The association between OGG1 Ser326Cys polymorphism and breast cancer risk: an updated meta-analysis of 20 case-control studies

Human 8-oxoguanine glycosylase 1 (hOGG1) plays an important role in the base excision repair (BER) pathway. Numerous epidemiological studies have explored the association between hOGG1 Ser326Cys polymorphism and breast cancer risk, but the results are inconsistent. We performed this meta-analysis to assess the association between Ser326Cys polymorphism and the risk of breast cancer, by critically reviewing 20 case-control studies including 9989 cases and 11759 controls. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using fixed-or random-effects models to estimate the association strength. Our analysis suggested that Ser326Cys polymorphism was significant associated with an increased risk of breast cancer for recessive model (OR= 1.10, 95% CI= 1.01-1.19) in the whole population. In the subgroup analysis by ethnicity, a significant association was found among Asians (recessive model: OR= 1.10, 95% CI= 1.00-1.21; homozygote model: OR= 1.15, 95% CI= 1.01-1.31 and additive model: OR= 1.07, 95% CI= 1.01-1.14), but not Caucasians. When stratified by the source of controls, we observed a significantly increased risk of breast cancer in hospital-based studies (recessive model: OR= 1.19, 95% CI= 1.07-1.31; homozygote model: OR= 1.16, 95% CI= 1.01-1.32). Furthermore, we found a significant increased risk of breast cancer in hospital-based studies among both Asians (recessive model: OR= 1.17, 95% CI= 1.05-1.31; homozygote model: OR= 1.19, 95% CI= 1.02-1.39; additive model: OR= 1.10, 95% CI= 1.02-1.19) and Caucasians (recessive model: OR= 1.25, 95% CI= 1.01-1.56). This update meta-analysis suggests that OGG1 Ser326Cys polymorphism may be a risk factor of breast cancer. Nevertheless, large-scale, well-designed and population-based studies are needed to further evaluate gene-environment interaction on Ser326Cys polymorphism and breast cancer risk.