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

Anaplastic lymphoma kinase (ALK) is one of the major driver genes of non-small cell lung cancer (NSCLC). Several studies have shown that the efficacy of pemetrexed in ALK-positive lung cancer is controversial. The aim of this study is to explore the efficacy of pemetrexed-based chemotherapy in patients with ALK-positive and negative lung adenocarcinoma. The clinical data of 98 cases of epidermal growth factor receptor (EGFR), kirsten rat sarcoma viral oncogene (KRAS), V-rafmurine sarcoma viral oncogene homolog B1 (BRAF)-negative patients with advanced lung adenocarcinoma patients who diagnosed by histopathology from January 2015 to April 2016 in the First Affiliated Hospital of Zhengzhou University were collected. The relationships between ALK gene status, clinical characteristics and response and progression-free survival (PFS) were analyzed. All of the 98 patients' ALK status were determined. ALK gene fracture fusion occured in 34 cases (34.7%), no fracture fusion in 64 cases (65.3%). All patients underwent