Electromotive acceleration improves mitomycin C delivery for bladder cancer

As a treatment for high-risk superficial bladder cancer, electro-osmotic delivery of slightly ionized mitomycin C (MMC) achieves better bladder uptake and response rates than passive MMC, according to a report published in the September issue of Urology.

In fact, the response rates are so good that electromotive MMC could be considered an alternative or complementary therapy to bacillus Calmette-Guerin (BCG), the researchers say. They note that high-grade cancer cells are typically less chemosensitive than others, meaning that higher MMC concentrations are probably needed to destroy them. Simply allowing MMC to passively diffuse into such cells may not achieve adequate levels, but iontophoretic treatment of MMC produces an agent with electromotive forces that might be able to achieve higher levels. Dr. Savino M. Di Stasi, from Tor Vergata University in Rome, and colleagues assessed the outcomes of 108 patients with high-risk superficial bladder cancer who were randomized to receive intravesical instillation of electromotive MMC, passive MMC, or BCG after transurethral tumor resection.After receiving 6 weekly treatments, nonresponders received 6 additional weekly treatments, while responders underwent a further 10 monthly treatments.At 6-month follow-up, a complete response was seen in 58% of patients treated with electromotive MMC, compared with only 31% of patients treated with passive MMC (p = 0.012). Moreover, the median time to recurrence with electromotive MMC was 35 months, about 16 months longer than that seen with passive MMC (p = 0.013).In comparison, the response rate in the BCG group — 64% — was only slightly higher than that of the electromotive MMC group. The median time to recurrence with BCG was 26 months.Pharmacokinetic testing revealed that peak plasma MMC levels were significantly higher after the agent was given electromotively rather than passively, the authors note.Despite the encouraging results seen with electromotive MMC, “there remains an unresolved theoretical concern,” the researchers state. “At least in animals MMC is carcinogenic” and could place patients at risk for an additional malignancy, they add.”All of our patients are subject to lifelong surveillance, which should assist in resolving this issue,” the investigators note.(Source: J Urol 2003;170:777-782: Reuters Health: September 4, 2003: Oncolink)