It's not always clear what causes bladder cancer. Bladder cancer has been linked to smoking, a parasitic infection, radiation and chemical exposure.

Bladder cancer develops when cells in the bladder begin to grow abnormally. Rather than grow and divide in an orderly way, these cells develop mutations that cause them to grow out of control and not die. These abnormal cells form a tumor.

Types of bladder cancer

Different types of cells in your bladder can become cancerous. The type of bladder cell where cancer begins determines the type of bladder cancer. Your bladder cancer type determines which treatments may work best for you. Types of bladder cancer include:

  • Transitional cell carcinoma. Transitional cell carcinoma occurs in the cells that line the inside of your bladder. Transitional cells expand when your bladder is full and contract when your bladder is empty. These same cells line the inside of your ureters and your urethra, and tumors can form in those places as well. Transitional cell carcinoma is the most common type of bladder cancer in the United States.
  • Squamous cell carcinoma. Squamous cells appear in your bladder in response to infection and irritation. Over time they can become cancerous. Squamous cell bladder cancer is rare in the United States. It's more common in parts of the world where a certain parasitic infection (schistosomiasis) is a prevalent cause of bladder infections.
  • Adenocarcinoma. Adenocarcinoma begins in cells that make up mucus-secreting glands in the bladder. Adenocarcinoma of the bladder is rare in the United States.

Some bladder cancers include more than one type of cell.

Jun. 19, 2012