AIM: To investigate the expression of interleukin-6 (IL6) in colon cancer tissue, and to examine if the risk of relapse is influenced by IL6 expression.

MATERIALS AND METHODS: Fresh-frozen biopsies from tumor and normal adjacent tissues were taken from patients with colon cancer during surgery and stored at -80 °C. mRNA expression for interleukin-6 was evaluated with reverse transcription real time quantitative polymerase chain reaction. Survival analyses were carried-out using a Cox competing risk regression model.

RESULTS: IL6 mRNA was significantly more highly expressed in tumor tissue compared to normal adjacent tissue (p<0.001). We found no significant association with regard to IL6 expression and histological differentiation or cancer stage. We found a significant association between high IL6 expression and risk of relapse (Hazard Ratio=2.23, 95% CI=1.10-4.53; p<0.05), also when adjusted for clinicopathological characteristics (Hazard Ratio=2.16, 95% CI=1.07-4.40; p<0.05).

CONCLUSION: Interleukin-6 is up-regulated in colon cancer tissue at the transcriptional level and is significantly associated with increased risk of relapse.