Association between gene polymorphisms and breast cancer: the role of estrogen.

: The fat mass and obesity-associated () gene may be associated with breast cancer risk. This study aimed to systematically investigate the association between gene polymorphisms and breast cancer and the possible role of estrogen in this association.: We performed an extensive search of electronic databases such as PubMed, Science Direct, Scopus, and Cochran for published original studies on the association of gene polymorphisms with breast cancer risk. Keywords such as breast cancer and/or gene and/or polymorphism were used in order to identify the related articles. We excluded studies unrelated to the genotype and the outcome of breast cancer.: gene may have a significant association with the risk of breast cancer. The association between gene polymorphisms and breast cancer was influenced by the status of estrogen receptors. Estrogen may promote breast cancer cell proliferation through up-regulation of FTO gene expression and activation of the PI3 K/Akt signaling pathway in estrogen receptor positive patients. Further studies are warranted to identify the underlying mechanisms and signaling pathways involved in the interactions between gene, estrogen, and the risk of breast cancer.