Diagnostic and Prognostic Role of HBME-1, Galectin-3, and β-Catenin in Poorly Differentiated and Anaplastic Thyroid Carcinomas

Abstract

Thyroid cancer represents the first endocrine malignant neoplasm, accounting for 1% of human malignancy. The majority of which are well-differentiated cancer representing up to 90% of thyroid cancer and pursuing a favorable clinical course. The groups of poorly differentiated thyroid cancer (PDC) and anaplastic thyroid cancer (ATC) have a poor outcome and need a strict clinical surveillance. Thirty-four cases including 23 PDC/insular cancer and 9 ATC were examined for the expression of an immunohistochemical panel made up by HBME-1, galectin-3, and β-catenin and correlated either with histologic prognostic parameters or the overall surveillance. HBME-1 and galectin-3 were expressed in 100% of the PDC/insular cases and in none of the ATC cases. The data for β-catenin pointed out an 80% expression (12/15) in the PDCs and only a focal and nonspecific positivity in the ATCs. A β-catenin-positive expression was found in all patients with a worse outcome/death and in the presence of vascular invasion and metastatic disease. All 3 PDC patients with β-catenin negativity are alive, whereas only 41% (5/12) are alive in the β-catenin-positive group. Our data set up the idea that PDC represents an intermediate step in the biological process of dedifferentiation of thyroid tumors toward ATC. This shift is underlined by the β-catenin expression, which seems to be related to a worse prognostic behavior. HBME-1 and galectin-3 show a similar pattern in PDC compared with well-differentiated carcinoma, whereas they are not expressed, as well as β-catenin, in anaplastic carcinomas.