Associations Between Three Polymorphisms in the Interleukin-4 Receptor Gene and Risk of Cancer: a Meta-analysis

Interleukin-4 receptor (IL-4R) gene single nucleotide polymorphisms (SNPs) are implicated in cancerdevelopment. However, results from the published reports have remained inconclusive. The objective of thisstudy was to conduct a meta-analysis investigating the association between polymorphisms in IL-4R gene andcancer risk. Pubmed, EMBASE and China National Knowledge Infrastructure (CNKI) were searched for casecontrolstudies published up to October 30, 2012 that investigated IL-4R polymorphisms and cancer risk. Oddsratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the strength of any associations. ThreeIL-4R polymorphisms (Q576R, rs1801275; I75V, rs1805010; S503P, rs1805015) in 21 case-control studies wereanalyzed. Our meta-analysis indicated that these three polymorphisms are not associated with cancer risk whenall studies were pooled together. In the subgroup analysis by tumor site, the results showed that Q576R G allelecarriers were associated with a significantly decreased cervical cancer risk (recessive model: OR = 0.77, 95%CI= 0.60-0.98; homozygote comparison: OR = 0.76, 95%CI = 0.58-0.98). I75V G allele carriers were associatedwith a decreased risk of renal cancer (dominant model = 0.71, 95%CI = 0.57-0.89, heterozygote comparison:OR = 0.69, 95%CI = 0.55-0.87). When stratified by ethnicity, Q576R G allele carriers were associated with adecreased cancer risk in Caucasians (dominant model: OR = 0.90, 95%CI = 0.83-0.98; heterozygote comparison:OR = 0.89, 95%CI = 0.82-0.98). I75V G allele carriers were associated with a decreased cancer risk in Asians(heterozygote comparison: OR = 0.76, 95%CI = 0.62-0.94). S503P C allele carriers were also associated with adecreased cancer risk in Asians (CC VS TT: OR = 0.29, 95%CI = 0.08-0.99). Our results suggest that Q576R,I75V and S503P may be associated with a decreased cancer risk for certain types of cancers and in some specificethnic groups. Future case-control studies with large sample size are needed to evaluate these associations indetail.