Serum interleukin-10 is an independent prognostic factor in advanced solid tumors

Interleukin (IL)-10 is a Th2 type pleiotropic cytokine that has been found to be produced at the tumor site and to be increased in sera of patients suffering from different types of cancer. IL-10 has been shown to hinder a number of immune functions, i.e., T lymphocyte proliferation, Th1 type cytokine production, antigen presentation, and lymphokine-activated killer cell cytotoxicity. To assess its prognostic value, we measured serum levels of IL-10 in 118 patients with advanced solid tumors before treatment, after completion of therapy, and during follow-up. Other prognostic variables, to which IL-10 results were compared, were analyzed as well. IL-10 serum levels were found significantly elevated in cancer patients with respect to healthy controls. Of interest, a significant decrease in IL-10 serum levels was observed in the responder group, whereas a significant increase was recorded in the non-responder group. Using univariate and multivariate analyses, a significant relationship was shown between IL-10 serum levels and both overall survival (OS) and time to treatment failure (TTF). Stepwise regression analysis selected IL-10 serum level, performance status (PS), and stage as the best association of variables with significant impact on OS and TTF. In conclusion, this study shows that IL-10 has an independent prognostic significance in patients with advanced solid tumors and may be useful for monitoring disease progression.