Cannabinoids ineffective for cancer pain
Cannabinoids did not appear to reduce cancer-associated pain among adults with cancer, according to results of a systemic review and meta-analysis published in BMJ Supportive & Palliative Care.
“There is growing public interest in cannabinoids, and patients experiencing pain from cancer are asking about cannabinoids more often,” Jason W. Boland, PhD, FRCP, SFHEA, senior clinical lecturer and honorary consultant in the department of palliative medicine at Wolfson Palliative Care Research Centre of Hull York Medical School in the U.K., told Healio.
“Furthermore, the medicinal use of cannabis is already legal in 40 countries and 29 U.S. states,” he added. “Several recent high-quality studies have been published, so performing a systematic review with a meta-analysis was the next step in strengthening the evidence from which we practice clinically.”
The systemic review included six randomized controlled trials that involved 1,460 adults and the meta-analysis included five studies of 1,442 adults that assessed use of cannabinoids compared with placebo and other active agents for the treatment of cancer-associated pain. The studies all had a low risk for bias.
Absolute mean change in average pain, from baseline to the end of treatment, on a Numeric Rating Scale served as the primary outcome. Adverse effects and study dropout served as secondary outcomes.
Boland and colleagues observed no significant difference between cannabinoids and placebo in average Numeric Rating Scale pain score change (mean difference, 0.21; 95% CI, 0.48 to 0.07). The same remained true with only phase 3 studies included in the meta-analysis (mean difference, 0.02; 95% CI, 0.21 to 0.16).
The cannabinoid group demonstrated higher risk for somnolence (OR = 2.69; 95% CI, 1.54-4.71) and dizziness (OR = 1.58; 95% CI, 0.99-2.51), as well as a nonsignificant higher likelihood for study dropout because of adverse events (OR = 1.33; 95% CI, 0.95-1.85). However, researchers observed no treatment-associated deaths.
The analysis may not have included all relevant studies, researchers acknowledged, and inconsistencies existed among the studies in terms of the patients included, interventions, comparators and outcomes.
“Our systematic review brought together randomized studies assessing the effects of cannabinoids vs. placebo [and other active agents] on pain in patients with cancer. Based on the pooled findings from these high-quality studies, cannabinoids do not have a role in cancer-associated pain,” Boland told Healio. – by Jennifer Southall
For more information:
Jason Boland, PhD, FRCP, SFHEA, can be reached at Wolfson Palliative Care Research Centre of Hull York Medical School, Allam Medical Building, University of Hull, Hull, HU6 7RX U.K.; email: firstname.lastname@example.org.
Disclosures: The authors report no relevant financial disclosures.