Could diabetes drug prevent cancer?

A well known drug which is commonly used to treat Type 2 diabetes may prevent cancer tumours, according to researchers at the University of Dundee.

Preliminary findings have shown that people with Type 2 diabetes who do not have cancer are more likely to have been taking metformin compared with diabetics with cancer. They are even more likely to have been taking the drug for longer periods of time. The results suggest that people with Type 2 diabetes who take metformin may have a reduced risk of developing cancer of more than 25%.

Two years ago, Professors Dario Alessi and Grahame Hardie in the University's School of Life Sciences discovered that the enzyme AMPK was the target for the protein LKB1, which also acts as a tumour suppressor. Because AMPK is the target enzyme for metformin, this finding led to the hypothesis that metformin might reduce the risk of cancer. Professor Alessi, together with Professor Andrew Morris, Scotland’s leading clinician on diabetes, and Dr Josie Evans, an epidemiologist, from the University’s Medical School, then started an observational study of diabetic patients with and without cancer to see how many had been treated with metformin. This research is therefore the result of collaboration between researchers in laboratory, clinical and community sciences at the University.

A large scale study will get underway soon to verify the results. But the exciting factor according to Professor Alessi, who with a grant from Scottish-based charity the Association for International Cancer Research (AICR) came up with the idea that metformin could work to prevent cancer, is that the drug is already on the market. This will cut out 10-15 years of drug testing that is usually the timescale with a new breakthrough. Metformin could then be evaluated as a preventative cancer drug within the next couple of years.

Professor Andrew Morris treats patients with Type 2 diabetes with the drug metformin. "Metformin has been used to treat people with Type 2 diabetes in the United Kingdom since 1957. Despite being the most widely used drug for people with the condition, it is only recently that we have learnt how it works. The possibility that it may have beneficial effects beyond diabetes control is very exciting indeed".

The findings require further study. Dr Josie Evans is planning a larger scale observational study linked to a cancer registration database. "The results are promising, but this is a preliminary study. We need further concrete evidence and more research; this was only the first step in our research programme. It is hoped that a more precisely designed study will provide more reliable evidence of the effect that metformin has on cancer".

Derek Napier, AICR's Chief Executive believes the work demonstrates perfectly how basic research can lead to a clinical application with the potential to help cancer patients. "Cancer research is a painstaking business. It starts with a dedicated scientist who has a novel idea and who has the courage and determination to see it through to a conclusion. Here at the University of Dundee we have such a scenario, and further studies will prove just how useful this inexpensive drug, that has proved so effective in treating diabetes, can be in the fight against cancer".