Serum interleukin-6 levels reflect the disease status of colorectal cancer.

Interleukin-6 (IL-6) has been shown to be associated with cancer development. However, its role in the progression of colorectal cancer has never been elucidated. Our intention was to investigate this role and identify its prognostic significance. One hundred and sixty-four consecutive colorectal cancer patients, whose local lesions were resected, were selected. The preoperative serum IL-6 levels were measured and the relationships between the elevation of IL-6 and both the clinicopathological factors and prognosis of patients were investigated. Median IL-6 level was significantly higher in patients with colorectal cancer than in normal controls. High levels of serum IL-6 (>12 pg/ml) were correlated with larger tumor size, elevated serum CRP levels, and liver metastases (P < 0.05). IL-6 levels also increased in a stage-related manner (P < 0.01). Although serum IL-6 correlated with survival, it is not an independent prognostic indicator. Serum IL-6 levels correlated with disease status of colorectal cancer but could not be regarded as an independent predictor for prognosis.