Intravesical chemotherapy versus immunotherapy for superficial bladder cancer

The decision to treat superficial bladder cancer with intravesical therapy should be predicated primarily on disease stage and grade as well as the patient's clinical history. Once the decision to proceed with intravesical therapy has been made, the clinician must select the appropriate agent. Several agents are available and the choice of which agent to use should be based on careful consideration of the potential benefit of a given drug versus its inherent risk of complications. The first drug to be administered intravesically, thiotepa is an alkylating agent used as first-line treatment for low-grade lesions; it has limited use against higher-grade tumors or carcinoma in situ. In addition, the low molecular weight of thiotepa results in significant systemic absorption, which often results in myelosuppression. Mitomycin, also an alkylating agent, has shown significant activity as both first-line therapy and in patients with recurrent disease. Unlike thiotepa, mitomycin has a relatively high molecular weight, and the incidence of significant bladder absorption and systemic side effects is low. Doxorubicin, which also possesses a high molecular weight, is used intravesically against superficial bladder cancer more frequently in Europe and Japan than in the United States. Immunotherapy with bacille Calmette-Guérin is the treatment of choice for carcinoma in situ and high-grade T1 lesions. It is associated with the highest incidence of both minor and major adverse reactions, however, and its use should be tempered by its potential toxicity.