Dr. Mellar Davis discusses the joint guideline from MASCC, ASCO, AAHPM, HPNA, and NICSO on opioid conversion in adults with cancer. He reviews the limited evidence, and the formal consensus process used to develop the guideline. He shares the key recommendations on pre-conversion assessment, how opioid conversion should be conducted, including opioid conversion ratios, and post-conversion assessment. We touch on gaps and questions in the field and the impact of these new recommendations. 

Read the full guideline, “Opioid Conversion in Adults with Cancer: MASCC-ASCO-AAHPM-HPNA-NICSO Guideline” at www.asco.org/supportive-care-guidelines.

TRANSCRIPT

This guideline, clinical tools, and resources are available at http://www.asco.org/supportive-care-guidelines. Read the full text of the guideline in the Supportive Care in Cancer, https://link.springer.com/article/10.1007/s00520-025-09286-z

Brittany Harvey: Hello and welcome to the ASCO Guidelines podcast, one of ASCO's podcasts delivering timely information to keep you up to date on the latest changes, challenges and advances in oncology. You can find all the shows, including this one at asco.org/podcasts.

My name is Brittany Harvey and today I'm interviewing Dr. Mellar Davis from Geisinger Medical Center, lead author on “Opioid Conversion in Adults with Cancer: Multinational Association of Supportive Care and Cancer, American Society of Clinical Oncology, American Academy of Hospice and Palliative Medicine, Hospice and Palliative Nurses Association, Network Italiano Cure di Supporto and Oncologia Guideline.”

Thank you for being here today, Dr. Davis.

Dr. Mellar Davis: Thank you. I'm glad to be here.

Brittany Harvey Before we discuss this guideline, I'd like to note that ASCO takes great care in the development of its guidelines and ensuring that the ASCO Conflict of Interest Policy is followed for each guideline. The disclosures of potential conflicts of interest for the guideline panel, including Dr. Davis, who has joined us here today, are available online with the publication of the guideline, which is linked in our show notes.

So then, to dive into the content here, Dr. Davis, can you provide an overview of both the scope and purpose of this guideline on opioid conversion in people with cancer?

Dr. Mellar Davis: This is an important topic in management of cancer pain and this topic came up as a result of a survey that MASCC had done, which involved 370 physicians in 53 countries. They were queried about how they change or convert one opioid to another, which is a common practice, and we found that there was quite a divergence in opioid conversion ratios. To step back a little bit, about two thirds of patients with advanced cancer have moderate to severe pain and most of the time they're managed by opioids. But about 20% or 40% require a switch either because they have an adverse reaction to it or they don't respond to it, or the combination of both. Rarely, it may be that they need a route change, perhaps because they have nausea or vomiting. So, the opioid conversion works basically because of the complexity of the new opioid receptor which has at least four exons to it as a result of that non-cross tolerance between opioids.

As a result of the survey, we convened a group of specialists, 14 international specialists, to look to see if we could develop an international guideline. And we did a systematic review which involved viewing 21,000 abstracts and we came up with 140 randomized trials and 68 non-randomized trials. And after reviewing the data, we found that the data was really not strong enough to provide a guideline. As a result, ASCO, MASCC, the AAHPM, the HPNA and the Italian Group formed a supportive network that allowed us then to do a Delphi guideline based upon ASCO modified criteria for doing Delphi guidelines.

And so we then involved 27 additional international experts informing the guideline to it. And this guideline is then the result of the Delphi process. It consists basically of a pre-conversion ratio recommendations, conversion ratios, which is actually a major contribution of this guideline, and then what to do after converting someone to another opioid. Our target audience was not only oncologists, but also we wanted to target nurses, pharmacists, hospitalists, primary care physicians, patients and caregivers.

Brittany Harvey: I appreciate that background information, particularly on the evidence that is underpinning this and the lack of quality of evidence there, which really transformed this into a formal consensus guideline. We're glad to have all of these organizations coming together to collaborate on this guideline.

So then next I'd like to review the key recommendations. So starting with, what is recommended for pre-conversion assessment?

Dr. Mellar Davis: In regards to pre-conversion, physicians and clinicians need to be aware of pain phenotypes. That is, there are pains that are more opioid refractory than others, such as neuropathic pain, hence, they may be more resistant to the opioid that you're converting to. One needs to be aware of the fact that patients may not be compliant, they're either afraid of opioids not taking what was prescribed, so it's important to query patients about whether they are taking their opioid as prescribed. Occasionally, there are patients who will divert their medication for various reasons. Pain may be poorly controlled also because of dosing strategies that are poorly conceived, in other words, giving only ‘as needed’ opioids for continuous cancer pain. And there are rare circumstances where an opioid actually induces pain and simply reducing the opioid actually may improve the pain. The other issue may be cancer progression. So that poorly controlled pain or rapidly increasing pain may actually be a result of progressive cancer and changing treatment obviously will be important. And you need to assess the pain severity, the quality of the pain, the radiating localizing effects, which does require not only a physical exam but also radiographic examinations.

But the other thing that's very important in opioid conversions are pain scales with function. A significant number of patients don't quite understand a numerical scale which we commonly use: 0 to 10, with 10 being severe pain and