EGFR and lung cancer: By contrast, although only few comparative studies of EGFR-TKI targeting only elderly patients with EGFR mutation-positive lung cancer have been conducted, the results of the NEJ001 trial, which included patients with a PS of 3 or 4 and aged younger than 74 years, those with a PS of 2–4 and aged between 75 and 79 years, and those with a PS of 1–4 and aged older than 80 years, showed favorable outcome improvement in PS in most patients in the group given gefitinib (PFS: 6.5 months; OS: 17.8 months) [45].