Bladder Cancer

Bladder Cancer: Cancer that forms in tissues of the bladder (the organ that stores urine). Most bladder cancers are transitional cell carcinomas (cancer that begins in cells that normally make up the inner lining of the bladder). Other types include squamous cell carcinoma (cancer that begins in thin, flat cells) and adenocarcinoma (cancer that begins in cells that make and release mucus and other fluids). The cells that form squamous cell carcinoma and adenocarcinoma develop in the inner lining of the bladder as a result of chronic irritation and inflammation.

Estimated new cases and deaths from bladder cancer in the United States in 2009:

New cases: 70,980


Deaths: 14,330

Incidence & Mortality

The bladder is a hollow organ in the lower abdomen. It stores urine, the liquid waste produced by the kidneys. Urine passes from each kidney into the bladder through a tube called a ureter.

An outer layer of muscle surrounds the inner lining of the bladder. When the bladder is full, the muscles in the bladder wall can tighten to allow urination. Urine leaves the bladder through another tube, the urethra.

There are three types of bladder cancer that begin in cells in the lining of the bladder. These cancers are named for the type of cells that become malignant:

Transitional cell carcinoma: Cancer that begins in cells in the innermost tissue layer of the bladder. These cells are able to stretch when the bladder is full and shrink when it is emptied. Most bladder cancers begin in transitional cells.

Squamous cell carcinoma: Cancer that begins in squamous cells, which are thin, flat cells that may form in the bladder after a long- term infection or irritation.

Adenocarcinoma: Cancer that begins in glandular (secretory) cells that may form in the bladder after a long-term inflammation or irritation.
Cancer that is only in cells in the lining of the bladder is called superficial bladder cancer. The doctor might call it carcinoma in situ. This type of bladder cancer often comes back after treatment. If this happens, the disease most often recurs as another superficial cancer in the bladder.

Cancer that begins as a superficial tumor may grow through the lining and into the muscular wall of the bladder. This is known as invasive cancer. Invasive cancer may extend through the bladder wall. It may grow into a nearby organ such as the uterus or vagina (in women) or the prostate gland (in men). It also may invade the wall of the abdomen.

When bladder cancer spreads outside the bladder, cancer cells are often found in nearby lymph nodes. If the cancer has reached these nodes, cancer cells may have spread to other lymph nodes or other organs, such as the lungs, liver, or bones.

When cancer spreads (metastasizes) from its original place to another part of the body, the new tumor has the same kind of abnormal cells and the same name as the primary tumor. For example, if bladder cancer spreads to the lungs, the cancer cells in the lungs are actually bladder cancer cells. The disease is metastatic bladder cancer, not lung cancer. It is treated as bladder cancer, not as lung cancer. Doctors sometimes call the new tumor "distant" disease.