Effect of standard chemotherapy and antiangiogenic therapy on plasma markers and endothelial cells in colorectal cancer

INTRODUCTION: The importance of the endothelium in angiogenesis and cancer is undisputed, and its integrity may be assessed by laboratory markers such as circulating endothelial cells (CECs), endothelial progenitor cells (EPCs), plasma von Willebrand factor (vWf), soluble E selectin, vascular endothelial growth factor (VEGF) and angiogenin. Antiantigenic therapy may be added to standard cytotoxic chemotherapy as a new treatment modality. We hypothesised that additional antiangiogenic therapy acts in a contrasting manner to that of standard chemotherapy on the laboratory markers. METHODS: We recruited 68 patients with CRC, of whom 16 were treated with surgery alone, 32 were treated with surgery followed by standard chemotherapy (5-flurouracil), and 20 were treated with surgery followed by standard chemotherapy plus anti-VEGF therapy (Avastin). Peripheral blood was taken before surgery, and again 3 months and 6 months later. CD34(+)/CD45(−)/CD146(+) CECs and CD34(+)/CD45(−)/CD309[KDR](+) EPCs were measured by flow cytometry, plasma markers by ELISA. RESULTS: In each of the three groups, CECs and EPCs fell at 3 months but were back at pre-surgery levels at 6 months (P<0.05). VEGF was lower in both 3-and 6-month samples in the surgery-only and surgery plus standard chemotherapy groups (P<0.05), but in those on surgery followed by standard chemotherapy plus anti-VEGF therapy, low levels at 3 months (P<0.01) increased to pre-surgery levels at 6 months. In those having surgery and standard chemotherapy, soluble E selectin was lower, whereas angiogenin was higher at 6 months than at baseline (both P<0.05). CONCLUSIONS: We found disturbances in endotheliod cells regardless of treatment, whereas VEGF returned to levels before surgery in those on antiangiogenic therapy. These observations may have clinical and pathophysiological implications.