Guidance on Cannabis Use in Palliative Oncology

Dr. Brooke Worster and Dr. Nathan Handley of Sidney Kimmel Cancer Center – Jefferson Health shine a spotlight on cannabis use in palliative oncology.  They discuss guidance on dosing, legal concerns, and resources for oncologists with host Dr. John Sweetenham of the UT Southwestern Simmons Cancer Center. Transcript Dr. John Sweetenham: Hello, I'm John Sweetenham, Associate Director of Clinical Affairs at UT Southwestern’s Harold C. Simmons Comprehensive Cancer Center, and host of the ASCO Daily News podcast. Recent reports in oncology journals suggest that 20% to 40% of all patients with cancer use cannabis in some form during or after treatment to manage symptoms. However, a national survey of medical oncologists in 2018 found that 70% of oncologists did not feel equipped to make clinical recommendations regarding cannabis and only 46% recommended it clinically. Joining me to discuss cannabis use in palliative oncology are Dr. Brooke Worster, an associate professor and the director of supportive medicine at the Sidney Kimmel Cancer Center at Jefferson Health. And Dr. Nathan Handley, a medical oncologist and an assistant professor who is also at the Sidney Kimmel Cancer Center. Our full disclosures are available on our show notes and disclosures of all guests on the podcasts can be found on our transcripts and at asco.org/podcasts. Dr. Worster and Dr. Handley, thanks for coming onto the podcast today. Dr. Brooke Worster: Thanks for having us. Dr. Nathan Handley: Thank you. Dr. John Sweetenham: Dr. Worster, can you tell us how cannabis and cannabinoid-based medicines are used in palliative oncology and how prevalent this is? In addition, could you say a little about the use of cannabis in patients with cancer in the United States and how it compares with other countries? Dr. Brooke Worster: Yeah, absolutely. I think we are realizing more and more that cannabis or cannabinoid-based medications are used much more often than we as clinicians were aware. We just weren't asking our patients enough. And so, you mentioned other surveys about the kind of nationally sample representative of patients with cancer, we actually just also completed one that was a National Institutes of Health (NIH)-funded study, looking at cancer centers across the country and found similar rates that patients with cancer under the age of 65, at some point during treatment or survivorship, about 50% of them had tried cannabis. Interestingly, the largest growing segment of patients with cancer starting to use and inquire about cannabis are our [age] 65 and older patients. So, a quarter of them now report using it. And we actually found that 45% of patients over the age of 65 were interested but didn't feel comfortable having the conversation. Our country is kind of middle of the road in terms of what's accessible and what we use. Certainly, countries like Canada and some places in Europe, as well as Australia have a much more advanced marketplace as well as legislation and access to cannabis. And so, it’s used more prevalently across kinds of the oncology spectrum, but there are still a lot of countries across the world where cannabis remains completely illegal. So, the United States is sort of in the middle. Dr. John Sweetenham: Thanks. You and Dr. Handley recently co-authored an article in the ASCO Daily News along with other colleagues. And in that, you write the patients most often want guidance about the formulation and dosing, which as I read your article seems to be somewhat elusive still, given the diversity and composition of the plant-based strains. You point out that understanding the onset of action and duration of effects are important first steps. Could you say a little bit more about this? Dr. Brooke Worster: Yeah, absolutely. I think when someone is trying this for the first time, or for the first time in years, understanding how and when they're going to feel the impact or the effects of primarily tetrahydrocannabinol (THC) but also cannabidiol (CBD) and other minor cannabinoids is important for them to be patient. We see that people that ingest either sublingual absorption or oral ingestion of products, don't recognize that it can take up to 60 to 75 minutes, even if you have other food in your stomach to really feel the effect. And then will kind of overdose in some ways or sort of re-dose and get more of an effect of the THC than they were looking for. Versus if someone is inhaling something, you're really going to feel that quite rapidly, right? Five minutes in terms of onset of action. The duration of effect for that is much less. You're talking 2 to 3 hours maximum for an inhalation form, versus 5 to 7 hours for something that's sublingual, or orally ingested. Dr. John Sweetenham: Thanks! Dr. Handley, we've read in your article and in others, that cannabis as a palliative treatment for patients is well-tolerated, safe, and an effective option to help them cope with malignancy-related