What is bladder cancer?
The bladder is a balloon-shaped, muscular organ that stores urine until ready for release. The bladder muscle aids urination by contracting (tightening) to help force out the urine. A thin surface layer called the urothelium lines the inside of the bladder. Next is a layer of loose connective tissue called the lamina propria. Covering the lamina propria is the bladder muscle, which is covered on the outside by fat.
About 90 percent of bladder cancers are transitional cell carcinomas, cancers that begin in the urothelium cells lining the bladder. Cancer that is confined to the lining of the bladder is called superficial bladder cancer.
In some cases, cancer that begins in the transitional cells spreads through the lining of the bladder and invades the muscular wall of the bladder. This is known as invasive bladder cancer. Invasive cancer may grow through the bladder wall and spread to nearby organs.
What are the symptoms of bladder cancer?
Painless blood in the urine (hematuria) is the most common symptom. Most often, the blood is visible during urination. In some cases, it is invisible except under a microscope and is usually discovered during urinalysis. Hematuria does not by itself confirm the presence of bladder cancer, as blood in the urine has many possible causes. A diagnostic investigation is necessary to determine whether bladder cancer is present.
Other symptoms of bladder cancer may include frequent urination and pain upon urination (dysuria).
How is bladder cancer diagnosed?
A diagnostic investigation begins with a thorough medical history and a physical examination. The doctor will ask about past exposure to known causes of bladder cancer, such as cigarette smoke or chemicals. Also, because hematuria can come from anywhere in the urinary tract, the doctor may order imaging of the kidneys, ureter and bladder to check for other potential problems.
Various types of urinalysis may also be performed. The urine may be examined under a microscope to look for cancer cells that have been shed into the urine from the bladder lining, or tested for substances known to be closely associated with cancer cells.
Perhaps the most important diagnostic tool is cystoscopy, which is a procedure that allows direct viewing of the inside of the bladder. This is most commonly performed as an office procedure under local anesthesia or light sedation.
If growths (tumors) are found, the doctor notes their appearance, number, location and size. As removal (resection) of the tumors cannot usually be done under local anesthesia, the patient is then scheduled to return for a surgical procedure to remove the tumor(s) under or general or regional anesthesia.
The removed tissue is sent to a pathologist for examination. The physician may also remove very small samples of tissue from any suspicious-looking areas of the bladder for analysis.
How is bladder cancer treated?
Transurethral resection of the bladder (TURBT) is the usual treatment for patients who, when examined with a cystoscope, are found to have abnormal growths on the urothelium and/or in the lamina propria. Alternative methods, such as laser therapy, compare favorably with TURBT in terms of treatment results. However, TURBT has a major advantage - it can provide tissue suitable for a pathologist to use in determining a tumor's progress.
Following removal, intravesical chemotherapy or intravesical immunotherapy may be used to try to prevent tumor recurrences. Intravesical means "within the bladder." Therapeutic agents are put directly into the bladder through a catheter, retained for one to two hours and then urinated out.
Once the bladder has been assessed disease-free, the physician may apply additional treatments to prevent future recurrence. Whether additional treatments are given or not, periodic cystoscopies are required to make sure that tumors do not recur.