Vitamin D receptor rs2228570 polymorphism and susceptibility to ovarian cancer: An updated meta-analysis

The FokI polymorphism (C>T, rs2228570) of the vitamin D receptor gene is a coding nonsynonymous single nucleotide polymorphism in the translational initiation codon reported to have functional significance. Although the role of rs2228570 in the risk of ovarian cancer has been widely researched, the association is still unclear. We performed an updated meta-analysis to clarify this issue.

Eligible studies were retrieved from electronic databases for the period 2007-2016. The association was measured by unadjusted odds ratio combined with 95% confidence intervals (CIs). Random-effect or fixed-effect models were used according to the heterogeneity of the studies. We further appreciated the strength of evidence according to Venice guidance.

Fourteen studies (4448 cases and 7242 controls) were included in the meta-analysis. Studies were predominantly conducted in Caucasian populations (4152 cases and 6693 controls). A dominant genetic model was determined to be the most appropriate genetic model. Overall meta-analysis showed a fixed-effect odds ratio of 1.14 (95% CI 1.05-1.23) under a dominant model. The fixed-effect odds ratios were 1.12 (95% CI 1.03-1.21) and 1.49 (95% CI 1.06-2.09) in Caucasian and Asian populations, respectively. The strength of the evidence was moderate.

The rs2228570 polymorphism increased the risk of ovarian cancer in Caucasian populations in a dominant genetic model. The role of this polymorphism in the risk of ovarian cancer in Asian populations should be further studied.