A new research review concludes that cannabinoids, specifically cannabidiol (CBD), demonstrates efficacy for cancer.
A team of Israeli scientists investigated the available literature on cannabinoids and cancer in children in a new research review published by The Israel Medical Association Journal.
“Overall, the cannabinoids, and specifically the non-psychoactive [cannabidiol], may show future promise in the treatment of cancer,” the review concludes.
Physicians Hana Golan, Tamar Fisher, and Amos Toren outlined their findings, splitting them into three sections: preclinical evidence of cannabinoids’ anti-cancer efficacy, clinical evidence of cannabinoids’ anti-cancer efficacy, and findings specifically on cannabinoids and pediatric tumors.
In preclinical findings, the researchers highlight a 1975 study by Munson, Harris, Friedman, Dewey, and Carchman as being the very first to report the ability of cannabinoids to reduce tumor growth. In their in vitro and in vivo experiments, tetrahydrocannabinol (THC) showed effective against lung cancer. It wasn’t until the 2000s, however, that research into cannabinoids’ anti-cancer effects were renewed. Through animal and cultural models, scientists found cannabinoids to have anti-cancer effects on gliomas and various types of tumors, including prostate, breast, leukemia, lymphoma, pancreas, melanoma, thyroid, colorectal, and heptocellular carcinoma tumors.
While the exact mechanism of cannabinoids’ anti-cancer capabilities has yet to be identified, preclinical research has revealed that cannabinoids produce their anti-tumor effects through the induction of cell death, inhibition of cell growth, and inhibition of tumor angiogenesis invasion and metastasis. The studies also found high levels of cannabinoid receptors, CB1 and CB2, in the tumors compared to normal, healthy tissue.
Clinical trials investigating cannabinoids and cancer, the researchers found, are limited. They identified just one human trial that examined cannabinoids’ effects on cancer. The study, involving nine patients, found THC treatments to be effective at decreasing tumor growth and tumor progression.
The researchers found no published clinical studies looking at the anti-cancer effect of cannabinoids on pediatric tumors, but did identify a few preclinical studies that looked at cancers that typically affect children. In one, CBD was effective at reducing the viability and invasiveness of the aggressive pediatric tumor, neuroblastoma. That same study found THC and CBD showed effectiveness for treating xenograft tumors in mice, with CBD showing a more significant effect.
The review urges the need for more clinical trials, explaining that a large reason for the lack of data is the legal status of cannabis in the U.S. and the associated barriers that status creates for conducting research. While 29 states have legalized medical marijuana, federally cannabis continues to be classified as a Schedule I substance. As a result, interested researchers must first acquire a Schedule I research registration from the U.S. Drug Enforcement Administration and are required to obtain their cannabis material from the National Institute on Drug Abuse (NIDA). These requirements can take months and add costs, hindering the volume of human clinical research and associated collection of data.
Despite the lack of research, the researchers found that most physicians in the U.S. support medical marijuana use. A survey conducted in 2013, the review highlights, found that 76 percent of 1446 physicians approved using marijuana for medical purposes.
You can access the entire study, “The Role of Cannabinoids in the Treatment of Children with Cancer,” via The Israel Medical Association Journal.