Abstract: Objective To explore the relationship between zinc-α-glycoprotein (ZAG) and lipid metabolic state of tumor patients, the serum levels of lipolytic factor ZAG in patients with various digestive system carcinoma were detected.Methods We collected serum samples from patients with various digestive system carcinoma, benign lesions and normal subjects. For each disease and normal subject we collected 6 cases. And then we detected lipid metabolism related indexes of all samples. The serum levels of ZAG were semi-quantitative identified by using western blotting. Results In each group, the serum levels of TC, TG, HDL-C, LDL-C were no significant difference among the normal, benign and malignant groups. In gastric, colonic, rectal groups, the expression of ZAG in serum among the normal, benign and malignant groups had no obvious difference (P=0.589, P=0.618, P=0.864). However,there was a significant difference between hepatocellular carcinoma group and normal group or benign group (P=0.013, P=0.008), but between the normal group and benign group, there was no statistical significance (P=0.804). Conclusion The expression of ZAG in serum were different among various digestive system carcinoma,especially, hepatocellular carcinoma group was more significant than gastric, colonic and rectal malignant groups. Compare with TC, TG, HDL-C and LDL-C, ZAG may be a more sensitive indicator for evaluating lipid metabolism of patients with hepatocellular carcinoma.

Key words: zinc-α-glycoprotein (ZAG), gastric cancer, hepatocellular carcinoma, colonic cancer, rectal cancer, lipid metabolism