Clinical relevance of serum vascular endothelial growth factor and interleukin-6 in patients with colorectal cancer

Some biological factors play a role in stimulation of malignant growth, metastasis and angiogenesis; however, their clinical relevance has not yet been well established for most of them. This work was aimed at studying the clinical relevance of serum vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6), in patients with colorectal cancer (CRC). Preoperative serum levels of VEGF and IL-6 were measured by enzyme-linked immuno-assay in 35 CRC patients and in 30 healthy controls. CRC patients with or without metastasis had significantly higher VEGF and IL-6 levels than healthy controls (all P < 0.001). Patients with advanced clinical stage had significantly higher levels of VEGF and IL-6 than those with early clinical stage (all P < 0.001). Also, patients with metastatic disease had significantly higher VEGF and IL-6 levels than those with localized disease (all P < 0.001). The diagnostic accuracy for invasiveness was 83% for VEGF (cut off value = 240 pg/ml) and 66% for IL-6 (cut off value = 6.7 pg/ml), with sensitivity 79% and 74% and specificity 68% and 59%, respectively. In CRC patients, preoperative measurement of serum VEGF and Il-6 may prove useful non-invasive diagnostic indicators associated with advanced clinical stage and tumor metastasis that warrants further investigations.