title: Association between the XRCC3 Thr241Met polymorphism and risk of colorectal cancer: a meta analysis of 5,193 cases and 6,645 controls.
abstract: BACKGROUND
  Many studies have reported associations of the X-ray repair cross-complementing group 3 (XRCC3) Thr241Met polymorphism with colorectal cancer (CRC) risk, but the results remained controversial. Hence, we performed the present meta-analysis with different inheritance models.
  
  
  METHODS
  We searched the PubMed and Google scholar databases for studies relating to associations between XRCC3 Thr241Met polymorphism and risk of CRC. 16 studies with 5,193 cases and 6,645 controls were finally included into the meta-analysis.
  
  
  RESULTS
  We found that the XRCC3 Thr241Met polymorphism was associated with increased CRC risk only under a dominant genetic model (CC+CT vs. TT: OR 0.575, 95%CI 0.498-1.665, p<0.001, Pheterogeneity=0.00, I2=83%). There was a significant association between XRCC3 Thr241Met polymorphism and CRC risk in Caucasian in the overall 8 studies under only in the heterozygote genetic model (CT vs. TT: OR=0.929, 95%CI=0.806-1.070, P=0.308, Pheterogeneity=0.002, I2=57%). Four studies evaluated the XRCC3 Thr241Met polymorphism and CRC risk in Asians. Two genetic models of the XRCC3 polymorphism were significantly correlated with increasing risk in Asians (dominant model: CC+CT vs. TT: OR= 0.609, 95%CI=411-0.902, P=0.013, Pheterogeneity=0.54, I2=0.00%; Allele model: C vs. T: OR=0.708, 95 %=CI 0.605-0.829, p=0.000, Pheterogeneity=0.000, I2=92%). The sensitivity analysis suggested stability of this meta-analysis and no publication bias was detected.
  
  
  CONCLUSIONS
  In conclusion, this meta-analysis indicates that XRCC3 Thr241Met shows an increased CRC risk, particularly in Asians rather than Caucasians.
authors.affiliation: Department of Internal Medicine, Shahid Sadoughi University of Medical Sciences and Health Services, Yazd, Iran E-mail : maryamabedinzadeh94@gmail.com.
authors.forename: Abolfazl
authors.initials: A
authors.lastname: Namazi
authors.forename: Maryam
authors.initials: M
authors.lastname: Abedinzadeh
authors.forename: Parisa
authors.initials: P
authors.lastname: Nourbaksh
authors.forename: Hossein
authors.initials: H
authors.lastname: Neamatzadeh
mesh_terms: D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D006801:Humans; D011110:Polymorphism, Genetic / Q000235:genetics*; D011379:Prognosis; D012307:Risk Factors
chemical_list: D004268:DNA-Binding Proteins; C110901:X-ray repair cross complementing protein 3