symptoms. Can you comment a little on whether or not there is a downside to cannabis and cannabinoid use and whether there are negative interactions with other cancer treatments? And are there certain patients who should avoid the use of cannabis? Dr. Nathan Handley: I would say that in general cannabis can be very safe if taken carefully and appropriately, and ideally with some guidance from a qualified practitioner. But it is important to consider some of the risks and side effects that cannabis carries. So, I think the first point is that if smoked, or otherwise, inhaled, the smoke can have many of the same carcinogens that are found in tobacco smoke. It's also interesting because smoking of marijuana or cannabis and tobacco are highly correlated. And so, it can be difficult for us to kind of assess if there are increased pulmonary risks associated specifically with cannabis use compared to tobacco use. And there have been a number of large cross-sectional and longitudinal studies that haven't found this link between cannabis use and impaired pulmonary function tests or chronic obstructive pulmonary disease (COPD) or lung cancer. But there are still potential risks associated with inhalational forms. There's also some evidence that there may be higher cardiovascular risks among cannabis users, specifically in patients who have heavy cannabis exposure. So, there have been some studies that have looked at the role cannabis can play in thrombosis, inflammation, and atherosclerosis. There have been some case reports that have linked its use to myocardial infarctions and arrhythmias, cardiomyopathy, stroke, and arthritis. But those haven't necessarily been played out in large clinical trials yet. And so, essentially, if someone is at increased cardiovascular risk at baseline, if they're elderly, or if they have pre-existing cardiovascular conditions, these are things worth discussing with the patient. So, I wouldn't say that they're necessarily absolute contraindications. I think some of the more immediate side effects of cannabis are also worth discussing with patients. And these are often related to the amount or the concentration of THC that is present in the preparation. A THC ingestion can result in a number of adverse side effects. There can be impaired concentration, impaired spatial relationships, memory can sometimes be affected. And in some rare cases, you can have increased anxiety, paranoia, or even psychosis. And so, there are not again, strong studies demonstrating a distinct correlation between cannabis use and psychiatric disorders. This is an area that merits further investigation still, and those risks likely vary based on the type of the product, the potency, the composition, if it's synthetic, if it's illicit, but we do have some hesitation about using cannabis in patients who have severe pre-existing mental health conditions like psychosis or schizophrenia, or something like that. On the issue of interactions with certain cancer treatments, I think one thing that patients often wonder is if cannabis can be used to treat cancer? And there is some interesting in vitro data and some in vivo data to suggest that cannabinoids can modulate tumor growth. But the data here is very limited. And so, really what we say is that more research needs to be done in this area. I think the other area of interest is there's some preliminary data, suggesting that patients who are on immunotherapy may have a reduced response to that treatment if they're taking cannabinoids, but these data are also very early. And so, we don't make any clinical decisions based on it at this point. Dr. John Sweetenham: Okay. Thank you. Another area, which I think is concerning certainly to some oncologists and other physicians is the legal issues surrounding the use of medical cannabis. And the core issue there, of course, is the contradiction in many cases between federal and state laws. Dr. Worster, can you tell us a little bit more about this and how oncologists can inform themselves of these issues and perhaps feel a little bit more comfortable about prescribing or recommending medical cannabis? Dr. Brooke Worster: Absolutely. I think at the crux of this issue, you're spot on. I mean, it's muddy. And if you look at the map of our country, the state-by-state variation changes year to year. So, I think one of the biggest things for all clinicians to recognize is that there have been challenges to the legality of recommending, we're not prescribing because that is still federally illegal, but certainly recommending cannabis to patients. There have been legal and court challenges that have worked their way up to federal courts, and have always supported that this is a right to free speech and well within your protected rights as a clinician to have a conversation with your patient along the lines of all kinds of other lifestyle choices we talk about with patients. So, there's no risk in terms of having the conversation, per se, or guiding patients into the