Gastric cancer was the fourth common cancer worldwide, and it was the second most common cause of death from cancer . Gastric cancer can generally be classified into two topographical subsites, the cardia (upper stomach) and noncardia (lower stomach). Chronic Helicobacter pylori infection is considered the principal cause of noncardia gastric cancer, with almost all cases attributed to this bacterium. Meanwhile, cardia gastric cancer is considered to be linked to H. pylori infection, excess body weight and gastroesophageal reflux disease injury .Early detection is important for improving the survival rate of patients with gastric cancer (GC).
Some serum tumor markers including CEA, CA19-9, CA50, and CA72-4 have been reported to be elevated in some patients with gastric cancer [3–5].
In advanced or recurrent gastric cancer, the estimation of either CA 19-9 or CA-50 and CEA serum values may help in checking the prognosis, determining the efficacy of palliative treatment modalities, and recognizing recurrences. 
CA72-4 is highly sensitive to gastric cancer, and the positive rate of serum CA72-4 in gastric cancer is reported to be 36% to 94%. And its specificity is also high, some of which even reach 100%.CA72-4 can be used to detect whether there are residual tumor cells after operation and judge the prognosis of gastric cancer.
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