Predictive Factors for Time to Progression after Hyperthermic Mitomycin C Treatment for High-Risk Non-Muscle Invasive Urothelial Carcinoma of the Bladder: An Observational Cohort Study of 97 Patients.

INTRODUCTION: Hyperthermic mitomycin (HM) is a novel treatment modality for selected patients with high-risk non-muscle invasive bladder cancer (NMIBC). We sought to determine predictors of response to this therapy.

PATIENTS AND METHODS: A longitudinal, cohort study of 97 patients with high-risk NMIBC treated with ≥4 HM instillations on a prophylactic schedule was conducted. The primary outcome was time-to-progression survival; secondary outcomes were overall survival, cancer-specific survival, and adverse events. Descriptive statistics, Kaplan-Meier survival analyses, Cox proportional hazards modelling, and univariate and multivariable regression were performed.

RESULTS: The presence of initial complete response (CR; no evidence of disease at first check video-cystoscopy and urine cytology) post-HM treatment was an independent predictor of good response to HM. Female patients and those without carcinoma in situ (CIS) also appeared to respond better to the intervention. The overall bladder preservation rate at a median of 27 months was 81.4%; 17/97 (17.5%) patients died during the course of the study.

CONCLUSIONS: High-risk NMIBC patients can be safely treated with HM and have good oncological outcome. However, those without an initial CR have a poor prognosis and should be counselled towards adopting other treatment methodologies such as cystectomy. Female gender and lack of CIS may be good prognostic indicators for response to HM.