Survey Finds Nearly One-Third of Cancer Patients Use Cannabis

Nearly a third of cancer patients used cannabis to treat their symptoms in a recent study conducted by researchers affiliated with Memorial Sloan Kettering Cancer Center in New York City. The study, which was published recently in the peer-reviewed journal Supportive Care in Cancer, also found that most patients who are using cannabis don’t report their use to their healthcare provider, a finding that’s consistent with previous research that showed patients are reluctant to discuss their use of medical marijuana with their doctors.

To conduct the study, researchers recruited patients with nine different cancers being treated at Memorial Sloan Kettering Cancer Center between March and August 2021. Patients were asked to complete an online or telephone survey designed to capture data on cannabis use and the patients’ attitudes and communication about cannabis. A subsequent analysis of the data estimated the association between cancer type and cannabis use, adjusting for sociodemographic characteristics and prior cannabis use.

Among the survey’s 1258 respondents, nearly a third (31%) of patients reported using cannabis after their cancer diagnosis, primarily to treat their symptoms. The rate of patients’ cannabis use varied by the type of cancer, ranging from 25% for lung cancer up to 59% for testicular cancer. Patients who used cannabis for palliative care “overwhelmingly reported improvements in their symptoms,” the researchers reported.

Characteristics associated with cannabis use included younger age, lower education level and type of cancer. Additionally, cannabis use in the year prior to a patient’s cancer diagnosis was strongly associated with cannabis use after diagnosis. In a multivariable analysis of the study data, gastrointestinal cancer patients were more likely to use cannabis compared to patients being treated for lung cancer. Patients reported different reasons for using cannabis, with 48% saying they used it to improve sleep, 46% saying they used cannabis to treat stress, anxiety or depression and 42% reported using cannabis use to treat pain. Among respondents who used cannabis to treat symptoms, 70-90% reported symptom improvement. Less than 5% said their cannabis use made their symptoms worse.

Study Finds Patients Are Reluctant to Discuss Cannabis

The new study also found that only 25% of those using cannabis to treat their symptoms discussed such use with their healthcare provider. Noting the prevalence of cannabis use among cancer patients, the authors of the study recommended that oncologists prepare themselves to have frank discussions about the potential harms and benefits of cannabis with their patients.

“Our study found that cannabis use among cancer patients is common across sociodemographic and clinical populations, with cannabis often obtained without oncologist involvement,” the researchers wrote in an abstract of the study. “Oncologists and other members of the oncology team are uniquely positioned to provide education about the harms and benefits of cannabis use specifically for cancer patients, which is especially important in the context of inconclusive and often conflicting evidence. Interventions to improve cannabis education and communication need not target oncologists who treat specific cancers, as cannabis use appears consistent across multiple patient characteristics.”

In an article about the research, the National Organization for the Reform of Marijuana Laws (NORML) noted that the study’s finding that only a quarter of the respondents who were using cannabis told their healthcare provider about their use is consistent with research published in 2020 by researchers affiliated with the University of Vermont. In a survey of 1,000 primary care patients in Vermont, where medical marijuana was legalized for qualified patients in 2004, less than a fifth of participants (18%) “rated their provider as a good source of information regarding cannabis.”

Many of the study participants reported using cannabis products in the month prior to the survey, with 21% saying they had used CBD products and 19% reporting using products with THC. Most respondents said they perceive their use of cannabis products to be “very” or “somewhat helpful” in treating a variety of symptoms including pain, depression and difficulty sleeping. Respondents also reported using cannabis to treat medical conditions including insomnia, migraine and arthritis.

“The results of our research pose important questions that should be investigated in the future,” the authors of the 2020 research wrote in the conclusion of their study. “Considering patients feel that their providers may not be an adequate source of information regarding cannabinoids, it would be interesting to explore the perceived knowledge and perceptions of cannabinoids by primary care providers, to identify opportunities for improvement. … Further research should consider how to assist primary care providers in having informed conversations about the risks and benefits of cannabis, especially in the setting of chronic pain.”

The new study, “Cannabis use among recently treated cancer patients: Perceptions and experiences,” was published in the journal Supportive Care in Cancer last month.