Objective  To compare the expressions of serum tumor markers such as carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9) and carbohydrate antigen 72-4 (CA72-4) in different early malignant tumors of digestive tract.

  Methods  Electrochemiluminescence immunoassay was used to detect the serum levels of CEA, CA19-9 and CA72-4 in 56 patients with early esophageal cancer, 91 patients with early gastric cancer and 100 patients with early colorectal cancer, and the positive rates and expression levels were compared.The positive rates of serum CEA in esophageal cancer, gastric cancer and colorectal cancer were 16.1%, 17.6% and 37.0% respectively, and there were significant differences (P < 0.01).The positive rates of serum CA19-9 in esophageal cancer, gastric cancer and colorectal cancer were 3.6%, 13.2% and 14.0% respectively, but there were no significant differences (P>0.05).The positive rates of serum CA72-4 in esophageal cancer, gastric cancer and colorectal cancer were 3.6%, 23.1% and 20.0% respectively, and there were significant differences (P < 0.05).The level of CEA was the highest in colorectal cancer patients, followed by esophageal cancer patients with the intermediate level and gastric cancer patients with the lowest level, and there were significant differences (P < 0.01).The level of CA19-9 was the highest in colorectal cancer patients, followed by gastric cancer patients with the intermediate level and esophageal cancer patients with the lowest level, and there were significant differences (P < 0.01).The level of CA72-4 was the highest in colorectal cancer patients, followed by gastric cancer patients with the intermediate level and esophageal cancer patients with the lowest level, and there were significant differences(P < 0.05).

  Conclusion  There are significant differences in the positive rates and expression levels of CEA, CA19-9 and CA72-4 in esophageal cancer, gastric cancer and colorectal cancer, which has a certain value for tumor diagnosis.