Bladder cancer is a disease in which the cells lining the urinary bladder lose the ability to regulate their growth and start dividing uncontrollably. This abnormal growth results in a mass of cells that form a tumor.
The urinary bladder is a hollow muscular organ that stores urine from the kidneys until it is excreted out of the body. Two tubes called the ureters bring the urine from the kidneys to the bladder. The urethra carries the urine from the bladder to the outside of the body.
Bladder cancer has a very high rate of recurrence following treatment. Even after superficial tumors are completely removed, there is a 75% chance that new tumors will develop in other areas of the bladder. Hence, patients need very frequent and thorough follow-up care. When detected at the early stages, the prognosis for bladder cancer is excellent. At least 94% of patients survive five years or more after initial diagnosis. If the disease has spread to the nearby tissues, however, the survival rates drop to 49%. If it has metastasized to distant organs such as the lung or liver, only 6% of patients will survive five years or more.
Bladder cancer is the sixth most common cancer in the United States. The American Cancer Society (ACS) estimated that in 2001, approximately 54, 300 new cases of bladder cancer would be diagnosed (about 39, 200 men and 15, 100 women), causing approximately 12, 400 deaths.
The highest occurrences of bladder cancer are found in industrialized countries such as the United States, Canada, France, Denmark, Italy, and Spain. In all countries, the incidence of bladder cancer is higher for men than women. Among men, the highest rates occur in white non-Hispanic males (33.1 per 100, 000). The rates for men of African descent and Hispanic men are similar and are approximately one-half of the rate among white non-Hispanic men. The lowest rate of bladder cancer occurs in the Asian population. Among women, the highest rates also occur in white non-Hispanic females and are approximately twice the rate for Hispanics. Women of African descent have higher rates of bladder cancer than Hispanic women.
Age is also an important factor: bladder cancer is significantly more common in older men and women in all populations. Bladder cancer rates for people aged 70 years and older are two to three times higher than for people in the 55 to 69 age group, and approximately 15 to 20 times higher than for people between the ages of 30 and 54.
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Author Info: Lata Cherath Ph.D., Monique Laberge Ph.D., The Gale Group Inc., Gale, Detroit, Gale Encyclopedia of Cancer, 2002 |