Gene Polymorphisms and Circulating Levels of MMP-2 and MMP-9: A Review of Their Role in Breast Cancer Risk

MMP-2 and MMP-9 genes have been suggested to play a role in breast cancer. Their functions have been associated with invasion and metastasis of breast cancer; however, their involvement in the development of the disease is not well-established. Herein, we reviewed the literature investigating the association between circulating levels and polymorphisms of MMP-2 and MMP-9 and breast cancer risk. Various studies report conflicting results regarding the relationship of polymorphisms in MMP-2 and MMP-9 and breast cancer risk. Nevertheless, it appears that the T allele in rs243865 and rs2285053 in MMP-2 are associated with reduced risk of breast cancer. In addition, high levels of latent form and low levels of active form of MMP-2 were observed in breast cancer patients compared to controls. For MMP-9, high latent levels and low total levels were found in breast cancer patients compared to controls. Additional studies are needed to comprehend the role of these genes in breast carcinogenesis.