June 25 2024
Many Americans, including patients with cancer, use cannabis and cannabinoids. In response to this reality, ASCO has issued a guideline for clinicians, adults with cancer, caregivers, and researchers on their medical use.1 The recommendations cover all cancer types and address products ranging from synthetic cannabinoids to full-spectrum cannabis.
“This guideline clearly states that cannabis and cannabinoids can be medicinal in oncology and also lays bare where the holes lie in the scientific evidence. I hope the [recommendations] serve as a clarion call for researchers to systemically plug the knowledge gaps evaluating cannabis therapeutics in oncology,” said Guideline Co-Chair Ilana Braun, MD, of the Dana-Farber Cancer Institute.
Ilana Braun, MD
Current data suggest that about 20% to 40% of adults with cancer report cannabis use.2-7 The cannabis plant has hundreds of compounds, with most research focused on delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). Although cannabis has clear medicinal benefits, its use has outpaced the clinical research informing the care of people living with cancer. In addition, less than one-third of oncology clinicians feel confident making clinical recommendations about cannabis and cannabinoids with their patients, who often go to nonmedical sources, including staff at their cannabis dispensary, for advice.8,9
“I have had multiple patients with cancer who have tried cannabis for the first time at the urging of one of their well-intentioned loved ones and then experienced bad side effects, which may even include ending up in the emergency department,” said Guideline Co-Chair Eric Roeland, MD, FAAHPM, of the Oregon Health & Science University Knight Cancer Institute.
Eric Roeland, MD, FAAHPM
ASCO convened a guideline Expert Panel that culled through 366 publications to identify 13 systematic literature reviews, 4 randomized controlled trials, and 1 cohort study on the efficacy and safety of cannabis and cannabinoids in adults with cancer. The final recommendations provide strategies for open, nonjudgmental communication between clinicians and their patients about cannabis and cannabinoids.
“Clinicians should be open to talking about cannabis and cannabinoid use, because our patients are already using them, and we do have evidence regarding their use in certain areas,” Dr. Roeland said.
The guideline states that clinicians should recommend against patients using cannabis or cannabinoids as a cancer-directed treatment unless doing so is within the context of a clinical trial. For other uses, the greatest level of evidence supports the potential use of cannabis and/or cannabinoids in improving refractory, chemotherapy-induced nausea and vomiting in conjunction with standard-of-care antiemetic regimens. The guideline also notes insufficient data verifying cannabis and cannabinoid safety and efficacy in other areas of supportive care.
“Empirically supported indications [for cannabis and cannabinoids] are narrow in oncology and mainly include chemotherapy-induced nausea and vomiting when standard treatments don’t work well enough,” Dr. Braun said.
The guideline also calls for more research on cannabis and cannabinoid use for adults with cancer, and, fortunately, more studies are underway. For example, Dr. Braun’s research team at Dana-Farber is assessing oral CBD oil in managing cancer scan–related anxiety.
“Cannabis and cannabinoid trials are being carried out in different places around the globe, including Australia,” Dr. Braun added.
As more studies are completed, Dr. Roeland noted, he anticipates further updates to the guideline. “I’m very excited this is going to be the first of many iterations of this guideline, and [I] am very hopeful ongoing high-quality research will inform best practices in the future,” he said.
REFERENCES
1. Braun IM, Bohlke K, Abrams DI, et al: Cannabis and cannabinoids in adults with cancer: ASCO guideline. J Clin Oncol. March 13, 2024 (early release online).
2. Azizoddin DR, Cohn AM, Ulahannan SV, et al: Cannabis use among adults undergoing cancer treatment. Cancer 129:3498-3508, 2023.
3. Pergam SA, Woodfield MC, Lee CM, et al: Cannabis use among patients at a comprehensive cancer center in a state with legalized medicinal and recreational use. Cancer 123:4488-4497, 2017.
4. Weiss MC, Hibbs JE, Buckley ME, et al: A Coala-T-Cannabis Survey Study of breast cancer patients’ use of cannabis before, during, and after treatment. Cancer 128:160-168, 2022.
5. Salz T, Meza AM, Chino F, et al: Cannabis use among recently treated cancer patients: Perceptions and experiences. Support Care Cancer 31:545, 2023.
6. Worster B, Ashare R, Meghani SH, et al: Prevalence and perceptions of cannabis use among racially diverse patients with cancer pain: Results from a multi-site survey. J Clin Oncol 40(16 suppl):12125, 2022.
7. McClure EA, Walters KJ, Tomko RL, et al: Cannabis use prevalence, patterns, and reasons for use among patients with cancer and survivors in a state without legal cannabis access. Support Care Cancer 31:429, 2023.
8. Braun IM, Wright A, Peteet J, et al: Medical oncologists’ beliefs, practices, and knowledge regarding marijuana used therapeutically: A nationally representative survey study. J Clin Oncol 36:1957-1962, 2018.
9. Braun IM, Nayak MM, Roberts JE, et al: Backgrounds and trainings in cannabis therapeutics of dispensary personnel. JCO Oncol Pract 18:e1787-e1795, 2022.
Originally published in ASCO Daily News. © American Society of Clinical Oncology. ASCO Daily News, March 14, 2024. All rights reserved.
