 Bladder cancer is one of the most common malignancies worldwide. The rate of occurrence of these tumors is highest in the developed countries, ranking as the sixth most frequent neoplasm. Approximately 90 of malignant tumors arising in the bladder are of epithelial origin, the majority being transitional cell carcinomas. Early stage bladder tumors have been classified into two groups with distinct behaviors and different molecular profiles: Low-grade tumors always papillary and usually superficial, and high-grade tumors either papillary or non-papillary and often invasive. Clinically, superficial bladder tumors stages Ta, Tis and T1 account for 75-80 of bladder neoplasms, while the remaining 15-20 are invasive T2, T3, T4 or metastatic lesions at the time of presentation. Over 70 of patients affected with superficial tumors will have one or more recurrences after initial treatment, and about one-third of those patients will progress and eventually succumb to their disease. 