(Open access funding provided by Semmelweis University)
As cancer survival rates are increasing, alternative treatments to improve quality
of life, such as cannabinoids, are gaining attention. Although cannabinoids are widely
used to manage cancer-related symptoms, clear guidelines are lacking. This systematic
review and meta-analysis assessed the safety and efficacy of cannabinoids in the management
of symptoms among cancer patients. The study protocol was registered on PROSPERO (CRD42023479375).
A systematic search was conducted using three main databases (PubMed, Embase, and
CENTRAL) on 4 November 2023. We included interventional and observational studies
that evaluated cannabinoids for symptom management in cancer patients compared to
standard care, placebo, or baseline values. Pooled mean differences (MD), proportions
and odds ratios (OR), and the 95% confidence intervals (CI) were calculated with a
random-effects model.Overall, 98 articles were eligible. Cannabinoids reduced pain
(MRAW: -1.22, CI: -1.92; -0.52) and anxiety (MRAW: -1.30, CI: -2.22; -0.39) as compared
to baseline values. Appetite (MRAW: -1.88, CI: -6.23; 2.46), chemotherapy-induced
nausea and vomiting (OR: 2.18, CI: 0.79; 6.00), as well as insomnia (MD: -1.08, CI:
-2.48; 0.33) presented with a tendency toward improvement. Cannabinoids do not influence
constipation, depression, fatigue, mobility or overall quality of life. In terms of
safety issues, THC-predominant formulations increase the risks of psychiatric (OR:
10.62, CI: 1.35; 83.57), neurological (OR:2.24, CI: 1.15; 4.35), and gastrointestinal
(OR:2.69, CI:0.73;9.90) side effects. The risk of bias of articles included varied
from some concerns to high. Cannabinoids may be beneficial for the treatment of cancer-related
pain and anxiety; however, their use carries a significant risk of adverse effects,
particularly psychiatric complications. Careful patient selection is essential when
considering cannabinoid-based treatments.
