Recommendations for reporting tumor budding in colorectal cancer based on the International Tumor Budding Consensus Conference (ITBCC) 2016.
Lugli AInstitute of Pathology, University of Bern, Bern, Switzerland.
Kirsch RPathology and Laboratory Medicine, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada.
Ajioka YDivision of Molecular and Diagnostic Pathology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
Bosman FUniversity Institute of Pathology, Lausanne University Medical Center, Lausanne, Switzerland.
Cathomas GInstitute of Pathology, Kantonsspital Liestal, Liestal, Switzerland.
Dawson HInstitute of Pathology, University of Bern, Bern, Switzerland.
El Zimaity HDynacare Laboratory, Brampton, Ontario, Canada.
Fléjou JFPathology Department, Saint-Antoine Hospital, Pierre et Marie Curie University, Paris, France.
Hansen TPDepartment of Pathology, Copenhagen University Hospital, Herlev, Denmark.
Hartmann ADepartment of Pathology, University Hospital Erlangen, Erlangen, Germany.
Kakar SDepartment of Anatomic Pathology, University of California, San Francisco, CA, USA.
Langner CInstitute of Pathology, Medical University of Graz, Graz, Austria.
Nagtegaal IDepartment of Pathology, Radboud University Medical Centre, Nijmegen, The Netherlands.
Puppa GDepartment of Clinical Pathology, Geneva University Hospital, Geneva, Switzerland.
Riddell RPathology and Laboratory Medicine, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada.
Ristimäki ADepartment of Pathology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.
Sheahan KDepartment of Pathology, St Vincent's University Hospital, Dublin, Ireland.
Smyrk TDivisions of Anatomic Pathology and Mayo Clinic, Rochester, MN, USA.
Sugihara KDepartment of Surgical Oncology, Tokyo Medical and Dental University, Graduate School of Medical and Dental Sciences, Bunkyo-ku, Tokyo, Japan.
Terris BPathology Department, Hôpital Cochin and Université Paris Descartes Sorbonne Paris Cité, Paris, France.
Ueno HDepartment of Surgery, National Defense Medical College, Tokorozawa, Saitama, Japan.
Vieth MInstitute of Pathology, Klinikum Bayreuth, Bayreuth, Germany.
Zlobec IInstitute of Pathology, University of Bern, Bern, Switzerland.
Quirke PPathology and Tumour Biology, University of Leeds, St James's University Hospital, Leeds, UK.
English
Tumor budding is a well-established independent prognostic factor in colorectal cancer but a standardized method for its assessment has been lacking. The primary aim of the International Tumor Budding Consensus Conference (ITBCC) was to reach agreement on an international, evidence-based standardized scoring system for tumor budding in colorectal cancer. The ITBCC included nine sessions with presentations, a pre-meeting survey and an e-book covering the key publications on tumor budding in colorectal cancer. The 'Grading of Recommendation Assessment, Development and Evaluation' method was used to determine the strength of recommendations and quality of evidence. The following 10 statements achieved consensus: tumor budding is defined as a single tumor cell or a cell cluster consisting of four tumor cells or less (22/22, 100%). Tumor budding is an independent predictor of lymph node metastases in pT1 colorectal cancer (23/23, 100%). Tumor budding is an independent predictor of survival in stage II colorectal cancer (23/23, 100%). Tumor budding should be taken into account along with other clinicopathological features in a multidisciplinary setting (23/23, 100%). Tumor budding is counted on H&E (19/22, 86%). Intratumoral budding exists in colorectal cancer and has been shown to be related to lymph node metastasis (22/22, 100%). Tumor budding is assessed in one hotspot (in a field measuring 0.785 mm2) at the invasive front (22/22, 100%). A three-tier system should be used along with the budding count in order to facilitate risk stratification in colorectal cancer (23/23, 100%). Tumor budding and tumor grade are not the same (23/23, 100%). Tumor budding should be included in guidelines/protocols for colorectal cancer reporting (23/23, 100%). Members of the ITBCC were able to reach strong consensus on a single international, evidence-based method for tumor budding assessment and reporting. It is proposed that this method be incorporated into colorectal cancer guidelines/protocols and staging systems.