Aims: Nausea and vomiting in people living with cancer may negatively affect appetite, compromising patients’ nutritional status and cancer outcomes. Medicinal cannabis might have a role in supporting appetite in adults with cancer. This review examined the efficacy and safety of medicinal cannabis, compared with any control, as an intervention for appetite and nutritional status in people living with cancer.
Methods: A systematic review searched five databases in May 2023, for any type of interventional study that included humans (any age, cancer type, or cancer stage). Primary outcomes were appetite and nutrition status. Secondary outcomes were gastrointestinal symptoms and adverse events. Data were pooled using Review Manager. Confidence was assessed using GRADE.
Results: Fifteen studies (18 interventions; N=1898 total participants; 100% adults) measured appetite (n=11), nutritional status (n=5), gastrointestinal symptoms (n=14), and adverse events (n=14). Medicinal cannabis increased the likelihood of improved appetite (OR: 12.3; 95%CI: 3.5, 45.5; p<0.001; GRADE: Moderate) and reduced severity of appetite loss (SMD: -0.4; 95%CI: -0.8, -0.1; p=0.009; GRADE: Very low). Medicinal cannabis had no effect on food intake (n=2 studies: no effect, not pooled), unintentional weight loss (n=2 studies, not pooled), or gastrointestinal symptoms (n=5 studies, pooled [OR: 1.5 [95%CI: 0.8, 2.6]; GRADE: Very low). Higher doses of synthetic THC increased the likelihood of any adverse event (OR: 0.5; 95%CI: 0.3, 0.7; p<0.001; GRADE: Very low).
Conclusions: Although the medicinal cannabis formulations and dosing regimens tested had no effect on gastrointestinal symptoms such as nausea and vomiting, appetite improved. There was insufficient data to evaluate how this impacted nutritional status and careful monitoring should be used if prescribing high dose THC due to the risk of adverse events. Medicinal cannabis may improve appetite in adults living with cancer; however, further research is required to improve confidence and inform optimal dosing regimens.