Diabetes Drug Slows Breast Cancer

Metformin may decrease breast cancer growth

(RxWiki News) What if you could take a drug that costs less than $10 a month to prevent or treat breast cancer? Not a bad deal. Just such a scenario may not be too far off.

A recent study has found that an inexpensive drug used to treat type 2 diabetes - metformin - slows the growth of breast cancer cells in the lab.

"A diabetes drug may one day be used to treat breast cancer."

The study conducted by James Trosko and colleagues at South Korea's Seoul National University adds biological evidence to what's already known about the metformin, which is sold under the brand names Fortamet, Glucophage, Glumetza and Riomet.

Trosko, who is a professor in the College of Human Medicine's Department of Pediatrics and Human Development, says metformin has been shown to reduce the risk of diabetes-associated cancers of the breast, liver and pancreas.

The concept behind Trosko's study was that cancers start in adult human stem cells and a number of both natural and synthetic chemicals can promote breast cancer cell growth.

The team grew miniature human breast tumor called mammospheres in the lab. These tumors were exposed to natural estrogen, which drives the majority of breast cancers and various man-made chemicals that promote tumor growth.

While the mammospheres increased in size and numbers when exposed to these chemicals, when metformin was added, just the opposite occurred. The tumors shrank in size and numbers dramatically.

Trosko says that the exact mechanism is still not understood, but the evidence is clear that metformin blunts the growth of breast cancers. He adds "this study reveals the need to determine if the drug might be used as a preventive drug and for individuals who have no indication of any existing cancers." 

The research appears in the November, 2011 edition of PLoS One.

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Review Date: 
November 29, 2011