International Expert Consensus Recommendations for the Standardized Pathological and Clinical Assessment of Submucosal Invasion in Endoscopic Submucosal Dissection

Aims Endoscopic submucosal dissection (ESD) is a minimally invasive treatment for early gastrointestinalcancers. However, pathological assessment of invasive carcinoma in ESD specimens lacksstandardization. Variability in the evaluation of submucosal invasion (SMI) depth, lateral extent,resection margins, tumor budding, and related prognostic features can alter staging, prognostication,and management. In the absence of prior international standards, we convened a multinationalexpert panel to establish consensus on key pathological and clinical parameters to improveconsistency, reliability, and clinical utility of post-ESD pathology reporting [ 1 ] [ 2 ] [ 3 ] [ 4 ] [ 5 ] [ 6 ] [ 7 ] [ 8 ] [ 9 ]. Table 1 Domain Key Statement Mean Score Criteria for Submucosal Invasion Depth Proper orientation and embedding of ESD specimens is essential to minimize measurement bias (tangential cuts, fragmentation, distortion). 9.48 Submucosal Invasion Breadth Measuring and reporting invasion breadth supports standardized T1 cancer reporting and future research. 6.56 Margin Evaluation Techniques Immediate specimen pinning on a firm surface and detailed grossing diagram are essential for orientation and artifact prevention. 9.48 Staining Methods H&E remains the standard for assessing invasion depth. 9.52 Measurement Protocols Parallel sectioning throughout ESD specimens preserves orientation and margin mapping accuracy. 9.48 Risk Assessment of Lymph Node Metastasis & Tumor Budding Lymph-node risk assessment should integrate histologic and clinical factors (PNI, margins, depth, site). 9.48 Clinical Evaluation ESD margins need distinct interpretation vs. surgery due to narrow margins and thermal artifacts; multidisciplinary review recommended. 9.36 Methods A modified Delphi process (five rounds) was used among 42 international experts (28 pathologists, 14endoscopists). Participants represented 15 countries across five continents. In Round 1, statementswere generated; in Rounds 2–4, panelists rated statements on a five-point Likert scale withconsensus predefined as≥80% agreement (score≥4). In Round 5, consensus statements wereprioritized on a 10-point scale ([ Table 1 ]). Results Fifty-six statements reached consensus across seven domains: SMI depth, SMI breadth, marginevaluation techniques, staining methods, measurement protocols, prognostic factors for lymph nodemetastasis (tumor budding [TB], lymphovascular invasion (LVI), and differentiation), and clinicalevaluation. Mean priority scores (10-point scale) ranged from 6.24 to 9.52; SMI breadth had thelowest mean (6.59), whereas measurement protocols had the highest (8.99). Conclusions This international consensus provides standardized, synoptic-ready criteria for post-ESD pathologicalassessment of invasive carcinoma, including SMI depth and breadth, margin interpretation, andselective ancillary staining. By specifying measurement landmarks, artifact handling, and reportingterminology, it improves reproducibility and comparability across institutions. Incorporation intosynoptic templates and institutional QA can facilitate immediate implementation, while the inclusion ofSMI breadth offers a standardized adjunct metric for future prognostic validation and multicenterresearch. Publication History Article published online: 05 June 2026 © 2026. European Society of Gastrointestinal Endoscopy. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany