Background: Although serum interleukin-6 (IL-6) has been associated with the development of colorectal cancer, IL-6 expression in cancer tissues has never been elucidated. The role of the tissue expression of IL-6 in colorectal cancer was investigated to identify any prognostic significance.
Materials and methods: One hundred and sixty consecutive patients, whose primary lesions had been resected, were studied. Immunoreactivity of IL-6 in cancerous tissue was measured by immunohistochemical staining; the relationships between the positive expression of IL-6 and both clinicopathological factors and survival were evaluated.
Results: Seventy-four specimens expressed IL-6, and this expression correlated with an elevated serum carcinoembryonic antigen level, lymph node metastasis, venous invasion and advanced stage (p < 0.05). IL-6 expression correlated with poor survival (p < 0.05) and was an independent predictor of prognosis.
Conclusion: Because tissue expression of IL-6 correlates with aggressive colorectal cancer behavior, it may be a useful predictor of prognosis.