The results in Table 6 show that the sensitivity of AFP, CEA, CA125, CA199, and CA242 to detect gastric cancer was 16.04%, 25.00%, 19.78%, 23.88%, and 24.25%, respectively, and the sensitivity of combined detection was 44.78%, with a specificity of 95.22% and an accuracy of 66.88%. Here, CEACAM5 is linked to gastric cancer.