Thyroid : official journal of the American Thyroid Association 2018 01 29() doi 10.1089/thy.2017.0127
Papillary thyroid carcinoma (PTC) variants have several overlapping clinical and pathological features. The World Health Organization (WHO) published recently a new classification of thyroid tumors containing significant revisions. the encapsulated papillary thyroid carcinoma (EPTC) has been recognized as a distinctive variant of PTC. The noninvasive encapsulated follicular variant of PTC has been reclassified as "Noninvasive follicular thyroid neoplasms with papillary-like nuclear features (NIFTP)". Different neoplasms are associated with different outcomes and require different clinical management. The objective of this study was to explore the miRNA expression patterns specific for classic PTC (cPTC), encapsulated PTC (EPTC), follicular variant of PTC (FVPTC) and NIFTP to identify biomarkers of diagnostic and prognostic utility aiming for better clinical decisions.
The expression of 84 miRNAs was determined by quantitative real time PCR in 113 thyroid tissues of PTC (classic, encapsulated and follicular), NIFTP and hyperplasia lesions. Expression of the same miRNAs were tested in preoperative and postoperative whole blood samples.
Several miRNAs were differentially expressed in the different groups. Expression profile of miRNAs in the tissue was similarly reflected in the circulation. Receiver operating characteristic (ROC) curve analysis shows that miR-7-5p, miR-222-3p and miR-146b-5p can discriminate between the different groups with high sensitivity and specificity. Downregulation of miR-144-3p, miR-15a-5p, miR-20a-5p, miR-32-5p miR-142-5p, miR-143-3p and miR-20b-5p is associated with aggressive behavior in cPTC. Circulating miR-146b-5p, miR-222-3p, miR-155-5p and miR-378a-3p are potential diagnostic and follow up biomarkers in PTC .
Downregulation of miR-7-5p discriminates NIFTP from hyperplasia; Upregulation of miR-222-3p discriminates FVPTC from NIFTP. High levels of miR-146b-5p distinctively characterizes cPTC. These miRNAs are useful biomarkers in the diagnosis of PTC and NIFTP, and help to avoid unnecessary thyroidectomy and improve clinical management.