title: Association between PTEN Gene IVS4 polymorphism and risk of cancer: a meta-analysis.
abstract: BACKGROUND
  Phosphatase and tensin homolog (PTEN) is a well established tumor suppressor gene. Recently, increasing studies investigated the association between PTEN IVS4 polymorphism (rs3830675) and risk of various types of cancer. However, the results from the individual studies were controversial. The aim of this meta-analysis was to elucidate whether PTEN IVS4 polymorphism was associated with cancer risk.
  
  
  METHODS
  Databases including PubMed, Web of knowledge and Chinese National Knowledge Infrastructure (CNKI) were systematically searched to identify potentially eligible literatures. Odds ratios (OR) and their 95% confidence interval (CI) were used to assess the strength of association between PTEN IVS4 polymorphism and cancer risk.
  
  
  RESULTS
  A total of seven case-control studies were finally included in this meta-analysis. The pooled analysis suggested that individuals with PTEN IVS4 (-/-) genotype were significantly associated with increased risk of cancer (OR = 1.45, 95% CI = 1.19-1.76, P<0.001) and subgroup of digestive tract cancer (OR = 1.67, 95% CI = 1.28-2.18, P<0.001) compared with (+/+) genotype. The allele analysis revealed that (-) allele was significantly associated with increased risk of cancer (OR = 1.30, 95% CI = 1.12-1.50, P = 0.001) and subgroup of digestive tract cancer (OR = 1.42, 95% CI = 1.16-1.74, P = 0.001) compared with (+) allele. No significant association was observed between PTEN IVS4 (+/-) genotype and risk of cancer.
  
  
  CONCLUSIONS
  PTEN IVS4 (-/-) genotype was significantly associated with increased risk of cancer especially for digestive tract cancer compared with (+/+) genotype. The (-) allele of PTEN IVS4 (rs3830675) polymorphism was significantly associated with increased risk of cancer especially for digestive tract cancer compared with (+) allele. The recessive effect model and dominant effect model also demonstrated significant association between PTEN IVS4 (rs3830675) polymorphism and increased cancer risk especially for digestive tract cancer. Further large-scale and well-designed studies regarding different ethnicities are still required to confirm the results of our meta-analysis.
authors.affiliation: Tumor Etiology and Screening Department of Cancer Institute and General Surgery, the First Affiliated Hospital of China Medical University, and Key Laboratory of Cancer Etiology and Prevention (China Medical University), Liaoning Provincial Education Department, Shenyang, China.
authors.forename: Liping
authors.initials: L
authors.lastname: Sun
authors.affiliation: Tumor Etiology and Screening Department of Cancer Institute and General Surgery, the First Affiliated Hospital of China Medical University, and Key Laboratory of Cancer Etiology and Prevention (China Medical University), Liaoning Provincial Education Department, Shenyang, China.
authors.forename: Jingwei
authors.initials: J
authors.lastname: Liu
authors.affiliation: Tumor Etiology and Screening Department of Cancer Institute and General Surgery, the First Affiliated Hospital of China Medical University, and Key Laboratory of Cancer Etiology and Prevention (China Medical University), Liaoning Provincial Education Department, Shenyang, China.
authors.forename: Quan
authors.initials: Q
authors.lastname: Yuan
authors.affiliation: Tumor Etiology and Screening Department of Cancer Institute and General Surgery, the First Affiliated Hospital of China Medical University, and Key Laboratory of Cancer Etiology and Prevention (China Medical University), Liaoning Provincial Education Department, Shenyang, China.
authors.forename: Chengzhong
authors.initials: C
authors.lastname: Xing
authors.affiliation: Tumor Etiology and Screening Department of Cancer Institute and General Surgery, the First Affiliated Hospital of China Medical University, and Key Laboratory of Cancer Etiology and Prevention (China Medical University), Liaoning Provincial Education Department, Shenyang, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yuan
mesh_terms: D000483:Alleles; D016022:Case-Control Studies; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007438:Introns; D009369:Neoplasms / Q000235:genetics*; D016017:Odds Ratio; D051059:PTEN Phosphohydrolase / Q000235:genetics*; D011110:Polymorphism, Genetic; D017594:Publication Bias; D012306:Risk
chemical_list: D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human