The A2756G polymorphism in the
methionine synthase (MTR) gene has been implicated in
breast cancer risk. However, the published findings are inconsistent. We therefore performed a meta-analysis to investigate this relationship. Eleven published case-control studies, including 8,438
breast cancer cases and 10,515 controls were identified. Odds ratios (
ORs) and 95% confidence intervals (CIs) were used to assess the strength of the association. Overall, no significant associations between the MTR A2756G polymorphism and
breast cancer risk were found for GG versus AA (OR = 0.98, 95% CI: 0.84-1.15), AG versus AA (OR = 0.95, 95% CI: 0.89-1.01), GG/AG versus AA (OR = 0.95, 95% CI = 0.89-1.01), and GG versus AG/AA (OR = 1.00, 95% CI: 0.86-1.17). However, in the stratified analysis, significantly decreased
breast cancer risks were found among Europeans (AG versus AA, OR = 0.90, 95% CI = 0.83-0.98; GG/AG versus AA, OR = 0.90, 95% CI = 0.82-0.97) and studies with population-based controls (AG versus AA, OR = 0.93, 95% CI = 0.86-1.00; GG/AG versus AA, OR = 0.93, 95% CI = 0.86-1.00). When stratifying by the menopausal status, no significant result was observed in all genetic models. Taken together, the results suggest that the MTR A2756G polymorphism may contribute to susceptibility to
breast cancer among Europeans.