Relationship between preoperative serum TSH levels and expression of VEGF in papillary thyroid carcinoma

Abstract

Vascular endothelial growth factor (VEGF) stimulates angiogenesis, increases vascular permeability and seems to correlate to aggressiveness of tumors. Increased expression of VEGF has been observed in papillary thyroid carcinoma (PTC). Thyroid stimulating hormone (TSH) is the major thyroid hormone, but its relationship with VEGF has seldom been studied. Therefore, we explored whether the immunohistochemical expression of VEGF was related to the serum TSH level. VEGF expression was analyzed in 43 archived PTC specimens using immunohistochemistry, with adjacent normal thyroid tissues used as controls. Serum TSH was measured by immunoradiometric assay before surgery and correlated to VEGF expression. Positive VEGF expression was found in 90% of 43 PTC tissue specimens, but not in normal tissue. The serum TSH levels revealed a positive correlation with VEGF expression, R = 0.592 (P < 0.01). TSH is a major thyroid hormone. Whether TSH promotes the progression of PTC is not known but the serum TSH levels reveal a positive correlation with VEGF expression.