title: The association between UGT1A7 polymorphism and cancer risk: a meta-analysis.
abstract: BACKGROUND
  studies investigating the associations between UDP-glucuronosyltransferase 1A7 (UGT1A7) gene polymorphisms and various carcinomas risk reported conflicting results. To derive a more precise estimation of the association, we have conducted a meta-analysis.
  
  
  METHODS
  data were collected from the following electronic databases: PubMed, Medline and Chinese Biomedical Literature Database, with the last report up to September 2011. Case-control studies containing available genotype frequencies of UGT1A7 were chose. The odds ratio (OR) and its 95% confidence interval (95%CI) were used to assess the strength of association.
  
  
  RESULTS
  a total of 22 separate case-control studies including 3852 cases and 5604 controls based on the search criteria were involved in this meta-analysis. The combined results based on all studies showed that there was a statistically significant link between UGT1A7*3 allele and cancer risk (OR = 1.31, 95%CI = 1.14-1.50, P = 0.0001). In the stratified analysis by racial descent, significant increased risk was found in Asian population for UGT1A7*3 allele (OR = 1.41, 95%CI = 1.22-1.63, P < 0.00001). No significant associations were found between the UGT1A7 polymorphism and cancer susceptibility among Caucasians and African-Americans. In the subgroup analysis by cancer types, significant associations were found in UGT1A7*2 allele (OR = 1.23, 95%CI = 1.06-1.43, P = 0.006) and *3 allele (OR = 1.51, 95%CI = 1.11-2.06, P = 0.009) for hepatocellular carcinoma, *3 allele for lung cancer (OR = 1.36, 95%CI = 1.11-1.68, P = 0.004) and for bladder cancer (OR = 1.50, 95%CI = 1.09-2.07, P = 0.01).
  
  
  CONCLUSIONS
  This meta-analysis suggests that the UGT1A7*3 allele is a risk factor for cancer among Asians, especially for hepatocellular carcinoma.
authors.affiliation: Department of General Surgery, The Second Affiliated Hospital of Harbin Medical University, 246 Xuefu Road, Harbin 150086, China.
authors.forename: Shuang-Xi
authors.initials: SX
authors.lastname: Han
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: De-Quan
authors.initials: DQ
authors.lastname: Wu
mesh_terms: D020022:Genetic Predisposition to Disease; D014453:Glucuronosyltransferase / Q000235:genetics*; D006801:Humans; D009369:Neoplasms / Q000201:enzymology* / Q000235:genetics*; D011110:Polymorphism, Genetic
chemical_list: D014453:Glucuronosyltransferase; C524630:UGT1A7 protein, human