Bladder Cancer: An Evidence-Based ApproachAbout This Hardback A bladder is a hollow muscular organ in the lower abdomen that stores urine. Bladder cancer begins in the urothelial cells that line the inside of the bladder. There are three types of bladder cancer, namely, urothelial carcinoma, squamous cell carcinoma and adenocarcinoma. It is caused by mutations in the DNA of the cells of the bladder. The symptoms of bladder cancer are blood in urine, frequent urination, painful urination, and