肿瘤分级是指导非肌层浸润性膀胱癌患者治疗的关键预后参数。 2004年，世界卫生组织（WHO）采用二元（低级别/高级别）分级系统来取代自1973年以来用于尿路上皮癌分级的三级（1-3级）系统。尿路上皮癌分级的全球差异。一些病理学和临床指南建议同时报告 WHO 1973 年和 2004 年等级，而其他指南则要求仅报告 WHO 2004 年等级。病理学实践中的这种差异具有临床意义，因为这两种分级系统不易转换。一些专家提出了新的尿路上皮癌分级系统，其中包括对 WHO 1973 年和 2004 年分级类别的划分。支持和反对将尿路上皮癌分为两级、三级和四级类别的论点由三位作者独立讨论。© 2023 John Wiley

Tumour grade is a critical prognostic parameter for guiding the management of patients with non-muscle invasive bladder cancer. In 2004, the World Health Organisation (WHO) adopted a binary (low-grade/high-grade) grading system to replace the three-tier (grades 1-3) system used to grade urothelial carcinoma since 1973. However, there is significant global variation in the grading of urothelial carcinoma. Some pathology and clinical guidelines recommend reporting of the WHO 1973 and 2004 grades in parallel, while others require reporting only of the WHO 2004 grade. This variation in pathology practice is clinically significant, because the two grading systems are not readily translatable. Some experts have proposed novel systems for grading urothelial carcinoma that involve splitting of the WHO 1973 and 2004 grade categories. The arguments for and against splitting urothelial carcinomas into two-, three- and four-grade categories are independently discussed by the three authors.© 2023 John Wiley & Sons Ltd.