Association Between Photodynamic Diagnosis and Risk of Recurrence and Progression in Bacillus Calmette-guérin-treated Nonmuscle Invasive Bladder Cancer Patients: A Nationwide Follow-up Study

OBJECTIVE: To investigate whether photodynamic diagnosis (PDD) influences recurrence and progression risk in patients with nonmuscle invasive bladder cancer treated with Bacillus Calmette-Guérin (BCG). METHODS: We performed a nationwide cohort study using Danish health registries. Patients with a first-time diagnosis of nonmuscle invasive bladder cancer who received BCG between 2009 and 2022 were included. Patients were followed until death, cystectomy, or December 31, 2023. Exposure was PDD at primary transurethral resection of the bladder. We estimated cumulative incidences and relative risks for recurrence and progression, anid calculated crude and adjusted odds ratios for BCG response according to PDD status. RESULTS: A total of 4318 patients were included, of whom 2388 (55%) underwent PDD-assisted diagnosis. At 1 year, the age-adjusted relative risk for recurrence was 0.85 (95% CI, 0.76-0.96) in the PDD group compared with the non-PDD group. At 5 years, the relative risk was 0.94 (95% CI, 0.87-1.03). No significant differences were observed in BCG response among adequately treated patients between the PDD and non-PDD groups. CONCLUSION: This large registry-based cohort study found no evidence that the use of PDD was associated with differences in BCG treatment outcomes. While PDD was associated with a modest reduction in recurrence risk at 1 year, no long-term benefit was observed regarding recurrence, progression, or BCG response.