Long-term outcomes of a randomized controlled trial comparing thermochemotherapy with mitomycin-C alone as adjuvant treatment for non-muscle-invasive bladder cancer (NMIBC)

Abstract

Objective: • To present long-term efficacy data of intravesical thermochemotherapy vs chemotherapy alone with mitomycin-C (MMC) randomly administered to patients with non-muscle-invasive bladder cancer (NMIBC) as an adjuvant treatment after complete transurethral resection.

Patients and methods: • In all, 83 patients with intermediate-/high-risk NMIBC, following complete transurethral resection, were randomly assigned to receive either intravesical thermochemotherapy by means of Synergo® (Medical Enterprises, Amsterdam, The Netherlands) or intravesical chemotherapy alone, for prophylaxis of tumour recurrence. • Two doses of MMC (20 mg dissolved in 50 mL distilled water administered throughout two consecutive sessions) was used as the chemotherapeutic agent in both arms. • In all, 75 patients completed the original study (35 of 42 in the treatment arm, 40 of 41 in the control arm), whose results at minimum 2-year follow-up have already been published. • Recently, the files of these patients have been updated for long-term outcome definition. Data on general health, follow-up examinations, tumour relapse or progression, and cause of death were collected and analysed.

Results: • Updated complete data collection was available for 65/75 (87%) of the original patients. • The median follow-up for tumour-free patients was 91 months. The 10-year disease-free survival rate for thermochemotherapy and chemotherapy alone were 53% and 15%, respectively (P < 0.001). • An intent-to-treat analysis performed to overcome the potential bias introduced by the asymmetrical discontinuation rate still showed a significant advantage of the active treatment over the control treatment. Bladder preservation rates for thermochemotherapy and chemotherapy alone were 86% and 79%, respectively.

Conclusion: • This is the first analysis of long-term follow-up of patients treated with intravesical thermochemotherapy. The high rate (53%) of patients who were tumour-free 10 years after treatment completion, as well as the high rate (86%) of bladder preservation, confirms the efficacy of this adjuvant approach for NMIBC at long-term follow-up, even in patients with multiple tumours.