About 53,200 cases of bladder cancer are diagnosed each year in the United States. It is the fifth most common cancer and is three times more likely to strike men than women. Bladder cancer is rarely found in people under age 40. When bladder cancer is detected and treated early, the chances for survival are good.

There are three types of bladder cancer: transitional cell carcinoma (TCC), which accounts for about 90 percent of bladder cancer cases; squamous cell carcinomas, which make up 8 percent of bladder cancers and adenocarcinomas, which comprise 1 to 2 percent of bladder cancers. All three types are able to spread beyond the bladder, although TCC frequently does not. The distribution of these cancers is influenced by geography, industrial exposure environmental factors.

TCC can be grouped into two important stages: superficial and invasive disease. These categories determined by depth of invasion or growth pattern (flat or papillary) and are frequently subdivided as follows:

• Superficial TCC, limited to the transitional cells toward the inside of the bladder. It may spread into the layer of connective tissue (lamina propria) beneath the transitional cells.
• Invasive TCC spreads to the bladder's muscle layer (muscularis propria) and sometimes to the fatty layers outside the muscle.
• Superficial noninvasive papillary TCC grows into the hollow center of the bladder, while invasive papillary TCC grows toward the center and out into the muscle layer.
• Noninvasive flat TCC or carcinoma in situ (CIS), which grows in the layer of cells closest to the inside of the bladder, and frequently appears as flat lesions on the inside surface of the bladder.
• Flat invasive TCC invades the deeper layers of the bladder, particularly the muscle layer.