National brain tumour research funding needs to increase to £30-35 million a year
Conventional cancer therapies might lead to tumour regrowth
A study recently published in the Journal of Experimental Medicine has suggested that some of the most widely used cancer therapies may start a series of processes that actually promote the survival of some cancer cells. In turn, these could permit them to grow and form into new, more aggressive tumours.
One of the challenges associated with the treatment of brain tumours is to ensure that the therapy kills the majority of the tumour cells while having minimal impact on the surrounding brain tissue. However, we also need to ensure that the therapies don’t inadvertently have a positive side effect on the tumours.
The issue of tumour reoccurrence is particularly relevant for brain tumours as they are one of the more difficult types of tumour to treat, given the small number of effective drugs. Therefore, increasing our understanding of the underlying processes of tumour development is essential in developing better therapies.
According to the study, many conventional therapies leave behind a build-up of dead cancer cells. While they will eventually be removed by the body's local disposal systems, in the short term they can induce a local immune reaction, as the body identifies them as potential toxic substances. This can then stimulate and accelerate the growth of the remaining malignant cells by fuelling tumour-promoting inflammation. One group of proteins called resolvins has been identified to counteract this effect. Research is being carried out to develop potential drugs which may act to activate this protective mechanism.
There is also the potential to regulate the tumour-promoting inflammation with anti-inflammatory drugs, by blocking specific mediators or boosting resolution of inflammation. These could enhance the efficacy of anti-cancer therapies, particularly in the context of immunotherapy. However, this needs to be tested in a clinical trial before new therapies can be introduced into the clinic.
While there are many anti-inflammatory drugs available, many of these cannot enter into the brain. However, repurposing or reformulating existing drugs is an exciting area of research in cancer therapy development that could be applied to the treatment of local inflammation. Initial study results by our scientists at the University of Portsmouth have demonstrated that liquid aspirin may enter into the brain and could act to boost other existing anti-brain tumour drugs. Essentially, this would be a dual approach – the anti-cancer drug would kill the tumour while the aspirin would block the anti-inflammatory reaction. This could make the therapy much more effective.