Expression of vascular endothelial growth factor and angiogenesis in gastrointestinal stromal tumor of the stomach

Vascular endothelial growth factor (VEGF) is associated with the malignant potential of several types of carcinoma. The aim of this study was to elucidate the clinical significance of VEGF expression in gastrointestinal stromal tumor (GIST). METHODS: Specimens obtained from 53 patients who had underwent surgical resection for GIST of the stomach were used in this study. Specimens were examined immunohistochemically for VEGF expression and Ki-67 expression. Tumor microvessel density (MVD) was determined immunohistochemically with anti-CD31 antibody, and was estimated by averaging the counts from three high-power fields in the area showing the greatest neovascularization. RESULTS: VEGF expression was detected in 14 (26.4%) of the 53 lesions and correlated significantly with tumor size, liver metastasis, Ki-67 labeling index, and MVD. Prognosis was significantly poorer than in patients with tumors expressing VEGF than in patients with tumors lacking VEGF expression. Multiple logistic regression analysis for 10-year survival showed VEGF expression and high mitotic rate to be independent predictor of a poor outcome. CONCLUSIONS: Angiogenesis associated with VEGF may play an important role in the progression of GIST. VEGF expression may serve as an indicator of a poor prognosis.