doi:10.1155/2012/404581 Review Article Oncolytic Viruses in the Treatment of Bladder Cancer

which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Bladder carcinoma is the second most common malignancy of the urinary tract. Up to 85 % of patients with bladder cancer are diagnosed with a tumor that is limited to the bladder mucosa (Ta, T1, and CIS). These stages are commonly termed as non-muscle-invasive bladder cancer (NMIBC). Although the treatment of NMIBC has greatly improved in recent years, there is a need for additional therapies when patients fail bacillus Calmette-Guérin (BCG) and chemotherapeutic agents. We propose that bladder cancer may be an ideal target for oncolytic viruses engineered to selectively replicate in and lyse tumor cells leaving normal cells unharmed. In support of this hypothesis, here we review current treatment strategies for bladder cancer and their shortcomings, as well as recent advancements in oncolytic viral therapy demonstrating encouraging safety profiles and antitumor activity. 1. Transitional Cell Carcinomas In the United States, it is estimated that 73,510 men and women (55,600 men and 17,910 women) will be diagnosed with and 14,880 will die of cancer of the urinary bladder in 2012, making it the fourth and ninth most common cancers among men and women, respectively [1]. The most common cause for bladder cancer is smoking and othe