Vascular endothelial growth factor (VEGF) – a valuable serum tumour marker in patients with colorectal cancer?

Introduction Neo-angiogenesis, of great importance for tumour growth and nutrition, is preferentially mediated by the cytokine vascular endothelial growth factor (VEGF), which has a direct effect on vascular endothelial cell proliferation and migration. This study was designed to clarify whether VEGF is a suitable tumour marker in sera of patients with a colorectal cancer, and whether VEGF concentrations in sera and tumour tissues are correlated with tumour extension (pTNM) and especially with tumour volume or size. Furthermore, the influence of VEGF levels on patients» prognosis was examined. Methods VEGF serum concentrations of 122 patients with colorectal cancer and 65 controls were determined with an ELISA kit. Additionally, VEGF concentrations of tumour and normal tissue were measured in 38 patients using the same ELISA.Results Our results demonstrate that VEGF is not a suitable diagnostic tumour marker in patients with colorectal cancer due to its low sensitivity (36%). However, a combination of the serum tumour markers CEA and VEGF can significantly increase the pre-operative diagnostic sensitivity to 62%. VEGF serum levels differed significantly between patients (mean 438 pg/ml) and controls (mean 203 pg/ml), and also between tumour and normal tissue (984 vs 89 pg/mg protein). Serum concentration showed a significant correlation to tumour volume and size. Patients with VEGF serum levels greater than cut-off had a poorer prognosis than those less than or equal to cut-off. For this reason VEGF could be used as a predictor of patients» outcome.