CEACAM5 and malignant colon neoplasm: In the presence of malignant lesions, relevant antigens can be discharged from the blood circulation through the thoracic duct, exhibiting the elevation of CA199 in the blood.18 In our study, CEA and CA199 in patients with colon cancer were significantly higher than those in patients with benign lesions, with statistically significant differences (p=0.000).