title: XRCC1 polymorphisms and risk of colorectal cancer: a meta-analysis.
abstract: OBJECTIVE
  Previous studies investigating the association between X-ray repair cross-complementation group 1 (XRCC1) polymorphisms and colorectal cancer (CRC) risk has provided inconsistent results. The aim of our study was to clarify the effects of XRCC1variants on CRC risk.
  
  
  METHODS
  We conducted searches of the published literature in PubMed, Embase, and CBM databases up to July 6, 2009. Meta-analysis was performed by critically reviewing 14 studies with a total of 2,776 CRC cases and 4,402 controls on Arg399Gln polymorphism, four studies with a total of 931 CRC cases and 1,547 controls on Arg280His polymorphism, and nine studies with a total of 1,709 CRC cases and 3,233 controls on Arg194Trp polymorphism, respectively. Statistical analysis was performed with the software programs Review Manager (version 5.0.10) and STATA (version 9.2).
  
  
  RESULTS
  No significant association between Arg399Gln polymorphism and CRC risk was observed in both total population analyses and subgroup analyses based on ethnicity (OR(Co-dominant model) = 1.04, 95% CI 0.74-1.45, P (OR) = 0.82; OR(Dominant model) = 1.02, 95% CI 0.80-1.30, P (OR) = 0.88; OR (Recessive model) = 1.04, 95% CI 0.81-1.34, P (OR) = 0.78). Arg280His polymorphism also had no significant association with CRC risk (OR(Co-dominant model) = 0.85, 95% CI 0.32-2.31, P (OR) = 0.76; OR(Dominant model) = 1.11, 95% CI 0.87-1.40, P (OR) = 0.40; OR(Recessive model) = 0.85, 95% CI 0.32-2.31, P (OR) = 0.75). Besides, there was also no evidence of association between Arg194Trp polymorphism and CRC risk (OR(Co-dominant model) = 1.43, 95% CI 0.83-2.48, P (OR) = 0.20; OR(Dominant model) = 1.14, 95% CI 0.87-1.51, P (OR) = 0.34; OR(Recessive model) = 1.32, 95% CI 0.82-2.13, P (OR) = 0.25).
  
  
  CONCLUSIONS
  No association is found between the polymorphisms in XRCC1 (Arg399Gln, Arg280His, and Arg194Trp) and risk of colorectal cancer.
authors.affiliation: Department of Intern Team, Changhai Hospital, The Second Military Medical University, Shanghai, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.forename: Dan
authors.initials: D
authors.lastname: Wang
authors.forename: Gang
authors.initials: G
authors.lastname: Huang
authors.forename: Chao
authors.initials: C
authors.lastname: Zhang
authors.forename: Dong-hua
authors.initials: DH
authors.lastname: Xu
authors.forename: Weiping
authors.initials: W
authors.lastname: Zhou
mesh_terms: D015179:Colorectal Neoplasms / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D018740:Genetic Heterogeneity; D020022:Genetic Predisposition to Disease; D006801:Humans; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D017594:Publication Bias; D000076105:X-ray Repair Cross Complementing Protein 1
chemical_list: D004268:DNA-Binding Proteins; D000076105:X-ray Repair Cross Complementing Protein 1; C000619371:XRCC1 protein, human