UK research into cannabidiol (CBD) comes after surge in parents administering it to children without medical advice.

British scientists are investigating whether a compound found in cannabis could be used to shrink brain tumours in children.

The study of the effects of cannabidiol (CBD), the non-psychoactive ingredient in marijuana, was prompted by a growing number of parents giving it to children with a brain tumour after buying it online. The lead researcher, Prof Richard Grundy of Nottingham University’s children’s brain tumour centre, said in the last six months there had been a surge in parents administering it without medical advice in the belief it might help.

While no research has been done into how CBD can help children’s brain tumours, some work has been done looking at how cannabis-based molecules can help adult cancer patients. Products containing cannabidiol can be bought online, although recent changes mean companies now require a licence to sell them.

“New ways to treat childhood brain tumours are urgently needed to extend and improve the quality of life in malignant brain tumour patients, so we are excited at the prospect of testing the effect of cannabidiol on brain tumour cells,” said Grundy.

Brain tumours kill more children in the UK than any other type of cancer. Around 1,750 under-18s each year are diagnosed with cancer, of which about 400 are cancers of the brain and spinal cord.

The study, thought to be the first of its kind in the world, will seek to establish whether CBD reduces tumours. The researchers will grow cells from different brain tumours in lab conditions, some with the addition of cannabidiol molecules and others without. They will then compare how the presence of tumour cells differs in both samples through a technique called cell staining. This will help them see how many of the cells are dividing and whether any are dying.

Grundy said: “We expect the cells – brain tumour and normal brain – grown in our standard conditions to be healthy and actively dividing. We expect that normal brain cells grown in cannabidiol will remain healthy. However, we expect the brain tumour cells grown in cannabidiol to stop growing and die.”

Katie Sheen, of the Astro Brain Tumour Fund, which is co-funding the study, said if it proved to be successful CBD could be a gentler, less toxic way of treating cancer than chemotherapy or radiotherapy.

Dr Wai Liu, a research fellow at St George’s University of London, said: “We have performed experiments using CBD in leukaemia and it can deactivate signalling pathways, making cells more responsive to chemotherapy.” 

He said some drug companies combined CBD with psychoactive component tetrahydrocannabinol (THC) with positive responses, especially when combined with chemotherapy.

Liu added: “All cells need to communicate and these communications get jammed up, and CBD tries to correct this by restoring them. This ultimately results in these cells being able to undergo cell death.”

“People think that children’s cells are more flexible so there is a possibility that CBD may have a slightly different effect. We will only be able to understand the precise mechanism and value of this treatment when studies like this are done.”

Among those supporting the project are the parents of William Frost, a four-year-old who was diagnosed with a ependymoma brain tumour in 2014 and is being treated at the Nottingham centre. William’s father, Steve, said: “We were told halfway through 2016 that nothing more could be done for William. We couldn’t bear to accept the news and decided to look into alternative treatments. 

“We started William on a low-carbohydrate (ketogenic) diet and cannabidiol. Six months later William’s tumour had shrunk by two-thirds. He is slowly improving and attending school part-time.”