title: Peroxisome proliferator-activated receptor-gamma Pro12Ala polymorphism could be a risk factor for gastric cancer.
abstract: BACKGROUND
  Due to the strong inhibitory effects of PPARγ gene on the growth of cancer cells, the role of Pro12Ala polymorphism in PPARγ gene has been extensively investigated in cancer recently. However, the results were inconsistent according to cancer type. The aim of this study was to comprehensively evaluate the PPARγ Pro12Ala polymorphism and gastric cancer susceptibility.
  
  
  METHODS
  Search strategies were conducted in Pubmed, Medline (Ovid), Chinese biomedical database (CBM), China national knowledge infrastructure (CNKI), VIP, and Wanfang database, covering all publications, with the last search up to November 01, 2014. The strength of association between PPARγ Pro12Ala polymorphism and gastric cancer risk was assessed by OR with 95%CI.
  
  
  RESULTS
  A total of 546 cases and 827 controls in 5 case-control studies were included in this meta-analysis. The results indicated that the variant G allele carriers (CG+GG) had a 2.31 times higher risk for gastric cancer when compared with the homozygote CC (odds ratio (OR)=2.31, 95% confidence interval (CI)=1.67- 3.21 for CG+GG vs. CC). In the subgroup analysis by ethnicity, significantly elevated risks were both found in Asians (OR=2.56, 95% CI=1.42-4.64) and Caucasians (OR=2.20, 95% CI=1.48-3.25). Similarly, in the subgroup analysis by H. pylori status, a significantly increased risk was identified in H. pylori (+) populations (OR=3.68, 95%CI=2.07-6.52), but not in H. pylori(-) populations (OR=1.17, 95%CI=0.58-2.39).
  
  
  CONCLUSIONS
  This pooled analysis suggested that the PPARγ Pro12Ala polymorphism could be an independent predictive risk factor for gastric cancer especially in H. pylori infected populations in Asians and Caucasians. Nevertheless, prospectively designed cohort studies are needed to further investigate gene-gene and gene-environment interactions to confirm the combined effects of PPARγ Pro12Ala polymorphisms and H. pylori infection on gastric cancer risk.
authors.affiliation: The First Department of Oncology, Hebei General Hospital, Shijiazhuang, Hebei, China E-mail : sguangyao2@163.com.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhao
authors.forename: Zheng
authors.initials: Z
authors.lastname: Zhi
authors.forename: Guangyao
authors.initials: G
authors.lastname: Song
authors.forename: Juan
authors.initials: J
authors.lastname: Wang
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.forename: Huijuan
authors.initials: H
authors.lastname: Ma
authors.forename: Xian
authors.initials: X
authors.lastname: Yu
authors.forename: Aixia
authors.initials: A
authors.lastname: Sui
authors.forename: Hongtao
authors.initials: H
authors.lastname: Zhang
mesh_terms: D016022:Case-Control Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D015201:Meta-Analysis as Topic; D047495:PPAR gamma / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics*; D011379:Prognosis; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000235:genetics*
chemical_list: D047495:PPAR gamma