Expression of VEGF and its receptors and angiogenesis in bone and soft tissue tumors

Background: Tumor angiogenesis and vascularization are essential requirements for the growth and metastasis of tumors. There is evidence that overexpression of the vascular endothelial growth factor (VEGF) is correlated with an adverse prognosis in some tumors. The expression of VEGF, its receptors and microvessel density (MVD) of bone and soft tissue tumors was evaluated. Materials and Methods: Tissue specimens of 60 patients including 30 malignant and 30 benign tumors confirmed by biopsy were examined. Expression of VEGF and its receptors (flt-1 and KDR/flk-1) was observed by immunohistochemistry. Tumor angiogenesis was assessed morphologically by measuring intratumoral MVD. Results: Semi-quantitative evaluation of immunoreactivity showed that VEGF was significantly higher in malignant tumors than in benign tumors. A correlation was found between the immunoreactivity of VEGF and KDR. Moreover, correlations were found either between MVD and VEGF or between MVD and KDR/flk-1. Conclusion: Signal transduction, in particular by VEGF and KDR, potentially contributes to the angiogenesis of bone and soft tissue tumor.