The Importance of Being Grade 3 : A Plea for a Three-tier Hybrid Classification System for Grade in Primary Non–muscle-invasive Bladder Cancer
Grade is an important determinant of progression in non–muscle-invasive bladder cancer. Although the World Health Organization (WHO) 2004/2016 grading system is recommended, other systems such as WHO1973 and WHO1999 are still widely used. Recently, a hybrid (three-tier) system was proposed, separating WHO2004/2016 high grade (HG) into HG/grade 2 (G2) and HG/G3 while maintaining low grade. We asses