GI Cancer Research at ASCO25: Plenary Highlights and More

Dr. Shaalan Beg and Dr. Kristen Ciombor discuss practice-changing studies in GI cancers and other novel treatment approaches that were presented at the 2025 ASCO Annual Meeting. Transcript Dr. Shaalan Beg: Hello, I'm Dr. Shaalan Beg, welcoming you to the ASCO Daily News Podcast. I'm a medical oncologist and an adjunct associate professor at UT Southwestern Medical Center in Dallas, Texas. There were some remarkable advances in gastrointestinal cancers that were presented at the 2025 ASCO Annual Meeting, and I'm delighted to be joined by Dr. Kristen Ciombor to discuss some exciting GI data. Dr. Ciombor is the Ingram Associate Professor of Cancer Research and a co-leader of Translational Research and the Interventional Oncology Research Program at the Vanderbilt Ingram Cancer Center. Our full disclosures are available in the transcript of this episode. Dr. Ciombor, it's great to have you on the podcast today. Dr. Kristen Ciombor: Thanks, Dr Beg. It's great to be here. Dr. Shaalan Beg: Alright, let's kick it off. Big year for GI cancers. We'll start off with LBA1. This was the ATOMIC study sponsored by NCI and the National Clinical Trials Network (NCTN) and the Alliance group. This is a randomized study of standard chemotherapy alone or combined with atezolizumab as adjuvant therapy for stage III mismatch repair deficient colorectal cancer. Dr. Kristen Ciombor: I think this study was really definitely practice-changing, as you can tell because it was a Plenary. But I do have some concerns in terms of how we're actually going to implement this and whether this is the final answer in this disease subtype. So, as you said, the patients were enrolled with stage III resected mismatch repair deficient colon cancer, and then they were randomized to either modified FOLFOX6 with or without atezolizumab. And that's where it starts to become interesting because not many of us give FOLFOX for 6 months like was done in this study. Obviously, the study was done over many years, so that was part of that answer, but also the patients received atezolizumab for a total of 12 months. So the question, I think, that comes from this abstract is, is this practical and is this the final answer? I do think that this is practice-changing, and I will be talking to my patients with resected mismatch repair deficient colon cancer about FOLFOX plus atezolizumab. I think the big question is, do these patients need chemotherapy? And can we do a neoadjuvant approach instead? And that's where we don't have all the answers yet. Dr. Shaalan Beg: Yeah, but it has been great to see immunotherapy make its way into the adjuvant space after having made such a big impact in the metastatic space, but still some unanswered questions in terms of the need for chemotherapy and then the duration of therapy, which I guess we'll have to stay tuned in for the next couple of years to to get a lot of those questions answered. Dr. Kristen Ciombor: Yeah, but a big congratulations to the study team, to the NCTN, the NCI. I mean, this is really a great example of federally funded research that needs to continue. So, great job by the study team. The DFS 10% difference is really very large and certainly a practice-changing study. Dr. Shaalan Beg: Yeah, and and sticking with colon cancer, and and this another federally funded study, but this time funded by a Canadian cancer clinical trials group was LBA3510. This is the CHALLENGE study. It's a randomized phase 3 trial of the impact of a structured exercise program on disease-free survival for stage III or high-risk stage II colon cancer. This study got a lot of buzz, a lot of mainstream press coverage, and a lot of discussions on what that means for us for the patients who we're going to be seeing next week in our clinic. What was your takeaway? Dr. Kristen Ciombor: Yeah, this is a really interesting study, and I was so glad to see it presented because this partially answers one of the questions that patients always have for