Peritumoural oedema or brain swelling is a very serious side effect of glioma and underpins many of the neurological symptoms caused by the tumour. Management of this inflammation sees the use of high-dose corticosteroids use such as dexamethasone, which is thought to suppress inflammation and decrease vasogenic oedema through partial restoration of blood–brain barrier. However, significant side effects are associated with its use, including insomnia, mood changes, headache, dizziness, nausea, stomach pain, leading to considerable extra suffering for these patients. Additionally, recent data also shows that high-dose steroids protects gliomas from the genotoxic stress (cell death) caused by radiotherapy and chemotherapy, reducing treatment efficacy and decreasing overall survival.
For the past 18 months, Dr Dun’s laboratory has been investigating the anti-leukaemia properties of medicinal cannabis, revealing remarkable leukaemia specific anti-cancer activity using plant extracts very low in Δ9-tetrahydrocannabinol (THC, concentration <0.40%). Previously, the majority of studies have shown that the anti-cancer properties of cannabis relate to their THC content. However, the THC content of medicinal cannabis has led to its prohibition due to the serious mental health side effects, limiting its clinical utility.
We are currently testing whether low-THC cannabis (lacking harmful THC) is an effective therapy for DIPG. Additionally, we hope to harness the anti-inflammatory properties of medicinal cannabis, to relieve some of the debilitating symptoms associated with brain inflammation in DIPG – helping children to increase their quality of life.