Off the Shelf
A drug approved for type 2 diabetes may also target cancer’s wayward metabolism.
As researchers continue to probe the role of cell metabolism in cancer—and to develop new therapies designed to starve cancer cells of nourishment—they’ve found that one existing treatment already targets metabolism.
Some scientists believe that metformin, the drug most commonly prescribed for type 2 diabetes, targets cancer metabolism. Metformin reduces glucose production in the liver, in turn lowering blood sugar levels that are elevated in diabetes. Insulin, an alternative diabetes treatment, cuts blood sugar by encouraging cells to absorb glucose. Studies have shown that diabetes patients taking metformin have lower rates of cancers than those who take insulin, and Lewis Cantley, director of the Cancer Center at Beth Israel Deaconess Medical Center, is one of those who believe metformin actively protects against cancer—because reducing blood sugar also lowers the level of insulin in the blood. Insulin, by helping cancer cells suck in glucose, aids in the growth of some tumors.
Researchers also suggest that insulin itself is behind the higher cancer risk of diabetic patients who opt to take insulin rather than metformin. Several current studies will try to settle this question.