CYP17 polymorphisms are associated with decreased risk of breast cancer in Chinese han women: A case–control study

Introduction: CYP17 is the second most important enzyme in estradiol synthesis. Epidemio-logical studies have shown the associations between CYP17 polymorphisms and cancer risk. We conducted a case–control study to evaluate the relationship between CYP17 polymorphisms (rs743572 and rs2486758) and breast cancer (BC) risk. Patients and methods: This case–control study included 560 BC patients and 583 age-matched healthy controls from Northwest China. Two polymorphisms (rs743572 and rs2486758) of CYP17 were genotyped by using Sequenom MassARRAY. ORs and 95% CIs were used to evaluate the relationship. Results: Compared with the wild genotype of rs743572, we found a significantly reduced risk of BC associated with the variant genotypes (heterozygote model: OR=0.69, 95% CI=0.53– 0.89; homozygote model: OR=0.68, 95% CI=0.49–0.95; dominant model: OR=0.69, 95% CI=0.54–0.87; overdominant model: OR=0.78, 95% CI=0.62–0.98; allele model: OR=0.79, 95% CI=0.66–0.93). For rs2486758 polymorphism, we did not find any difference in any of the genetic models. Further stratification analysis by clinical characteristics showed rs743572 was associated with estrogen receptor status (heterozygote model: OR=2.13, 95% CI=1.47–3.08; homozygote model: OR=3.29, 95% CI=1.94–5.58; dominant model: OR=2.39, 95% CI=1.69–3.37) and progesterone receptor status (homozygote model: OR=3.17, 95% CI=1.82–5.55), but there was no association between rs2486758 and clinical characteristics of BC. Haplotype analysis showed that G_rs743572C_rs2486758 haplotype was a protective factor of BC (OR=0.52, 95% CI=0.40–0.67). Survival analysis did not find that CYP17 rs743572 polymorphism was associated with triple-negative BC, either in terms of overall survival or progression-free survival. Conclusion: Our results suggest that CYP17 polymorphisms may reduce the susceptibility to BC in Chinese women.