (5.12%), 2 case of PIK3CA (5.12%), 2 case of BRAF (5.12%), 11 case of MET (DUP) (28.2 %), 8 case of ERBB2 (DUP) (20.5%) and 5 case of PTEN (Del) (12.8%) mutations were observed respectively. Meanwhile, none of primary resistance gene mutations could be found in non-small cell lung squamous cell cancer(0/1). Conclusions: The presence of different mutation frequency in the primary resistance genes associated with EGFR TKIs in patients with early NSCLC was proved. Our study suggested it was necessary for patients to test mutations in primary resistance genes before accepted the adjuvant and neoadjuvant therapy using TKIs. As a retrospective study with a relatively small population, the conclusions of this study needed to be verified with a larger sample.