EGFR and non-small cell lung carcinoma: In the present study, we found a longer OS in stage IV NSCLC patients with an ECOG score of 0 and 1 than in those with an ECOG score of 2 or greater (P = 0), and ECOG score was identified as an independent prognostic factors for OS and PFS, indicating that ECOG score remains a prognostic factor in advanced EGFR-mutant NSCLC patients.