Objectives: To assess the intravesical efficacy of 60 million units of interferon (IFN) alpha-2b in preventing recurrences of Stage pT1 transitional cell carcinoma of the bladder, as well as to assess its local and systemic toxicity.
Methods: A total of 90 patients were included in a double-blind, randomized, prospective clinical trial and divided into two groups of 45 patients. After complete transurethral resection, 60 million units IFN alpha-2b was instilled in one group; in the other, double-distilled water was used. The therapeutic regimen consisted of weekly instillation for 12 weeks, followed by once-monthly instillation until patients had completed 1 year of treatment.
Results: Only 78 patients were evaluable. After 12 months of follow-up, the relapse rate was 28.2% (11 of 39) for the IFN group and 35.8% (14 of 39) for the control group (P = NS). After 43 months (range 9 to 67), relapse rates were 53.8% (21 of 39) and 51.2% (20 of 39), respectively (P = NS). Progression, mortality, and local or systemic toxicity were similar in both groups. Flu-like syndrome was not reported.
Conclusions: At the dose used in this study, IFN alpha-2b proved ineffective in the prophylaxis of Stage pT1 transitional cell carcinoma of the bladder compared with a control group. Toxicity was virtually absent.