title: Lack of an association between XRCC2 R188H polymorphisms and breast cancer: an update meta-analysis involving 35,422 subjects.
abstract: OBJECTIVE
  Several studies have investigated the associations between XRCC2 R188H polymorphism and the susceptibility to breast cancer, but the results have been inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed.
  
  
  METHODS
  PubMed and China National Knowledge Infrastructure (CNKI) searches were carried out for relevant studies published before March 2015. Meta-analysis was performed with the Stata, version 11.0.
  
  
  RESULTS
  A total of 17 case-control studies, including 17,986 cases and 17,436 controls, were selected. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association in the homozygous model, dominant model, and recessive model. When all the studies were pooled into the meta-analysis, there was no evidence showing a significant association between XRCC2 R188H polymorphism and breast cancer risk (for homozygous model, OR=0.84, 95% CI=0.62-1.14; for dominant model: OR=0.76, 95% CI=0.53-1.09; and for recessive model: OR=1.04, 95% CI=0.98-1.10). In the subgroup analysis by ethnicity, no significant association was found between the polymorphism and breast cancer risk.
  
  
  CONCLUSIONS
  In conclusion, this meta-analysis indicates that the XRCC2 R188H polymorphism is not a risk factor for developing of breast cancer.
authors.affiliation: Department of Breast Surgery, The Affiliated Hospital of Qingdao University Qingdao 266003, P. R. China.
authors.forename: Bin
authors.initials: B
authors.lastname: Kong
authors.affiliation: Department of Breast Surgery, The Affiliated Hospital of Qingdao University Qingdao 266003, P. R. China.
authors.forename: Zhi-Dong
authors.initials: ZD
authors.lastname: Lv
authors.affiliation: Institute of Basic Sciences, Shandong Academy of Medical Sciences Jinan 250000, P. R. China.
authors.forename: Li
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Anatomy, Medical College, Qingdao University Qingdao 266003, P. R. China.
authors.forename: Ruo-Wu
authors.initials: RW
authors.lastname: Shen
authors.affiliation: Institute of Cerebrovascular Disease Research, The Affiliated Hospital of Qingdao University Qingdao 266003, P. R. China.
authors.forename: Li-Ying
authors.initials: LY
authors.lastname: Jin
authors.affiliation: Department of Child Health Care, The Affiliated Hospital of Qingdao University Qingdao 266003, P. R. China.
authors.forename: Zhao-Chuan
authors.initials: ZC
authors.lastname: Yang
keywords: XRCC2; breast cancer; meta-analysis; polymorphism; susceptibility