Investigation of therapeutic modalities of G719X, an uncommon mutation in the EGFR gene in non-small cell lung cancer

作     者：Hua Zheng Yuan Gao Zan Liu Zhe Qian Tongmei Zhang Jie Li Hongmei Zhang Qunhui Wang Fanbin Hu Baolan Li 

作者机构：Department of Medical Oncology Beijing Chest Hospital Capital Medical University 

出 版 物：《Oncology and Translational Medicine》 (肿瘤学与转化医学（英文版）)

年 卷 期：2019年第5卷第2期

页      面：91-97页

学科分类：10[医学] 

主　　题：lung neoplasms EGFR uncommon mutation G719X target therapy 

摘      要：Objective G719 X is the most frequently seen uncommon mutation of the epidermal growth factor receptor(EGFR) gene, which is a point mutation at exon 18 with three common subtypes, G719 A/G719 C/G719 S. This study explored the clinicopathological characteristics of the G719 X mutation and investigated the efficacy of EGFR-tyrosine kinase inhibitor(TKI) treatment and chemotherapy in patients with the G719 X mutation; the survival rate after these different treatment modalities were then analyzed in order to provide evidence for clinical *** Clinical data of 41 patients with the G719 X mutation admitted in the Beijing Chest Hospital, Capital Medical University from September 2014 to July 2018, were collected and the EGFR mutations were detected by amplification refractory mutation system-polymerase chain reaction(ARMS-PCR). The clinicopathological characteristics of the G719 X mutation were analyzed, and the relationship among the G719 X mutation, the efficacy of different treatment modalities, and the progression-free survival(PFS) was analyzed. Results Of the 41 cases, 24(58.5%) were G719 X single mutations and 17(41.5%) were compound mutations, including G719 X/S768 I, G719 X/L861 Q, G719 X/19 del, and G719 X/c-Met compound mutation. The objective response rate(ORR) of first-line EGFR-TKI therapy was 50%(6/12), the disease control rate(DCR) was 83.3%(10/12), and the median PFS(mPFS) was 9 months. After resistance to EGFR-TKI in the previous treatment, the ORR(71.4%, 5/7) and DCR(100%, 7/7) were still high following EGFR-TKIs, by an mPFS of 8 months. The ORR of chemotherapy was 33.3%(2/6), the DCR was 100%(6/6), and the mPFS was 6 months. Conclusion G719 X is an uncommon mutation of the EGFR gene and is sensitive to many EGFR-TKIs. It can be treated with the second-or third-generation EGFR-TKIs after resistance to the first-generation EGFR-TKIs. G719 X mutation also showed favorable effect to chemotherapy.