Experimental bladder carcinogenesis-rodent models.

Several rodent models of bladder cancer development have been established. The aim of this review article is to provide a critical assessment of different animal models available for the study of bladder carcinogenesis, its chemoprevention and therapy. All, except for transgenic and knockout animals, require 8-12 months experimental periods in order to generate a high yield of neoplasias. Spontaneous bladder tumor models are extremely rare. The significance of the results from animal experiments is dependent upon the selection of a suitable animal model. There are no rules regarding the choice of a model, it is however very useful to have knowledge of relevant comparative medical aspects concerning this subject. We describe chemical carcinogens most commonly used to induce bladder cancer, pellet implantation and urinary calculi, agents that promote bladder cancer, and irradiation. We also evaluated other tools such as cell cultures, tumor implantation and transgenic models for bladder cancer, that have been developed to study the process. The review considers how several imaging techniques can be applied to study rodent bladder carcinogenesis.