Many patients use cannabis to manage cancer-related symptoms. However, research shows that patients often consult their oncologist without first consulting with them, and oncologists may be hesitant to broach the subject with patients.
Updated American Society of Clinical Oncology (ASCO) guidelines for the use of cannabis and cannabinoids in adults with cancer stress. This is an important discussion.
According to ASCO's expert panel, access to and use of cannabis alongside cancer treatment exceeds evidence-based indications and provides an overall high-quality report on the impact of cannabis in cancer treatment. There is a lack of data. Some observational studies support the use of cannabis to reduce chemotherapy-related nausea and vomiting, but there is little research in the literature regarding other potential benefits, such as reducing cancer pain and sleep disturbances. Opinions remain divided, and some evidence points to potential downsides to cannabis use.
Oncologists should “absolutely talk to their patients” about cannabis, Brooke Wurster, MD, medical director of the medical cannabis science and business master's program at Thomas Jefferson University in Philadelphia, told Medscape Medical News.
“Patients are interested and trying to find access to information. As health care professionals, it's our job to guide them through these areas in a safe and non-judgmental way.”
But Wurster pointed out that oncologists don't have to be cannabis experts to start a conversation with patients.
So “let yourself off the hook,” Wurster urged.
Furthermore, avoiding the conversation will not stop the patient from using cannabis. In a recent study, Wurster and his colleagues found that nearly one-third of patients at 12 National Cancer Institute-designated cancer centers had used cannabis since diagnosis, most of them for sleep problems, pain, and stress. , discovered that he was using cannabis for anxiety. Most (60%) were somewhat or very reluctant to talk to their health care provider about it, but only 21.5% said they had actually done so. Even fewer, about 10%, had consulted their oncologist.
Wurster, who is also enterprise director of Thomas Jefferson University Supportive Oncology, said it's especially important for oncologists to open lines of communication because patients may not be able to discuss cannabis use.
Evidence regarding cannabis during cancer treatment
A significant percentage of cancer patients believe that cannabis can help manage cancer-related symptoms.
In Wurster's recent research study, nearly 90% of those surveyed reported perceived benefits, regardless of whether the patient used cannabis. Although 65% reported being aware of the risks of cannabis use, including impaired concentration, lung damage, and memory loss, the perceived benefits outweighed the risks.
Despite generally positive perceptions, the overall literature regarding the benefits of cannabis in cancer patients paints a less clear picture.
The ASCO guidelines are based on 13 systematic reviews and five additional primary studies and show that adding cannabis to guideline-conforming antiemetic therapy can improve refractory chemotherapy-induced nausea and vomiting. report that there is no clear evidence of benefit or harm. For results of other supportive care.
“The certainty of the evidence for most results is low or very low,” the ASCO authors wrote.
ASCO experts explained that outside of clinical trials, there is insufficient evidence to recommend cannabis or cannabinoids for the management of cancer pain, sleep disorders, anorexia, anxiety or depression. Some studies show a benefit while others do not.
For example, real-world data from large registry studies shows that medical cannabis is a “safe and effective complementary treatment for pain relief in cancer patients.” However, a 2020 meta-analysis found that adding cannabinoids to opioids did not reduce cancer pain in adults with advanced cancer in studies with low risk of bias.
There are also downsides to using cannabis. In one recent study, some patients reported feeling physically and psychologically worse than those who did not use cannabis. Another study found that oral cannabis was associated with “troublesome” side effects, including sedation, dizziness, and temporary anxiety.
The ASCO guidelines also made clear that cannabis or cannabinoids should not be used as a treatment for cancer outside of clinical trials.
talking to patients about cannabis
Given the level of evidence and patient interest in cannabis, it is important for oncologists to bring up the topic of cannabis use with patients.
ASCO guidelines suggest that oncologists themselves can guide treatment or direct patients to appropriate “unbiased, evidence-based” resources to inform decision-making and approaches to treatment. I am. For those using cannabis and cannabinoids outside of evidence-based indications or clinician recommendations, it is important to explore patient goals, educate, and work to minimize harm.
One strategy for broaching this topic is to simply ask patients whether or not they have tried cannabis for symptoms such as nausea and vomiting, loss of appetite, or cancer pain. Just ask, Wurster suggested.
Conversations with patients should include an overview of the potential benefits and potential risks of cannabis use, as well as risk mitigation strategies, Wurster notes.
But “approach it with an open and non-judgmental mindset,” she said. “Please have a little conversation.”
It is also important to discuss the formulation and concentration of tetrahydrocannabinol (THC) and cannabidiol (CBD) in the product.
Is the product inhaled, ingested, or used topically? Inhaled cannabis is not ideal, but may be available to patients, Wurster explained. Inhaled formulations tend to take effect quickly and may be suitable for treating chemotherapy-related nausea and vomiting, whereas edible formulations may take longer to take effect.
It's also important to warn patients about overdose, she said, explaining that inhaling high doses of THC can increase the risk of cardiovascular effects, anxiety, paranoia, panic and psychosis.
Meanwhile, while CBD has anti-inflammatory properties, early data suggests that high doses can blunt the immune response and should be used with caution in patients receiving immunotherapy. .
Wurster said that as laws change and science advances, new cannabis products and formulations will emerge, as will artificial intelligence tools that can help guide patients and clinicians on how best to use cannabis in cancer treatment. pointed out. She said the state's website is a particularly useful tool for providing state-specific medical education about cannabis laws and use.
The bottom line is that it's “really important” to talk to patients about the details of their cannabis use, she said.
Wurster revealed that she is a medical consultant for EO Care.
Sharon Wooster, MA is an award-winning medical journalist based in Birmingham, Alabama who writes for Medscape Medical News, MDedge, and other affiliate sites. She currently practices oncology, but also writes about a variety of other medical specialties and healthcare topics. Contact her at sworcester@mdedge.com or X. @SW_MedReporter.
