Assessing the prevalence of BRAFV600 mutations within common brain tumours and the use of BRAF inhibitors as treatment

New research funded by Cancer Research UK and National Institute for Health Research Bristol Biomedical Research Centre (NIHR Bristol BRC) has identified the feasibility for using BRAF inhibitors as targeted treatments particularly for five types of brain tumour, most common in young people.

Overall mortality rates in patients with brain tumours is very high, with less than 20% surviving beyond five years after diagnosis. Treating these tumours can be difficult. Standard surgery and general chemoradiotherapy tend to have a low success rate with frequent tumour regrowth after treatment. It’s therefore urgent to develop new research and new personalised treatment options for patients.

To develop better treatment approaches the team needed to first understand prevalence of BRAFV600E – a mutation in the BRAF gene that codes for cell replication. When this mutation occurs, it means cells replicate at much faster rates, causing cancerous tumours. Their systematic review, which included 13,682 patients in 182 publications, established that the most common were a mixture of low and high-grade tumours which tend to be seen in younger patients. They were epithelioid glioblastoma, pleomorphic xanthoastrocytoma, anaplastic pleomorphic xanthoastrocytoma, ganglioglioma and anaplastic ganglioglioma.

The group then identified preliminary evidence that the use of BRAF and MEK (another gene used in cell replication) inhibitors, which have shown great success in treating skin cancers, should be trialled as a more effective treatment for brain tumours with the BRAF mutation. Although they stress that they must be very cautious about their evidence because there is no standard control group. It is thought that the patients with the lower grade tumours would have the best outcome.

Professor Kathreena Kurian, Professor of Neuropathology and co-senior author on the paper said:

“This is a very exciting result because these types of brain tumours tend to be seen in younger patients so they may have a better chance of tolerating treatment and responding more effectively than older patients. We may have a huge impact on their lives if we can give them new treatment options, particularly if these drugs are combined with other treatment strategies such as those that target the immune system for example.

“Currently these drugs are given on an individual basis and at different points in the brain tumour journey when standard treatments have failed. So a trial earlier in the patient journey would let us know when best to use these drugs and could potentially have significant impacts on survival rates in patients with this mutation.”

Paper: Prevalence of BRAFV600 in glioma and use of BRAF Inhibitors in patients with BRAFV600 mutation-positive glioma: systematic review Lily Andrews et al. in Neuro-Oncology