Studies have found that metformin appears to slow or stop the growth of a wide range of cancer cells.
Metformin is now available in various generic versions that cost just pennies per pill
Extensive trials will be needed before the drug can be used as a standard cancer treatment
The two-year survival rate was 30% among the 117 patients taking metformin
(Health.com) -- Each year billions of dollars are spent in the search to find new cancer drugs. Very few of these would-be treatments end up being approved by the government and entering widespread use, which makes it all the more intriguing that one of the most promising new cancer drugs in years is, in fact, an old drug.
Metformin, a diabetes drug, was approved by the Food and Drug Administration in 1995, and since then tens of millions of Americans with diabetes have taken it daily to control their blood sugar.
The first hint that metformin might also have anticancer properties came a decade later, when two research teams separately reported that diabetes patients were less likely to develop cancer, and less likely to die from the disease, if they were taking the drug.
This news wasn't entirely surprising: Metformin treats diabetes in part by lowering insulin levels, and several types of cancer -- such as those of the breast, colon, and prostate -- have been linked to high levels of that hormone.