First multicenter experience with thermotherapy and mitomycin of high risk NMIBC with a new recirculation system (COMBAT).

Abstract

425 Background: At a temperature of 43° (109°F) cytotoxicity of mitomycin increases 10 fold to tumor cells if used for instillation therapy of superficial bladder cancer (NMIBC).In the last years high organ preservation rates were reported for high risk NMIBC after radiofrequency induced hyperthermia and mitomycin (Synergo System).Unfortunately side effects were frequent and discontinuitation of 40% were reported with this method thus thermotherapy combined with instillation this therapy has not been very common.We here report about the first experience with a newly developed device using a recirculation heating system (COMBAT). Methods: After diagnosis by complete TUR/ReTUR patients received 40 mg mitomycin (mito-extra,medac) via transurethral catheter for 1 h heated up to constant 43° by a circulation pump system (COMBAT). Side effects were recorded pprospectively before and after each teratment and during follow up and success was validated by TUR/biopsy if possible. Results: A total of 20 patients were treated from 11/14-9/15 in 5 institutions. Follow up until now is 1-10 month (mean 8 m). All patients had high risk NMIBC including BCG failures. Therapy must be abondened in 1 patient after the 5th treatment, 50% had dysuria during treatment but symptoms decreased after the last treatment in all patients. 2 patients experienced mild allergic reaction also seen under conventional instillation therapy with mitomycin and were treated by corticosteroids. ReTUR was performed in 17/20 patients and revealed a persistent/recurrent tumor pTa GIII in 1 out of 20 patients. Conclusions: Compared to the microwave driven heating system the new device with recirculation of heated mitomycin seems to have less side effects without major complications. Treatment discontinuitation was recorded in 1/20 patients. Given the assumption that this system has the same high rate of organ preservation as the Synergo System at even much lower costs, it may alter the therapy algorythm in high risk NMIBC. Despite our first promising oncological results further research with longer follow up is necessary.Two prospective randomized studies are now underway in England and Spain and first results are awaited in 2 years.