title: Effect of Proliferator-Activated Receptor-γ Pro12Ala Polymorphism on Colorectal Cancer Risk: A Meta-Analysis.
abstract: BACKGROUND
  The association between peroxisome proliferators-activated receptor γ (PPARγ) Pro12Ala polymorphism and colorectal cancer (CRC) risk is still controversial. A meta-analysis was performed.
  
  
  METHODS
  We conducted a literature search using PubMed, EMBASE, and Cochran databases. The pooled odds ratio (OR) with 95% confidence intervals (CIs) were calculated. Fixed-effects and random-effects models were used. Dominant model, recessive model, and additive model were used in this meta-analysis.
  
  
  RESULTS
  Fifteen studies including 13575 cases and 17085 controls were included in our meta-analysis. Result of this meta-analysis found that PPARγ Pro12Ala polymorphism was significantly associated with a reduced risk of CRC (OR=0.90; 95% CI 0.83-0.98; P=0.01). No significant association was found between PPARγ Pro12Ala polymorphism and CRC risk in Asians (OR=0.80; 95% CI 0.60-1.09; P=0.15). However, PPARγ Pro12Ala polymorphism was significantly associated with a reduced risk of CRC in Caucasians (OR=0.91; 95% CI 0.83-0.99; P=0.03). When stratified analysis was performed by CRC site, no positive association was found between PPARγ Pro12Ala polymorphism and rectal cancer (OR=0.95; 95% CI 0.74-1.22; P=0.71). However, a reduced risk of colon cancer was observed (OR=0.85; 95% CI 0.76-0.94; P=0.002).
  
  
  CONCLUSIONS
  In summary, this study suggests that PPARγ Pro12Ala polymorphism was a protective factor of CRC.
authors.affiliation: 1st Department of Tumor Surgery, Cangzhou Central Hospital, Cangzhou, Hebei, China (mainland).
authors.forename: Zhijiang
authors.initials: Z
authors.lastname: Wei
authors.affiliation: 1st Department of Tumor Surgery, Cangzhou Central Hospital, Cangzhou, Hebei, Chile.
authors.forename: Guoda
authors.initials: G
authors.lastname: Han
authors.affiliation: 1st Department of Tumor Surgery, Cangzhou Central Hospital, Cangzhou, Hebei, Chile.
authors.forename: Xiyong
authors.initials: X
authors.lastname: Bai
mesh_terms: D044466:Asian People / Q000235:genetics; D015179:Colorectal Neoplasms / Q000235:genetics*; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006801:Humans; D008957:Models, Genetic; D020125:Mutation, Missense / Q000235:genetics; D016017:Odds Ratio; D047495:PPAR gamma / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics*; D044465:White People / Q000235:genetics
chemical_list: D047495:PPAR gamma