DaBlaCa-13 Study: Five-year Follow-up from the Randomized Controlled Trial of Chemoresection with Intravesical Mitomycin C in Recurrent Ta Non-muscle-invasive Bladder Cancer.

BACKGROUND AND

OBJECTIVE

Transurethral resection of bladder tumors (TURBT) remains the standard treatment for non-muscle-invasive bladder cancer (NMIBC) but is associated with procedural risks and health care burden. Chemoresection using intravesical mitomycin C (MMC) has emerged as a minimally invasive alternative. This randomized controlled trial presents 5-yr follow-up data evaluating long-term outcomes of MMC chemoresection versus standard surgical management in patients with intermediate-risk NMIBC.

METHODS

From 2018 to 2024, 120 patients with recurrent Ta low-grade or high-grade NMIBC and >1 papillary tumor <2 cm were randomized 1:1 to receive either short-term, intensive chemoresection (6 MMC instillations over 2 wk) or standard care with TURBT/biopsy followed by adjuvant instillations with a 5-yr follow-up. Primary end points were the number of procedures (TURBT or biopsy/fulguration) and recurrence-free survival (RFS).

KEY FINDINGS AND LIMITATIONS: Fewer patients in the intervention group underwent TURBT (64% vs 89%, p = 0.003), and more patients avoided procedures entirely (17% vs 0%, p = 0.002). Nonresponders shifted from TURBT to office procedures (p = 0.029). At 5 yr, RFS was 14% vs 28% (p = 0.3), with no statistically significant between-group difference (hazard ratio = 1.32, 95% confidence interval 0.86-2.01). Patients with fewer baseline tumors had better RFS (p = 0.012). Findings are limited by a few high-grade tumors at baseline.

CONCLUSIONS AND CLINICAL IMPLICATIONS: Chemoresection reduces the need for surgical procedures in patients with recurrent NMIBC without compromising long-term oncological outcomes. These findings support its integration as a less-invasive treatment option in selected patients.