Relationship between plasma levels of vascular endothelial growth factor and serum levels of interleukin-12 in patients with colorectal cancer.

Background: Vascular endothelial growth factor (VEGF) is thought to be the most potent angiogenic factor in the numerous malignant tumors and a prognostic indicator for cancer patients. Interleukin 12 (IL-12) is a heterodimeric cytokine that has potent anti-tumor and anti-metastatic activities, Recently, it has been suggested that IL-12 regulates VEGF in a murine breast cancer model. Materials and Methods. Blood from 26 patients with colorectal cancer was obtained prior to surgery, Plasma levels of VEGF and serum levels of IL-12 were assessed using the quantitative sandwich enzyme immunoassay technique. We investigated the preoperative relationships between plasma levels of VEGF, serum levels of IL-12 and clinicopathological factors in patients with colorectal cancer. Results. Although not statistically significantly, high plasma levels of VEGF and low serum levels of IL-12 tended to occur with more advanced colorectal cancer. Plasma levels of VEGF in patients who had circumferential involvement of the tumor greater than 1/2 were only significantly increased. The preoperative relationship between plasma levels of VEGF and serum levels of IL-12 tended to be negatively correlated. Conclusion: These results suggest that high plasma levels of IL-12 or low serum levels of IL-12 may be observed in more advanced colorectal cancer patients. Thus, these patients may require additional immunochemotherapy after surgery. IL-12 may regulate VEGF in the patients diagnosed with colorectal cancer.