Bacillus Calmette-Guérin with or without interferon α-2b and megadose versus recommended daily allowance vitamins during induction and maintenance intravesical treatment of nonmuscle invasive bladder cancer

Purpose: In a multicenter, prospectively randomized study we evaluated bacillus Calmette-Guérin alone vs bacillus Calmette-Guérin plus interferon α-2b and megadose vitamins vs recommended daily allowance vitamins during induction and maintenance intravesical therapy in the treatment of nonmuscle invasive bladder cancer.

Materials and methods: Patients who were bacillus Calmette-Guérin naïve with carcinoma in situ, Ta or T1 urothelial cancer were randomized to receive intravesical bacillus Calmette-Guérin or bacillus Calmette-Guérin plus interferon α-2b. Patients were further randomized to receive a recommended daily allowance or megadose vitamin preparation. Induction bacillus Calmette-Guérin treatment was given weekly for 6 weeks, and patients who were recurrence-free received maintenance treatment at 4, 7, 13, 19, 25 and 37 months. Patients were followed with quarterly cystoscopy for 2 years, then semiannually through year 4 and then annually. The primary end point was biopsy confirmed tumor recurrence or positive cytology.

Results: A total of 670 patients were accrued and randomized. At 24-month median followup recurrence-free survival was similar in all groups with 63% in the bacillus Calmette-Guérin with recommended daily allowance vitamins group, 59% in bacillus Calmette-Guérin with megadose vitamins, 55% in bacillus Calmette-Guérin/interferon α-2b with recommended daily allowance vitamins and 61% in bacillus Calmette-Guérin/interferon α-2b with megadose vitamins (p >0.05). The addition of interferon α-2b was associated with a more frequent incidence of fever (11% vs 5%) and constitutional symptoms (18% vs 11%) vs bacillus Calmette-Guérin alone (p <0.05).

Conclusions: Interferon α-2b added to bacillus Calmette-Guérin induction and maintenance intravesical therapy did not decrease tumor recurrence in bacillus Calmette-Guérin naïve cases, but was associated with increased fever and constitutional symptoms. No difference in time to recurrence was present in patients receiving recommended daily allowance vs high dose vitamins.