Benzalkonium bromide as a new potential instillation drug for bladder cancer: Hypothesis and pilot study

Summary Non-muscle-invasive urothelial carcinoma of the bladder has a high rate of recurrence, necessitating use of a variety of adjuvant treatments. A single, immediate post-operative administration of chemotherapy is an important measure for reducing the rate of recurrences, but the overall effect is not satisfactory and the treatment is a burden to the patient. Hence, there is a need for a new, more effective and cheaper agent for adjuvant treatment of non-muscle-invasive bladder carcinomas. Although cationic surfactants such as benzalkonium salts are used clinically and hygienically for the control of bacterial growth, there have been reports that cationic surfactants such as benzethonium chloride induce apoptosis in normal and in cancerous cells. We report our experience with benzalkonium bromide (BB) accidentally administered into a patient‘s bladder as saline. It caused severe hematuria and pain, but after a week of persistent administration in the bladder, the patient was cured, as supported by evidence from cystoscopy, indicating that BB destroys bladder mucosa and suggesting that BB maybe a novel agent for use in a single, immediate post-operative administration. We present preliminary data to support this hypothesis and provide discussion we hope will be useful as the foundation for further experiments.