Its primary function is to store urine, the waste that is produced when the kidneys filter the blood. Urine passes from the two kidneys into the bladder through two tubes called ureters and urine leaves the bladder through another tube called the urethra. The bladder has a muscular wall that allows it to get larger and smaller as urine is stored or emptied.
The wall of the bladder is lined with several layers of cells called transitional cells. Cancer arising from these cells makes up more than 90% of all bladder cancers and these are referred to as transitional cell carcinomas. Because transitional cell carcinomas are the most common type of bladder cancer, the information in this section only addresses treatment of transitional cell cancer of the bladder.
Bladder cancer occurs predominantly in elderly men and less frequently in women and younger men. Many bladder cancers are thought to be caused by exposure to cancer-causing agents that pass through the urine and come into contact with the bladder lining. The most important risk factor for bladder cancer is smoking, which increases risk by at least four-fold.1
The most common sign of bladder cancer is hematuria or blood in the urine, which will turn the urine rust or red in color.2 Other signs of bladder cancer may include pain during urination and frequent urination. Most patients with bladder cancer do not have symptoms other than hematuria. Unfortunately, most bladder cancers are not diagnosed until they have become very large. As a result, research is ongoing in order to develop urine tests that would enable earlier detection of bladder cancer when it is small and more easily treated. There are several promising tests under evaluation, but currently none are reliable enough for routine use.
An outpatient procedure called a cystoscopy is usually used to diagnose bladder cancer. During a cystoscopy, the physician (a urologist) inserts a thin, lighted tube (cystoscope) into the bladder through the urethra to examine the internal lining of the bladder. The procedure enables the urologist to remove (biopsy) small samples of any abnormal appearing areas of the bladder and examine them under the microscope. When bladder cancer is diagnosed, the urologist will want to learn the stage or extent of the cancer, as well as the grade (aggressiveness) of the cancer as determined by its appearance under the microscope. Grade is important because it indicates how closely the cancer resembles normal tissue and suggests how fast the cancer is likely to grow. Low-grade cancers more closely resemble normal tissue and are likely to grow and spread more slowly than high-grade cancers.
Staging is an attempt to determine the extent to which the cancer has spread. The stage of bladder cancer may be determined at the time of diagnosis or it may be necessary to perform additional tests such as computerized tomography (CT) scans, magnetic resonance imaging (MRI) or an intravenous pyelogram (IVP), a procedure which involves the injection of dye into the blood. When the dye (contrast) travels through the kidneys and ureters, it allows them to be visualized with X-rays (fluoroscopy).
Some risk factors, such as a genetic mutation within a gene called the p53 gene, are associated with a poor outcome following treatment with chemotherapy and/or radiation therapy. Therefore, physicians may look for the presence of such risk factors upon a diagnosis of bladder cancer in order to best plan a treatment regimen. Research is ongoing to identify risk factors that are associated with a poor outcome, as well as factors that indicate that some patients may require less treatment. By identifying such factors, physicians are better able to tailor treatment to meet the needs of individual patients.
Cancers confined to the inner lining of the bladder are called “superficial” and comprise 70-80% of all bladder cancers.3 Cancers that have spread into the bladder wall are called “deep” bladder cancers and those that have spread to lymph nodes and/or distantly to lungs, liver or other organs are referred to as “metastatic.” In order to learn more about the most recent information available concerning the treatment of bladder cancer, click on the appropriate stage.
- National Cancer Institute. Bladder and Other Urothelial Cancers (PDQ®): Screening. Health Professional Version. Available at: http://www.cancer.gov/cancertopics/pdq/screening/bladder/HealthProfessional (Accessed May 5, 2008).
- Pashos CL, Botteman MF, Laskin BL, Redaelli A. Bladder Cancer: Epidemiology, Diagnosis, and Management. Cancer Practice 2002;10:311-322.
- National Cancer Institute. Bladder Cancer (PDQ®): Treatment. Health Professional Version. Available at: http://www.cancer.gov/cancertopics/pdq/treatment/bladder/HealthProfessional (Accessed February 9, 2007).
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