Effectivity of intravescical thermo-chemotherapy prophylaxis for patients with high recurrence and progression risk for non-muscle invasive bladder cancer

Background&Aim: High grade non-muscle invasive bladder cancer (NMIBC) is common in urological practice. Most of these cancers are or become refractory to intravesical immunotherapy and chemotherapy. Here we evaluated the efficacy of combined local bladder hyperthermia and intravesical mitomycin-C (MMC) instillation in patients with high-risk recurrent NMIBC. Materials and methods: Between February 2014 and December 2015, 18 patients with high risk NMIBC were enrolled. Patients were treated in an outpatient basis with 6 weekly induction sessions followed by monthly maintenance sessions with intravesical MMC in local hyperthermia with bladder wall thermo-chemotherapy (BWT) system (PelvixTT system, Elmedical Ltd., Hod Hasharon, Israel). The follow-up regimen included cystoscopy after the induction cycle and thereafter with regular intervals. Time to disease recurrence was defined as time from the first intravesical treatment to endoscopic or histological documentation of a new bladder tumour. Adverse events were recorded according to CTC 4.0 (Common Toxicity Criteria) score system. Results: Mean age was 72 (32-87) years. 10 patients had multifocal disease, 9 had CIS, 6 had recurrent disease and 2 had highly recurrent disease (> 3 recurrences in a 24 months period). 6 patients underwent previous intravesical chemotherapy with MMC. The average number of maintenance sessions per patient was 7.6. After a mean follow-up of 433 days, 15 patients (83.3%) were recurrence-free. 3 patients had tumour recurrence after a mean period of 248 days without progression. Side effects were limited to grade 1 in 2 patients and grade 2 in 1 patient. Conclusions: BWT seems to be feasible and safe in high grade NMIBC. More studies are needed to identify the subgroup of patients who may benefit more from this treatment.