Bladder cancer is an abnormal and unregulated growth of the cells that make up the urinary bladder.

The urinary bladder is a hollow muscular organ located in the pelvic cavity. In females, it is in front of the vagina and in males, it is in front of the rectum. The bladder stores urine produced by the kidneys. Each kidney has a tube (ureter) leaving it that leads to the bladder. The body’s blood is filtered through the kidneys. Substances from the blood that can be used by the body and a certain amount of water are sent back into the bloodstream. Waste products and excess fluid (together called urine) from each kidney travel down the ureters and into the bladder. This urine is stored in the bladder until it is discharged from the body (urinated).

The Bladder

The bladder
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A bladder tumor grows when cells of the bladder become cancerous. These cancer cells begin to divide and multiply more quickly than normal cells. Cancer cells also lack the ability to organize themselves in a normal way, and have the capability to invade other normal tissue.

There are two major types of bladder cancer: papillary and nonpapillary. A papillary bladder tumor is a warty growth that is attached to the bladder by a stalk. A nonpapillary bladder tumor lies flat against the bladder tissue itself, and therefore has the potential to be more serious. Luckily, the majority of bladder tumors are papillary (about 70%).

Who Is Affected

Bladder cancer is the second most common type of tumor that affects the genitourinary tract, which includes the kidney, bladder, and reproductive organs. Prostate cancer is the most common. Bladder cancer is the fourth most common type of solid tumor. In the United States, about 57,400 new cases of bladder cancer are diagnosed yearly, and about 12,500 people die of the disease annually. The average age at diagnosis is 65. Men are more likely than women to develop bladder cancer; approximately five men to every two women will be diagnosed with the disease. Caucasians are more likely than African-Americans to develop bladder cancer.

Causes and Complications

Most people who develop bladder cancer seem to have been exposed to certain toxic substances. Smokers are particularly likely to develop bladder cancer, possibly due to the cancer-causing chemicals in tobacco; in fact, research shows that more than half of all people with bladder cancer are smokers. Industrial chemicals are also known to cause bladder cancer. Other things that irritate the bladder over long periods of time—such as certain parasites in developing countries, the presence of bladder stones, or chronic, untreated bladder infections—can also predispose the bladder to the development of cancer.

Left to grow over time, a bladder tumor will destroy and replace normal bladder tissue. Untreated, cancer cells from the bladder can invade other tissues within the pelvis, such as the lymph nodes, ureters, vagina, uterus, prostate, and rectum. In advanced cases, bladder cancer cells can also travel through the body, causing cancer to invade other organs and tissues, including the lymph nodes, lungs, liver, and bones.