1. Introduction EGFR (epidermal growth factor receptor) mutation is a major oncogenic driver in non-small cell lung carcinoma (NSCLC), and inhibition of EGFR signaling by EGFR-tyrosine kinase inhibitors (TKIs) represent the optimal clinical treatment strategy for NSCLC patients with EGFR mutations. Currently, the approved EGFR-TKIs in Japan are gefitinib and erlotinib as the first generation, afatinib and dacomitinib as the second generation, and osimertinib as the third generation.
