Studies have explored the diagnostic value of CEA, CA724, CA199 and CA125 for gastric cancer, and the results suggest that the sensitivity of these tumor markers in diagnosing gastric cancer is between 20% and 40%, and the sensitivity of combining these four tumor markers is only 60.9%25.In this study, it was found that the sensitivity of single tumor markers in the diagnosis of gastric cancer was 32%-67%, and the sensitivity increased to 91.7% after combined detection, which was somewhat inconsistent with previous reports. This evidence concerns the gene CEACAM5 and gastric cancer.