Genetic variation of the CYP17 and susceptibility to endometrial cancer: a meta-analysis.

Excessive estrogenic influence is known to be associated with initiation/promotion of endometrial cancer (EC). Common variants among genes coding for enzymes in sex steroid biosynthetic pathways may influence the risk of EC. Cytochrome P450c17α (CYP17), a gene that codes for a key enzyme (cytochrome P450c17α) in a rate-limiting step of estrogen biosynthesis has attracted considerable attention as a candidate gene for EC. The relationship between CYP17 and EC has been reported in various ethnic groups; however, these studies have yielded contradictory results. To investigate this inconsistency, we performed a meta-analysis of 13 studies involving a total of 3,258 cases and 4,614 controls for -34T>C (rs743572) polymorphism of the CYP17 gene to evaluate the effect of CYP17 on genetic susceptibility for EC. An overall random effects odds ratio of 0.71 (95% confidence interval 0.58-0.88, P=0.001) was found under recessive genetic model. Stratified analysis based on ethnicity, sample size and Hardy-Weinberg equilibrium status was conducted to explore potential heterogeneity. This meta-analysis demonstrated that the C allele of -34T>C in CYP17 is a protective factor associated with decreased EC susceptibility, but these associations vary in different ethnic populations.