An association was found between reduced expression of miR-34a, miR-146a with both metastasis to regional lymph nodes (relative risk RR=10.50 and RR=5.25, respectively) and the development of distant metastases (RR=9.50 and RR=4, 40, respectively) in gastric cancer. They are excellent classifiers: AUC>0.9 for both miRNAs. The association of miR-335 expression with metastasis to the lymph nodes is much weaker, but it is also a good classifier for identifying a group with distant metastasis (RR=5.90). A correlation was found between the expression of miR-34a and miR-146a during metastasis, which is absent in non-metastatic tumors. Thus, miR-34a, miR-146a, and miR-335 miRNAs can be proposed as candidates for biomarkers of the risk of gastric cancer metastasis.
Keywords: gastric cancer; metastasis; miR-146a; miR-335; miR-34a.