title: Vascular endothelial growth factor -2578C/A polymorphism and colorectal cancer risk: A meta-analysis.
abstract: BACKGROUND
  The effects of the vascular endothelial growth factor (VEGF) gene -2578C/A polymorphism on colorectal cancer (CRC) risk have been investigated in some studies; however, the results of these studies were conflicting and ambiguous. Therefore, we aimed to do a meta-analysis to investigate the association of VEGF -2578C/A polymorphisms with CRC risk from all eligible case-control studies published to date.
  
  
  METHODS
  An electronic search of the PubMed, Embase and Medline was performed. Retrieve terms were utilized as following: ("VEGF a" [MeSH Terms]) and ("polymorphism, genetic" [MeSH Terms]) and ("colorectal neoplasms" [MeSH Terms]). The association between VEGF -2578C/A polymorphisms with CRC risk was calculated with odds ratios (ORs) and their corresponding 95% of confidence intervals (CIs), and stratified analysis was also conducted with respect to ethnicity.
  
  
  RESULTS
  A comprehensive meta-analysis of eight studies, including 2312 cases and 2308 controls was performed in this work. Combined analysis revealed that a significant association between the VEGF -2578C/A polymorphism with CRC risk was identified in three comparison models including C allele versus A allele (OR = 0.85, 95% CI 0.75-0.97, P = 0.02), AA versus CA + CC (OR = 1.28, 95% CI 1.09-1.51, P = 0.003), and AA versus CC (OR = 0.77, 95% CI 0.64-0.93, P = 0.006). Moreover, a similar result was obtained in the subgroup analysis that comparison models of C allele versus. A allele (OR = 0.85, 95% CI 0.76-0.95, P = 0.004), AA versus CA + CC (OR = 1.31, 95% CI 1.09-1.57, P = 0.004), and AA versus CC (OR = 0.73, 95% CI 0.59-0.90, P = 0.004) was confirmed to be associated with CRC risk in Caucasian.
  
  
  CONCLUSIONS
  It has been proved that the C allele versus A allele, AA versus CA + CC, and AA versus CC comparison models of VEGF -2578C/A polymorphism might be risk factors for CRC, but further studies with larger sample sizes are required to make a better assessment of above association.
authors.affiliation: Institute of Drug Metabolism and Pharmacokinetics, School of Pharmaceutical Sciences, Central South University, Changsha, Hunan, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.affiliation: Institute of Drug Metabolism and Pharmacokinetics, School of Pharmaceutical Sciences, Central South University, Changsha, Hunan, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Ji
authors.affiliation: Institute of Drug Metabolism and Pharmacokinetics, School of Pharmaceutical Sciences, Central South University, Changsha, Hunan, China.
authors.forename: Zeneng
authors.initials: Z
authors.lastname: Cheng
keywords: Colorectal cancer; meta-analysis; polymorphism; vascular endothelial growth factor