Hyperthermic intravesical chemotherapy with mitomycin-C for the treatment of high-risk non-muscle-invasive bladder cancer patients.

Objectives: The objectives of the study are to explore tolerability, acceptability and oncological outcomes for patients with high-risk non-muscle-invasive bladder cancer (NMIBC) treated with hyperthermic intravesical chemotherapy (HIVEC) and mitomycin-C (MMC) at our institution.

Patients And Methods: Our single-institution, observational study consists of consecutive high-risk NMIBC patients treated with HIVEC and MMC. Our HIVEC protocol included six weekly instillations (induction), followed by two further cycles of three instillations (maintenance) (6 + 3 + 3) if there was cystoscopic response. Patient demographics, instillation dates and adverse events (AEs) were collected prospectively in our dedicated HIVEC clinic. Retrospective case-note review was performed to evaluate oncological outcomes. Primary outcomes were tolerability and acceptability of HIVEC protocol; secondary outcomes were 12-month recurrence-free, progression-free and overall survival.

Results: In total, 57 patients (median age 80.3 years) received HIVEC and MMC, with a median follow-up of 18 months. Of these, 40 (70.2%) had recurrent tumours, and 29 (50.9%) had received prior Bacillus Calmette-Guérin (BCG). HIVEC induction was completed by 47 (82.5%) patients, but only 19 (33.3%) completed the full protocol. Disease recurrence (28.9%) and AEs (28.9%) were the most common reasons for incompletion of protocol; five (13.2%) patients stopped treatment due to logistical challenges. AEs occurred in 20 (35.1%) patients; the most frequently documented were rash (10.5%), urinary tract infection (8.8%) and bladder spasm (8.8%). Progression during treatment occurred in 11 (19.3%) patients, 4 (7.0%) of whom had muscle invasion and 5 (8.8%) subsequently required radical treatment. Patients who had received prior BCG were significantly more likely to progress ( = 0.04). 12-month recurrence-free, progression-free and overall survival rates were 67.5%, 82.2%, and 94.7%, respectively.

Conclusions: Our single-institution experience suggests that HIVEC and MMC are tolerable and acceptable. Oncological outcomes in this predominantly elderly, pretreated cohort are promising; however, disease progression was higher in patients pretreated with BCG. Further randomised noninferiority trials comparing HIVEC versus BCG in high-risk NMIBC are required.