In the weeds: a retrospective study of patient interest in and experience with cannabis at a cancer center

BACKGROUND: Cannabis products, including the cannabinoids CBD and THC, are rising in popularity and increasingly used for medical purposes. While there is some evidence that cannabinoids improve cancer-associated symptoms, understanding regarding appropriate use remains incomplete. PURPOSE: To describe patient experiences with medical cannabis with focus on use contexts and patients’ reported benefits and harms. METHODS: A standardized intake form was implemented in a dedicated medical cannabis clinic at an NCI-designated cancer center; data from this form was abstracted for all initial visits from October 2019 to October 2020. We report descriptive statistics, chi-square analysis, and multivariate logistic regression. RESULTS: Among 163 unique new patients, cannabis therapy was commonly sought for sleep, pain, anxiety, and appetite. Twenty-nine percent expressed interest for cancer treatment; 40% and 46% reported past use of CBD and THC, respectively, for medical purposes. Among past CBD users, the most commonly reported benefits were less pain (21%) or anxiety (17%) and improvement in sleep (15%); 92% reported no side effects. Among those with past THC use, reported benefits included improvement in appetite (40%), sleep (32%), nausea (28%), and pain (17%); side effects included feeling “high.” Seeking cannabis for anti-neoplastic effects was associated with receipt of active cancer treatment in both univariate and multivariate analysis. CONCLUSION: Cancer patients seek medical cannabis to address a wide variety of concerns despite insufficient evidence of benefits and harms. As more states move to legalize medical and recreational cannabis, cancer care providers must remain aware of emerging data and develop knowledge and skills to counsel their patients about its use. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00520-022-07170-8.