Concentrations of VEGF and VEGFR1 in paired tumor arteries and veins in patients with rectal cancer.

Increased plasma concentrations of vascular endothelial growth factor (sVEGF) are associated with poor prognosis of colorectal cancer patients. The aim was to investigate the contribution of the tumor to plasma concentrations of VEGF and VEGF receptor 1 (VEGFR1). Preoperative blood samples from a peripheral vein and intraoperative blood samples from a tumor artery, a tumor vein, and from a peripheral vein were drawn from 28 patients undergoing elective surgical resection of primary rectal cancer. Plasma concentrations of VEGF and VEGFR1 were determined by ELISA. Counts of white blood cells and platelets were performed in all samples. No significant difference between plasma VEGF levels in the obtained blood samples was found (0.35 < P < 0.86). Plasma sVEGFR1 concentrations were significantly increased in tumor veins compared with tumor arteries. In addition, a significant reduction in plasma sVEGFR1 concentrations from preoperative to intruoperative samples was observed. There was a significant efflux of neutrophils to the tumor, but none of the observed changes in plasma VEGF or VEGFR1 levels correlated to changes in counts of white blood cells or platelets (sVEGF: 0.33 < P < 0.73 and sVEGFR1: 0.32 < P < 0.98). No changes in sVEGF plasma concentrations from tumor arteries to tumor veins were demonstrated, whereas there was a significant increase in sVEGFR1 from tumor arteries to tumor veins. Changes in sVEGF or sVEGFR1 from tumor arteries to tumor veins were not associated with changes in counts of white blood cells or platelets.