Study Reports High Rates of Cannabis Use in Cancer Patients

A high rate of cancer patients reported using legalized cannabis, according to the results of a survey conducted at a National Cancer Institute–designated cancer center in Washington State, which has legalized the medicinal and recreational use of cannabis. These results were published in Cancer.

“Despite the limited evidence for a medical role for cannabis in oncology, our data suggest that cannabis may be currently used frequently in this setting,” wrote Steven A. Pergam, MD, MPH, of Fred Hutchinson Cancer Research Center in Seattle, and colleagues. “Patients are interested in receiving information about how cannabis might benefit them and prefer that this information come directly from their cancer providers.”

According to the study, close to 2 million people with cancer in the United States “will be exposed to increased local availability, permissiveness, and nonscientific reports suggesting benefits of cannabis.”

Because of this, Pergam and colleagues suggested the development of a framework for understanding the utility of cannabis among patients diagnosed with cancer. They conducted this cross-sectional, anonymous survey to determine the prevalence and methods of cannabis use among cancer patients, and its perceived benefits.

They surveyed 2,737 patients at their cancer center about cannabis use, and also gathered demographic and clinical information; 926 patients (34%) responded. The median age of patients was 58 years. The participants also had random urine samples taken, testing for tetrahydrocannabinol.

Most respondents (74%) reported having a strong interest in learning about cannabis during treatment and wanted information from their cancer providers.

Sixty-six percent of respondents reported having used cannabis at some point in their life, and one in four considered themselves to be active users. The majority of active users had used cannabis before their cancer diagnosis.

“More than half of active users reported that legalization significantly increased their likelihood of using, and cannabis use was spread across demographic subsets, including age, sex, and cancer diagnosis subsets,” the researchers wrote.

Twenty-four percent of respondents reported cannabis use in the last year, and 21% reported use in the last month. The researchers noted that “these levels are more than double those reported in national prevalence studies, where rates vary between 1.8% and 8.3% over 1 month and between 2.8% and 12.9% over 1 year.”

The most common forms of consumption among active users was inhalation (70%) or edibles (70%); 40% of active users reported using both modalities.

Respondents listed physical use (75%; pain, nausea, upset stomach) and neuropsychiatric symptoms (63%) as their most common reasons for cannabis use.

Finally, active users reported that they were significantly more likely to use cannabis because of its legalization (P < .001).

“There is a need to better understand methods of cannabis use to maximize benefit and limit risk because patients are already using a wide variety of products,” the researchers wrote. “There is a need for clinical trials evaluating the role of cannabis in symptom management and for the development of formalized education for patients and healthcare professionals about the risks and benefits of use in this population.”