Grading is the mainstay for treatment decisions for patients with non-muscle-invasive bladder cancer (NMIBC).
To determine the requirements for an optimal grading system for NMIBC via expert opinion.
A multidisciplinary working group established by the International Society of Urological Pathology reviewed available clinical, histopathological, and molecular evidence for an optimal grading system for bladder cancer.
Bladder cancer grading is a continuum and five different grading systems based on historical grounds could be envisaged. Splitting of the World Health Organization (WHO) 2004 low-grade class for NMIBC lacks diagnostic reproducibility and molecular-genetic support, while showing little difference in progression rate. Subdividing the clinically heterogeneous WHO 2004 high-grade class for NMIBC into intermediate and high risk categories using the WHO 1973 grading is supported by both clinical and molecular-genetic findings. Grading criteria for the WHO 1973 scheme were detailed on the basis of literature findings and expert opinion.
Splitting of the WHO 2004 high-grade category into WHO 1973 grade 2 and 3 subsets is recommended. Provision of more detailed histological criteria for the WHO 1973 grading might facilitate the general acceptance of a hybrid four-tiered grading system or-as a preferred option-a more reproducible three-tiered system distinguishing low-, intermediate (high)-, and high-grade NMIBC.
Improvement of the current systems for grading bladder cancer may result in better informed treatment decisions for patients with bladder cancer.
European urology focus. 2021 Mar 24 [Epub]
Theo van der Kwast, Fredrik Liedberg, Peter C Black, Ashish Kamat, Bas W G van Rhijn, Ferran Algaba, David M Berman, Arndt Hartmann, Antonio Lopez-Beltran, Hemamali Samaratunga, Murali Varma, Liang Cheng
Princess Margaret Cancer Center, Toronto, Canada. Electronic address: ., Department of Translational Medicine, Lund University, Malmö, Sweden; Department of Urology Skåne University Hospital, Malmö, Sweden., University of British Columbia, Vancouver, Canada., University of Texas MD Anderson Cancer Center, Houston, TX, USA., Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands., Fundació Puigvert, Universitat Autónoma de Barcelona, Barcelona, Spain., Queen's University, Kingston, Canada., Friedrich-Alexander University of Erlangen-Nürnberg, Erlangen, Germany., Córdoba University Medical School, Cordoba, Spain., Aquesta Uropathology and University of Queensland, Brisbane, Australia., University Hospital of Wales, Cardiff, UK., Indiana University School of Medicine, Indianapolis, IN, USA.