Associations between three XRCC1 polymorphisms and glioma risk: a meta-analysis

Glioma, especially its most aggressive histological type glioblastoma, is a challenge to human health due to its poor prognosis. Identifying glioma risk factors will improve early diagnosis to prevent tumor progression. Three polymorphisms of X-ray repair cross-complementing groups 1 (XRCC1) Arg399Gln, Arg194Trp, and Arg280His have drawn attention because of their potential associations with the development of glioma. However, the conclusions from different studies are inconsistent. Here, we performed XRCC1 polymorphism-glioma association analyses on data gathered through searching PubMed, ISI Web of Knowledge, Cochrane, and EBSCO databases and meta-analyzing extracted eligible studies. For XRCC1 Arg399Gln (G>A) polymorphism, there were 12 studies with 4,356 cases and 6,616 controls; for Arg194Trp (C>T) polymorphism, there were nine studies with 3,760 cases and 5,971 controls; and for Arg280His (G > A) polymorphism, there were five studies with 1,883 cases and 3,144 controls. Odds ratios as well as their 95 % confidence intervals in three genetic models were used to estimate the strength of the association between XRCC1 genotypes and glioma risk. Based on our main analyses, increased risk was observed in Arg399Gln codominant and dominant models and Arg194Trp homozygous codominant and recessive models. In the stratified analyses for some genetic models, Arg399Gln and Arg194Trp were recognized as risk factors in the Asian but not in the Caucasian population. No associations were detected for Arg280His in any genetic model. This meta-analysis indicates that XRCC1 399Gln and 194Trp variants increase glioma risk. Both of these polymorphisms might raise the susceptibility of glioma in Asian populations.