Association between the HER2 Gene Status and the Efficacy of First-line Pemetrexed Combined with Platinum Chemotherapy in Patients with Advanced Lung 
Adenocarcinoma

Human epidermal growth factor receptor 2 (HER2) is one of the driver genes of non-small cell lung cancer (NSCLC). Several studies have shown that the efficacy of pemetrexed in HER2-mutant NSCLC is controversial. The aim of this study is to investigate the efficacy of pemetrexed combined with platinum chemotherapy in patients with HER2-mutant and HER2 wild-type lung adenocarcinoma. The clinical data of 106 cases of EGFR, ALK, ROS-1, KRAS, BRAF, RET and MET-negative patients with advanced lung adenocarcinoma patients who diagnosed by histopathology in the First Affiliated Hospital of Zhengzhou University were retrospectively reviewed. The relationships between HER2 gene status, clinical characteristics and response and progression-free survival (PFS) were analyzed. All of the 106 patients' HER2 status were determined. HER2 mutations occurred in 32 cases (30.2%), no mutations in 74 cases (69.8%). HER2 mutations were common in young, non-smoking and female patients. All patients received first-line pemetrexed and