Patterns of expression and secretion of vascular endothelial growth factor in malignant soft-tissue tumours.

Vascular endothelial growth factor (VEGF) is an important cytokine especially in the process of tumour angiogenesis. A total of 46 soft-tissue sarcomas were analysed for the expression and possible secretion of VEGF by immunohistochemistry, in-situ hybridisation, and enzyme-linked immunosorbent assays (ELISA). VEGF was demonstrated immunohistochemically in tumour tissue in 45 of 46 cases. The detection of mRNA transcripts yielded evidence of synthesis of VEGF in these sarcomas. ELISA could be performed in 21 cases. Higher concentrations of VEGF were found in tumour-related intraoperatively sampled venous blood in 16 out of 21 patients (76%) than in systemic concentrations taken preoperatively. The results indicated the secretion of VEGF by tumour cells although these raised concentrations were not statistically significant. In 12 out of these 16 patients (75%) a concurrent moderate to strong immunoexpression of VEGF was detected. The relevance of VEGF blood concentrations as a potential "progress parameter" for the course of disease remains questionable. This is mainly due to the lack of statistical significance in the difference between systemic VEGF concentrations in patients and those of a control group. Further long-term follow-up studies are needed, which should include patients with tumour recurrences.