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

Abstract

Purpose 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. Materials and Methods 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. Results 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<0.001; hazard ratio [HR], 3.11; 95% confidence interval [CI], 1.88–5.14). Grade 3 predominance (3+2 or 3+3) occurred in 48 (18.9%) and independently predicted time to disease-specific death. Conclusions Grade 3 presence and predominance are independent predictors of progression and disease-specific death and occur in about 40% and 20% of cT1HG, respectively. Describing qualitative and quantitative heterogeneity in urothelial carcinoma grading might improve the stratification of patients. This gives three prognostic high-grade groups based on WHO/ISUP 1973: prognostic grade group I (grade 3 absence), prognostic grade group II (grade 3 presence), and prognostic grade group III (grade 3 predominance).

Bladder cancer grading using the four‐tier combination of the World Health Organization (WHO) 1973 and WHO 2004 classifications

“…[18] and Reis et al. [19], have emphasised the importance of G3 for recurrence and progression, in line with our results. These results favour the use of WHO73 or the combined WHO73/04 rather than the WHO04.…”