Cannabinoids for cancer-associated symptoms: A systematic review and meta-analysis

BackgroundCancer survivors will be more the 22 million by 2030, which makes quality of life as important as antitumoral therapy. Cannabinoids are a new class of drugs for the palliation of cancer-associated symptoms. Although popular among patients, cannabinoids still lack clear indications, given the immense variability of the products, study designs and recent discoveries. Our aim is to investigate the safety and efficacy of cannabinoids for symptom control in advanced cancer patients.MethodsThe study protocol was registered on PROSPERO (CRD42023479375), and a systematic search was conducted using three main databases (PubMed, Embase, and CENTRAL). Interventional and observational articles, where cancer patients were administered any type of cannabinoid for symptom control, including pain, constipation, nausea and insomnia, were eligible for analysis. The change from baseline (two-arm studies) or mean difference from baseline (one-arm studies) in symptom intensity was assessed, for which weighted means and pooled proportions were calculated with a 95% confidence interval (CI) and a random-effects model.ResultsAfter title-abstract and full-text selection, 96 articles were found to be eligible. Symptom improvement was rated using different scales (0-lowest, highest score-worst). Cannabinoids modestly improve pain compared to baseline, mean change of -0.57 (-0.85;-0.3 95% CI). When subgrouping the data based on the THC and CBD content, THC-based drugs were the best, decreasing pain with 1.27 points (-2.12;-0.43 95%CI), which is clinically and statistically significant. Cannabinoids modestly improve sleep quality, mean change from baseline -0.14 (-0.85;0.58 95% CI) and nausea, mean difference from baseline -0.06 (-0.42;0.29 95%CI), however not clinically significant. Further, cannabinoids don’t improve constipation, mean change from baseline 0.05 (-0.65;0.75 95% CI).ConclusionsCannabinoids could be beneficial for advanced cancer patients, but the effects may vary significantly depending on the type of cannabinoid, dosage, and form of administration. These preliminary results need to be followed by further analysis, so proper indication/contraindication of the drugs can be suggested.Legal entity responsible for the studyThe authors.FundingHas not received any funding.DisclosureAll authors have declared no conflicts of interest.