EGFR and non-small cell lung carcinoma: Gefitinib and erlotinib are recommended in elderly patients with age ≥ 75 years and in patients with performance status (PS) decreased to ≥2 in The Japanese Lung Cancer Society Guideline for non-small cell lung cancer stage IV [1] because of their efficacy and safety [3–6], although the guidelines recommend osimertinib as first-line therapy in NSCLC patients with exon 19 deletions or L858R point mutations in exon 21 of EGFR [1].