Strategies to enhance the efficacy of intravescical therapy for non-muscle invasive bladder cancer.

Transitional cell carcinoma (TCC) is the second most common urologic malignancy, and 70% of patients present with superficial, or non-muscle invasive disease (NMIBC). Bacillus Calmette-Guerin (BCG), currently the most effective intravesical agent at preventing disease recurrence, is the only therapy shown to inhibit disease progression. Unfortunately, approximately 20% of patients discontinue BCG due to local and systemic toxicity and more than 30% show evidence of recurrence; this has led to increased interest in alternate chemotherapeutic agents. Induction intravesical chemotherapy has shown comparable efficacy to BCG in select patients and the immediate perioperative instillation of chemotherapeutic agents has become standard of care. Clinical trial evidence demonstrating the efficacy of BCG plus interferon 2B, gemcitabine and anthracyclines (doxorubicin, epirubicin, valrubicin) in patients refractory or intolerant to BCG is accumulating. Phase I trials investigating alternative agents such as apaziquone, taxanes (docetaxel, paclitaxel), and suramin are reporting promising data. Current efforts are also being directed towards optimizing the administration of existing chemotherapeutic regimens, including the use of novel modalities including hyperthermia, photodynamic therapy, magnetically targeted carriers, and liposomes. Despite recent enthusiasm for new intravesical agents, radical cystectomy remains the treatment of choice for patients with NMIBC who have failed intravesical therapy and select patients with naive T1 tumors and aggressive features. Our aim in this report is to provide a comprehensive review of contemporary intravesical therapy options for NMIBC with an emphasis on emerging agents and novel treatment modalities.