Association between vitamin D receptor gene Cdx2 polymorphism and breast cancer susceptibility

Vitamin D receptor (VDR) gene polymorphisms have been reported to influence susceptibility to breast cancer. However, published findings on the association between VDR Cdx2 polymorphism and breast cancer susceptibility are conflicting. To get a precise estimation of the association between VDR Cdx2 polymorphism and breast cancer susceptibility, we conducted a meta-analysis of four case-control studies with a total of 8,880 subjects (3,841 cases and 5,039 controls). The results showed that VDR Cdx2 polymorphism was not associated with risk of breast cancer (A versus G: OR = 0.96, 95 % CI 0.84-1.09; AA versus GG: OR = 0.97, 95 % CI 0.64-1.45; AA/GA versus GG: OR = 0.94, 95 % CI 0.80-1.10; AA versus GG/GA: OR = 0.99, 95 % CI 0.65-1.51). Subgroup analysis in Caucasians also showed that VDR Cdx2 polymorphism was not associated with risk of breast cancer in Caucasians. However, there was a significant association in Africans (A versus G: OR = 0.75, 95 % CI 0.60-0.94; AA versus GG: OR = 0.53, 95 % CI 0.29-0.99; AA/GA versus GG: OR = 0.75, 95 % CI 0.57-0.97). Therefore, the association between VDR Cdx2 polymorphism and breast cancer susceptibility is only found in Africans. More studies are needed to further assess the association in Asians or Africans.