Bladder cancer represents the most common malignancy of the urinary tract and the 7th most frequent cancer in men and 17th in women. The prevalence of this malignancy varies between regions and countries. In Europe for example, the highest age-standardized incidence rate has been reported in Spain and the lowest in Finland (1). In the United States, the incidence and mortality due to bladder cancer is also high (more than 60,000 new cases and up to 13,000 deaths annually) (2). Therefore, in the last decades, it has been noticed an increased prevalence of bladder cancer, probably caused by tobacco abuse, industrial carcinogens risk factors and overall aging process of the population (3).
75-85% of all newly diagnosed bladder tumors is represented by non-muscle-invasive bladder cancer (NMIBC), a multifocal disease, that includes stages pTa, pT1 and carcinoma in situ (CIS) (4). Furthermore, this pathology has a high recurrence rate within the first 5 years after the initial diagnosis (5), despite the recent technological advances (6).