Improving tumor budding reporting in colorectal cancer: a Delphi consensus study

Femke Simmer,Irıs D Nagtegaal ,Darren Treanor,Tariq Sami Haddad,Valeria Barresi,Hala El‐Zimaity ,Jeroen Van Der Laak,Gieri Cathomas,Michael Vieth,John‐Melle Bokhorst ,Maurice B Loughrey,Tine Plato Kühlmann ,Cord Langner,Susan Aherne,Benoı̂t Terris ,David Gourichon ,Sanjay Kakar,Richard Kirsch,Inti Zlobec,Jean‐François Fléjou ,Míriam Cuatrecasas ,Robert H Riddell ,Alessandro Lugli,Ari Ristimäki,Scarlet Brockmoeller ,Kieran Sheahan

doi:10.1007/s00428-021-03059-9

Abstract

Tumor budding is a long-established independent adverse prognostic marker in colorectal cancer, yet methods for its assessment have varied widely. In an effort to standardize its reporting, a group of experts met in Bern, Switzerland, in 2016 to reach consensus on a single, international, evidence-based method for tumor budding assessment and reporting (International Tumor Budding Consensus Conference [ITBCC]). Tumor budding assessment using the ITBCC criteria has been validated in large cohorts of cancer patients and incorporated into several international colorectal cancer pathology and clinical guidelines. With the wider reporting of tumor budding, new issues have emerged that require further clarification. To better inform researchers and health-care professionals on these issues, an international group of experts in gastrointestinal pathology participated in a modified Delphi process to generate consensus and highlight areas requiring further research. This effort serves to re-affirm the importance of tumor budding in colorectal cancer and support its continued use in routine clinical practice.

Highlights

The phenomenon of tumor budding (TB), defined as single cells and isolated cells clusters up to 4 cells at the tumor invasive front, has captured the interest of pathologists, clinicians, and researchers since it was first described in the 1950s [1]
Since the publication of the International Tumor Budding Consensus Conference (ITBCC) consensus recommendations in 2017, TB has been incorporated as an additional prognostic factor in the World Health Organization Classification of Tumors (2019), the Tumor, Nodes, Metastasis (TNM) staging system, and included in the reporting guidelines and protocols of the College of American Pathologists (CAP) [4], the National Comprehensive Cancer Network (NCCN) [5], and the International Collaboration on Cancer Reporting [6]
Seventy-nine and 64 percent indicated that their clinicians are aware of the relevance of TB in pT1 and stage II colorectal cancer (CRC), respectively (III, VII), while 50% and 15% indicated that TB is taken into account in clinical decision-making for pT1 and stage II CRCs, respectively (IV, VIII)

Summary

Introduction

The phenomenon of tumor budding (TB), defined as single cells and isolated cells clusters up to 4 cells at the tumor invasive front, has captured the interest of pathologists, clinicians, and researchers since it was first described in the 1950s [1]. Until recently, the absence of a standardized scoring system made it difficult to implement TB in routine pathology practice This prompted a group of international experts to meet in Bern, Switzerland, in 2016 to host the International Tumor Budding Consensus Conference (ITBCC) to reach consensus on a single, evidence-based method for TB assessment and reporting in CRC [3]. Since the ITBCC recommendations were not intended to be an end point, but rather a foundation for further research, refinement, and periodic review, its members organized a modified Delphi consensus process The aim of this effort was to reach consensus on a number of emerging issues, ongoing challenges, and areas in need of further research

Methods

Results

Conclusion