Diabetes Drug May Also Be Cancer Drug

Could getting a mild case of Type 2 Diabetes, while something anybody would want to avoid, actually be a blessing in disguise for some people? It looks like it could be true, especially for people with a family history of cancer. This story hits home with me, because I'm one of those people.

For those of you that don't know me, I'm an older guy. Like a lot of other people my age, I let my weight get out of control and developed a mild (at least so far) case of diabetes. My doctor demanded I lose some weight and prescribed a drug to control the diabetes. That drug was Metformin, which I take twice a day. I have since lost about 45 pounds and the drug is keeping my blood sugar down to acceptable levels.

It did not really surprise me that I developed diabetes. Both of my parents developed the disease later in life and controlled it with medication. But my family also has a history of an even scarier disease -- cancer. My father died of lymphoma and my mother had breast cancer (from which she has recovered and is now cancer-free). I've always been surprised that I have never contracted cancer. Now I discover there may be a medical reason for that.

It seems that Metformin, currently only used for diabetes, is effective in preventing cancer. The evidence is strong enough that the National Cancer Institute (NCI) is currently organizing clinical trials using the drug in patients without diabetes but who are smokers. Others are testing the drug for breast and prostate cancer.

An oncologist for the NCI, Dr. Phillip A. Dennis, says, "The epidemiological evidence in diabetic humans is convincing and strong. It is real, and the reduction in risk ranges from 30% to 70% (depending on the type of cancer)." This was first noticed in a 2005 observational study by British doctors, who noticed that those taking Metformin had a 40% lower incidence of cancer.

Dr. Dennis and his NCI colleagues have performed tests in mice. They injected three groups of mice with NNK, the carcinogen in cigarette smoke. In the control group 100% of the mice got lung cancer. In the group that took Metformin orally, at least 33% did not develop cancer. And in the group that got injections of Metformin, around 70% did not develop cancer.

Reachers say that while the evidence is not yet strong enough to prescribe Metformin to people without diabetes, it should probably be considered the drug of choice for those with the disease because of its oncological effect. Metformin is currently one of the most widely used diabetes drugs (40 million prescriptions were issued in 2008). It is also "off patent", which means generics are available and the drug is cheap.

This is very good news for those of us with diabetes.

NOTE -- The picture above is of the chemical structure of Metformin.