space. Where I would tell people to familiarize themselves is really the intricacies of your own state's laws, as well as where a patient may be living if you're seeing them across state lines. One really great resource for this is the National Consortium of State Legislatures. They do a very good job and keep very up to date on a state-by-state basis in terms of what's legal, what conditions, how to access it, if there's reciprocity between states or not, if you can bring product across state lines, who can access it, all of the things that our patients are concerned about, and thus, bringing very valid questions to us that we want to be able to kind of help support them in this conversation. Dr. John Sweetenham: Yeah. Thank you! You know, another issue that you do bring up in your recent article is that of pain management, which of course is a very important component of cancer care in general. But studies in the Journal of Clinical Oncology and elsewhere have recently found there's been a sharp decline in access to opioids among patients with terminal cancer, and some patients have had to turn to hospital emergency departments for pain control. The decline in access has been in part a response to the opioid crisis in the U.S. But do you think this raises an important question about whether we're doing enough to proactively address pain management with some of our patients, Dr. Worster? Dr. Brooke Worster: That’s always a really important conversation that we aren't talking about enough. I think, truly, certainly, the pendulum has swung very far to the other side. And in some ways, this is beneficial, because as more and more of our patients with cancer are living into survivorship, we have certainly seen where iatrogenically, we have created dependency and substance misuse issues in the past, and it continues to happen. But I think that we need better ways to have honest conversations with our patients about both. What nuances to their pain exist? Pain is not pain is not pain, right? So, the etiology of their pain is important. And the way that we treat it shouldn't all be the same—neuropathic versus visceral versus a post-operative or inflammatory type of pain certainly should be looked at differently. I think access to opioids is critical for patients with cancer, although it really shouldn't be the only tool in our toolbox. Some of the work that we've done recently, it's interesting. There remains a wide racial gap in terms of access to opioids, as well, as we know this but less well-controlled pain in certain groups of patients with cancer, primarily minority Black and Hispanic patients versus White counterparts. And some of that has to do with the underlying responsiveness to opioids for various people, but also, how much are we talking about it? How much are we having the conversation? Is cannabis a helpful adjuvant, there? Are opioids something that are helpful? It should be talked about and continually readdressed. Dr. John Sweetenham: Thank you. Dr. Handley, Dr. Wooster just mentioned there in her previous comments, the issue of having honest conversations with our patients in the realm of pain control. But on a broader kind of perspective, do you have any recommendations on how to broach conversations with patients about cannabis use as a potential option for symptom management? Dr. Nathan Handley: Yeah, I think that's a really important question. These can be very difficult conversations. Cannabis use is something that is socially, culturally, and regulatory charged. It's very complex. And so, it can be a challenge to have these conversations. I think some general principles about how to effectively engage others, whether they're patients or friends or colleagues can be really helpful. So, I often reflect on this dictum from Stephen Covey, who is the author of this book called, The Seven Habits of Highly Effective People. In this book, he describes the fifth habit as being, “Seek first to understand then to be understood.” So, basically, what he's saying is if your goal is to motivate others, you have to understand where they're coming from before you can meaningfully affect their behavior. So, this sentiment is really a core principle behind the technique called motivational interviewing, which can be very useful to help motivate behavior change in patients and understand where patients are coming from, at the start of a conversation even. So, this technique is really built on 4 foundational principles. And those are acceptance, which is essentially empathizing with the patient, recognizing that they are an important participant in their own care. They're really the driver of their own care. Compassion, which is really emphasizing the well-being of the patient first and foremost. Collaboration, which is partnering with the patient, and not necessarily having a paternalistic relationship with them. And then curiosity, which is about understanding a patient's behaviors and motivations in a non-judgmental way. And