A preclinical study carried out at St George’s, University of London (UK) has determined that certain chemical components of cannabis are able to reduce brain tumor growth when used in combination with radiotherapy treatment. The study was recently published in Molecular Cancer Therapeutics.
Cannabinoids, the active chemical components of the cannabis plant, have previously been demonstrated to specifically inhibit glioma growth as well as neutralize oncogenic processes such as angiogenesis.
There are 85 known cannabinoids in the cannabis plant. Two of these, tetrahydrocannabinol (THC) and cannabidiol (CBD), were tested in high-grade glioma. This malignancy is one of the most aggressive cancers in adults and standard treatments remain largely unsuccessful, meaning the disease claims the lives of approximately 5200 patients each year. Prognosis for these patients is poor, with a 5-year survival rate of approximately 10%
The group investigated the effects of THC/CBD in combination with radiotherapy and dramatic reductions of tumor volume in the brains of mice were observed.
“The results are extremely exciting. The tumors were treated in a variety of ways, either with no treatment, the cannabinoids alone, and irradiation alone or with both the cannabinoids and irradiation at the same time,” commented Wai Liu (St George’s, University of London), Senior Research Fellow and lead researcher on the project.
“Those treated with both irradiation and the cannabinoids saw the most beneficial results and a drastic reduction in size. In some cases, the tumors effectively disappeared in the animals. This augurs well for further research in humans in the future. At the moment this is a mostly fatal disease. The benefits of the cannabis plant elements were known before but the drastic reduction of brain cancers if used with irradiation is something new and may well prove promising for patients who are in gravely serious situations with such cancers in the future,” Liu continued.
This research is the first to demonstrate a drastic effect when combining THC and CBD with irradiation and suggests a potential clinical benefit for glioma patients in combining these two treatment modalities. The group is now hoping to combine cannabinoids with irradiation in a human clinical trial.
Sources: Scott K A, Dalgleish A G, and Liu W M. The Combination of Cannabidiol and Δ9-Tetrahydrocannabinol Enhances the Anticancer Effects of Radiation in an Orthotopic Murine Glioma Model. Molecular Cancer Therapeutics, doi: 10.1158/1535-7163.MCT-14-0402 (2014) (Epub ahead of print); University of St George’s London press release