OBJECTIVES
Gefitinib, a tyrosine kinase inhibitor (TKI) targeting epidermal growth factor receptor (EGFR), shows excellent clinical benefit in treating advanced non-small-cell lung cancer (NSCLC). The aim of this study was to compare the efficacy and toxicity of gefitinib as first-line therapy and second-line therapy for advanced lung adenocarcinoma patients with positive exon 21 (L858R) or exo...