Combining skin cancer drug with diabetes treatment almost doubles its ability to halt tumours

Researchers have found that using the diabetes drug metformin with Avastin (bevacizumab) to treat skin cancer almost doubles its ability to block tumour growth.

Recent research has shown that metformin has anticancer properties, so a team from the ICR set out to find if these effects were seen in melanoma cells containing two of the most common genetic mutations, BRAF and NRAS.

When treating aggressive skin cancer in mice with just avastin, tumour growth was blocked by 34 per cent. But when combined with metformin, tumour growth was suppressed by 64 per cent.  

Intriguingly, when melanoma cells - the most aggressive form of skin cancer - were treated with just metformin, tumour growth increased. The ICR scientists found that metformin was causing melanoma cells with a BRAF mutation to secrete a protein called VEGF-A, which encourages new blood vessels to form in the tumour and increases tumour growth.

But when combined with drugs such as avastin that block VEGF-A, the dual action appeared to overcome this resistance and helped increase the effectiveness of VEGF-A inhibitors.

The study was published in Cancer Discovery.