Reduction of residual tumors by photodynamic diagnosis-assisted TURBT using 5-aminolevulinic acid for high-risk nonmuscle-invasive bladder cancer (BRIGHT study).

Abstract

489 Background: High-risk non-muscle invasive bladder cancer (NMIBC) has high tumor residual rate of 40–60% after TURBT, and second TUR is strongly recommended. Photodynamic diagnosis-assisted TURBT (PDD-TURBT) using 5-aminolevulinic acid (5-ALA) has been reported to reduce residual tumors and intravesical recurrence. The purpose of this study is to investigate the residual tumor-reducing effect of PDD-TURBT for high-risk NMIBC and to explore the possibility that second TUR could be omitted by PDD-TURBT. Methods: We conducted an investigator-initiated multicenter prospective observational study (BRIGHT study; UMIN000035712) involving patients who underwent PDD-TURBT using 5-ALA and second TUR for high-risk NMIBC (high-grade UC or pT1 or concurrent CIS). The primary endpoint was tumor residual rate and the secondary endpoint was recurrence-free survival, which were compared with historical data (conventional TURBT) using propensity score-matching (PSM; caliper: 0.2). Assuming that the difference between the two groups was 20%, the planned number of cases was statistically set to 200 PDD-TURBT cases and 300 historical data cases, and the registration period was 2 years from January 2019 to December 2020, and the follow-up period was 2 years after second TUR. Results: In this study, 188 patients in the PDD-TURBT group and 313 patients in the historical group were enrolled, and 177 patients and 306 patients were included in the final analysis, respectively. After PSM adjustment, 167 patients in both groups were compared, and no significant differences were observed in age, gender, history of bladder cancer, tumor diameter, number of tumors, history of upper tract urothelial cancer, and period from initial TURBT to second TUR. The tumor residual rate was 25.8% in the PDD-TURBT group compared with 47.3% in the historical group, showing a significant decrease (odds ratio 0.39 [95% CI: 0.24–0.63]; p = 0.000064). Logistic regression analysis revealed that significant factors predicting residual tumors in PDD-TURBT were current or past smoking history, multiple tumors, and non-pTa (pT1 or pTis) tumors. Focusing on these three factors, patients with 0–1 of these three factors have a significant less tumor residual rate compared with patients with 2–3 factors (8.33% vs. 33.3%; odds ratio 5.46 [95% CI: 1.81–22.3]; p = 0.00052). Conclusions: PDD-TURBT for high-risk NMIBC significantly reduced the tumor residual rate at the second TUR compared to the conventional TURBT. PDD-TURBT using 5-ALA may enable to omit second TUR in some high-risk NMIBC cases. Clinical trial information: UMIN000035712.