Endocrine Abstracts

Objectives: Finding novel tumor markers capable to recognize aggressive papillary thyroid carcinoma (PTC) forms are of great importance. We evaluated hsa-microRNA-204-3p (miR-204-3p) for differential diagnosis of thyroid tumors and assessed its prognostic usefulness.

Methods: MiR-204-3p levels were determined in 77 PTC cases of diverse histological variants, 12 cases of follicular thyroid adenoma (FTA), and 89 matched nonmalignant thyroid epithelial tissues (NMT) using RT-qPCR. The results were evaluated in comparison with the clinicopathological features of the patients.

Results: The relative expression of miR-204-3p is lower in PTC compared to the levels in paired NMT, with the median down-regulation of 65% (P < 0.05). The level of miR-204-3p down-regulation depends on PTC subtype – PTC cases with classical variant architecture had significantly more down-regulated values of miR-204-3p (median down-regulation was 85%) than all other PTC subtypes (median down-regulation in follicular variant was 41%, in cases with mixed architecture 60%, in rare variants, that included Warthin-like, tall cell, solid, clear cell, and oxyphilic cases, was 45%) (P < 0.05). Lower levels of relative miR-204-3p expression in PTC associate with the presence of metastasis to regional lymph nodes, intraglandular tumor dissemination and a degree of tumor infiltration through the gland (P < 0.05). On the other hand, miR-204-3p is up-regulated in FTA (median up-regulation 178%). Up-regulated expression of miR-204-3p is a sensitive (83.3%) and specific (74.7%) marker for distinction of FTA from PTC (cut off=1.08, P < 0.001, AUC=0.821).

Conclusions: MiR-204-3p is a useful marker for PTC detection, particularly its classical variant, and can help in risk stratification of PTC patients.