Feasibility and Clinical Roles of Different Substaging Systems at First and Second Transurethral Resection in Patients with T1 High-Grade Bladder Cancer

BACKGROUND: Decision making in T1 high-grade bladder cancer patients remains a challenging issue in urologic practice. OBJECTIVE: To assess the feasibility and potential prognostic role of three different substaging systems in specimens from both primary and second transurethral resection (TUR) of the bladder in T1 high-grade bladder cancer patients. DESIGN, SETTING, AND PARTICIPANTS: A total of 250 consecutive, confirmed pure transitional T1 high-grade bladder tumors submitted to second TUR entered the retrospective study. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Feasibility of two already clinically tested microstaging systems (anatomy-based T1a/T1b/T1c and micrometric T1m/T1e with 0.5-mm thresholds of invasion) and that of a micrometric substage designed by the authors and based on a 1-mm threshold of invasion (Rete Oncologica Lombarda [ROL] system) was assessed by five independent uropathologists on both first and second TUR specimens. Univariable Cox proportional hazards models were attempted to identify significant independent predictors of recurrence and progression after TUR. Kaplan-Meier curves were plotted to compare different substaging methods analyzing recurrence and progression.

Results and limitations: The ROL system proved to be feasible in nearly all cases at both first and second TUR. Median follow-up was 60 mo. The univariate Cox regression analysis documented the ROL substage (ROL2 vs ROL1) to be the only statistically significant predictor of progression (hazard ratio: 2.01; 95% CI, 1.03-3.79; p<0.03). For the first time to our knowledge, the substage was investigated and used to assess T1 tumors found at second TUR, registering a high rate of feasibility. Conclusions: T1 microstaging using different procedures is feasible on both primary- and second-TUR specimens. A high rate of feasibility may be expected for T1m/T1e and ROL systems. The clinical role of microstaging on second TUR remains to be defined. Patient summary: The Rete Oncologica Lombarda system showed feasible results in T1 high-grade bladder tumors. Our substratification was predictive of progression of disease.