Increased Serum Levels of Vascular Endothelial Growth Factor in Patients with Renal Cell Carcinoma

Neovascularization, an essential event for the growth of solid tumors, is regulated by a number of angiogenic factors. One such factor, vascular endothelial growth factor (VEGF), is considered to exert a potent angiogenic activity, as indicated by immunohistochemical and molecular evidence. In this study we investigated the serum VEGF level (s‐VEGF) in patients with renal cell carcinoma (RCC). s‐VEGF in peripheral blood samples was analyzed in 40 RCC patients and 40 patients without cancer (controls) using a sandwich enzyme‐linked immunoassay. In 20 RCC patients, serum samples were obtained separately from the bilateral renal veins. s‐VEGF was also measured before, 4 and 8 weeks after nephrectomy in 11 patients. There were significant differences in s‐VEGF between the RCC patients and the controls (207.3 ± 32.9 vs. 71.5 ± 9.1 pg/ml, mean ± SE) (P < 0.005), between the tumor‐bearing renal veins and the contralateral ones (P < 0.01), between the pre‐ and post‐nephrectomy situations (P < 0.01) and among the various parameters of tumor status such as tumor extent (P < 0.001) and existence of metastasis (P < 0.001). s‐VEGF significantly correlated with the tumor volume obtained by a three‐dimensional measurement (r= 0.802, P < 0.0001). The sensitivity and specificity of s‐VEGF at the cut‐off level of 100 pg/ml, as determined by the receiver‐operating‐characteristics curve, were 80.0% and 72.5%, respectively. The results indicate that tumor tissue of RCC liberates VEGF into the systemic blood flow and that s‐VEGF is a possible marker for RCC.