CEACAM5 and gastric cancer: However, the sensitivity and specificity of these indicators in gastric cancer are low, for example, the positive rate of CEA in gastric cancer is only 4.3%, the positive rates of CA19-9, glycohydrate chain antigen 72-4 (CA72-4) and carbohydrate chain antigen (CA-125) are 1.5%, 4.8% and 1.9%, respectively, and the positive rate of the combined detection of the above indicators is only 10.4% [64].