Serum concentrations of vascular endothelial growth factor and nitrite as an estimate of in vivo nitric oxide in patients with gastric cancer

The importance of tumour angiogenesis in the process of tumour growth and progression in solid tumours has been widely accepted. Among many angiogenic factors, vascular endothelial growth factor (VEGF) has been shown to play a major role in the development and dissemination of the malignant tumours. Nitric oxide (NO) production was also observed in solid tumour tissues. NO has been reported to play an important role for the mitogenic effect of VEGF in the angiogenic process. However, little is known about the correlation between VEGF and NO in circulating levels. Therefore, we investigated serum VEGF and NO concentrations in human gastric cancers as well as healthy individuals, and examined the influence of tumour stage on circulating level of VEGF. The study consisted of 11 healthy individuals and 37 patients with primary gastric cancer who did not receive any prior therapy. Patients were categorized into four groups according to TNM classification. The level of VEGF(165) in preoperative sera of gastric cancer patients and healthy donors was assayed using the quantitative sandwich enzyme immunoassay technique. NO concentration was estimated indirectly from serum nitrite. The ANOVA test showed a significant difference in serum VEGF(165) concentrations between tumour stages (P < 0.001). A striking relationship was found between serum NO levels and tumour stage (P < 0.001). A significant difference was also seen between healthy individuals and patients with stage 1 disease. The present study suggested that large tumour burden was associated with significantly increased levels of VEGF(165) and NO. © 1999 Cancer Research Campaign