Metastatic bladder cancer. Natural history, clinical course, and consideration for treatment.

Patients with metastatic transitional-cell carcinoma of the bladder have a poor prognosis with brief survival. Controversy exists as to the clonality of bladder cancer, as well as the natural history of muscle-invasive disease that subsequently becomes metastatic. Newer molecular biologic techniques may help us identify and understand the molecular changes involved in transforming normal urothelium into the malignant phenotype. In addition, newer chromosomal markers may enable us to determine the prognosis and the potential for progression to invasion and metastases. Additional work to find the optimum doses and dosing schedules and combinations of chemotherapeutic agents for metastatic transitional-cell carcinoma will be necessary before we can improve survival for all patients with this disease.