Researchers may have found a new strategy to improve the treatment of brain tumours after discovering how cancerous cells can form a resistance to existing drug therapies.

The study, led by the University of Sussex and supported by the charity Action Against Cancer, looked at the impact of the drug bevacizumab, sold under the trade name Avastin®, on glioblastoma, which is the most aggressive type of brain tumour.

The drug works by targeting the tumour’s blood supply and is known to have a positive effect on the quality of life and survival of patients, largely through its anti-inflammatory effects.

However, unexpectedly, cancer cells also react directly to this drug and become resistant via still uncharacterised mechanisms. Research shows that cancerous cells could discard the drug from their microenvironment and patients ultimately relapse.

The authors of the study – from the University of Sussex, Queen Mary University of London and Imperial College London (all in the UK) - have found that by actively inhibiting these changes within cells, the tumour-fighting property of the drug significantly improves.

Professor Georgios Giamas, Professor of Cancer Cells at the University of Sussex (School of Life Sciences) and Principal Investigator of this study, said: “Our study revealed a potential mechanism about how the most aggressive type of brain tumour defends itself against anti-cancer drugs at a cellular level. This gives us hope that we can improve the effectiveness of existing treatments and, in the future, design new and better treatments that bypass this ‘shield’”.

Dr Thomas Simon, first author in this paper (University of Sussex) highlighted that, “Even though glioblastoma resistance to bevacizumab has been repeatedly reported, both in patients and via in vitro studies, our study is the first one to show such a ‘drug disposal’ mechanism in cancer cells.”

“These tumours have a poor prognosis typically so understanding how they are resistant to anti-cancer therapies, we think, is key to improving survival. We’ve shown here a new mechanism that tumour cells pump drugs out of them so we need to design future studies thinking of ways to overcome this”, said Professor Stebbing, Professor of Cancer Medicine and Oncology at Imperial College.

Researchers believe that their findings could not only improve current treatments but also extend beyond the brain tumour research field to inspire scientists working on treatments for other types of cancer.

Hilary Craft, Chairwoman of Action Against Cancer, said: “Action Against Cancer is delighted to fund this cutting-edge research, and will continue to do so. We hope that this excellent work will lead to improved treatments for patients.”