Serum interleukin-10 levels in patients with advanced gastrointestinal malignancies

BACKGROUND: Interleukin-10 (IL-10) is a cytokine with immunosuppressive properties. In this study, the authors investigated the prognostic significance of IL-10 levels in the sera of 58 patients with advanced gastric or colorectal carcinoma. METHODS: IL-10 serum levels were measured before chemotherapy, on completion of chemotherapy, and at follow-up by means of a commercially available enzyme-linked immunoadsorbent assay kit. The results then were analyzed in comparison with other prognostic variables and a model predicting overall survival (OS) and time to disease progression (TTP) was generated. RESULTS: Elevated levels of serum IL-10 were found in carcinoma patients compared with healthy controls (19.6 +/- 6.8 pg/mL vs. 9.2 +/- 1.5 pg/mL; P < 0.0001), with those patients with metastatic disease showing significantly higher levels than patients with undisseminated disease (21.9 +/- 6. 7 pg/mL vs. 15.5 +/- 3.6 pg/mL; P = 0.0003). Retrospective analysis of prechemotherapy IL-10 serum levels showed a significant difference between responders and nonresponders (15.8 +/- 2.5 pg/mL vs. 21.6 +/- 7.6 pg/mL; P < 0.0001). Moreover, a further significant increase in IL-10 serum levels was observed in nonresponders at the end of therapy (21.6 +/- 7.6 pg/mL prechemotherapy vs. 31.3 +/- 11.6 pg/mL postchemotherapy; P < 0.0001) whereas no significant differences were observed in responders. Using univariate analysis, both OS and TTP were shown to be affected by the median pathologic levels of IL-10; multivariate analysis related to OS and TTP identified performance status and IL-10 serum level as the relevant prognostic factors, respectively. Finally, stepwise regression analysis identified IL-10 serum level and metastases as the prognostic factors related to both OS and TTP. CONCLUSIONS: The results of the current study show that measurement of pretreatment serum levels of IL-10 is of independent prognostic utility in patients with advanced gastrointestinal carcinoma and may be useful for the detection of disease progression.