Abstract
BACKGROUND: The evidence for vitamin D reducing cancer risk is inconsistent, and it is not clear whether this reduction is related to variation in cytochrome P450 (CYP)24A1, the only enzyme known to degrade active vitamin D. We focused on evaluating the association of CYP24A1-rs2296241 polymorphism with hormone-related cancer risk by conducting a meta-analysis. METHODS: A systematic literature search was conducted in April 2014 (updated in December 2014) to identify eligible studies. A random-effects model was used to pool the odds ratio (OR). RESULTS: Eleven studies including 5,145 cases and 5,136 controls were considered for the allelic model, and eight studies of 3,959 cases and 3,560 controls were utilized for the additive, recessive, and dominant models. There was no significant association between CYP24A1-rs2296241 and hormone-related cancer risk in any of the models, yet substantial heterogeneity was observed. Subgroup analyses indicated that CYP24A1-rs2296241 variation reduced the prostate cancer risk in the additive (OR 0.91, 95% confidence interval 0.85-0.97) and recessive (OR 0.80, 95% confidence interval 0.67-0.95) models, with no evidence of heterogeneity. CONCLUSION: This meta-analysis indicated that CYP24A1-rs2296241 polymorphism reduced the androgen-related prostate cancer risk in additive and recessive models. More genetic loci are needed to confirm the effect of CYP24A1 variation on the risk of prostate cancer.