Efficacy of hyperthermic intravesical chemotherapy (HIVEC) in patients with non-muscle invasive bladder cancer after BCG failure

Purpose To evaluate hyperthermic intravesical chemotherapy (HIVEC) efficacy regarding 1-year disease-free survival (RFS) rate and bladder preservation rate in patients with non-muscle invasive bladder cancer (NMIBC) who fail bacillus Calmette–Guérin (BCG) therapy. Methods This is a multicenter retrospective series from a national database (7 expert centers). Between January 2016 and October 2021, patients treated with HIVEC for NMIBC who failed BCG have been included in our study. These patients had a theoretical indication for cystectomy but were ineligible for surgery or refused it. Results A total of 116 patients treated with HIVEC and with a follow-up > 6 months were included in this study and retrospectively analyzed. The median follow-up was 20.6 months. The 12 month-RFS (recurrence-free survival) rate was 62.9%. The bladder preservation rate was 87.1%. Fifteen patients (12.9%) progressed to muscle infiltration, three of them having a metastatic disease at the time of progression. Predictive factors of progression were T1 stage, high grade and very high-risk tumors according to the EORTC classification. Conclusion Chemohyperthermia using HIVEC achieved an RFS rate of 62.9% at 1 year and enabled a bladder preservation rate of 87.1%. However, the risk of progression to muscle-invasive disease is not negligible, particularly for patients with very high-risk tumors. In these patients who fail BCG, cystectomy should remain the standard of care and HIVEC may be discussed cautiously for patients who are not eligible for surgery and well informed of the risk of progression.