Research has shown that the medicine, called metformin, causes tumours to shrink by slowing the rate at which cancerous cells grow.
If the results are confirmed in bigger trials, it raises the possibility that men could be given the cheap, readily available drug as soon as they are diagnosed.
Hope for the future: Diabetes drug metformin, which costs as little as 2p a tablet, could offer a major breakthrough in the treatment of prostate cancer
The risks of developing a tumour increase with age, and there is a strong genetic element to the disease.
Metformin is widely used on the NHS to treat patients with type 2 diabetes.
But recent studies highlighting the drug’s effects against a variety of tumours have generated considerable excitement among cancer researchers looking for powerful new treatments.
Last year, scientists discovered it could slash the risk of ovarian cancer by around 40 per cent.
And Cancer Research UK is currently funding a major five-year study, involving early 5,000 British women with breast cancer, to see if the drug will stop the disease returning and boost survival rates.
Other research teams around the world are investigating metformin’s powers against skin, lung and pancreatic cancer, with promising early results.
Read more: http://www.dailymail.co.uk/health/article-2174015/Diabetes-drug-costing-just-2p-beat-prostate-cancer-shrinking-tumours.html#ixzz20yOUvLMl