Investigation on peripheral blood TSHR mRNA for differentiation of benign and malignant thyroid nodules

Abstract

Objective To assess the value of peripheral blood thyroid stimulating hormone receptor(TSHR) mRNA determination in differential diagnosis of benign and malignant thyroid nodules.Methods Fine needle aspiration cytology (FNAC) and (or) postoperative histopathology as the gold standard were carried out,the expression of circulating TSHR mRNA was determined by RT-PCR in 33 patients with benign thyroid nodules,39 patients with thyroid cancer,and 20 normal controls.Results TSHR mRNA signals were not detected in normal controls,the positive rate of TSHR mRNA was higher in the group with malignant nodules than the group of benign nodules (91.2％ vs 48.5％,P＜0.01).TSHR mRNA level in the preoperative malignant group was significantly higher than that in the normal,benign,and postoperative cancer groups (all P ＜ 0.01).Using peripheral blood TSHR mRNA for differentiating benign or malignant of thyroid nodule had a sensitivity,specificity,and accuracy of 91.2％,51.5％ and 71.6％,respectively.The sensitivities of TSHR mRNA,FNAC,and these two methods combined in detecting malignant nodules were 91.3％,86.9％,and 100.0％ respectively,while diagnostic accuracies were respectively 84.0％,80.0％,and 92.0％.TSHR mRNA expression showed no significant relationship with sex,age,size,and number of nodule in these patients (all P ＞ 0.05),but it did exhibit significant difference between benign and malignant nodules(P＜0.01).Conclusion The peripheral blood TSHR mRNA could be used as a molecular marker for thyroid cancer,and it would help enhance the preoperative differentiation of benign and malignant thyroid nodules. Key words: Thyroid cancer; Peripheral blood; Thyroid stimulating hormone receptor; Molecular markers