Medical cannabis use among individuals with cancer: An unresolved and timely issue

Abstract

The role of cannabis in cancer care is a complex and challenging issue. Cancer and its treatments currently are designated as qualifying conditions in the majority of the 33 states that now have legalized medical cannabis. 1 Consequently, cannabis use in patients with cancer is common: nearly one-quarter of individuals with cancer report current cannabis use 2,3 and >90% of cancer survivors view cannabis as potentially beneficial for symptom management and support its legalization. 4 Recent studies have suggested that physicians may be more likely to recommend cannabis to patients with cancer compared with patients with other serious illnesses, 5 and that oncologists are becoming increasingly accepting of patients using cannabis, despite their continued concerns regarding its safety and efficacy. 6,7 For example, approximately 46% of oncologists reported recommending medical cannabis clinically and approximately 80% discussed it with their patients, despite the fact that approximately 70% acknowledged that they were insufficiently educated regarding medical cannabis. 8 Thus, there appears to be a disconnect between medical cannabis's legal status and high acceptance by patients, recommendations from clinicians, and a poor evidence base concerning its safety and efficacy.A more complete and nuanced understanding of the relevant issues is imperative in this current climate of growing cannabis availability and acceptance. In this commentary, we have discussed key clinical issues related to the efficacy and safety of cannabis in patients with cancer and noted important lingering questions for clinical practice and research in this area. Cannabis: Indications, Use Versus Evidence BaseApproximately 75% of individuals with cancer use cannabis for symptom management, most commonly pain, nausea, and sleep disruption 9,10 ; however, to the best of our knowledge, the evidence base supporting this has been limited. It is important to note at the outset that the majority of the cannabis research conducted in oncology patients lacks the rigor that would be required of most other oncology treatments in practice. Even the limited number of randomized controlled trials that exist for comparing the efficacy of cannabis with that of placebo or other drugs in oncologic patients are homogeneously low or very low in quality. 11 A recent systematic review characterized the available evidence regarding cannabis for cancer symptom management as low quality and found no benefit for its common indications of pain, sleep, or a reduction of opioid dose. 12 In addition, to our knowledge, evidence for the antiemetic properties of plantbased preparations is seriously lacking. In effect, the best evidence exists for oral, pharmaceutically prepared, synthetic tetrahydrocannabinols (THCs) such as nabilone and dronabinol, which have been found to be superior to placebo and equivalent to other antiemetic medications. [13][14][15] For example, one observational prospective study found at least a 30% reduction in symptoms such as vomiting and fatigue ...

Cannabis use among cancer survivors in 22 states: Results from the Behavioral Risk Factor Surveillance System, 2020

“…However, we were unable to assess these components because of limitations in available data. It is important to acknowledge that it may be difficult to ascertain an individual's true exposure because of the lack of regulatory oversight (e.g., product screening programs, accurate labeling) of cannabis in many states 10,51–53 …”

“…It is important to acknowledge that it may be difficult to ascertain an individual's true exposure because of the lack of regulatory oversight (e.g., product screening programs, accurate labeling) of cannabis in many states. 10,[51][52][53] Clinicians are becoming increasingly more accepting of patients using cannabis for medical purposes; however, most report not feeling equipped to make clinical recommendations. 10,54,55 Evidence shows that patients are using medical cannabis with minimal medical oversight including obtaining medical cannabis authorization from a provider who is unfamiliar with their medical history and relying on unregulated sources for information regarding cannabis.…”

“…10,[51][52][53] Clinicians are becoming increasingly more accepting of patients using cannabis for medical purposes; however, most report not feeling equipped to make clinical recommendations. 10,54,55 Evidence shows that patients are using medical cannabis with minimal medical oversight including obtaining medical cannabis authorization from a provider who is unfamiliar with their medical history and relying on unregulated sources for information regarding cannabis. [56][57][58][59] Specifically, most patients report obtaining information regarding strains, ratios of active ingredients, routes of administration, and dosages from cannabis dispensaries.…”

“…Despite the lack of strong clinical evidence for its effectiveness, as of mid‐2020, 35 states have approved medical cannabis, with almost every one of those states identifying cancer as a qualifying condition 9 . Cancer survivors in particular are likely exposed to various messaging regarding the potential benefits of cannabis, either for treatment of cancer or management of symptoms and side effects, and inconsistent clinician support 10 …”

“…9 Cancer survivors in particular are likely exposed to various messaging regarding the potential benefits of cannabis, either for treatment of cancer or management of symptoms and side effects, and inconsistent clinician support. 10 Quantifying the current patterns of cannabis use is imperative as the sociocultural context of cannabis rapidly evolves, as well as the availability and variety of cannabis products increase. Estimates of cannabis use among cancer survivors based on nationally representative population-based samples have varied from 5% to 12% among cancer survivors, and 7% to 16% among individuals without a history of cancer.…”