Breast cancer is the most common
cancer in women. To date, many publications have evaluated the association between
Cytochrome P450 1B1 (CYP1B1) Val432Leu polymorphism and
breast cancer risk. However, the results remain inconclusive. In order to derive a more precise estimation of the association, a meta-analysis was performed in this study. By searching Medline, Pubmed, and ISI Web of Knowledge databases, 26 studies including 19,028 cases and 21,275 controls were collected for CYP1B1 Val432Leu polymorphism. Crude
ORs with 95% CIs were used to assess the strength of association between CYP1B1 Val432Leu polymorphism and
breast cancer risk. The pooled
ORs were performed for codominant model, dominant model, and recessive model, respectively. Overall, no significant associations between CYP1B1 Val432Leu polymorphism and
breast cancer susceptibility were found for
Val/Val versus
Leu/Leu (OR = 0.98; 95% CI: 0.90-1.06),
Val/Leu versus
Leu/Leu (OR = 1.01; 95% CI: 0.93-1.09),
Val/Val + Val/Leu versus
Leu/Leu (OR = 1.00; 95% CI: 0.93-1.08) and
Val/Val versus
Val/Leu +
Leu/Leu (OR = 0.96; 95% CI: 0.91-1.01). In the stratified analysis by ethnicity, menopausal status and sources of controls, significant associations were still not observed in all genetic models. In conclusion, this meta-analysis provides strong evidence that CYP1B1 Val432Leu polymorphism is not associated with
breast cancer risk.