Cannabis Use Is Common Among Cancer Survivors, but Reported Benefits Outpace Risk Awareness

A survey of 1,886 cancer survivors found that cannabis use is widespread among people managing cancer or its effects—but many users had limited awareness of potential risks.

The study, published online in 2023 in the Journal of Cancer Survivorship, analyzed responses from adults receiving care at a comprehensive cancer center who lived in 41 U.S. states. Overall, 17.4% of participants said they currently used cannabis, 30.5% were former users, and 52.2% had never used it.

Among the 510 survivors who reported using cannabis during or after their cancer diagnosis, symptom management was the most common reason. Sixty percent used it for sleep disturbances, while 51% cited pain, 44% stress, 34% nausea, and 32% mood disorders or depression. About one in five of these respondents—91 people—said they used cannabis as part of their efforts to treat cancer itself.

Many participants perceived cannabis as helpful. For each symptom examined, more than half of the survivors who used cannabis for that reason said it improved the problem “to a great extent.” Nausea produced one of the strongest reported responses: 73.6% described cannabis as highly effective, and another 24.4% said it was somewhat effective. Similar patterns were reported for pain, sleep, stress, appetite, depression, and coping with illness.

These findings describe patients’ experiences and perceptions; they do not show that cannabis caused the improvements. The research was a cross-sectional survey, meaning participants reported their own cannabis use and symptoms at one point in time. It did not compare cannabis with a placebo or establish which products, doses, or methods of consumption were most effective. Participants may also have been affected by recall bias or other factors unrelated to cannabis.

The survey’s findings on risk awareness were particularly notable. Only 167 participants reported being aware of potential health risks associated with cannabis use during cancer management. Among those who recognized possible harms, awareness varied: 35% knew cannabis could interact with cancer drugs, 31% identified breathing problems, 14% anxiety, 11% depression, 6% intense nausea and vomiting, and 5% suicidal thoughts.

The results reinforce the need for open, nonjudgmental conversations between cancer survivors and their healthcare providers. Cannabis products vary widely in their THC and CBD content, strength, formulation, and method of use, and cannabinoids may interact with some medications. The National Cancer Institute’s evidence summary notes that the FDA has not approved cannabis as a cancer treatment, although the cannabinoid medicines dronabinol and nabilone are approved for chemotherapy-related nausea and vomiting in certain circumstances.

Evidence is stronger for some specific uses than for others. A clinical practice guideline from the American Society of Clinical Oncology recommends against using cannabis or cannabinoids as a cancer-directed treatment outside a clinical trial. It says cannabinoids may help some patients with chemotherapy-induced nausea and vomiting that remains uncontrolled despite standard antiemetic treatment, while evidence for other supportive-care benefits remains uncertain.

Similarly, a National Academies review of cannabis and cannabinoids found substantial or conclusive evidence for certain applications, including chronic pain in adults and chemotherapy-induced nausea and vomiting treated with oral cannabinoids. It found insufficient evidence to determine whether cannabinoids can treat cancer itself.

The survey therefore offers an important picture of how cancer survivors are using cannabis, but not a clinical recommendation. Its central message is that many survivors turn to cannabis for sleep problems, pain, nausea, stress, and other symptoms—and often believe it helps. Better clinical research, clearer guidance, and more informed discussions are needed so that patients can weigh those perceived benefits against possible side effects, drug interactions, and the limitations of current evidence.