Serum IL-10 Predicts Worse Outcome in Cancer Patients: A Meta-Analysis

Background IL-10 is an important immunosuppressive cytokine which is frequently elevated in tumor microenvironment. Some studies have reported that overexpression of serous IL-10 is correlated with worse outcome in patients with malignant tumor. Here, we conducted a meta-analysis to assess the prognostic impact of serous IL-10 expression in cancer patients. Methods We searched PubMed and EBSCO for studies in evaluating the association of IL-10 expression-in serum and clinical outcome in cancer patients. Overall survival (OS) was the primary prognostic indicator and disease-free survival (DFS) was the secondary indicator. Extracted data were computed into odds ratios (ORs) and 95% confidence interval (CI) or a P value for survival at 1, 3 and 5 years. Pooled data were weighted using the Mantel-Haenszel Fixed-effect model. All statistical tests were two-sided. Results A total of 1788 patients with cancer from 21 published studies were incorporated into this meta-analysis. High level of serum IL-10 was significantly associated with worse OS at 1-year (OR = 3.70, 95% CI = 2.81 to 4.87, P < 0.00001), 3-year (OR = 3.33, 95% CI = 2.53 to 4.39, P < 0.0001) and 5-year (OR = 2.80, 95% CI = 1.90 to 4.10, P < 0.0001) of cancer. Subgroup analysis showed that the correlation between serous IL-10 expression and outcome of patients with solid tumors and hematological malignancies are consistent. The association of IL-10 with worse DFS at 1-year (OR = 3.34, 95% CI = 1.40 to 7.94, P = 0.006) and 2-year (OR = 3.91, 95% CI = 1.79 to 8.53, P = 0.0006) was also identified. Conclusions High expression of serous IL-10 leads to an adverse survival in most types of cancer. IL-10 is a valuable biomarker for prognostic prediction and targeting IL-10 treatment options for both solid tumors and hematological malignancies.