EGFR and adenocarcinoma: Multivariate analysis indicated that erlotinib treatment was significantly less likely among smokers compared to non-smokers (OR: 0.27; 95% CI: 0.12–0.59) and patients with other/not specified NSCLC histologies compared to patients with adenocarcinoma (OR: 0.14; 95% CI: 0.04–0.54) and more likely among patients with EGFR mutations (OR: 9.90; 95% CI: 3.04–32.24).