Zhengbo Song1, Xuzhou Wang2, Yuhui Zheng3, Haiyan Su4, Yiping Zhang5. 1. Department of Medical Oncology, Zhejiang Cancer Hospital, Hangzhou, China; Key Laboratory Diagnosis and Treatment Technology on Thoracic Oncology, Hangzhou, China. 2. Department of Pathology, Fuzhou General Hospital of Nanjing Military Command, Fuzhou, China. 3. Department of Pathology, Fujian Medical University, Union Hospital, Fuzhou, China. 4. Department of Pathology, Zhangzhou Municipal Hospital of Fujian Province, Zhangzhou, China. 5. Department of Medical Oncology, Zhejiang Cancer Hospital, Hangzhou, China; Key Laboratory Diagnosis and Treatment Technology on Thoracic Oncology, Hangzhou, China. Electronic address: zjzlyy16@163.com.
Abstract
BACKGROUND: The prevalence and clinical pathologic characteristics of MET amplification and overexpression in Chinese patients with non-small-cell lung cancer (NSCLC) remain unknown. In this multicenter study, we sought to reveal the frequency and clinical pathologic characteristics of MET amplification and to explore the predictive value of MET amplification and overexpression status in relation to survival in Chinese NSCLC patients. PATIENTS AND METHODS: MET amplification was detected by fluorescence in-situ hybridization in 791 patients with EGFR wild-type samples. MET protein expression was detected by immunohistochemistry. RESULTS: In total, 8 of 791 NSCLC patients with EGFR wild type patients were identified as harboring MET amplification. Among these 8 patients, 1 had adenosquamous carcinoma histology and 7 adenocarcinoma. There was no statistically significant difference among age, sex, smoking status, and histologic type between patients with and without MET amplification. MET amplification was more frequent in advanced-stage disease and in the solid predominant subtype of adenocarcinoma. MET protein expression was performed in 395 patients, and 138 were positive. Patients positive for MET protein expression had worse overall survival (OS) compared to those without MET protein expression (45.0 vs. 65.8 months; P = .001). Multivariate analysis revealed that MET expression was an independent prognostic factor for poor OS (R = 1.497, P = .017), while MET amplification had weak relevance for OS (hazard ratio = 1.974, P = .251). CONCLUSION: MET amplification was rare in Chinese NSCLC patients without EGFR mutation, with a prevalence of about 1%. MET expression but not amplification could be an independent prognostic factor for shorter OS among these EGFR wild-type NSCLC patients.
BACKGROUND: The prevalence and clinical pathologic characteristics of MET amplification and overexpression in Chinese patients with non-small-cell lung cancer (NSCLC) remain unknown. In this multicenter study, we sought to reveal the frequency and clinical pathologic characteristics of MET amplification and to explore the predictive value of MET amplification and overexpression status in relation to survival in Chinese NSCLCpatients. PATIENTS AND METHODS: MET amplification was detected by fluorescence in-situ hybridization in 791 patients with EGFR wild-type samples. MET protein expression was detected by immunohistochemistry. RESULTS: In total, 8 of 791 NSCLCpatients with EGFR wild type patients were identified as harboring MET amplification. Among these 8 patients, 1 had adenosquamous carcinoma histology and 7 adenocarcinoma. There was no statistically significant difference among age, sex, smoking status, and histologic type between patients with and without MET amplification. MET amplification was more frequent in advanced-stage disease and in the solid predominant subtype of adenocarcinoma. MET protein expression was performed in 395 patients, and 138 were positive. Patients positive for MET protein expression had worse overall survival (OS) compared to those without MET protein expression (45.0 vs. 65.8 months; P = .001). Multivariate analysis revealed that MET expression was an independent prognostic factor for poor OS (R = 1.497, P = .017), while MET amplification had weak relevance for OS (hazard ratio = 1.974, P = .251). CONCLUSION: MET amplification was rare in Chinese NSCLCpatients without EGFR mutation, with a prevalence of about 1%. MET expression but not amplification could be an independent prognostic factor for shorter OS among these EGFR wild-type NSCLCpatients.