Immunotherapy of murine transitional cell carcinoma of the bladder using alpha and gamma interferon in combination with other forms of immunotherapy

BCG immunotherapy is very effective in the treatment of superficial transitional cell carcinoma of the bladder, but its significant toxicity may limit its use in some patients. In an effort to find less toxic and potentially more effective treatments we investigated the possible immunotherapeutic potential of combinations of Alpha Interferon (1000 IU) and Gamma Interferon (500 IU) with bacillus Calmette Guerin (BCG) (10⁷ cfu), Interleukin-2 (4000 IU), and Keyhole Limpet Hemocyanin (50 μg.) in the MBT2 murine bladder cancer model. Significant reductions (p <0.05) in tumor incidence relative to the saline control, 83%, Day 35) was observed in groups receiving alpha interferon (42%), Keyhole limpet hemocyanin (42%), interleukin-2 (25%), alpha interferon+Keyhole limpet hemocyanin (17%), alpha interferon+interleukin-2 (33%), gamma interferon+BCG (42%), and gamma interferon+interleukin-2 (17%). All treatment groups with the exception of the group receiving gamma interferon had significantly reduced tumor volume (p <0.05) relative to the saline control. Combination treatment groups were significantly more effective than single agent treatments (p = 0.0057). The exhibited anti-tumor effect of these immunotherapeutic agents alone and in combination suggest that they may prove to be effective forms of immunotherapy for transitional cell carcinoma of the bladder.