TSH Receptor mRNA in Peripheral Blood in Conjunction with Fine Needle Aspiration for the Pre-Operative Identification of Papillary Thyroid Cancer.
Natalie S Freed, Mira Milas, Deborah J Chute. Cleveland Clinic Foundation, OH
Background: Thyrotropin stimulating hormone receptor (TSHR) mRNA in peripheral blood is a newly developed test that has shown some utility in the pre-operative detection of papillary thyroid carcinoma (PTC). We assessed the accuracy of the TSHR mRNA blood test to pre-operatively identify PTC in patients undergoing thyroidectomy and investigated the impact of adding TSHR mRNA results on the sensitivity and specificity of fine needle aspiration (FNA) in detecting PTC.
Design: We retrospectively examined patients who underwent a total thyroidectomy at one institution from 2007-2010 who also had a TSHR mRNA peripheral blood test and thyroid FNA pre-operatively. Cases were included if the thyroid gland was entirely submitted for histology regardless of diagnosis, or was partially submitted with a diagnosis of PTC. TSHR mRNA peripheral blood levels were performed using quantitative PCR, and were considered positive if greater than 1.0 ng/ug. Pre-operative thyroid FNAs within the previous year were categorized as positive, atypical, or negative for PTC. For the purpose of sensitivity and specificity calculations, FNA interpretations of positive and atypical were included together as a positive result.
Results: TSHR mRNA testing demonstrated a sensitivity of 50.3% and specificity of 86.2% for the detection of PTC as illustrated in Table 1.
|Table 2||PTC||No PTC|
|TSHR mRNA +||TSHR mRNA -||TSHR mRNA +||TSHR mRNA -||Total|