Diabetes drug Metformin lower breast cancer risk

The study, published in the journal Diabetes Care, adds to evidence that metformin, a generically available drug commonly used for type 2 diabetes, may have anti-cancer effects. Women who have used the diabetes drug metformin for more than five years may have a lower risk of breast cancer than diabetic women on other treatments, a new study finds.

A number of epidemiological studies have found that among people with type 2 diabetes, metformin users may have lower risks of certain cancers. And a recent study in mice found that adding metformin to a chemotherapy drug called doxorubicin was more effective than the cancer drug alone in treating breast tumors.

Researchers at Harvard University are currently developing a large clinical trial to test whether using metformin after standard treatment for early breast cancer helps prevent cancer recurrence.