Clinical Experience with First-generation Epidermal Growth Factor Receptor 
Tyrosine Kinase Inhibitors in Non-small Cell Lung Cancer Patients 
with Brain Metastasis

Background and objective A survival analysis and the influencing factors for non-small cell lung cancer (NSCLC) patients with brain metastases accepting first-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKIs) treatment have not yet been elucidated to date. In this study, we collected and analyzed the survival data of NSCLC patients with brain metastasis to obtain evidence and to provide guidance in clinical practice. Methods NSCLC patients with brain metastases who were treated with first-generation EGFR-TKIs were retrospectively collected in 2012-2013 from Shanghai Chest Hospital, Shanghai Jiao Tong University. The Kaplan-Meier method and Cox regression were performed for univariate and multivariate analyses, respectively, to explore the independent predictors influencing the survival of patients with NSCLC brain metastases. Results The median progression-free survival (PFS) and median overall survival (OS) of all patients treated with first-generation EGFR-TKIs were 10.0 months (95%CI: 8.3-11.7) and 28.0 months (95%CI: 22.9-33.1), respectively. Pathological subtypes were the independent predictors of PFS (P=0.001), and tumor differentiations were the independent predictors of OS (P=0.050). Conclusion First-generation EGFR-TKIs showed promising efficacy in NSCLC patients with brain metastases. PFS was longer in patients with adenocarcinoma than in those with a non-adenocarcinoma subtype. OS was longer in patients with differentiated tumors than in those who developed poorly differentiated tumors