An RCT found cannabidiol given to adults with advanced cancer and symptom distress did not add value to specialist palliative care alone
Cannabidiol (CBD) oil given to patients with advanced cancer receiving palliative care provided no additional benefit to that care according to the findings of a randomised trial by Australian researchers.
Although there have been several advances in medical care, a proportion of patients with advanced cancer still experience substantial symptom distress. The use of palliative care seeks to improve both symptom control and quality of life but despite this, some symptoms can be difficult to control, necessitating more effective medications. Both cannabis and cannabinoid drugs containing cannabidiol, are widely used to treat disease or alleviate symptoms. However, a 2015 meta-analysis concluded that whilst there was moderate-quality evidence to support the use of cannabinoids for the treatment of chronic pain and spasticity, there was low-quality evidence suggesting that cannabinoids were associated with improvements in nausea and vomiting due to chemotherapy. In a feasibility study, Australian researchers examined the use of global symptom burden measures to assess the response to medicinal cannabis with both cannabidiol and tetrahydrocannabinol. They concluded that doses of both cannabidiol and tetrahydrocannabinol were generally well tolerated and that the outcome measure of total symptom distress was promising as a measure of overall symptom benefit.
Based on the these early and promising findings, the same group undertook a randomised trial to determine whether cannabidiol oil could improve symptom distress in patients with advanced cancer receiving palliative care. They included adult participants with advanced cancer and symptom distress which was measured using the Edmonton Symptom Assessment Scale [ESAS]. Participants received titrated CBD oil 100 mg/mL, 0.5 mL once daily to 2 mL three times a day, or matched placebo for 28 days. The ESAS scale is designed to rate the intensity of nine common symptoms experienced by cancer patients, including pain, tiredness, nausea, depression, anxiety, drowsiness, appetite, well-being and shortness of breath. For the trial participants, the inclusion criterion was an ESAS score greater than or equal to 10/90. The primary outcome was set as the total ESAS symptom distress score (TSDS) at day 14, with a response defined as a decrease greater than or equal to, 6 at day 14.
Cannabidiol oil and symptom distress
A total of 58 patients receiving CBD and 63 placebo, reached the primary analysis point (i.e., day 14) and the median dose of participant-selected CBD was 400 mg per day.
The unadjusted change in TSDS from baseline -6.2 for the placebo group and -3.0 for those receiving CBD and this difference was non-significant (p = 0.24). Equally, there was no significant difference in proportion of responders (placebo = 58.7% and CBD = 44.8% p = 0.13).
In fact, during the study, all components of the ESAS improved (that is, reduced) over time with no difference between the placebo and CBD arms. In addition, there was no detectable effect of CBD on quality of life, depression, or anxiety. Overall, most participants reported feeling better (53% CBD vs 65% placebo) or much better (70% CBD and 64% placebo) by day 14.
The authors concluded that CBD oil did not add value to the reduction in symptom distress provided by specialist palliative care alone.
Hardy J et al. Phase IIb Randomized, Placebo-Controlled, Dose-Escalating, Double-Blind Study of Cannabidiol Oil for the Relief of Symptoms in Advanced Cancer (MedCan1-CBD). J Clin Oncol 2022