title: Cyclooxygenase-2 polymorphisms and susceptibility to colorectal cancer: a meta-analysis.
abstract: OBJECTIVE
  Four polymorphisms, -765G>C, -1195G>A, 8473T>C, and Val511Ala, in the cyclooxygenase-2 (COX-2) gene were identified to be associated with colorectal cancer (CRC) risk. However, the results are inconsistent. The objective of this meta-analysis was to evaluate the association between these four polymorphisms and the risk of CRC.
  
  
  METHODS
  All eligible case-control studies published up to December 2012 on the association between the four polymorphisms of COX-2 and CRC risk were identified by searching PubMed and Web of Science. The CRC risk associated with the four polymorphisms of the COX-2 gene was estimated for each study by odds ratio (OR) together with its 95% confidence interval (CI), respectively.
  
  
  RESULTS
  A total of 15 case-control studies were included. Overall, no evidence has indicated that the -1195A allele, -765C allele, 8473C allele, and 511Ala allele are associated with susceptibility to CRC (-1195G>A: OR=1.11, 95% CI: 0.82-1.51, p=0.78; -765G>C: OR=1.08, 95% CI: 0.96-1.21, p=0.07; 8473T>C: OR=1.03, 95% CI: 0.89-1.18, p=0.91; Val511Ala: OR=0.71, 95% CI: 0.46-1.09, p=0.94). However, stratified analysis with ethnicity indicated that individuals with -765GC or GC/CC genotypes had an increased risk of CRC among Asian populations (GC vs. GG: OR=1.05, 95% CI: 0.87-1.28, p=0.03; GC+CC vs. GG: OR=1.08, 95% CI: 0.96-1.21, p=0.07).
  
  
  CONCLUSIONS
  This meta-analysis indicated that -765G>C polymorphism was significantly associated with susceptibility to CRC in Asian populations.
authors.affiliation: Department of Gastroenterology, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuhan 430060, Hubei Province, China. dwg@whu.edu.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Xufeng
authors.initials: X
authors.lastname: Guo
authors.forename: Jixiang
authors.initials: J
authors.lastname: Zhang
authors.forename: Jia
authors.initials: J
authors.lastname: Song
authors.forename: Mengyao
authors.initials: M
authors.lastname: Ji
authors.forename: Shijie
authors.initials: S
authors.lastname: Yu
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Cao
authors.forename: Weiguo
authors.initials: W
authors.lastname: Dong
mesh_terms: D044466:Asian People; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000235:genetics*; D051546:Cyclooxygenase 2 / Q000235:genetics*; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D011110:Polymorphism, Genetic / Q000235:genetics*
chemical_list: D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human
keywords: Colorectal cancer; cyclooxygenase-2; meta-analysis; polymorphism