Cannabis Use During Immune Checkpoint Inhibitor Therapy Among Patients with Kidney Cancer and Melanoma

Introduction: Although cannabis has promise as a supportive care agent for patients with cancer undergoing chemotherapy or radiation, there is little evidence about its use among patients undergoing immune checkpoint inhibitor (ICI) therapy. We evaluated the extent of and reasons for cannabis use among patients currently receiving ICIs at a large cancer center. Materials and Methods: We conducted a survey among adults undergoing ICI treatment for melanoma or kidney cancer. Patients reported frequency of cannabis use since the start of ICI treatment, modes of ingestion, reasons for use, and experiences with cannabis. Results: Among 160 respondents, the median age was 65 years, 90% were White, 70% were male, and 68% had kidney cancer. Twenty-one percent of respondents used cannabis during ICI treatment ( n = 34). Most users ingested cannabis through food (71%) or by smoking it (41%). The most common reasons for using cannabis during ICI treatment were for recreation (68%) or to address symptoms (65%), which included mood impairment (44%), difficulty sleeping (32%), and aching muscles or joints (30%). Of patients reporting cannabis use to address those symptoms, >80% reported symptom improvement. Eighteen percent of respondents spoke to their oncology team about using cannabis during ICI treatment. Discussion: Cannabis use during ICI treatment is relatively common. Patients report using cannabis for recreation and to successfully address symptoms. Additional research into the symptom management benefits of cannabis and its impact on ICI treatment effectiveness is needed to inform patients and their providers and to establish clinical care guidelines.