so, I think this is really important because it can lead to openness when having a conversation with a patient. So, this has been summed up more simply as “Don't tell. Ask.” So, the idea with motivational interviewing, is you need to be open to understanding where a patient is, and this approach can be taken with 4 steps. So, first, you, you just listen, there's interesting data about how clinicians and physicians spend a lot of time talking in interactions with patients, and not as much time listening. And then we may have a tendency to jump in very quickly and be uncomfortable with silence. And so, this is just a real opportunity to just be open to patients and hear them to understand what pre-existing perceptions they may have. And so, it's hard to have a conversation with a patient about cannabis, if you think that they are going to be very open to it. And it turns out that 5 minutes into the conversation, they have some really deeply held reservations about the use of cannabis. So, first, you engage and listen to them to understand where they're coming from. And then you can focus. You can focus specifically on what the patient's goals are with respect to treatment, with something—in this case with cannabis. What are they hoping to get out of it? Is it improved pain management? Is it some other symptom that they're seeking? And then you can kind of evoke, this next step is evoking what their motivations are? Why do they want to improve this particular component of their treatment? Why did they want to feel better in this way? What are they hoping to achieve? And then, once you've kind of gotten through that groundwork, you can then plan together about how best to approach, in this case, cannabis use, in a way that is mutually agreeable, you can come to a plan together. And this approach epitomizes the concept of shared decision making where this is a conversation that happens together and between 2 people with the interest of the patient kept, first and foremost. Dr. John Sweetenham: Great advice. Thank you! Dr. Worster, just before we close up, you did mention earlier 1 potential resource for oncologists who need guidance on how to safely use cannabis for palliative pain management. Do you have any other recommendations in terms of resources that can be helpful to them? Dr. Brooke Worster: Yeah, absolutely. I wish there were a lot more here. And truth be told, we're still working hard to certainly develop the body of research and then disseminate it in terms of education. But if people are interested, there are increasing amounts of continuing medical education (CME) options that are out there. Each state that has medically legal or medically approved cannabis use on their state websites will have recommended or required depending on which state, I practice in Pennsylvania, and there are required CME courses that you need to take. But all of the states have different ones that are either recommended or required, and that's certainly an easy place to start in terms of some quality education. Thanks to the work that you and others are doing. I think it's certainly coming out through various oncology publications and multimedia access and things like that. And we also have, and some other academic centers around the country now have, online certificate and Master's programs that if people are really interested, they can kind of dive in and take courses or even get a certificate in cannabis medicine or cannabis science, things like that, to help them feel a lot more educated and informed. Dr. John Sweetenham: Well, I'd like to thank you both for sharing your insights with us on the podcast today. And also, for the valuable research that you've been doing on this topic. This is something that I'm sure is going to gain increasing importance to us all in elevating the awareness of this among the oncology community is really important. Thank you for the work that you're doing. Dr. Brooke Worster: Absolutely. Thank you for having us. Dr. Nathan Handley: Yes, thank you. A pleasure! Dr. John Sweetenham: And thank you to our listeners for your time today. If you're enjoying the call sent on the ASCO Daily News podcast. Please take a moment to rate, review and subscribe wherever you get your podcasts.     Disclosures: Dr. John Sweetenham: Consulting or Advisory Role: EMA Wellness Dr. Brooke Worster: Consulting or Advisory Role: Ethos Cannabis (Inst), PAX Therapeutics Research Funding: Ethos Cannabis (Inst) Dr. Nathan Handley: Research Funding: Nektar Therapeutics (Inst) Disclaimer: The purpose of this podcast is to educate and to inform. This is not a substitute for professional medical care and is not intended for use in the diagnosis or treatment of individual conditions. Guests on this podcast express their own opinions, experience, and conclusions. Guest statements on the podcast do not express the opinions of ASCO. The mention of any product, service, organization, activity, or therapy should not be construed as an ASCO endorsement.