Article Text

other Versions

Download PDFPDF
Cannabinoids for adult cancer-related pain: systematic review and meta-analysis
  1. Elaine G Boland1,
  2. Michael I Bennett2,
  3. Victoria Allgar3 and
  4. Jason W Boland4
  1. 1Hull University Teaching Hospitals NHS Trust, Cottingham, UK
  2. 2Academic Unit of Palliative Care, University of Leeds, Leeds, UK
  3. 3Hull York Medical School, University of York, York, UK
  4. 4Hull York Medical School, University of Hull, Hull, UK
  1. Correspondence to Dr Jason W Boland, Hull York Medical School, University of Hull, Hull HU6 7RX, UK; Jason.Boland{at}


Objectives There is increased interest in cannabinoids for cancer pain management and legislative changes are in progress in many countries. This study aims to determine the beneficial and adverse effects of cannabis/cannabinoids compared with placebo/other active agents for the treatment of cancer-related pain in adults.

Methods Systematic review and meta-analysis to identify randomised controlled trials of cannabinoids compared with placebo/other active agents for the treatment of cancer-related pain in adults to determine the effect on pain intensity (primary outcome) and adverse effects, including dropouts. Searches included Embase, MEDLINE, PsycINFO, Web of Science,, Cochrane and grey literature. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed.

Results We identified 2805 unique records, of which six randomised controlled trials were included in this systematic review (n=1460 participants). Five studies were included in the meta-analysis (1442 participants). All had a low risk of bias. There was no difference between cannabinoids and placebo for the difference in the change in average Numeric Rating Scale pain scores (mean difference −0.21 (−0.48 to 0.07, p=0.14)); this remained when only phase III studies were meta-analysed: mean difference −0.02 (−0.21 to 0.16, p=0.80). Cannabinoids had a higher risk of adverse events when compared with placebo, especially somnolence (OR 2.69 (1.54 to 4.71), p<0.001) and dizziness (OR 1.58 (0.99 to 2.51), p=0.05). No treatment-related deaths were reported. Dropouts and mortality rates were high.

Conclusions Studies with a low risk of bias showed that for adults with advanced cancer, the addition of cannabinoids to opioids did not reduce cancer pain.

Trial registration number CRD42018107662.

  • cannabis
  • cannabinoids
  • neoplasia
  • other cancer
  • pain
  • systematic review

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Contributors EGB, MIB and JWB contributed to study design. EGB and JWB performed the searches and contributed to data collection and data analysis. JWB and EGB drafted the article. VA undertook the statistical analysis. MIB contributed to writing of the article. All authors were responsible for approval of the final report.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient consent for publication Not required.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement All data relevant to the study are included in the article or uploaded as online supplementary information.