Small cell bladder cancer: biology and management.

Small cell bladder cancer (SCBC) is a rare and aggressive form of bladder cancer. It exhibits similar biological behavior to small cell lung carcinoma. Untreated, it is associated with a very poor prognosis. Appropriate oncologic surgery remains the mainstay of treatment of this disease but is not curative alone in the majority of the cases. Adding systemic therapy to the treatment regimen has been shown to improve survival. The most common chemotherapy regimens used in published series include a platinum complex plus etoposide, although doxorubicin-based regimens and standard urothelial cancer regimens also have been associated with response. Despite robust chemotherapy responses, metastatic disease is associated with relapse and a median overall survival of 18 months or less. Better understanding of the molecular alterations driving SCBC may facilitate the development of new therapeutic strategies and improved outcomes.