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 cannabid