Cancer, Cannabis, and the Search for Relief
JNCCN—Journal of the National Comprehensive Cancer Network, 2019, Volume 17, Issue 9, 1142-1144.
doi : 10.6004/jnccn.2019.7347
“How about medical marijuana?” is a common and often challenging question in oncology clinics today. It is easy to see why. Answering the question is fraught with clinical, legal, and administrative uncertainties. We all want to give patients the best advice, but not much about medical cannabis seems straightforward today. Whatever answer we provide can feel unsatisfactory to patients or ourselves. Answering clinical questions through high-quality research will take many years. And significant political power will be needed to clarify many of the legal and administrative hurdles. In the meantime, how should we approach patients who inquire about medical cannabis?
A retrospective study by Chang et al1 in this issue of the journal points to an intriguing observation: patients who use medical cannabis seem to have less adequate symptom control than those who do not. In the study, researchers analyzed charts of patients in an outpatient supportive care clinic at a cancer center. At the visit, clinicians assessed patients using the 11-point numerical Edmonton Symptom Assessment Scale (ESAS) and also obtained routine urine drug testing (UDT) to ensure safe prescribing. The charts of those who underwent both ESAS and UDT on the same day were further analyzed. The study found that 22.9% of the patients had cannabis metabolites in their urine. These patients were more likely to be young and male and reported more frequent cannabis use. However, as the analyses of their ESAS showed, they also self-reported a higher severity of pain, nausea, and insomnia, and worse overall and spiritual well-being compared with those who did not have positive UDT results. The use of cannabis in this group may be related to a number of factors. The authors postulated that inadequate control of symptoms drove the interest in and use of cannabis, which is consistent with other research.1
Patients with cancer are among the most frequent users of medical cannabis. Yet, the exact prevalence of cannabis use in these patients is not well established. In a recent survey conducted at a cancer center in Canada, 1 in 5 surveyed patients had used cannabis within the preceding 6 months; 46% of the users used it for cancerrelated pain; 34% for cancer-related nausea; and 31% for other cancer symptoms.2 In an anonymous survey conducted at the Seattle Care Alliance, 24% of responders considered themselves active cannabis users.3 Of all responders, 26% used it with intent to treat their cancer. They listed pain, nausea, and loss of appetite as the main reasons for their use. Responders also admitted to using cannabis recreationally.3
Patients with cancer experience a high symptom burden that tends to increase with disease progression. Many of the symptoms remain inadequately managed throughout the trajectory of the illness.4
Moreover, as surveys confirm, cannabis users see cannabis-based products as safe, devoid of dangerous interactions, and useful for symptom control and even for the treatment of cancer. Unfortunately, only some of these many hopes are backed by clinical evidence. Meanwhile, across the United States, cannabis has gained a more positive public image that helped fuel the burgeoning industry. That patients with cancer reach for cannabis for symptom relief is hardly surprising.