Objective: To investigate the changes of annexin A7 (ANXA7) level in cancer tissue and peripheral blood in patients with gastric cancer, and its diagnostic value for gastric cancer. 
Methods: One-hundred and five patients with gastric cancer undergoing surgical treatment from January 2013 to December 2015 were enrolled as study subjects. The mRNA and protein expressions of ANXA7 in the cancer tissues and their adjacent tissues of the patients were determined by qRT-PCR and Western blot analysis, and the serum levels of ANXA7 in these patients and 50 healthy individuals were measured by ELISA assay. The relations of ANXA7 expression in cancer tissue and serum ANXA7 level with the clinicopathologic factors of gastric cancer patients were analyzed, and the diagnostic efficiency of serum ANXA7 level for gastric cancer was evaluated by using ROC curve. 
Results: Both mRNA and protein expression levels of ANXA7 in gastric cancer tissue were significantly higher than those in cancer-adjacent tissue (t=17.361, P<0.01; t=15.368, P<0.01); the serum ANXA7 level in gastric cancer patients was significantly higher than that in healthy population (t=12.823, P<0.01). The mRNA and protein expression levels of ANXA7 in gastric cancer tissue as well as the serum ANXA7 level were significantly related to the degree of differentiation and T stage of the tumor, and the mRNA expression level of ANXA7 in gastric cancer tissue and serum ANXA7 level were also significantly related to lymph node metastasis (all P<0.05). There was a significant correlation between the protein level of ANXA7 in cancer tissue and serum (r=0.789, P<0.01). At a cut-off value of concentration of 67.21 ng/L, the sensitivity, specificity, positive predictive value and negative predictive value of the serum ANXA7 level for diagnosis of gastric cancer were 96.59%, 70.15%, 80.95% and 94.00%, respectively.
Conclusion: The ANXA7 expression is increased in gastric cancer tissue, and its expression level is closely related to the degree of malignancy and progression of gastric cancer. The peripheral blood ANXA7 level can better reflect its expression level in cancer tissue, so ANXA7 is likely to become a gastric cancer marker for use in clinical practice.