EGFR and metastatic neoplasm: In the multivariate analysis, EGFR exon 19 deletion showed independent association with favorable OS (p=0.028), while age >70 years (p=0.017), ECOG performance status ≥2 (p=0.001), primary metastatic disease (p=0.007), and synchronous brain metastasis (p=0.026) were independent prognostic factors for unfavorable OS (Table 2).