The relationship between circulating interleukin-6 and carcinoembryonic antigen in patients with colorectal cancer

PURPOSE: The purpose of this study was to clarify whether or not preoperative serum levels of interleukin-6 (IL-6) correlate with well-established prognostic variables (serum level of carcinoembryonic antigen (CEA), stage, histological grade, lymphatic and venous invasion) in colorectal cancer patients. PATIENTS AND METHODS: Serum levels of IL-6 and CEA were determined in 62 patients who underwent resection of colorectal cancer. The patients were divided into two groups based on a selected cut-off value: high and low IL-6 and CEA groups. RESULTS: The median serum level of IL-6 in colorectal cancer patients was significantly higher than the median level in normal controls (p = 0.0014). Multivariate logistic regression analysis showed that a high serum level of CEA is an independent predictor for a high serum level of IL-6 (odds ratio, 4.10; p = 0.046). CONCLUSION: A high serum level of IL-6 is significantly associated with a high serum level of CEA in preoperative colorectal cancer patients.