Single-Dose Post-Office Fulguration Mitomycin C Instillation Appears to Improve Recurrence-Free Survival in Patients With Low-Grade Noninvasive Bladder Cancer

Introduction Perioperative instillation of mitomycin-C (MMC) has shown effectiveness in reducing the recurrence of low-grade non-muscle invasive bladder cancer (NMIBC). Data is lacking about the impact of single-dose MMC following office fulguration of low-grade urothelial carcinoma. We compared the outcomes of small-volume low-grade recurrent NMIBC in patients treated with office-fulguration - with and without an immediate single-dose instillation of MMC. Patients and Methods A retrospective analysis of medical records of patients with recurrent small-volume (≤1 cm) low-grade papillary urothelial cancer who underwent fulguration in a single institution between January 2017 and April 2021 either with or without instillation of post-fulguration MMC (40mg/50 mL). The primary outcome was recurrence-free survival (RFS). Results Of 108 patients (27% women) who underwent fulguration, 41% received intravesical MMC. The treatment and control groups had similar sex ratio, mean age, mass size, tumor multifocality and or tumor grade. Median RFS was 20 months (95% CI 4-36) in the MMC group and 9 months (95% CI 5-13) in the control group (P = .038). Multivariate Cox regression analysis showed that MMC instillation was associated with longer RFS (OR = 0.552, 95% CI 0.320-0.955, P = .034) and multifocality was associated with shorter RFS (OR = 1.866, 1.078-3.229, P = .026). A higher rate of grade 1-2 adverse events was observed in the MMC group (18.2%) vs. the control (6.8%, P = .048). No complications grade 3 or higher were observed. Conclusion A single dose of MMC instilled after office fulguration is associated with longer RFS compared to patients who did not receive MMC after the procedure, with no associated high-grade complications.