Cannabis May Help Chemo Nausea, Not a Substitute for Cancer Treatment

Here's what patients with cancer should know about cannabis, an expert explained to CURE®.

Cannabis and cannabinoid access and use among patients with cancer “has outpaced the science supporting their clinical use,” according to the findings issued by an expert panel convened by the American Society of Clinical Oncology (ASCO).

“Clinicians should recommend against using cannabis or cannabinoids as a cancer-directed treatment unless within the context of a clinical trial,” experts wrote in the guidelines published in the Journal of Clinical Oncology. “Cannabis and/or cannabinoids may improve refractory, chemotherapy-induced nausea and vomiting when added to guideline-concordant antiemetic regimens. Whether cannabis and/or cannabinoids can improve other supportive care outcomes remains uncertain.”

However, the Associated Press reported that the U.S. Drug Enforcement Agency is poised to reclassify the substance as a less dangerous drug and recognize its medical uses.

Dr. Ilana M. Braun of the Dana-Farber Cancer Institute in Boston, immediate past chief of the division of adult psychosocial oncology as well as co-leader and first author of the guideline working group, discussed some of the misconceptions that persist regarding cannabis and cancer and conversations patients should have with their care team regarding this issue.

What are some of the major misconceptions about cannabis in cancer that persist these days? What would you like patients to know about these issues?

We know from survey and interview research that patients with cancer are turning to cannabis for the management of multiple symptoms and side effects — for instance, for cancer pain, to improve appetite, to help with nausea or mood, for an overall sense of wellbeing. We also know that not infrequently patients with cancer consume cannabis in an effort to treat cancer itself. Sometimes they do so as an adjunct — as an add-on to standard cancer therapies. Sometimes they even do it in lieu of standard cancer therapies. So that's what's happening empirically.

Of all the reasons people with cancer turn to cannabis, the one with the greatest scientific evidence to support it is cannabis to manage nausea and vomiting due to chemotherapy — and then, only when standard treatments for nausea and vomiting have failed.

The ASCO panel that created the guidelines felt strongly that cancer patients should be cautioned against using cannabis as a means of treating cancer itself when added to standard treatments, and should be cautioned very strongly against using cannabis as a replacement for standard cancer treatments.

What are some reliable sources that patients can look to for current guidance on cannabis use during cancer?

First, the ASCO Cannabis and Cannabinoid Guidelines. The organization really did subject cannabis to the same rigorous scrutiny as they would any other corner of medicine. And importantly, the guidelines they published are accompanied by a tip sheet, a pocket card and a podcast all intended for the general public touched by cancer.

Beyond that, I would encourage patients to lean on the medical professionals who care for them to either guide them personally or direct them to appropriate resources within the community.

As far as you're aware, how common is cannabis use among patients with cancer and survivors, and are those numbers rising?

The National Cancer Institute recently tried to understand the scope of cannabis consumption among cancer patients. The data coming in now suggest that rates range from one in five to one in four to one in three and even 41% to 42% in a couple of studies. Because this is the first time that such rigorous attention has been paid to rates of cannabis use in the population, I don't know that we're positioned yet to understand trends over time. That will come [later].

Do any disparities or barriers and equities exist regarding education around cannabis and cannabis use among patients and survivors?

This is an excellent question, and I don't believe it has been rigorously interrogated scientifically yet. I will say that anecdotally much of the education including the ASCO guidelines are in English, which in itself is a barrier to some patients.

What are some potential short-term and long-term risks of cannabis use among patients?

Acute side effects might include confusion, anxiety, nausea, vomiting, drug/botanical interactions including with some cancer-related medicines, driving liabilities and accidental exposures — so think of children and pets in the home.

Longer term, there's an increased risk of triggering a psychotic disorder, particularly in those with a personal or familial history. Also, with heavy use a cyclic nausea and vomiting syndrome has been described.

Another thing to mention is there's a risk of breaking the bank. Cannabis isn't cheap. Scientific evidence indicates that cancer patients are spending $80 to $100 a month on cannabis and cannabis is not covered by insurance usually.

If patients are still curious about cannabis use, what sorts of conversations should they be having with their care team?

Another wonderful question. A very important thing when it comes to cannabis consumption during cancer is transparency about it during clinical encounters. The guidelines call upon clinicians and healthcare institutions to provide cancer patients with evidence-based education to help them make informed decisions. The guidelines go on to emphasize that clinical communication should be non-judgmental.

In that vein, topics that might be relevant to discuss include goals of use, where to source cannabis products, the formulations to use, so ratios of active ingredients and inactive ingredients in the product, as well as preferred routes of administration, how often to consume, a careful medication review and consideration of potential drug/botanical interactions, whether cannabis will be used as an add-on or replacement for standard therapies, and how to safely store the product, not to mention the risks inherent with use.

Do you have anything else you'd like patients to know about this topic?

If you are consuming cannabis during cancer or considering consuming cannabis during cancer, your clinical team really wants to know.

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