Newly diagnosed head and neck cancer patients who used marijuana recreationally reported better quality of life (QOL) outcomes and reduced psychosocial symptoms, a prospective case-matched study of Canadian patients found.
Compared with non-users, those who used loose-leaf marijuana at least weekly reported less pain, fatigue, depression, and anxiety, were less drowsy, and had better scores for appetite and general well-being on symptom and QOL questionnaires given prior to treatment initiation, reported Michael Gupta, MD, MSc, of McMaster University in Hamilton, Ontario, and colleagues in JAMA Otolaryngology — Head & Neck Surgery.
“The literature in marijuana is very unclear and limited, particularly in head and neck cancer patients,” Gupta told MedPage Today. “This is one of the strongest papers that’s come out showing that marijuana looks promising for controlling both the pain related to cancer and the anxiety related to the diagnosis.”
These benefits correlate well to those reported in post-traumatic stress syndrome (PTSD) patients, he said.
As confirmed by Wilcoxon rank sum testing, patients who used marijuana had z score improvements of âˆ’2.60 for pain/discomfort and âˆ’6.71 for anxiety/depression on EuroQOL-5D questionnaires. Similarly, statistically significant improvements were noted on the Edmonton Symptom Assessment System, with z scores of marijuana users all lower than the mean:
Barbara Burtness, MD, of the Yale Cancer Center in New Haven, Connecticut, told MedPage Today that while interesting, the research is “of limited relevance to clinical practice in head and neck cancer” given that the patients who used marijuana were self-selected.
“The differences between the groups are modest for some of the domains, and no information is given about how well matched the patients were for the treatment regimen, for other narcotic-sparing strategies, and for use of narcotics,” she added. “As well, no data are given on tobacco use, compliance with primary therapy, swallowing rehabilitation, or long-term outcomes.”
Burtness, who was not involved in the research, noted that a randomized trial of patients who are not habitual marijuana users and who otherwise receive identical definitive treatment and supportive care “would seem to be indicated.”
For the study, researchers consecutively enrolled 148 patients upon diagnosis of head and neck cancer at a single tertiary care cancer center from 2011 to 2015. Patients were a mean age of 62, and most were male (83.5%). There were no significant differences in age, sex, tumor subsite, clinical TNM staging, treatment modality, or mean Karnofsky scores (92.4 and 90.8, respectively) between the 74 recreational marijuana users and 74 non-users.
Despite limited research data, access to and acceptance of medical marijuana has been growing over the past decade, Gupta’s group wrote, pointing to studies of cannabis as a medicinal therapy showing antiemetic and analgesic effects among patients with cancer, anti-anxiety and anti-depression effects among PTSD patients, and as an adjunct for neuropathic pain in patients with chronic pain syndromes.
The two major neuroactive phytocannabinoids within marijuana, tetrahydrocannabinol (THC) and cannabidiol (CBD), have distinctive pharmacological and behavioral effects. “A central role is played by THC in the regulation of fear-related and anxiety-related behavior, whereas CBD activates receptors that constrain fear-related and psychological stress responses,” the group explained.
“One of the big weaknesses of this paper is that we don’t know how much or how the marijuana was used,” Gupta said. “Pain specialists use varied titrations of CBD and THC. I think any new drug has to be titrated to effect — it is possible that experienced users know how to do that already and new users may not.”
Long-term follow-up of this cohort of patients is planned, which will no doubt provide thought-provoking insights into the effects of marijuana on the QOL challenges among patients who undergo treatment and among long-term survivors, the group concluded.
The authors reported no conflicts of interest with respect to the research presented herein.