갑상샘 종양에서 RET/PTC와 galectin-3의 발현 : 임상병리학적 특징과의 상관성

Abstract

The rearrangement of RET proto-oncogene has been reported to be the most common genetic change in papillary thyroid carcinoma. However, its prevalence has been reported variably and its relation to clinical outcome has been controversial. Galectin-3 is a β-galactoside binding protein, recently recognized as a promising molecular marker of thyroid malignancy. The aim of this study was to investigate the expression rate of RET/PTC protein and galectin-3 and to assess its potential as a marker in the diagnosis and prognosis of thyroid malignancy and the role in thyroid cancer biology. I studied the expression of RET/PTC protein and galectin-3 in 132 cases of thyroid tumors (74 papillary carcinomas, 17 micropapillary carcinomas, 13 follicular carcinomas, 8 undifferentiated carcinomas, 20 follicular adenomas) by immunohistochemical analysis. Analysis for correlation between the results of immunohistochemistry and clinicopathological factors (age, sex, multicentricity, vascular invasion, tumor size, extrathyroidal extension, lymph node metastasis and stage) was conducted. The prevalence of RET/PTC and galectin-3 expressions were 60.4% and 90.1% in papillary carcinoma (including micropapillary carcinoma), respectively. The RET/PTC and galectin-3 expressions were higher frequency in papillary carcinoma than other tumors. The RET/PTC and galectin-3 is a reliable marker of papillary carcinoma. There was no statistically significant association between the RET/PTC expression and galectin-3 expression. The RET/PTC expression or galectin-3 expression did not correlate with clinicopathological factors. The RET/PTC and galectin-3 expression by immunohistochemistry itself is not an indicator of local metastatic spread or extrathyroidal extension in papillary thyroid carcinoma. The high expression of RET/PTC and galectin-3 in micropapillary carcinoma and no correlation between their expression and tumor size may indicate that they are not related to proliferative activity and growth of papillary thyroid carcinoma but play some other role in thyroid cancer biology. However, its detection can be a useful diagnostic tool for diagnosing papillary thyroid carcinoma.