A systematic review of evidence for cannabis and cannabinoids as adjuvant therapy in palliative and supportive oncology care.

Abstract

12091 Background: Medical cannabis use is increasing significantly in the United States as states reduce restrictions. However, ambiguity concerning the evidence for medical cannabis efficacy and safety, especially in the field of oncology, is persistent. Clinicians therefore face challenges in examining benefits and risks of medical cannabis as adjuvant treatment for cancer patients. This study identifies and evaluates the most recent available evidence for the efficacy of cannabis and cannabinoids as adjuvant in supportive and/or palliative use in patients with cancer. Methods: Electronic databases searched included PubMed, Embase, Web of Science, and Cochrane Library to identify studies published following the latest available systematic review, between July 2016 through October 2019. Studies conducted outside the United States, studies not evaluating cannabis or cannabinoids in Oncology care, and preclinical studies were excluded. Findings were organized in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) framework. Lastly, qualitative synthesis was used to generate summary statements about the role of cannabis and cannabinoids as adjuvant in supportive and/or palliative cancer care. Results: We screened 2,267 articles and included 96 studies in our qualitative synthesis. Among those were 2 RCT’s (1 completed), 6 Systematic reviews with Meta-analysis, 4 Systematic reviews without Meta-analysis, 71 other types of reviews and 13 observational studies. The most frequently reported outcomes assessed were efficacy of cannabis and cannabinoids for: pain (40 of 96; 17 indicating improvement), nausea and vomiting (26 of 96; 20 indicating improvement), cachexia (22 of 96; 2 indicating improvement), and utilization patterns of cannabis and/or cannabinoids among cancer patients (8 of 96). Conclusions: Latest available prevalence estimates indicate that a significant proportion of patients in the United States with cancer use cannabis and/or cannabinoids (18.3-40.0%). There is substantial evidence for the effectiveness of cannabis and cannabinoids in treating cancer-related pain; specifically, oromucosal THC/CBD spray. There is conclusive evidence for the effectiveness of cannabis and cannabinoids in relieving chemotherapy-induced nausea and vomiting; specifically, oral THC. There is inconclusive evidence regarding the effectiveness of cannabis and cannabinoids in treating cancer-related cachexia.