A drug commonly used to treat diabetes could cut the risk of all tumor types by more than 25%, British researchers claimed.

Professor Dario Alessi and colleagues at the University of Dundee looked at the rates of cancers recorded among about 6,000 people with diabetes, half of whom were taking the drug, metformin, and half of whom were not.

They found the metformin group had far fewer cancers than the other group - in the order of 20-40%.

The drug is though to work by "switching on" the enzyme AMPK in the body which is thought to inhibit cancer cell growth.

The researchers believe that this effectively tricks cancer cells into thinking they have an insufficient source of cellular energy to divide.

A larger study to verify the findings is scheduled to begin soon. 

If the theory is confirmed, this could yield major benefits as the drug is already on the market, cutting out 10 to 15 years of drug testing usually associated with a medical breakthrough.

(Xinhua News Agency/Agencies April 22, 2005)