Associations between the SRD5A2 gene V89L and TA repeat polymorphisms and breast cancer risk: a meta-analysis

The 5α-reductase type 2 (SRD5A2) gene plays a significant role in the development of breast cancer. The V89L and TA repeat polymorphisms of the SRD5A2 gene have been considered as risk factors for breast cancer. However, the results have been inconsistent. To resolve this conflict, we performed a meta-analysis of studies with V89L (1144 patients and 808 controls) and with TA repeat genotyping (1952 cases and 1008 controls). The associations were evaluated by calculating odds ratios (ORs) and 95% confidence intervals (CIs). The result showed that there was no relationship between the V89L polymorphism of the SRD5A2 gene (V/V versus V/L + L/L genotypes) and breast cancer susceptibility (OR = 1.21; 95%CI = 0.99-1.47; P = 0.28). In addition, there was no difference between patients with breast cancer and healthy people in the distributions of the L allele (OR = 1.06; 95%CI = 0.75-1.49; P = 0.003). Similarly, no significant association between the SRDA5A2 TA repeat polymorphism and breast cancer risk was discovered. The comparison of (TA)0/(TA)0versus (TA)0/(TA)9 + (TA)9/(TA)9 genotypes found no difference in the risk of breast cancer (OR = 0.91; 95%CI = 0.66-1.25; P = 0.05). The OR for the (TA)0 versus (TA)9 allele was 0.89 (95%CI = 0.67-1.19). In conclusion, the V89L and TA repeat polymorphisms of SRD5A2 gene were found to have no significant associations with breast cancer risk.