In the first episode of a special daily series during the 2025 ASCO Annual Meeting, Dr. John Sweetenham discusses the results of 2 studies on the treatment of advanced colorectal cancer plus an additional study exploring the association of Medicaid expansion with cancer survival outcomes.
TranscriptDr. John Sweetenham: Hello, and welcome to our special coverage of the 2025 ASCO Annual Meeting on the ASCO Daily News Podcast. I'm your host, Dr. John Sweetenham, and I'll be bringing you brief analysis on selected abstracts from each day of the Meeting. My disclosures are available in the transcript of this episode.
Today, I'll be reviewing three abstracts, the first two of which address the treatment of advanced colorectal cancer.
Today's first study is Abstract 3501. These data were presented by Dr. Heinz-Josef Lenz from the USC Norris Comprehensive Cancer Center and report on the expanded analysis of the CheckMate-8HW trial. This was a phase 3, international, multicenter trial in patients with MSI-high/MMR-deficient metastatic colorectal cancer, who were randomized between nivolumab (nivo) alone, nivolumab plus ipilumomab (ipi) or investigators' choice of chemotherapy (FOLFOX or FOLFIRI) with or without bevacizumab or cetuximab. The study showed that nivo plus ipi demonstrated superior progression-free survival compared with chemotherapy in the first-line setting and superior progression-free survival compared with nivo alone across all lines of therapy. These results led to the approval of nivo + ipi in the first-line setting in patients with MSI-H/dMMR mCRC in the U.S., the EU, and many other countries.
In today's presentation, Dr. Lenz reported on the expanded analyses of nivo plus ipi versus nivo across all lines of therapy and longer follow-up results for nivo and ipi versus chemo in the first-line setting. With longer follow up (the median is now at 47 months) nivo and ipi continued to show progression-free survival benefit compared with chemotherapy with a median PFS of 54.1 months versus 5.9 months, for a hazard ratio of 0.21.
Additionally, the analysis of the effects on PFS2, defined as the time from randomization to progression after subsequent systemic therapy, start of second subsequent systemic therapy, or death, showed that compared with chemotherapy, first-line nivo and ipi was associated with a 72% reduction in the risk of death or disease progression, despite the fact that 71% of those who progressed following chemotherapy crossed over to receive subsequent immunotherapy.
The study also showed that across all lines, nivo and ipi demonstrated superior progression-free survival compared with nivo alone, the median not reached versus 39.3 months, for a hazard ratio of 0.62. No new toxicity signals emerged after further analysis. Most treatment-related adverse events with possible immune etiology were observed within the first six months of therapy.
The results for PFS2 are particularly significant. Up to now, there has been some reluctance to use nivo and ipi as first-line therapy, partly because of its toxicity profile and based on the rationale that it would be active after other frontline therapies. The observation in this study that the beneficial effects of nivo and ipi are maintained downstream is compelling. The results suggest that delaying the use of this combination to the second line or later may compromise subsequent PFS and supports the use of nivo and ipi as a standard-of-care frontline option for MSI-H/dMMR metastatic colorectal cancer.
Moving on, the next study I'm featuring today is Abstract 3503, presented by Dr. Jeanne Tie from the Peter MacCallum Cancer Centre and the Walter and Eliza Hall Medical Institute of Medical Research from Melbourne, Australia. This study reported the impact of circulating tumor DNA (ctDNA)-guided adjuvant chemotherapy escalation in stage III colon cancer, focused on the primary analysis of the ctDNA-positive cohort from the randomized DYNAMIC-III trial.
As background, about 30% of patients with stage III colon cancer will recur following standard-of-care adjuvant therapy with oxaliplatin-based regimens. And current data show that for those patients with high-risk disease, 6 months of chemotherapy is associated with a lower recurrence rate than 3 months. Circulating tumor DNA following initial surgery has been shown to be a strong independent prognostic factor for these patients, but questions remain about how ctDNA can be used for adaptation of treatment. Questions regarding treatment adaptation were addressed in the DYNAMIC-III trials – specifically, does treatment escalation benefit those who are ctDNA positive following surgery, and can therapy be de-escalated for those who are ctDNA negative. The first of these 2 questions – treatment escalation in the positive group – is the subject of this report.
One thousand and two patients were randomized in this study, between ctDNA-informed therapy (502) or standard management (500). Of those patients included in the intent to treat cohorts, 129 were ctDNA positive in the ctDNA-informed arm compared with 130 in the standard management arm. Various pre-planned treatment escalation protocols were used, depending on the choice of first-line therapy.
With a median follow up of 42.2 months, there was no difference in 3-year relapse free survival between the ctDNA informed group (48%) and the standard management group (52%). There was, however, a highly significant difference in relapse-free survival for patients who cleared ctDNA by the end of treatment compared with those who didn't.
The authors concluded that the recurrence risk for this group remains high, at about 50%, after adjuvant therapy and that it increases with higher ctDNA burden, but treatment escalation didn't appear to reduce the recurrence risk. Clearance of ctDNA was associated with a favorable outcome, suggesting that as more effective treatments are developed in the future for this group, ctDNA will likely prove to have major utility.
Changing gears now, my final selection for today is Abstract 11006, presented by Dr. Elizabeth Shafer from the American Cancer Society. This study explored the association of Medicaid expansion with 5-year survival after a cancer diagnosis.
Dr. Schafer began her presentation by providing some historical perspective on the impact of the Affordable Care Act on reducing the number of uninsured adults aged less than 65 years in the United States. She then reviewed some recent data on the impact of Medicaid expansion on cancer care, including improved screening rates, improved access to cancer surgery, and an increase in earlier cancer diagnosis.
The current study builds on earlier data from the American Cancer Society which showed improved 2-year overall survival for patients with newly diagnosed cancer following Medicaid expansion. The new study reported by Dr. Schafer examined 5-year cause-specific survival in individuals with cancer since Medicaid expansion, analyzed according to cancer type and various demographic and social factors.
Using data from more than 813,000 individuals from 26 states that expanded Medicaid compared with more than 610,000 from 12 states that did not, the authors reported that similar improvements in 5-year cause-specific survival were observed in the expansion and the non-expansion states, but when analyzed by other factors, differences in outcome emerged.
For example, although similar improvements in survival between expansion and non-expansion states were seen in urban communities, there was a significant improvement of 2.55 percentage points in survival for individuals in rural communities in expansion states compared with those in non-expansion states. Similar trends were observed in high poverty areas, where improvements in survival were superior in expansion versus non-expansion states.
When examined by cancer type, the authors observed greater improvements in 5-year survival for those with pancreatic, lung, and colorectal cancer, possibly due to improvements in screening and early access to treatment.
The authors concluded that those residing in rural and high-poverty areas experienced the most improvement in cause-specific cancer survival following Medicaid expansion.
In summary, it's encouraging to see an improving trend in cancer mortality overall, independent of Medicaid expansion, but it's also important to remember that this is yet another study which confirms how implementation of the ACA has improved cancer outcomes and begun to address some of the disparities in cancer care.
Join me again tomorrow to hear more top takeaways from ASCO25. And if you value the insights that you hear on the ASCO Daily News Podcast, please remember to rate, review, and subscribe wherever you get your podcasts.
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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.
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Dr. John Sweetenham:
No relationships to disclose