The predictive model with the univariate Cox regression analysis, clinical covariates of pathologic stage, tumor size, and lymph node metastasis had some predictive value; however, sex, age, race, EGFR mutation, gross pathology, and distant metastasis did not correlate with OS (Figure 4(a)). Here, EGFR is linked to metastatic malignant neoplasm in the lymph nodes.