Abstract
Transitional cell carcinoma (TCC), which is the pathological diagnosis for the majority of bladder cancers, is a solid tumor entity that is responsive to immunotherapy as evidenced by a substantial cure rate documented with the use of intravesical bacillus Calmette-Guérin (BCG) therapy in selected patients with high-grade superficial disease. The nonspecific immune modulation that occurs as a result of BCG therapy is not well understood; however, the success of BCG therapy provides a basis for the exploration of mechanisms related to immune responses and the development of novel immunotherapeutic agents for the treatment of high-risk disease. In this review, we discuss the complexity of the immune system and therapies that are considered capable of manipulating it to potentially benefit patients with bladder cancer.