ABSTRACT
INTRODUCTION: von Willebrand factor (vWf) is thought to mediate binding of tumour cells to platelets and to favour their systemic spreading capacity. Platelets involved in tumour angiogenesis are capable of releasing vascular endothelial growth factor (VEGF). Hence, levels of vWf and VEGF may correlate with cancer stage. The objectives are determine the impact of surgery and chemotherapy on vWf and VEGF in colorectal cancer (CRC) patients. MATERIAL AND METHODS: Twenty healthy volunteers (group 1), 14 patients with locally advanced CRC (group 2) and 12 patients with metastatic CRC (group 3) were enrolled. Blood samples were taken at recruitment in group 1, and before and after surgery and chemotherapy in groups 2 and 3, respectively. Blood levels of vWf, VEGF, platelet count, C-reactive protein (CRP), ceruloplasmin and carcinoembrionary antigen (CEA) were measured. RESULTS: At baseline, group 3 showed higher concentrations of vWf than the other groups (p<0.05). In group 2, vWf became elevated 40% post-surgery (p=0.016), independently of changes in CRP or ceruloplasmin. In group 3, chemotherapy caused a 42% reduction in VEGF (p=0.015). CONCLUSIONS: There was a strong correlation between higher vWf levels and more advanced CRC stage at diagnosis. These levels were elevated post-surgery in patients with locally advanced CRC. Chemotherapy significantly decreased VEGF in metastatic CRC patients before CEA showed any significant change.