Doctors Seek To Prevent Breast Cancer Recurrence by Lowering Insulin Levels

Extract

Even in this era of targeted molecular therapies, an old drug can sometimes provide a surprising new benefit. A case in point, the diabetes drug metformin is emerging as a potential treatment for breast cancer on the basis of evidence that cancer patients with lower insulin levels have better outcomes. But using a diabetes drug to lower insulin levels in patients who are not diabetic has caused concern among some researchers, who say that doctors first need to know more about how metformin works in the oncology setting.

First isolated as an active ingredient in the medieval herbal remedy goat's rue, metformin has been used to treat type II diabetes for more than 50 years. The U.S. Food and Drug Administration approved its use in the United States in 1995, and it is now the most prescribed drug for type II diabetes, the adult-onset form of the disease that accounts for 90%–95% of all diabetes cases.