The EGFR mutation rate was significantly lower in the younger age group than in the older age group (53.3% versus 66.7%, P = 0.035) in never-smoking male patients with adenocarcinoma; and also in never-smoking female patients with adenocarcinoma (58.6% versus 69.9%, P = 0.001). This evidence concerns the gene EGFR and adenocarcinoma.