One in Four Cancer Patients Reports Using Medical Cannabis

By Anne Harding

June 23, 2020

NEW YORK (Reuters Health) - Nearly a quarter of cancer patients report using medical cannabis (MC), according to a new survey from one hematology-oncology practice.

Patients with more severe symptoms were more likely to use MC, and to find it helpful, Dr. David M. Macari of Beaumont Health in Royal Oak, Michigan, and colleagues found. But just half had discussed MC with their oncologist.

"MC use among cancer patients is a frequent and likely under-recognized reality," Dr. Macari and his colleagues write in the American Journal of Clinical Oncology.

Thirty-three states and the District of Columbia have legalized MC, the authors note, but research on its use in cancer patients is scarce. They surveyed oncology patients who visited their hospital in July-December 2018. Out of 327 surveys distributed, 188 could be analyzed (response rate 57.5%).

Forty-six patients (24.5%) reported using MC. Most used more than one type of product, including inhalation MC, oils and edibles. Just half had told their oncologist about their MC use, and 43 had MC licenses.

The mean baseline composite symptom score (BCCS) was 15.2 overall, 17.5 for MC users and 14.4 for non-users. Possible scores range from 8 (no symptoms) to 32 (severe in all symptoms)

MC users reported the most improvement in pain symptoms (80.9%); 77.3% said MC improved appetite and 72.7% reported decreased anxiety. Cloudy thinking was the most frequent adverse effect, reported by seven patients.

"Despite improving awareness of MC and decreasing stigma, only 50% of patients had discussed MC use with their oncologist and a minority of patients had obtained a medical marijuana license," Dr. Macari and his team note.

Michigan patients must have a medical-marijuana license to buy MC, they add. "Since the license requires a physician verification of a covered diagnosis, patients may be limited in their access to regulated and licensed MC without increased oncologists' awareness," they note.

Dr. Dylan Zylla, medical director of HealthPartners/Park Nicollet Cancer Research Center in St. Louis Park, Minnesota, told Reuters Health by email, "While I don't think this particular paper added significantly to what is already known, it does give a glimpse of cannabis use in a community setting, supporting prior work on cannabis utilization rates, patterns of use, and potential risks and benefits."

"One of the most interesting points to me was they reported only 50% of patients report their cannabis use to their oncologist," he said. "This can have important implications for patient care, and oncology providers need to do a better job asking patients about patients' views and usage of medical cannabis."

He added: "More prospective, interventional cannabis-focused research is clearly needed to provide data that helps educate and inform patients, providers and even policy-makers."

The best online source for information on MC for cancer, Dr. Zylla said, is a PDQ on the National Cancer Institute website (

Dr. Macari was not available for an interview by press time.

SOURCE: American Journal of Clinical Oncology, June 2, 2020.