title: The -137G>C polymorphism in interleukin-18 promoter region and cancer risk: evidence from a meta-analysis of 21 studies.
abstract: Interleukin-18 (IL-18) is a key cytokine responsible for immune response and involved in the process of cancer development. The association of -137G>C polymorphism in the promoter region of IL-18 with cancer risk is still elusive based on current genetic association studies. We performed this meta-analysis to determine whether the -137G>C polymorphism is associated with cancer risk. A comprehensive search was conducted for databases of PubMed, EMBASE, and China National Knowledge Infrastructure. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the association strength. Publication bias was detected by Egger's and Begg's test. Twenty-one eligible studies including 3,498 cancer patients and 5,222 controls were identified and analyzed. In the overall analysis, no significant association between -137G>C polymorphism and cancer risk was observed. In the sub-group analyses of ethnicities, the -137G>C polymorphism significantly increased cancer risk in Asian population (GC/CC vs. GG: OR = 1.313, 95% CI = 1.053-1.638, heterogeneity P < 0.001) but not in Caucasian population. Further stratified analyses showed that the variant -137C allele was significantly associated with increased risk of nasopharyngeal carcinoma (C vs. G: OR = 1.484, 95% CI = 1.193-1.847, heterogeneity P = 0.213). No publication bias was detected. We provide evidence that the -137G>C polymorphism in IL-18 promoter region significantly increases cancer risk in Asian population but not in Caucasian population, and the variant -137C allele is associated with increased risk of nasopharyngeal carcinoma.
authors.affiliation: Department of Digestive Diseases, Provincial Hospital affiliated to Shandong University, Jinan, 250021, People's Republic of China.
authors.forename: Tie-Jun
authors.initials: TJ
authors.lastname: Liang
authors.forename: Hui
authors.initials: H
authors.lastname: Ma
authors.forename: Cong-Xiao
authors.initials: CX
authors.lastname: Wang
authors.forename: Yin-Rong
authors.initials: YR
authors.lastname: Liu
authors.forename: Xing-Guo
authors.initials: XG
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000235:genetics; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease / Q000208:ethnology / Q000235:genetics*; D005838:Genotype; D006801:Humans; D020382:Interleukin-18 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000208:ethnology / Q000235:genetics; D009369:Neoplasms / Q000208:ethnology / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012307:Risk Factors; D044465:White People / Q000235:genetics; D055815:Young Adult
chemical_list: D020382:Interleukin-18