EGFR and metastatic malignant neoplasm in the lymph nodes: For OS, tumor lymph node metastasis (p = 0.000), EGFR overexpression (p = 0.049), and gene amplification (p = 0.002) were the significant predictive factors in univariate analysis, among which lymph node metastasis and EGFR gene amplification were significant predictive factors using multivariate analysis (p = 0.001 and 0.022).