Clinical importance of vascular endothelial growth factor (VEGF) for papillary thyroid carcinomas.

Vascular endothelial growth factor (VEGF) is a major regulator of angiogenesis and may be produced by some cancer cells. Several recent reports have documented that increased expression of VEGF is associated with risk of recurrence or decreased recurrence-free survival in papillary thyroid cancers (PTC). The aims of this study were to determine whether immunohistochemical expression of VEGF is related to local and distant recurrence of PTC and to evaluate the relationship between hypervascularization and VEGF expression in papillary thyroid carcinomas. VEGF expression was examined immunohistochemically in 48 papillary carcinomas. Ten normal thyroids were used as controls. Patients were followed for 61.7 (range 24-143) months. Twelve of the patients had local and distant recurrences. VEGF immunostaining, blinded for clinicopathological data, was evaluated semiquantitatively by two pathologists. The difference between the recurrent (n:12) and nonrecurrent (n:36) carcinomas was statistically significant (p:0.001). VEGF expression was also stronger in papillary thyroid carcinomas than in normal thyroid tissues. The mean microvascular densities were significantly higher than in normal thyroid tissues. These data indicate that VEGF staining is strongly associated with increased frequency of local and distant recurrence in PTC and that the immunohistochemical profile of the expression may be used as a marker for predicting which tumors have metastatic potential.