Associations of IL-10 genetic polymorphisms with the risk of urologic cancer: a meta-analysis based on 18,415 subjects

Background: Interleukin-10 (IL-10) is a powerful modulator of anti-tumor immune responses. The IL-10 promoter region polymorphisms are known to regulate IL-10 production, and thus are thought to be implicated in tumorigenesis. Recently, the roles of these polymorphisms in urologic cancer have been extensively studied, with conflicting results. Therefore, we conducted the present meta-analysis to better elucidate the correlations between IL-10 polymorphisms and urologic cancer risk. Methods: Eligible articles were searched in PubMed, Medline, Embase, Scopus and CNKI up to May 2016. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to detect any potential associations between IL-10 polymorphisms and the risk of urologic cancer. Results: A total of 22 case-control studies including 8572 patients and 9843 controls were analyzed. The overall meta-analysis results showed that IL-10 -592C>A polymorphism was significantly associated with urologic cancer in CA versus AA (P = 0.04, OR 0.87, 95% CI 0.76-0.99) and AA versus CC+CA (P = 0.03, OR 1.15, 95% CI 1.02-1.31). Subgroup analyses by cancer types suggested there were significant associations between all the three investigated IL-10 polymorphisms and bladder cancer. However, subgroup analyses by ethnicity only detected a weak association between IL-10 -819C> T and Asian population. Conclusions: Our findings suggests that IL-10 -592C> A polymorphism may implicate with urologic cancer risk. Besides, promoter region polymorphisms of IL-10 may serve as potential biological markers, especially for bladder cancer. Furthermore, IL-10 -819C> T polymorphism may contribute to urologic cancer susceptibility in Asians while all the three studied variants of IL-10 did not relate to Caucasian urologic cancer predisposition.