Causes

Bladder cancer begins when cells in the bladder develop changes (mutations) in their DNA. A cell's DNA contains instructions that tell the cell what to do. The changes tell the cell to multiply rapidly and to go on living when healthy cells would die. The abnormal cells form a tumor that can invade and destroy normal body tissue. In time, the abnormal cells can break away and spread (metastasize) through the body.

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. Doctors use this information to determine which treatments may work best for you.

Types of bladder cancer include:

• Urothelial carcinoma. Urothelial carcinoma, previously called transitional cell carcinoma, occurs in the cells that line the inside of the bladder. Urothelial cells expand when your bladder is full and contract when your bladder is empty. These same cells line the inside of the ureters and the urethra, and cancers can form in those places as well. Urothelial carcinoma is the most common type of bladder cancer in the United States.
• Squamous cell carcinoma. Squamous cell carcinoma is associated with chronic irritation of the bladder — for instance, from an infection or from long-term use of a urinary catheter. 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 common cause of bladder infections.
• Adenocarcinoma. Adenocarcinoma begins in cells that make up mucus-secreting glands in the bladder. Adenocarcinoma of the bladder is very rare.

Some bladder cancers include more than one type of cell.