Conclusions
There’s a lot of interesting research about the role of cannabinoid receptors in cancer and whether targeting them with cannabinoid agonists from marijuana or other natural sources, synthetic agonists, or endocannibinoids will be a useful tool to add to the armamentarium of anticancer therapies. From what we know now, it is quite clear that cannabis does not cure cancer, at least not by itself and certainly not ingested or smoked as marijuana or ingested or applied topically as hemp oil. Even in purified form, naturally- derived or synthetic cannabinoid agonists show relatively modest antitumor activity in preclinical models, which means that they will have to be combined with existing chemotherapeutic regimens. If they do find their way into the routine clinical treatment of cancer, it will be through rigorous pharmacological studies and rigorous clinical trials, the latter of which, in particular, are painfully lacking. Indeed, if you search ClinicalTrials.gov, you’ll quickly find lots of trials of cannabinoids to treat cancer-related symptoms and side effects, but precious few to treat cancer itself. There’s this phase I trial of Dexanabinol in Patients With Advanced Solid Tumors, which has been open two years and is still accruing patients, as well as this one of Dexanabinol against brain cancers. It’s not a lot, and suggests that there is not much interest in even synthetic cannabinoids as a treatment for cancer. After all, there are so many other promising avenues that a class of drugs that show the modest effects that the cannabinoids I’ve discussed do just don’t excite researchers that much.
In any event, the claims of advocates that “cannabis cures cancer” are nothing more than herbalism infused with the magical thinking of the naturalistic fallacy. Just because it’s “natural” does not make it better. In the case of cannabis for cancer, the only potentially promising way forward is to isolate the active components and figure out which of the hundreds of different cancers in which these components have activity against.
Finally, I have no objection to lobbying for the legalization of marijuana for recreational use. I would support such measures myself. However, trying to use hugely exaggerated claims of medicinal benefit as a back door path to legalization gets my skeptical antennae all a’twitchin’ about all the other claims made by advocates and provides ammunition for critics whose real goal is prohibition.
David H. Gorski is an American surgical oncologist, Professor of surgery at Wayne State University School of Medicine,
and a surgical oncologist at the Barbara Ann Karmanos Cancer Institute, specializing in breast cancer surgery. Click to read the complete report.
