EGFR and adenocarcinoma: The results showed that the EGFR mutation rate was significantly higher in females (30/45, 66.7%) than in males (25/72, 34.7%; P = 0.0011), in never smokers (35/57, 61.4%) than in smokers (20/60, 33.3%; P = 0.0030), in patients with metastasis (44/78, 56.4%) than in those without metastasis (11/39, 28.2%; P = 0.0057), and in patients with adenocarcinoma (51/96, 53.1%) than in those with squamous (3/15, 20%; P = 0.025).