Nov 2, 2023
Drs. Shaalan Beg and Priyanka Kanth discuss the readiness, logistics, and barriers to implementing universal germline multigene panel testing for colorectal cancer (CRC) following new guidelines from the National Comprehensive Cancer Network that recommend genomic testing for all individuals with CRC younger than age 50. The experts also address other areas of unmet needs as new data emerge on moderate-risk genes and their association with CRC.
TRANSCRIPT
Dr. Shaalan Beg: Hello, and welcome to the ASCO Daily News Podcast. I'm Dr. Shaalan Beg, your guest host of the podcast today. I'm the vice president of oncology at Science 37 and an adjunct associate professor at UT Southwestern Medical Center in Dallas.
Last year, the National Comprehensive Cancer Network, or NCCN, updated its guidelines on colorectal cancer (CRC), recommending that all patients with colorectal cancer who receive a diagnosis before the age of 50 have multigene panel testing and that multigene testing should also be considered for patients 50 years of age and older with colorectal cancer, regardless of a personal or family history or other criteria.
This represents a huge paradigm shift in the screening and care of patients with inherited cancers. And today, I'm joined by Dr. Priyanka Kanth, an associate professor of medicine and the director of the GI Cancer Prevention Program at MedStar Georgetown University Hospital in Washington, DC, to discuss new research that explores the readiness, logistics, and barriers associated with the implementation of universal germline testing in clinical practice.
You'll find our full disclosures in the transcript of this episode, and disclosures of all guests on the podcast are available at asco.org/DNpod.
Dr. Kanth, it's great to have you on the podcast today.
Dr. Priyanka Kanth: Thank you, Dr. Beg. It's wonderful to be here today and discuss this very exciting topic.
Dr. Shaalan Beg: As a gastroenterologist who sees patients and families with a high risk for GI cancer, including medically underserved populations, can you comment on the significance of the expanded NCCN guidelines for colorectal cancer?
Dr. Priyanka Kanth: Yes, absolutely. So this is, I would say, a big change from NCCN recommending pretty much every colorectal cancer patient can undergo multigene panel testing or universal. So everyone who's younger than age 50 and has colon cancer should get multigene panel testing. But we are also expanding it to pretty much anyone who may have colorectal cancer, and we can offer multigene panel testing. So, we are broadening the pool of patients who can get tested, and this will bring in more patients from very different demographics. So I think it will expand to every arena of patients with different insurance profiles, underserved, and, as more insurance companies and Medicare/Medicaid picks up, I think this will help a lot more patients in not only following on their genetic testing, but also their family members.
Dr. Shaalan Beg: Medical oncologists are very familiar with the challenges of implementing somatic molecular testing for people who have cancer. I can only imagine that implementing universal germline testing also has significant logistical challenges and barriers. You recently published a study in JCO Precision Oncology along with your colleagues and captured some interesting perspectives from clinicians on their practice of implementing universal genomic testing for colorectal cancer. Can you tell us more about this?
Dr. Priyanka Kanth: Absolutely. So I would first like to thank the lead authors and senior authors of this study. They are Linda Rodgers-Fouche and Sanjeevani Arora and Rachel Hodan, who literally wrote the study and created and did all the legwork. And as you know how hard it is to do these big survey studies, so really thank them.
The study is a cross-sectional survey of the members of this Community Collaborative Group of America, IGC, which I would say comprises a lot of genetic counselors, gastroenterologists, oncologists, and colorectal surgeons who take care of these patients. So these are highly specialized groups that work in the field of GI genetics. Roughly 300 plus members were sent the survey to get their take on how they think [multigene panel testing] can be implemented for all colorectal cancer patients.
So to give you a synopsis of the study, the majority of members who participated, 70% or more, they supported this universal germline testing for colorectal cancer patients. But interestingly, more than 50% also thought that it will require a change in their practice or how this will be delivered. So that's the major takeaway, I would say. We are all supportive but how to really deliver to the patient would be the biggest challenge or barrier for us in the future.
