title: Association of TLR2 and TLR4 polymorphisms with risk of cancer: a meta-analysis.
abstract: BACKGROUND
  The activation of Toll-like receptors (TLRs) may be an important event in the immune evasion of tumor cell. Recently, numerous studies have investigated the associations between TLR2 -196 to -174 del and two SNPs of TLR4 (rs4986790 and rs4986791) and the susceptibility to different types of cancer; however, the results remain conflicting. The aim of this study was to assess the association between TLR2 and TLR4 polymorphisms and cancer risk in a meta-analysis with eligible published studies.
  
  
  RESULTS
  A dataset composed of 14627 cases and 17438 controls from 34 publications were included in a meta-analysis to evaluate the association between overall cancer risk or cancer-specific risk and three SNPs of TLRs (TLR2 -196 to -174 del, TLR4 rs4986790 and rs4986791). The results showed that all of these three polymorphisms were significantly associated with the increased cancer risk (dominant model: OR = 1.64, 95% CI: 1.04-2.60 for TLR2 -196 to -174 del; OR = 1.19, 95% CI: 1.01-1.41 for TLR4 rs4986790; and OR = 1.47, 95% CI: 1.120-1.80 for TLR4 rs4986791; respectively). In stratified analysis, we found the effect of TLR2 -196 to -174 del on cancer risk remained significant in the subgroup of Caucasians and South Asians, but not in East Asians. However, the association between rs4986791 and cancer risk was significant in both South Asians and East Asians, but not in Caucasians. Furthermore, the association between rs4986790 and cancer risk was statistically significant in digestive cancers (dominant model: OR = 1.76, 95% CI: 1.13-2.73) and female-specific cancers (dominant model: OR = 1.50, 95% CI: 1.16-1.94). However, no significant association with risk of digestive system cancers was observed for TLR2 -196 to -174 del and TLR4 rs4986791.
  
  
  CONCLUSIONS
  This meta-analysis presented additional evidence for the association between TLR2 and TLR4 polymorphisms and cancer risk. Further well-designed investigations with large sample sizes are required to confirm this conclusion.
authors.affiliation: Institute of Stomatology, Nanjing Medical University, Nanjing, China ; Section of Clinical Epidemiology, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Cancer Center, Nanjing Medical University, Nanjing, China.
authors.forename: Longbiao
authors.initials: L
authors.lastname: Zhu
authors.affiliation: Institute of Stomatology, Nanjing Medical University, Nanjing, China ; Section of Clinical Epidemiology, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Cancer Center, Nanjing Medical University, Nanjing, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Yuan
authors.affiliation: Department of Epidemiology and Biostatistics, MOE Key Laboratory of Modern Toxicology, School of Public Health, Nanjing Medical University, Nanjing, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Jiang
authors.affiliation: Institute of Stomatology, Nanjing Medical University, Nanjing, China.
authors.forename: Ruixia
authors.initials: R
authors.lastname: Wang
authors.affiliation: Section of Clinical Epidemiology, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Cancer Center, Nanjing Medical University, Nanjing, China ; Department of Epidemiology and Biostatistics, MOE Key Laboratory of Modern Toxicology, School of Public Health, Nanjing Medical University, Nanjing, China.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Ma
authors.affiliation: Central Lab, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, China.
authors.forename: Shuangyue
authors.initials: S
authors.lastname: Zhang
mesh_terms: D044466:Asian People; D001943:Breast Neoplasms / Q000208:ethnology / Q000235:genetics* / Q000276:immunology / Q000473:pathology; D004067:Digestive System Neoplasms / Q000208:ethnology / Q000235:genetics* / Q000276:immunology / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D020641:Polymorphism, Single Nucleotide; D011471:Prostatic Neoplasms / Q000208:ethnology / Q000235:genetics* / Q000276:immunology / Q000473:pathology; D012306:Risk; D051195:Toll-Like Receptor 2 / Q000235:genetics* / Q000276:immunology; D051197:Toll-Like Receptor 4 / Q000235:genetics* / Q000276:immunology; D044465:White People
chemical_list: C495342:TLR2 protein, human; C495345:TLR4 protein, human; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4