The bladder is located in the lower abdomen. It is a hollow organ with flexible muscular walls. It stores urine until a person is ready to urinate. Bladder cancer is a disease in which cancer cells grow in the bladder.

Cancer occurs when cells in the body (in this case bladder cells) divide without control or order. Sometimes cells divide uncontrollably when new cells are not needed. A mass of tissue called a growth or tumor can form. The term cancer refers to malignant tumors. Malignant tumors can invade nearby tissue and spread to other parts of the body.

Three main types of cancer affect the bladder. They are named for the type of cell that becomes cancerous:

  • Transitional cell (urothelial) carcinoma—more than 90% of bladder cancers
  • Squamous cell carcinoma—about 4% of bladder cancers
  • Adenocarcinoma—about 1%-2% of bladder cancers

Bladder Cancer
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The cause of bladder cancer is unknown. However, several risk factors have been identified.