[Animal experiment aspects of bladder cancer]

Many aspects of bladder cancer remain obscure under clinical conditions. The natural course of the illness is seldom known in human patients, in whom only the treated natural history is subject to investigation. Cancer research in animals can complement clinical investigations. The following experimental set-ups are of importance; chemically induced bladder cancer; transplantation of human urothelial carcinoma in immunodeficient nude mice (xenograft model); transplantation of clinically induced bladder cancer in syngenetic animals (syngenetic model). These models are used for tumour induction and the development of immunotherapy, chemotherapy and new techniques. The extrapolation of these experimental results to clinical situations is being discussed. Some experimental results are of interest for practising urologists, e.g. increased incidence of tumour development in dilated upper urinary tract or in the bowel segment after urinary diversion; new therapeutic approaches such as breakdown of multidrug resistance to chemotherapy or administration of photodynamic therapy; planning of intravesical therapy relating to aspects of cell proliferation.