Metformin: Focus on Breast Cancer.

Metformin is one of the prevalent treatments for type 2 diabetes. It is widely used in diabetology due to its safety and effectiveness. For more than a decade, there was a growing interest on the benefit of metformin in multiple tumor locations, especially in the breast cancer. Epidemiological data shows a reduced incidence of breast cancer in patients on metformin. The underlying mechanism of this benefic effect could be the limitation of tumor cell proliferation by downregulating the insulin/IGF-1 axis and phosphorylation of mTOR. However, the available data are not sufficient to support the use of metformin in breast cancer as an anti-tumor therapy. Ongoing trials are evaluating the benefit of metformin in different stages of breast cancer. Additional researches including potential biomarkers are needed to confirm the accurate efficacy of metformin treatment in the prevention and the recurrence of breast cancer. [ABSTRACT FROM AUTHOR]