EGFR and lung adenocarcinoma: As a result, ECOG PS 2–4 (Hazard ratio (HR): 5.52, 95% confidence interval (CI): 2.04–14.95; p = 0.001) and positive staining of EGFR IHC (HR: 0.29, 95% CI: 0.12–0.68; p = 0.004) were the independent factors that significantly affected PFS for the lung adenocarcinoma patients treated with EGFR TKIs (Table 5).