Prognostic Significance of Circulating IL-10 and IL-6 Serum Levels in Colon Cancer Patients Undergoing Surgery

The prognostic significance of IL-10 and IL-6 serum levels in colon cancer patients undergoing surgery was investigated. To this end, 50 candidate patients with colon cancer for surgery were admitted to the study. Of these, 30 could be subjected to a potentially curative surgery. Cytokine serum levels at several time points before and after surgery were measured by ELISA. Circulating levels of IL-10 and IL-6 were found to be elevated in cancer patients with respect to controls. Both IL-10 and IL-6 serum levels were demonstrated to predict the likelihood of curative surgery (predictive accuracy, 83.3%). IL-10 serum levels returned to normal in all but 6 patients who underwent curative surgery. These latter had tumor recurrence (predictive accuracy, 100%). In contrast, IL-6 serum levels significantly decreased in all patients, regardless of whether cure was surgically achieved, but did not normalize. On multivariate analysis, basal IL-10 serum levels were found to be among the variables significantly predicting the disease-free survival rate. Stepwise regression selected tumor stage, basal IL-10 serum level, and basal CEA serum level as the best combination of variables for prediction of the likelihood of tumor recurrence. In conclusion, preoperative serum levels of IL-10 were shown to be useful markers for predicting both likelihood to perform curative surgery and, in combination with the 16th postoperative day IL-10 serum levels, tumor recurrence (predictive accuracy, 73.6 and 96%, respectively). IL-6 serum levels were found to have a more limited prognostic role.