Abstract: Objective To investigate the expression levels and the clinical diagnostic value of miR-21, miR-204 and miR-34a in serum of gastric cancer patients. Methods A total of 42 patients with gastric cancer, 22 patients with benign gastric lesion and 25 healthy volunteers, who were treated at the First Affiliated Hospital of Air Force Medical University from February 2017 to January 2018, were collected. The expressions of serum miR-21, miR-204 and miR-34a were assessed by the real-time PCR, and the diagnostic efficiency were evaluated by the receiver operating characteristic(ROC) curve. Results The expression of miR-21 in the serum of gastric cancer patients was higher than that of benign lesion and healthy volunteers(all P<0.001), but the expressions of miR-204 and miR-34a were lower than those of the other two groups(all P<0.001). The expression of miR-204 was correlated with distant metastasis(P=0.048). ROC curve showed that the areas under the curve(AUC) of miR-21, miR-204 and miR-34a in the single diagnosis of gastric cancer were 0.736, 0.724 and 0.654, respectively; the AUC of combined diagnosis was 0.849, which was significantly higher than that of single diagnosis(all P<0.05), and the sensitivity and specificity were 92.86% and 65.96%, respectively. The AUC of combined diagnosis of early stage gastric cancer patient was 0.828, and the sensitivity and specificity were 87.23% and 69.23%, respectively. Conclusion Combined detection of serum miR-21, miR-204 and miR-34a can improve diagnostic efficiency of gastric cancer, with important value in the diagnosis of early gastric cancer.

Key words: Gastric cancer, miR-21, miR-204, miR-34a, Diagnostic value