Dr. Shaalan Beg: So, your study reported concerns on knowledge among non-genetics providers. I would assume that includes a lot of clinicians who are the first people to be in contact with potential patients who would require testing. How can the field mitigate this problem? And what are some alternate delivery service models for increasing awareness and making the process of ordering and following up on the results more efficient for practices?
Dr. Priyanka Kanth: We all know the biggest barrier I would say is resources like who's going to deliver the added pool of patients that get genetic testing. So most of the current scenario, they're all seen by genetic counselors, but we have a limited number of genetic counselors and they cannot truly deal with this big influx. So how to educate non-genetic providers would be the biggest barrier. But also implementing in the system itself, like can we do pretest counseling as the first contact with the patient to deliver to discuss like you should undergo genetic testing. So that contact, can that be done with a non-genetic provider or even by other modes like telemedicine? Or can we do something like an online chat box or something which could just not only go over all the types of testing but opens the door for the patient to ask questions. So if there are alternate modes of delivery where the pretest is taken care of, that would be one big change required.
The other part is like when the test is done, who returns the results? So where does it go and who explains the results? So at that point, we surely need more genetic and even non-genetic providers if they are comfortable. So how to educate them would be the biggest barrier. At that point, I think, we are still figuring out the biggest change is in the system and requiring a take from all the stakeholders who are part of taking care of these patients. So not only genetic counselors, but oncologists, gastroenterologists, pathologists who are taking care of this patient to be on board and have a really clear-cut flow of how these are delivered, how these results are returned, and how they are explained to family members.
Dr. Shaalan Beg: The workflows and the resources that you have in a high-risk GI clinic at a center like Georgetown’s, I think it's safe to say, are much more than what typical resources a practicing provider will have in the clinic. How do you envision clinics resourcing for this type of test either through training or retraining their existing staff or by adding additional resources?
Dr. Shaalan Beg: At the community setting, it is really hard to educate essentially everyone as well. So, I feel like taking the load off the genetic counselor at the pretest level is the biggest implementation or change that can be done. And if we can remove that because not every patient is going to be positive for the gene mutation either; it does filter many patients who eventually will need returns. So at that place, how do you implement and where do you implement is the key and it is so system-based that I cannot even pinpoint. But I agree, bigger academic centers have better advantages and a knowledge base as compared to smaller community cancer centers or practices.
Dr. Priyanka Kanth: Yeah, and I noticed that many of the respondents in your survey agreed with offering multigene panels, but there was variability by profession, and I was wondering if that resonated with you and that was an expected finding or not.
Dr. Priyanka Kanth: Yes, and it was more so in terms of standardized multigene panel versus customized panel. So, this is fairly understandable because the genetic counselor is so well versed in offering which genes should be tested based on family history, but a non-genetic provider may not be fully equipped with the knowledge. So for example, myself, I do GI genetics, but if I have a patient with a lot of breast cancer in the family, I do defer them to a high-risk breast team. So there are nuances, too. The major difference here was also in standardized multigene panel, most of the gastroenterologists, oncologists were all for it compared to customized, which were more heavily leaned by the genetic counselor based on family history. And I can see why it's different because standardized, I would say, is much easier to implement and compared to customizing, which is based on family history or other cancer history and family. That's the major difference in the study. It comes down to education and experience and the follow-up based on what comes back from it.
Dr. Shaalan Beg: You've highlighted many factors, both from the pre-test, sort of preparing and selecting the right individuals, to ordering the right test based on the participant's risk factor profile and then optimal ways of following up on the results of these genomic tests. What are other areas of unmet needs when it comes to genomic testing for colorectal cancer?
Dr. Priyanka Kanth: We know a lot about high-risk genes that are associated with colorectal cancer. We still are finding and learning about many genes, many moderate-risk genes, and their association with colorectal cancer. We don't have enough data or long-term cohort data to understand how they truly affect their lifetime risk for colorectal cancer and how do we truly surveil these patients. So that's one of the big barriers. Genetics still cannot explain all colorectal cancers. So as we get more data, we may discover more things and more genes that may be associated. But understanding these moderate-risk genes and their association with colorectal cancer would be, I think, one of the key areas to be looked into in the future.
