What are your top takeaways in GI Cancers from ASCO 2025?

1. MATTERHORN: it’s practice-changing and establishes durvalumab/FLOT as the new standard for perioperative therapy for gastric cancer
   
   
2. DESTINY-Gastric04: it confirms the superiority of 2L trastuzumab deruxtecan vs. ramucirumab/paclitaxel for HER2-positive gastric CA.
   
   
3. CHALLENGE study in colorectal CA: ...

1. ATOMIC - adding atezolizumab checkpoint inhibitor for 1 year to 6 months of adjuvant FOLFOX is the new standard of care for MSI-High stage III colon cancer.
   
   
2. MATTERHORN trial - adding durvalumab to perioperative FLOT in resectable gastric adenocarcinoma significantly improved event-free survival...

1. The MATTERHORN study has redefined the perioperative treatment of resectable gastric cancer. It is now beautifully simple. Anywhere from the top of the esophagus to the bottom of the stomach, if a person has a resectable squamous cell carcinoma, then they should be treated c/ neoadjuvant chemoXRT ...

As a gastrointestinal medical oncologist, it was very gratifying that 2 of the plenary session presentations provided the results from randomized gastrointestinal trials, including an NCI cooperative group study.

1. The first plenary presentation was a late-breaking abstract for a trial coordinated by ...

There are quite a few interesting/important GI studies reported at the ASCO Annual meeting, and here are several studies I personally felt may change my practice.

1. ATOMIC study: adding atezolizumab to adjuvant FOLFOX treatment showed clear disease-free survival for dMMR stage III colon cancer patie...

1. ATOMIC trial – culmination of an outstanding national effort to investigate the use of an anti-PDL1 as ADJUVANT therapy combined with chemotherapy for MSI-High stage III colon cancer. The results show a major benefit for the addition of ICI therapy – i.e., 10% improvement in 3-yr DFS. Next study ne...

1. CheckMate 8HW

Building on what we already know, the expanded analyses of NIVO + IPI vs NIVO (all lines) and longer follow-up results for NIVO + IPI vs chemo were presented.

Not surprisingly, and what has already been reported, 1L NIVO + IPI continued to show PFS benefit vs chemo.

Across all lines, ...

1. CASSANDRA - A phase II study of neoadjuvant PAXG (Abraxane, cisplatin, capecitabine, gemcitabine) superior to FOLFIRINOX for borderline or resectable pancreatic ductal adenocarcinoma in terms of Ca 19-9 response, stage, N0 resection, and disease control. (Reni et al, non-colorectal oral abstracts) ...

1. BREAKWATER survival data
   
   
2. Exercise in colon cancer
   
   
3. ATOMIC in colon cancer

1. The phase III MATTERHORN study evaluated durvalumab (Imfinzi) combined with perioperative FLOT chemo in operable gastric and GEJ cancers. It showed a significant boost in 2-year overall survival from ~70% to ~76% in the Imfinzi arm without added toxicity. This supports the adoption of FLOT + durval...

1. ATOMIC

This was a phase III study that examined patients who were MMR-deficient (MSI-High) with stage III colon adenocarcinoma who underwent resection, and were randomized to receive either FOLFOX for 6 months vs FOLFOX for 6 months + Atezolizumab for 1 year. Slightly over half of the patients had...

1. I believe ATOMIC does establish a new standard of care for adjuvant atezolizumab in mismatch repair-deficient stage III colon cancer, but outstanding questions remain: a) does the chemotherapy backbone have to be 6 months of FOLFOX even for T3N1 tumors? b) Would other immunotherapy (specifically P...

1. The CHALLENGE trial: In this phase 3 randomized trial, patients with resected CRC who had completed adjuvant chemotherapy were assigned to either a 3-year structured exercise program (exercise group) or to receive health-education materials alone (health-education group). Patients were selected t...

1. MATTERHORN: This trial evaluated perioperative FLOT chemotherapy versus FLOT combined with durvalumab in patients with resectable gastric or gastroesophageal junction (GEJ) adenocarcinoma. Notably, 90% of patients had PD-L1 expression and only 5% were MSI-H, reflecting a typical biomarker distribut...

MATTERHORN

Summary: Adding durvalumab to FLOT perioperatively improved 2-year event-free survival (67.4% vs. 58.5%; HR 0.71) in resectable gastric or GE junction adenocarcinoma, with a numerical OS improvement.

Comments:

• These findings specifically apply to adenocarcinoma; squamous cell carcinoma of ...