Bladder cancer prospective cohort study on high-risk non-muscle invasive bladder cancer after photodynamic diagnosis-assisted transurethral resection of the bladder tumor (BRIGHT study).

Objectives: Transurethral resection of bladder tumor with photodynamic diagnosis has been reported to result in lower residual tumor and intravesical recurrence rates in non-muscle invasive bladder cancer. We aimed to evaluate the usefulness of photodynamic diagnosis-transurethral resection of bladder tumor combined with oral 5-aminolevulinic acid hydrochloride for high-risk non-muscle invasive bladder cancer.

Methods: High-risk non-muscle invasive bladder cancer patients with an initial photodynamic diagnosis-transurethral resection of bladder tumor (photodynamic diagnosis group) were prospectively registered between 2018 to 2020. High-risk non-muscle invasive bladder cancer cases with a history of initial white-light transurethral resection of bladder tumor (white-light group) were retrospectively registered. Propensity score-matching analysis was used to compare residual tumor rates, and factors that could predict residual tumors at the first transurethral resection of bladder tumor were evaluated.

Results: Analyses were conducted with 177 and 306 cases in the photodynamic diagnosis and white-light groups, respectively. The residual tumor rates in the photodynamic diagnosis and white-light groups were 25.7% and 47.3%, respectively. Factor analysis for predicting residual tumors in the photodynamic diagnosis group showed that the residual tumor rate was significantly higher in cases with a current/past smoking history, multiple tumors, and pT1/pTis. When each factor was set as a risk level of 1, cases with a total risk score ≤1 showed a significantly lower residual tumor rate than cases with a total risk score ≥2 (8.3% vs 33.3%, odds ratio 5.46 [1.81-22.28]).

Conclusions: In high-risk non-muscle invasive bladder cancer cases, the odds of a residual tumor after initial photodynamic diagnosis-transurethral resection of bladder tumor were 0.39-fold that of the odds of those after initial white-light transurethral resection of bladder tumor. A risk stratification model could be used to omit the second transurethral resection of bladder tumor in 27% of the cases.