Association of TGF-β1 Polymorphisms with Breast Cancer Risk: A Meta-Analysis of Case-Control Studies

Reports on the association of TGF-beta 1 polymorphisms with breast cancer (BC) have been conflicting, inconsistent, inconclusive, and controversial. PubMed, EMBASE, and Google Scholar were used to identify studies on TGF-beta 1 polymorphisms and BC risk. Data were extracted independently, and of the initial 3043 studies, 39 case-control studies were eligible for inclusion in the meta-analysis. Information from these studies was extracted, and the overall associations of three TGF-beta 1 polymorphisms (TGF-beta 1 29>T/C, TGF-beta 1-509 C/T, and TGF-beta 1*6A) with BC risk were analyzed using overall allele, homozygous, heterozygous, recessive, and dominant models. None of the three TGF-beta 1 polymorphisms studied had a significant influence on the development of BC. However, stratified analysis revealed a positive correlation between the TGF-beta 1 29T>C polymorphism and BC risk according to a heterozygous model of the Asian population (odds ratio (OR) = 1.115, 95% confidence interval (CI) = 1.006-1.237, p = 0.039). Interestingly, this polymorphism was associated with lower odds of BC according to a heterozygous model of the Middle Eastern population (OR = 0.602, 95% CI = 0.375-0.966, p = 0.035). Thus, our analysis of large datasets indicates that the TGF-beta 1 29T>C polymorphism is significantly associated with BC risk in the Asian population. In contrast, the TGF-beta 1*6A and TGF-beta 1-509 C/T polymorphisms failed to show an association with BC.