title: Association between CTLA-4 60G/A and -1661A/G polymorphisms and the risk of cancers: a meta-analysis.
abstract: OBJECTIVE
  CTLA-4 is one of the most fundamental immunosuppressive cotykines which belongs to the immunoglobulin super-family, and is expressed mainly on activated T cells. Previous studies have reported the existence of CTLA4 60G/A and CTLA4 -1661A/G polymorphism in cancers. However, the effects remain conflicting. Hence, we performed a meta-analysis to investigate the association between these polymorphisms and cancer risk.
  
  
  METHODS
  We searched the Pubmed and Web of Science databases until October 24, 2013 to obtain relevant published studies. Pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs) for the relationship between CTLA4 gene polymorphisms and cancer susceptibility were calculated by stata 11 software. Heterogeneity tests, sensitivity analyses and publication bias assessments were also performed in our meta-analysis.
  
  
  RESULTS
  A total of 22 articles comprising 31 case-control studies concerning the CTLA-4 60G/A and CTLA-4 -1661A/G polymorphisms were included in the meta-analysis. The pooled results suggested the CTLA-4 60G/A polymorphism was significantly associated with an increased skin cancer risk (AA vs. GG: OR = 1.32, 95%CI = 1.09-1.59; AA vs. GA+GG: OR = 1.26, 95%CI = 1.07-1.48). For CTLA-4 -1661 A/G polymorphism, the results showed that the CTLA-4 -1661A/G polymorphism was significantly associated with an increased cancer risk (GA vs. AA: OR = 1.44, 95%CI = 1.13-1.82; GA+GG vs. AA: OR = 1.35, 95%CI = 1.07-1.69; G vs. A: OR = 1.21, 95%CI = 1.01-1.47), especially in gastric cancer, breast cancer, other cancers and in Asians population subgroups.
  
  
  CONCLUSIONS
  Our meta-analysis suggests that the CTLA-4 -1661A/G polymorphism is a potential factor for the susceptibility of cancer, especially in gastric cancer, breast cancer and other cancers, and the CTLA-4 60G/A polymorphism is significantly associated with increased skin cancer risk. The effect of the CTLA-4 -1661A/G polymorphism on cancer susceptibility especially exists in Asians and population based subjects.
authors.affiliation: Department of neurosurgery, the First Affiliated Hospital, Nanjing Medical University, Nanjing, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Yan
authors.affiliation: Department of neurosurgery, the First Affiliated Hospital, Nanjing Medical University, Nanjing, China.
authors.forename: Pin
authors.initials: P
authors.lastname: Chen
authors.affiliation: Department of neurosurgery, the First Affiliated Hospital, Nanjing Medical University, Nanjing, China.
authors.forename: Ailin
authors.initials: A
authors.lastname: Lu
authors.affiliation: Department of neurosurgery, the First Affiliated Hospital, Nanjing Medical University, Nanjing, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China.
authors.forename: Aihua
authors.initials: A
authors.lastname: Gu
mesh_terms: D060908:CTLA-4 Antigen / Q000235:genetics*; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006801:Humans; D009369:Neoplasms / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide
chemical_list: D060908:CTLA-4 Antigen