Intravesical therapy for urothelial carcinoma of the urinary bladder: a critical review

The management of non-muscle-invasive urothelial carcinoma of the bladder (UCB) is a challenge for physicians and patients alike. This is largely due to the heterogeneous natural history of this disease, in which tumors range from indolent to rapidly progressive and eventually fatal. Moreover, the high rate of recurrence and progression cause significant morbidity, expense, and detriment to quality of life. The advent of effective and safe intravesical therapies has improved the management of non-muscle-invasive UCB. Nevertheless, despite over 30 years of research and clinical experience, the mechanism, risks, benefits, and optimal regimens and treatment algorithms remain unclear. Although immunotherapy with bacillus Calmette-Guerin (BCG) has been the mainstay of intravesical treatment and represents a significant advance in the interaction of immunology and oncology, its clinical effectiveness is accompanied by a wide range of adverse events. Here, we review the literature on intravesical immunotherapy and chemotherapy with the aim of evaluating the clinical utility of the different treatments and providing recommendations. Many studies over the years have compared efficacy and toxicities of different agents and regimens, and certain conclusions are now well supported by high-level evidence. Future perspectives and promising advances in drug development are discussed and areas of improvement are identified in order to promote better cancer control and decrease the rate and severity of side-effects