Interpreting Overall Survival and Subgroup Outcomes in MATTERHORN: Where DFLOT Shows Strength and Where Questions Remain

EP: 1.Selecting Neoadjuvant Strategies for Esophageal and GEJ Adenocarcinoma Across Multidisciplinary Practices

EP: 2.Current Standards in Resectable Gastric and GEJ Adenocarcinoma: Multidisciplinary Perspectives on Perioperative Management

EP: 3.Evaluating Total Neoadjuvant Approaches: Balancing Treatment Intensity, Surgical Timing, and Patient Selection

EP: 4.Managing FLOT Tolerability, Assessing Pathologic Response, and Addressing Unmet Needs in the Perioperative Setting

EP: 5.MATTERHORN Results Yield Promise in Resectable Gastric/GEJ Cancer

EP: 6.MATTERHORN Trial Design and DFLOT Adoption: Integrating Immunotherapy Into Perioperative Practice

EP: 7.DFLOT Implementation: Surgical Timing, Patient Selection, and the Evolving Role of Adjuvant Immunotherapy

EP: 8.Interpreting Endpoints and Pathologic Response: Applying EFS, PCR, and Biomarkers in Perioperative Decision Making

Now Viewing

EP: 9.Interpreting Overall Survival and Subgroup Outcomes in MATTERHORN: Where DFLOT Shows Strength and Where Questions Remain

This segment reviews the overall survival findings from the MATERHORN trial and explores how subgroup analyses shape understanding of who may benefit most from DFLOT. The panel discusses the sustained separation of survival curves through nearly five years of follow-up and the statistically significant hazard ratio observed despite median OS not yet being reached. They highlight known challenges in interpreting subgroups with small sample sizes, such as TAP-negative disease, diffuse-type tumors, and certain demographic subsets, where confidence intervals cross 1 and definitive conclusions cannot be drawn. The conversation also considers whether biology, rather than treatment, drives poorer outcomes in diffuse subtype and how PD-L1–negative cohorts may influence regulatory decisions, particularly in regions where biomarker thresholds determine immunotherapy access. The segment further examines geographic representation, differences in practice patterns between Asian and non-Asian centers, and the importance of understanding how these variations influence results. The panel closes by reflecting on pathologic complete response rates and whether higher PCR rates meaningfully translate into long-term survival advantages within immunotherapy-based perioperative strategies.