Abstract:
Objective:To study the correlations among the expression levels of cytokeratin-19(CK-19), vimentin, vascu -lar endothelial growth factor-C (VEGF-C) and cyclooxygenase- 2 (COX- 2) and the differentiation, invasiveness and meta -static potential in papillary and follicular thyroid carcinomas (FTC). Methods: Immunohistochemical SP method was used to assess the expression of CK-19, vimentin, VEGF-C and COX- 2 in the 94cases of papillary thyroid carcinoma (PTC) and 54cases of FTC enrolled in our study. Results: CK-19, VEGF-C and COX- 2 were expressed in the cytoplasm of tumor cells. Vimentin was expressed both in the mesenchyma and in the cytoplasm of tumor cells. Differences in expression were analyzed statistically using the positive rate and expression intensity. The positive rate of CK- 19was significantly higher in PTC ( 90.4%) than in FTC (61.1%). The positive rates of vimentin, VEGF-C and COX-2 in PTC ( 100 %,86.2% and 81.9%, respectively) were similar to those in FTC ( 100 % ,87.0% and 81.5% , respectively). The expression rates of the four pro-teins in PTC with and without lymph node metastasis (including the primary foci and metastatic lesions) were also similar to each other. Except for the positive rates of vimentin expression, both 100 % in the two differentiation types of FTC, the ex-pression rates of CK- 19, VEGF-C and COX- 2 were higher in well-differentiated FTC ( 74.1% ,88.9% and 85.2% ) than in poorly differentiated FTC ( 48.1%,85.2% and 77.8%). The expression intensities of vimentin and VEGF-C in PTC were sig-nificantly higher than those in FTC. The expression intensities of CK-19and COX-2 in PTC were similar to those in FTC. No significant difference was found in PTC between cases with and without metastasis, and no significant difference was found in FTC between the well-differentiated cases and the poorly differentiated cases. There is a positive correlation be -tween the expression intensity of VEGF-C and COX- 2 in PTC, but not between the expression of CK- 19and vimentin. Conclusion : Immunohistochemical detection of CK- 19, vimentin, VEGF-C and COX-2 expression may carry clinical signifi-cance in evaluating the degree of differentiation, invasiveness, metastatic potential, and prognosis of papillary thyroid carcinoma and follicular thyroid carcinoma.