Purpose: Interim results are provided from a large multicenter trial of combination bacillus Calmette-Guerin (BCG) plus interferon (IFN) alfa-2b for BCG naive (BCG-N) and previous BCG failure (BCG-F) cases of superficial bladder cancer.
Materials and methods: A total of 490 patients enrolled from May 1999 to May 2000 with a median of 24 months of followup were analyzed. The BCG-N group (259) was treated with a 6-week induction course of standard dose BCG plus 50 million units of IFN followed by 3, 3-week maintenance cycles of reduced dose BCG (1/3 to 1/10) plus 50 million units IFN at 3, 9 and 15 months after induction. The BCG-F group (231) was treated similarly except induction therapy began at a decreased (1/3 to 1/10) BCG dose.
Results: The simple tumor recurrence rates for BCG-N and BCG-F groups were 40% and 52%, and the Kaplan-Meier estimates for disease freedom at 24 months were 57% and 42%, respectively. Progression to muscle invasion occurred in 5% and 4.3% while metastasis occurred in 2.3% and 2.6%, respectively. In each group 3.9% of patients underwent cystectomy and 2 patients in each group died of bladder cancer. Serious adverse events occurred in 5.5% with infection related serious adverse events being less prevalent in the BCG-F group (2.6% vs 5.4%). Toxicity related dropout, treatment delay and/or further BCG dose reduction, and need for symptomatic drugs were similar. Moderate to severe local side effects during induction were higher in the BCG-F group (6.2% vs 16.9%) but equilibrated during maintenance therapy. Systemic reactions were rare.
Conclusions: This multicenter trial provides a benchmark for the efficacy and safety of combination BCG and IFN as up front and salvage therapy. The incremental value of IFN cannot be determined from this study.