Cannabis extract and radiation therapy have been found to be an extremely effective combination in treating brain cancer, virtually shrinking the tumors to nothing, according to a new mouse study by researchers at St. George’s, University of London.

For the study, researchers experimented with a variety of brain tumor treatments in the laboratory. The most effective treatment was found when they combined the active chemical components of the cannabis plant, known as cannabinoids, with radiation therapy.

There are 85 known cannabinoids in the cannabis plant. Two of these cannabinoids, called tetrahydrocannabinol (THC) and cannabidiol (CBD), were tested as part of the research on brain cancer.

Brain cancer is particularly difficult to treat and claims the lives of about 5,200 people each year. It has a particularly poor prognosis as the rate of survival after five years of a person’s diagnosis is only around 10 percent.

“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,” said Wai Liu, Ph.D., 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 new research is the first to demonstrate a significant effect when THC and CBD are combined with irradiation; tumors growing in the brains of mice were drastically slowed down with this combination.

“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.”

According to the American Brain Tumor Association, brain tumors are the second leading cause of cancer-related deaths in children under age 20; leukemia is the first. Brain tumors are also the second leading cause of cancer-related deaths in males ages 20-39, and the fifth leading cause in females.

The research team is discussing the possibility of combining cannabinoids with irradiation in a human clinical trial. The study was published in the journal Molecular Cancer Therapeutics.

Source: St. George’s, University of London