Measuring the dimension of invasive component in pT1 urothelial carcinoma in transurethral resection specimens can predict time to recurrence

Recurrences of nonmuscle-invasive urothelial bladder cancer are very common following resection. Predictive histopathologic variables in transurethral resection of bladder tumor (TURBT) specimens are of particular importance especially in determining the behavior of lamina propria-invasive tumors (high grade T1 stage). A total of 110 patients who underwent TURBT for urothelial carcinoma (1997-2005) from a single institution were retrospectively reviewed. Amount of tumor invasion by urothelial carcinoma was assessed in terms of percentage, focality (focal vs multifocal), and dimension (DI, aggregate length of invasion). Of 110 patients, 39 (35%) were found to have invasive high-grade urothelial carcinoma, including 9 females. Mean age was 70 years (range, 56-94 years). Twenty-three patients with high-grade T1 urothelial carcinoma had available follow-up information. Recurrence rate in these 23 patients was 96% (22/23). Nearly all of the recurences (221/22, 95%) occurred within 1 year of the initial TURBT. There was an inverse correlation of DI with time to recurrence (P < .05; correlation coefficient, −0.47). Urothelial carcinoma with a greater DI (>0.5 cm) had a mean time to recurrence of less than 6 months. Percentage of tumor invasion and focality was not associated with recurrence. The aggregate length of invasion may be a prognostic variable for high-risk nonmuscle-invasive bladder cancer. Measuring “aggregate length of invasive tumor,” if further validated in larger studies, could provide a practical alternative in substaging pT1 tumors in TURBT specimens.