BACKGROUND: Although various individual studies have been conducted to determine the association between X-ray repair cross-complementing group 1 (XRCC1) Arg399Gln polymorphism and breast cancer, the results remain inconclusive. To assess the influence of XRCC1 Arg399Gln polymorphism on the risk of breast cancer, a metaanalysis was performed in a single ethnic group. METHODS: Eligible studies were identified via databases such as PubMed, Springer Link, Ovid, Chinese Wanfang Data Knowledge Service Platform, Chinese National Knowledge Infrastructure, and Chinese Biology Medicine, throughout February 2016. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strengths of the associations. RESULTS: Ten studies documenting a total of 4732 breast cancer cases and 5677 controls were included in this metaanalysis. The results indicated no significant association between XRCC1 Arg399Gln polymorphism and breast cancer risk in both total analysis and subgroup analysis stratified by geographical areas and source of controls. CONCLUSIONS: This meta-analysis provided evidence that XRCC1 Arg399Gln variant might not be risk alleles for breast cancer susceptibility in the Chinese population. Further studies conducted in other ethnic groups are required for definite conclusions.
BACKGROUND: Although various individual studies have been conducted to determine the association between X-ray repair cross-complementing group 1 (XRCC1) Arg399Gln polymorphism and breast cancer, the results remain inconclusive. To assess the influence of XRCC1 Arg399Gln polymorphism on the risk of breast cancer, a metaanalysis was performed in a single ethnic group. METHODS: Eligible studies were identified via databases such as PubMed, Springer Link, Ovid, Chinese Wanfang Data Knowledge Service Platform, Chinese National Knowledge Infrastructure, and Chinese Biology Medicine, throughout February 2016. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strengths of the associations. RESULTS: Ten studies documenting a total of 4732 breast cancer cases and 5677 controls were included in this metaanalysis. The results indicated no significant association between XRCC1 Arg399Gln polymorphism and breast cancer risk in both total analysis and subgroup analysis stratified by geographical areas and source of controls. CONCLUSIONS: This meta-analysis provided evidence that XRCC1 Arg399Gln variant might not be risk alleles for breast cancer susceptibility in the Chinese population. Further studies conducted in other ethnic groups are required for definite conclusions.