A new study in mice shows that marijuana has the potential to reduce the size of gliomas, a kind of aggressive brain cancer, when combined with radiation therapy. More research needs to be done, but this could be a big step towards treating brain cancer, which currently has a very low cure rate.
A research paper detailing these findings was published on Friday, November 14 in the journal Molecular Cancer Therapies.
Researchers said that the group of mice who received marijuana and radiation therapy had "dramatic reductions" in the size of their brain tumors. Dr. Wai Liu, one of the lead authors of this study, called the results promising.
Other studies done previously show that marijuana has potential as a way to fight cancer. A 2013 study showed that marijuana could kill cancerous cells in patients with leukemia, for example. However, this is the first study that examines the combined effects of marijuana and radiation. Marijuana works better with radiation than either does alone, Liu said.
"The results showed that the final effect was superior to the sum of the parts. Hopefully, these results will support calls for formal trials in humans to test these combinations," Liu said.
The researchers experimented with mice with glioma tumors, giving them a range of treatments, including radiation without any marijuana, and different levels of two compounds found in marijuana: THC and CBD. The gliomas were reduced most effectively with all three forms of treatment: radiation, THC, and CBD. THC is the psychotropic substance in marijuana that gives users a "high." CBD has no effect on the mind. By combining the two separately, the researchers were able to find an effective dose that would treat cancer without a psychotropic dose of THC.
"Those treated with both irradiation and the cannabinoids saw the most beneficial results and a drastic reduction in size. In some cases, the tumours 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," Liu said.
If marijuana has a similar effect in humans with brain cancer, this could potentially save the lives of patients with aggressive brain cancer.