Abstract:Objective To investigate the correlation between MET gene amplification and clinicopathological features in non-small cell lung cancer (NSCLC) patients, and to reveal the sensitivity to crizotinib of patients with coexistence of MET amplification and other driver gene mutations.Methods Retrospective data from 252 non-small cell lung cancer (NSCLC) patients were collected. Gene status of EGFR, ALK, ROS1, RET, HER2, BRAF, and MET were performed using second generation sequencing platform of HYK-PSTAR-IIA. In special MET amplification cases, MET were also validated by Fish method. Patients were divided into groups according to MET amplification detection results, and their age, smoking history, gender, pathological type, disease stage, and other driver gene mutations were compared among the groups. The prognostic data were also collected and analyzed of patients with coexisting MET amplification and other driver gene mutations after crizotinib treatment.Results Of the included 252 patients, 49 (19.4%) were positive for MET gene amplification. The frequency of de novo MET amplification and acquired MET amplification occurred in patients received EGFR-TKIs was 16.2% (33/203) and 31.2% (15/48), respectively. MET amplification was significantly associated with advanced stage (Ⅲ~Ⅳ) (P=0.02), bone metastases (P=0.02) and ROS1 fusion-positive (P=0.02). No significant differences in the age, history of smoking, sex, and pathologic types were found. Of the 31 patients who had coexistent MET amplification and other genetic alterations, five patients including two cases of de novo MET amplification and three cases of acquired MET amplification, were treated with crizotinib. Four patients achieved good response to crizotinib, and one patient died of severe infection. All patients achieved certain response.Conclusion The frequency of MET amplification in this study was higher than that was reported in the literature. We observed a trend towards a high prevalence of advanced stage, bone metastases, and ROS1 fusion-positive patients. Patients with the coexistence of MET amplification and other driver gene mutations could also have some benefits from crizotinib.