RESUMEN
This study is conducted to evaluate prognostic significance of recently introduced WHO (World Health Organization) 1999 grading system for urothelial carcinoma on transurethral resection of urinary bladder tumor (TURBT) specimens reported during the period from 1996 to 2000. Progression free survival estimates were obtained by Kaplan-Meier method on SPSS software with log rank test application. Among 70 cases, progression occurred in 38 patients from which grade I were 3, grade II were 11 and grade III were 24. The mean period from diagnosis to progression was 76.8, 19.2 and 3.5 months for grade I, II, III respectively. The progression free survival rates at one year were 100% for grade I, 42% for grade II and 5% for grade III. (Log rank test: p < 0.001). WHO 1999 grading system can classify urothelial carcinomas into prognostically different groups, which is statistically significant.