Dr. Shaalan Beg: And I would imagine as new biomarkers are identified, there will need to be a strategy to retest people who may have had genomic testing in the past.
Dr. Priyanka Kanth: Absolutely. We are already encountering that in a practice. I have patients who have been tested maybe 10 years ago and just had Lynch mutation tested and were negative for that or so, and now we have so many other genes which are associated and also to understand family history changes. So, as family history changes, there might be clues to say that, “Okay, we should expand the panel or we should add these patients.” So it is a very dynamic situation. There could be a scenario in which we have a lot of patients who may need to be retested based on their current situation or even based on changing family history and the availability of genetic information. So, when I see a patient, I also tell them if we don't find anything or we are not doing anything major, we say, “Let's regroup in 3 to 5 years, let's see where we are,” or even with the risk mutation for some of the moderate-risk genes, we may change in a few years. So, revisiting that with these patients is highly useful.
Dr. Shaalan Beg: So, is it safe to say that as of 2023, if we're seeing people in our clinic who have not had testing in the last 3 to 5 years, that they should have a discussion for repeat testing today?
Dr. Priyanka Kanth: Yes, in terms of certain, I would say, newer polyposis genes in the GI world that have been included, some other moderate gene mutation which we have a little bit more sense of now and it has not been tested, I think that can be expanded. Five years is a safe bet. Last 2 to 3 years, maybe not so much, but you can revisit this. Also, some patients were tested for a smaller gene panel. So not 2 genes, but maybe 10 genes were included. That would probably still stand true. They may not need 70 gene panels, so it's still good to review that in the current scenario, and every few years, every 5 years, I would say.
Dr. Shaalan Beg: Whenever I think about any type of new test that has logistical challenges, has costs associated with it, and has operational demands of the clinic, I think about its disparate effect across different populations based on race, ethnicity, geography, demographics. Can you talk a little bit about how these guideline changes, what type of impact they may have, positive or not, for comprehensive genomic testing for colorectal cancer across different populations?
Dr. Priyanka Kanth: Yes, I think this is more positive than negative. This will include more patients and include more family members who were not being included, who were being missed. As we know that one of the reasons to do this multigene panel testing was the criteria, the family history criteria or the risk prediction models are not perfect. And the recent studies have shown that not every family member, every patient, is going to fit in these criteria. So we are getting more and more data in recent years that I think the much better, long-term option is to do a multi-chain panel and find it because we are missing patients. So it will increase the pool [of patients to be tested], and that will surely increase patients from all demographics. And as we do it more, there will be more buy-in from the payers and hopefully, this will decrease disparity.
The problem, I think the negative part is how do we deliver it to everyone? If it is there but we are not able to deliver and that there is disparity on who gets the test and who does not, then that will create another disparity in a sense that it's there and we could have used it, but it's not being delivered. So the pros are we can include everyone, but how to include everyone is the big question.
Dr. Shaalan Beg: So, Dr. Kanth, there are indeed challenges ahead in our pursuit for universal germline testing for colorectal cancer. I'd like to thank you for sharing your valuable insights with us today on the ASCO Daily News Podcast.
Dr. Priyanka Kanth: Thank you very much for having me here. It was great to talk to you, Dr. Beg.
Dr. Shaalan Beg: And thank you to our listeners for your time today. Finally, if you value the insights that you hear on the podcast, please take a moment to rate, review, and subscribe wherever you get your podcasts.
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.
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Disclosures:
Dr. Shaalan Beg:
Employment: Science 37
Consulting or Advisory Role: Ipsen, Array BioPharma, AstraZeneca/MedImmune, Cancer Commons, Legend Biotech, Foundation Medicine
Research Funding (Inst.): Bristol-Myers Squibb, AstraZeneca/MedImmune, Merck Serono, Five Prime Therapeutics, MedImmune, Genentech, Immunesensor, Tolero Pharmaceuticals
Dr. Priyanka Kanth:
Patents,
Royalties, Other Intellectual Property: Methods and Compositions
for Predicting a Colon Cancer Subtype