IMMUNOHISTOCHEMICAL EXPRESSION AND PROGNOSTIC SIGNIFICANCE OF VEGF-C IN WELL-DIFFERENTIATED THYROID CANCER

Context. Neoangiogenesis and lymphangiogenesis are essential for the growth of tumor and progression of malignancy. Objective. The study examined the significance of VEGF-C expression in comparison to classical prognostic factors in differentiated thyroid carcinoma (DTC), as well as an independent prognostic marker in DTC. Design. The study included 81 patients with DTC allocated in two groups according to the type of cancer (follicular versus papillary) and then compared to expression of VEGF-C and clinicopathological features. Methods. Expression of VEGF-C was identified with anti-VEGF-C antibody using tris-EDTA buffer Antigen Retrieval Protocol. Each specimen was scored with a semi-quantitative score system (H-score). Results. The analysis of T staging system showed a linear correlation between the size of a tumor, expression of VEGF-C and recurrence of a disease, with a statistical significance (p < 0.0001). There was a clear and significant correlation between VEGF-C expression and T stage in patients with papillary carcinoma (p = 0.0294). Analysis of invasion of a surgical margin demonstrated significant positivity in patients with papillary thyroid cancers who expressed VEGF-C (p = 0.0207) indicating the worse prognosis of a disease. Also a statistically significant correlation was between VEGF-C and extrathyroid extension, indicating the worse prognosis (p = 0.0133) in papillary cancers. The level of VEGF-C expression was statistically significant in patients with papillary thyroid cancer (p = 0.039). Conclusions. This study undoubtedly demonstrates that VEGF-C expression is an evident negative prognostic factor in patients with papillary thyroid carcinoma, along with the classic prognostic factors, such as a larger tumor size, tumor margin involvement, extrathyroid extension, i.e. local aggressiveness.