Angiogenesis and angiogenic growth factors in Wilms tumor

Purpose: Angiogenesis, that is new blood vessel formation, is a prerequisit e for growth and metastasis of solid tumors. This study was undertaken to q uantify tumor capillaries, investigate immunohistochemical expression and m easure serum concentrations of angiogenic growth factors in patients with W ilms tumor. Materials and Methods: The hospital records of 33 patients were reviewed an d new slides were stained for the endothelial cell marker CD31. Capillaries were quantified in the most vascularized part of the tumor (hot spot) and in the whole slide. New slides were stained immunohistochemically for the a ngiogenic growth factors angiogenin, basic fibroblast growth factor (bFGF), transforming growth factor alpha, transforming growth factor beta1-3, tumo r necrosis factor ct and vascular endothelial growth factor (VEGF), and the ir immunoreactivity was quantified. Pretreatment serum samples from 14 pati ents and 56 healthy control children were analyzed using enzyme-linked immu nosorbent assay kits for angiogenin, basic fibroblast growth factor, epider mal growth factor, hepatocyte growth factor, tumor necrosis factor alpha an d VEGF. Results: Logistic regression analysis and Kaplan-Meier estimates showed tha t quantifications based on the tumor hot spot had a significant impact on s urvival probability (p <0.05). The tumor hot spot counts were highest in th e blastemal compartment. Levels of hepatocyte growth factor and VEGF in ser um were 3 times higher than those in controls (p <0.01). Conclusions: Although the sample size is small in this study, the results i mply that angiogenesis in Wilms tumor is driven by angiogenic growth factor s, and that intratumoral capillary quantification and determinations of ser um levels of angiogenic growth factors may be of clinical value.