Update on the relationship between the SLC4A7 variant rs4973768 and breast cancer risk: a systematic review and meta-analysis

OBJECTIVE: This meta-analysis aimed to update knowledge about the association between the SLC4A7 variant rs4973768 and breast cancer incidence. METHODS: Studies were identified from relevant digital databases. Fixed- or random-effects models were used to calculate odds ratios and 95% confidence intervals. Statistical Q and I(2) tests and sensitivity analyses were used to detect interstudy heterogeneity and test the statistical stability of overall estimates, respectively. Egger’s tests were applied to detect publication bias among included studies. In silico analysis was used to ascertain increased expression of SLC4A7 mRNA in rs4973768 with the mutant allele. Trial sequential analysis was used to calculate the study’s sample size. RESULTS: The overall odds ratios reflected a positive correlation between the SLC4A7 rs4973768 polymorphism and susceptibility to breast cancer in five genetic comparisons of alleles T and C, and tests revealed significant heterogeneity in the allele comparison. After stratification by ethnicity, heterogeneity in Asian and White populations substantially decreased (Ph = 0.984, I(2) = 0%) and remained stable (Ph = 0.083, I(2) = 46.3%), respectively. The mutant allele was associated with increased expression of SLC4A7 mRNA in rs4973768. The cumulative z curve indicated that our conclusions were robust. CONCLUSIONS: Our updated consequence shows that the SLC4A7 rs4973768 polymorphism is associated with increased breast cancer risk.