Hyperthermic Intravesical Chemotherapy for BCG Unresponsive Non-Muscle Invasive Bladder Cancer Patients

Background: Adjuvant intravesical instillations with bacillus Calmette-Guerin (BCG) is the recommended treatment option for patients with intermediate- and high-risk non-muscle invasive bladder cancer (NMIBC). Despite adequate BCG treatment, a large proportion of patients experience a recurrence. Although radical cystectomy is the gold standard for BCG unresponsive NMIBC, some patients are unfit or unwilling to consider this option. Objective: To assess the effectiveness of Hyperthermic IntraVEsical Chemotherapy (HIVEC (R)) in BCG unresponsive NMIBC patients. Methods: A post-hoc analysis was conducted of prospectively included intermediate- and high-risk NMIBC patients who were planned to receive HIVEC (R) treatment between October 2014 and November 2017. For the present analysis, only patients who met the BCG unresponsive definition were included. Patients were followed by cystoscopy and cytology every 3 months and a CT-urography scan yearly. The primary outcome was the disease-free survival (DFS). The Common Terminology Criteria for Adverse Events (CTCAE) was used to assess side-effects. Results: The study population consisted of 55 BCG unresponsive NMIBC patients of whom 52 underwent >= 5 HIVEC (R) treatments. The median age and follow-up were 73 years and 14.0 months (IQR 7.6 - 24.6). The median DFS was 17.7 months (SE 6.72) and progression occurred in four patients. The 1-year cumulative incidence rate of disease recurrence/progression was 53%. Two patients experienced severe side-effects (CTCAE >= 3). Conclusions: HIVEC (R) seems a valid treatment option for BCG unresponsive NMIBC patients. We report a median DFS of 17.7 months (SE 6.72), potentially avoiding or postponing the need for radical surgery in a proportion of these patients.