Clinical significance of preoperative serum vascular endothelial growth factor levels in patients with colorectal cancer and the effect of tumor surgery

Abstract

Background: Vascular endothelial growth factor (VEGF) is an angiogenic cytokine involved in the progression of solid tumors. In this study we evaluated the clinical usefulness of preoperative serum VEGF concentrations in patients with colorectal cancer. The changes in serum VEGF levels after tumor surgery were also evaluated.

Methods: Serum VEGF levels were determined by an enzyme-linked immunosorbent assay in the sera of 61 healthy control subjects and 67 patients with colorectal cancer preoperatively and 7 and 30 days after surgery.

Results: Serum VEGF levels in patients with colorectal cancer (median, 492 pg/mL; interquartile range, 281 to 737 pg/mL) were higher (P <.0001) than in control subjects (median, 186 pg/mL; interquartile range, 100 to 273 pg/mL). There was a significant association between serum VEGF levels and disease stage, invasion depth of the tumor, the presence of lymph node and distant metastases, and the degree of differentiation. Curative but not palliative resection of the primary tumor resulted in a significant decrease of preoperative serum VEGF levels but normalized in only 72% of patients. Failure of a return of VEGF to normal after resection for cure was associated with an increased although not statistically significant risk of metastasis during follow-up. Univariate analysis showed a lower survival rate for patients with increased preoperative serum VEGF levels (P <.002). Multivariate regression analysis showed that the prognostic value of serum VEGF level was not independent of tumor stage.

Conclusions: These findings suggest that VEGF plays an important role in tumor progression and the formation of distant metastases in colorectal cancer. It is at present unclear whether serial estimation of serum VEGF is clinically useful in the prediction of tumor relapse.