A new study has shown the power of genetic testing to pick out the best drugs for children with cancer to extend and improve their lives – news which could signal a new era of precision medicine for young patients.

The pilot, which included more than 200 children, found that half had gene mutations that are targetable by adult cancer drugs that are either available as standard treatment or via clinical trials, and although few children on the study went on to receive adult drugs, those who did receive targeted therapies had significant benefits.

It also found that only 7% of those with targetable mutations were able to access the appropriate adult drug, due to regulatory and funding barriers to children receiving the newest drugs.

The researchers were also able to test for cancer gene mutations in DNA released from tumours into the bloodstream from a blood sample. They found blood tests picked up almost all of the mutations found in the tumour, and in some cases they also found extra mutations which were not detected in the tumour region biopsied.

The study was led by The Institute of Cancer Research, London, and The Royal Marsden NHS Foundation Trust, and offered genetic testing of tumours to children as part of a clinical trial with some 20 additional hospitals around the UK participating by sending children’s biopsies in for testing.

Study author Dr Sally George, clinical research Fellow at The Institute of Cancer Research commented: “Children deserve the very best cancer treatments, so they can live as long as possible and as well as possible. We desperately need better, more intelligently designed treatments which can give children longer with their families with fewer side effects.

“By testing tumours for specific gene mutations, we have shown it’s possible to identify new smarter, kinder treatment options for children, which may potentially give these patients much longer with their families after conventional therapies have failed.

“But our study also exposes the desperately frustrating barriers that children still face in receiving new treatments – barriers which lie in the regulations controlling how drugs for children are developed and approved.”

Solid tumours – such as those of the brain, central nervous system, bone and muscle – are rare but have much worse survival rates than children’s blood cancers such as leukaemia. Surgery is often not possible and treatment is limited to ‘blunt instrument’ chemotherapies.