Smokers Cancer - WONDER DRUG

Type 2 diabetes drug may prevent cancer in smokers

Los Angeles: Metformin, a safe and inexpensive drug widely used to lower blood glucose in Type 2 diabetics, may have a variety of other uses, researchers are finding. The newest is to prevent lung cancer in smokers.

             Metformin inhibits a hormone called insulin-like growth factor-1, or IGF-1, which explains its anti-diabetes activity. But IGF-1 also plays a crucial role in cancer development, and a variety of observational studies have hinted that, by blocking its activity, metformin may inhibit cancer. Studies have shown diabetic women being treated for breast cancer and taking merformin have a threefold better response to their chemotherapy.

           Dr Cristiano Ferrario of McGill University in Montreal, Canada, reported that metformin could inhibit the growth of prostate cancer cells in the laboratory -- albeit by inhibiting a different receptor.

            Some studies have suggested that smokers who are diabetic and taking metformin are less likely to develop lung cancer. Dr Phillip A Dennis of the National Cancer Institute tested that kdea by giving metformin to mice exposed to a tobacco carcinogen known as nicotine-derived nitrosamine, which normally induces tumours in experimental animals quite easily. He reported that administering the drug orally reduced tumour burden by 40% to 50% Injecting it reduced the burden by 72%. The levels of metformin used in the mice are easily achievable in humans and are not associated with significant side effects, he said.

             Some other studies have suggested that metformin may also reduce cardiovascular disease not directly related to diabetes. The problem with all these studies is that metformin is now a generic drug, so there is no incentive for pharmaceutical companies to launch an expensive clinical trial to demonstrate the drug's utility when they would not be the exclusive beneficiary of their findings.