Presence and predominance of histological grade 3 define cT1HG bladder cancer prognostic groups

Current World Health Organization/International Society of Urological Pathology (2004 WHO/ISUP) grading of bladder urothelial carcinoma relies on the highest pathologic grade of the specimen and does not reflect the inherent qualitative and quantitative heterogeneity of disease. We retrospectively studied consecutive urothelial high-grade cT1 (cT1HG) carcinomas submitted to adjuvant bacille Calmette-Guérin between 2008 and 2015 to evaluate the prognostic potential of grade 3 (presence or predominance) according to the 1973 WHO system concerning disease progression and cancer-specific death. Among 253 patients, grading distribution was 34.4% 1+2, 7.5% 2+1, 20.2% 2+2, 19.0% 2+3, 5.1% 3+2, and 13.8% 3+3. Recurrence was diagnosed in 115 (45.5%), progression in 83 (32.8%), and cancer-specific death in 50 patients (19.8%). Mean time to recurrence, progression, and death from disease were 35.9±31.7, 47.6±44.5, and 51.2±50.4 months, respectively. Grade 3 presence (2+3, 3+2, or 3+3) occurred in 96 (37.9%) and independently predicted time to progression (p