Mitomycin-C in superficial bladder cancer. Is long-term maintenance therapy worthwhile after initial treatment?

A total of 72 patients with recurrent superficial transitional cell carcinoma of the bladder (TCC) were treated with 40 mg intravesical instillations of mitomycin-C (MMC) weekly for 10 weeks, followed by monthly maintenance doses. With a mean follow-up period of 41 months, 30 patients (42%) had a complete and sustained response after the initial treatment course, and a further 14 (19%) achieved a complete response on maintenance therapy. Sixteen patients (22%) continued to have recurrent tumours and the remaining 12 (17%) developed recurrent tumours after an initial complete response. Of these, 4 patients with carcinoma in situ (CIS) showed symptomatic improvement, but the histological changes persisted and all of those with tumours > 2 cm in size did not respond. We conclude that maintenance treatment with MMC is beneficial in superficial bladder cancer but is of limited value in the presence of bulky tumours or CIS.