The effect of intravesical chemohyperthermia with mitomycin in non-muscle-invasive bladder tumour patients who cannot tolerate BCG treatment or recur after treatment and refuse cystectomy.

Purpose: Many patients receiving intravesical BCG treatment for non-muscle-invasive bladder cancer experience high recurrence rates despite initial adequate response. In this study, the effectiveness of intravesical chemohyperthermia (CHT) with mitomycin C (MMC) was evaluated in patients who developed relapse after intravesical BCG treatment or could not tolerate the treatment and could not undergo radical cystectomy for any reason.

Materials and methods: 59 patients who underwent complete bladder tumour resection, who had a T1 high-grade tumour and no variant histology was observed in the pathology, and who had previously received intravesical BCG treatment were included in the study. Adjuvant treatment with intravesical CHT-MMC was applied. As a treatment protocol, induction was applied once a week for 6 weeks, followed by maintenance treatment 6 times at 4-week intervals. Each treatment session, it involved bladder wall hyperthermia with a temperature of up to 42 ℃ ± 2 and intravesical administration of 20 mg/50 ml MMC solution twice at 30-min intervals.

Results: Recurrence-free survival after warm mitomycin was 58.7 and 48%, respectively, at 24 months and 44 months, and progression-free survival was 72.6 and 66.2%, respectively. In the subgroup analysis performed according to the number of tumours at diagnosis (single, 2-5, more than 5), recurrence-free survival rates were 81.8%, 48.2% and 11%, respectively, during the median follow-up period of 44 months.

Conclusions: Intravesical CHT-MMC can be considered as an alternative treatment in selected well-informed patients with non-muscle-invasive papillary urothelial carcinoma who are unresponsive to BCG or intolerant to BCG. Prospectively designed studies with larger number of patients are needed.