Abstract
The progression of cancer is largely dependent on neoangiogenesis. Circulating endothelial progenitor cells (EPC) have the ability to form complete vascular structures in vitro and play a crucial role in tumor vasculogenesis. Emerging evidence suggests that surgical injury may induce the mobilization of EPC in animal models, and this might have a negative effect on the prognosis of cancer patients. We studied 20 patients (10 men, 65±13 years) undergoing laparotomy for surgical treatment of various forms of abdominal cancer, and 20 age- and sex-matched healthy control subjects. The number of circulating EPC, defined as CD34+/KDR+ cells identified among mononuclear cells isolated from peripheral venous blood, was determined preoperatively and at days 1 and 2 after surgery. Surgery induced a significant increase in circulating EPC levels at day 1 (from 278/mL, interquartile range 171–334, to 558/mL, interquartile range 423–841, p<0.001) and day 2 (709/mL, interquartile range 355–834, p<0.001) compared with baseline values. EPC levels did not change in control subjects. Seven subjects who underwent laparotomic surgery for non-neoplastic disease also showed an increase in EPC levels after surgery (p=0.009 and p=0.028 at day 1 and day 2, respectively). We conclude that patients undergoing elective laparotomic surgery for cancer demonstrate an increase in EPC post-operatively. The potential adverse effects of surgical stress-induced EPC mobilization on tumor and metastasis growth in cancer patients need to be addressed in future studies.