Identification of thyroid follicular carcinoma and papillary thyroid carcinoma by plasma microRNA-21

Abstract

Objective To investigate the value of plasma microRNA (miRNAs, miR)-21 in differentiating thyroid follicular carcinoma from thyroid papillary carcinoma. Methods 45 patients with thyroid follicular carcinoma, 61 patients with thyroid papillary carcinoma and 50 normal subjects were selected as subjects. The expression of miR-21 in plasma was detected by real-time fluorescent quantitative polymerase chain reaction (FQ-PCR). Receiver operating characteristic (ROC) curve was established to analyze the cut-off value, sensitivity and specificity of miR-21 in differentiating thyroid follicular carcinoma from papillary thyroid carcinoma. Results The relative expression levels of miR in plasma of normal persons, follicular thyroid carcinoma and papillary thyroid carcinoma were 0.254±0.123, 4.047±1.499 and 1.274±0.581, respectively. There was significant difference among the three groups (P=0.010). The relative expression level of miR-21 in plasma of follicular thyroid carcinoma was significantly higher than that of papillary thyroid carcinoma. The relative expression of miR-21 in plasma of patients with thyroid papillary carcinoma was significantly higher than that of normal subjects (P=0.010). The ROC curves were established with plasma levels of miR as test variables and thyroid follicular carcinoma and thyroid papillary carcinoma as state variables. The area under the curve (AUC) was 0.931 [95% confidence interval (CI): 0.890-0.991]. The optimum cut-off value (Cut-off value) for differentiating follicular thyroid carcinoma from papillary thyroid carcinoma was 2.325. The sensitivity and specificity were 85.11% and 96.72% respectively, the positive predictive value and negative predictive value were 95.24% and 89.39% respectively, and the Yorden index was 81.83%. Conclusion Detection of the expression of microRNA-21 in plasma is helpful to differentiate follicular thyroid carcinoma from papillary thyroid carcinoma and to differentiate follicular thyroid carcinoma from follicular thyroid carcinoma. Key words: MicroRNA-21; Thyroid follicular carcinoma; Papillary thyroid carcinoma; Differential diagnosis