AFP and gastric cancer: Table 5 and Fig. 3 show that with the progression of gastric cancer, the proportion of positive tumor markers increased, and the AFP, CEA, CA125, CA199, and CA242 positive levels in the M1 stage were statistically significant compared with those in the M0 stage and control group (P < 0.001), although the AFP (P = 0.045) and CA125 (P = 0.752) positive levels were not statistically significant when compared with the M0 stage and control group.