Multiple variable analysis of age at diagnosis, gender, symptom(s) at presentation, smoking, tumor diameter, GGO status (GGO, mixed GGO, or pure solid tumor), pleural involvement, presence of air bronchogram sign on radiography, serum CEA concentration (ng/mL), and pathologic type showed that the following factors significantly predicted lymph node metastasis: GGO status, symptoms at presentation, and abnormal CEA titer (Table 3). This evidence concerns the gene CEACAM5 and metastatic malignant neoplasm in the lymph nodes.