Because preoperative s-CEA concentration > 5 ng/ml is an independent prognostic factor for poor OS, chemotherapy or intensive follow-up strategies should be considered, particularly in patients with negative lymph node metastasis, if preoperative s-CEA level is > 10 ng/ml8, 19, 22, 23. This evidence concerns the gene CEACAM5 and metastatic malignant neoplasm in the lymph nodes.