Diagnostic value of TROP-2 expression in papillary thyroid carcinoma and comparison with HBME-1, galectin-3 and cytokeratin 19

Abstract

In this study, we compared the diagnostic value of TROP-2 expression in distinguishing between benign and malignant thyroid lesions to those of HBME-1, CK19 and galectin-3. We selected 102 cases from our archive including 20 normal thyroid tissues, 23 follicular nodular diseases, 17 follicular adenomas, 20 follicular variant papillary carcinomas and 22 classical variant papillary carcinomas. Tissue microarrays constructed from these cases were immunohistochemically analyzed with HBME-1, CK19, galectin-3 and TROP-2. Respectively 73.8%, 83.3%, 69% and 50% of all papillary carcinomas were positive with HBME-1, CK19, galectin-3 and TROP-2. CK19 was positive respectively by 100%, 43.5% and 35.3% in cases of normal thyroid, follicular nodular diseases and follicular adenoma, while the other markers were negative. In distinguishing benign and malignant lesions, which constitutes this study, HBME-1, CK19, galectin-3 and TROP-2 were statistically significant (p < 0.001). In distinguishing cases of follicular variant papillary carcinoma from follicular nodular diseases and follicular adenoma, HBME-1 and galectin-3 were statistically significant (p < 0.001). Consequently, in this study, we found that all immunohistochemical markers were effective in distinguishing benign and malignant thyroid lesions. In determining malignancy, HBME-1 had the highest diagnostic accuracy, while CK19 was the most sensitive marker. The sensitivity increased when the markers were used together.

Thyroid Nodules in Diagnostic Pathology: From Classic Concepts to Innovations

“…Thus, in a recent study, TROP-2 was found in between 90.0 and 95.3% PC and 70.0% follicular variants [71]. However, other research groups have described significantly less frequent reactivity: 50% [61].…”

“…The reported expression rate of HBME-1 in PC ranges between 73.8% [61], 75.9% [62], 85.0% [63] and 96.1% [64]. Higher frequency has been found in classic PC, e.g., ranging between 95.9 and 100% in contrast to 45.0-81.1% in follicular variants [61,65].…”

“…The differences might be attributable to the evaluation (pattern: membranous only vs. membranous and cytoplasmic), cut-off threshold, selection of primary antibodies, epitope retrieval, dilution, incubation temperature and incubation time. Thus, although HBME-1 is among the most sensitive and specific antigens in the PC diagnostics [61] and has been included in most diagnostic panels [58] for PC or thyroid cancer (predominated by PC), controversies remain.…”

“…Few, but promising reports are available on human trophoblast cell surface antigen TROP-2 in PC, which seems to be a reliable marker in histology and cytology, holding high specificity and sensitivity [61,[69][70][71]. The TROP-2 protein is absent from MC, follicular tumours and non-neoplastic thyroid tissue [70,71], while it is present in 82.5% of PC.…”

“…Galectin-3 is upregulated by hypoxia-inducible factor (HIF)-1 [76]. In PC, the expression rate has been estimated as 64.7% [65] vs. 69% [61] vs. 92% [67] or even 100% [77]. Lower rate has been reported in follicular vari- [75].…”