Abstract: Objective To investigate the expression of microrna-451 in serum of patients with papillary thyroid carcinoma and its diagnostic significance.
Methods Thirty-six patients with papillary thyroid carcinoma were selected as the study group,and thirty-seven patients with benign thyroid tumor were selected as the control group.The relative expression of serum microrna-451 in the two groups was detected by real-time fluorescent quantitative PCR.The expression difference of serum microrna-451 between the two groups was compared,and the relationship between the expression of serum microrna-451 and different clinicopathological features in patients with papillary thyroid carcinoma was analyzed.The diagnostic value of serum microrna-451 in papillary thyroid carcinoma was analyzed by curve analysis.
Results The expression of serum microrna-451 in patients with papillary thyroid carcinoma was significantly lower than that in patients with benign thyroid tumor(1.09±0.27 vs 1.31±0.23);The expression of serum microrna-451 in patients with lymph node metastasis of papillary thyroid carcinoma was significantly lower than that in patients without lymph node metastasis(0.92±0.17 vs 1.28±0.22，P<0.001),the differences were statistically significant;By ROC curve analysis,the AUC of serum microrna-451 in the diagnosis of papillary thyroid carcinoma was 0.720,and 0.873 in the diagnosis of lymph node metastasis.
Conclusion The expression of microrna-451 in serum of patients with papillary thyroid carcinoma is low,especially in patients with lymph node metastasis,which indicates that it has certain diagnostic significance for preoperative diagnosis and lymph node metastasis of papillary thyroid carcinoma.

Key words: microRNA-451, papillary thyroid carcinoma, lymph node metastasis