Association of CYP3A5*3 polymorphisms and prostate cancer risk: A meta-analysis

Aim of Study: The CYP3A5*3 allele (A6986G transition in intron 3) is the major member of cytochrome P450 subfamily, which plays a pivotal role in exogenous carcinogens of liver. Variation of the CYP3A5*3 (rs776746 A > G) can lead to oxidation and inactivation of testosterone, which may result in individual susceptibility to prostate cancer. Methods: All eligible published studies about association between CYP3A5*3 polymorphisms and prostate cancer risk were searched in PubMed, Embase, Web of Science, and Cochrane Library, for the period up to August 2015. Odds ratios (ORs) together with 95% confidence intervals (95% CIs) were used to access the strength of the association. Results: Six case-control studies including 2522 cancer patients and 2444 healthy controls were finally included. The meta-analysis results suggested that CYP3A5*3 polymorphisms were significantly associated with an increased risk of prostate cancer under two genetic models (GG + AG vs. AA: OR = 1.53, 95% CI = 1.23-1.90, P = 0.000; GG vs. AA: OR = 1.46, 95% CI = 1.14-1.87, P = 0.000). Further subgroup analysis according to ethnicity indicated that CYP3A5*3 polymorphism may increase the risks of prostate cancer among African (G allele vs. A allele: OR = 1.34, 95% CI = 1.14-1.57, P = 0.000; GG + AG vs. AA: OR = 1.606, 95% CI = 1.27-2.04, P = 0.000). Sensitivity analysis indicated a reliable result and publication bias suggested no strong publication bias under the genetic models. Conclusion: Our data support that the CYP3A5*3 polymorphism may be associated with increased risk of prostate cancer, particularly in African populations. Large and well-designed studies are needed to validate this association.