Failure of intravesical interferon-alfa-2b for the treatment of patients with superficial bladder cancer previously failing intravesical BCG Therapy

Twelve patients with superficial bladder cancer who had failed one or two 6-week courses of intravesical bacillus Calmette-Guérin (BCG) therapy were treated with recombinant interferon-alfa-2b (rIFN-alfa-2b). Patients received 12 weekly instillations of rIFN-alfa-2b (100 MU) in 50 cc of normal saline. Those with an initial tumor-free response at the 3-month follow-up received maintenance rIFN-alfa-2b instillations (100 MU) monthly for an additional 9 months. Prior to rIFN-alfa-2b treatment, 6 patients had carcinoma in situ (CIS) with concurrent papillary tumor (pTa or pT I), and 6 had grades I or 2 pTa tumors. Patients were monitored every 3 months with urinary cytologies, cystoscopies, and biopsies when indicated. Median follow-up was 18 months (range 12 to 26 months). At the 3-month follow-up tumor recurrence was noted in 8 (66%) of 12 patients. An additional 3 (25%) patients had tumor recurrence at the 6-month follow-up period, and 3 (25%) patients also developed upper tract tumors during follow-up. Only 1 (8%) patient has maintained a continuous tumor-free response for 24 months. We are unable to demonstrate that rIFN-alfa-2b is likely to induce a tumor-free response in superficial bladder tumor patients who have failed intravesical BCG therapy, including those with CIS.