Cancerous growths that develop in the lining of the bladder
- Rare under the age of 50; more common with increasing age
- More common in males
- May be a significant factor
- Smoking and some occupations using chemicals are risk factors
Tumours in the bladder are all treated as cancerous. Most of these tumours begin as superficial, wart-like growths, called papillomas, which grow from the lining of the bladder and project into the bladder cavity. Bladder tumours are about three times more common in men than in women.
What are the causes?
More than half of all bladder tumours develop in people who smoke. About 1 in 6 tumours occurs in people who are employed in the rubber-manufacturing industry or work with industrial dyes or solvents. These people are susceptible to tumours since they handle carcinogens (cancer-causing substances), which are absorbed by the body and excreted in the urine. Carcinogens therefore come into contact with the bladder lining, where they can trigger the growth of abnormal tissue. The underlying cause of bladder tumours is unknown, but the possibility that they may be inherited is currently under investigation.
In tropical regions, a common cause of bladder tumours is the parasitic infestation schistosomiasis.
What are the symptoms?
Bladder tumours initially do not cause symptoms, but the following symptoms may develop over time:
Blood in the urine.
Dull ache in the lower abdomen.
Difficulty passing urine.
If urine flow is restricted, urine may stagnate, leading to infections in the urinary tract (see Cystitis). Large tumours may block the bladder outlet, causing urinary retention. Left untreated, the cancer may spread to nearby areas. Cancerous cells can also break away from the tumour and travel in the blood to other parts of the body.
What might be done?
Your doctor will have a urine sample tested in the laboratory for blood and cancerous cells. Ultrasound scanning, intravenous urography, CT scanning, or MRI may be used to image the bladder and reveal abnormalities. Your doctor will also arrange for you to have cystoscopy, in which a viewing instrument is used to examine the bladder lining. If a tumour is found, surgical instruments are inserted through the cystoscope to take a tissue sample, remove the tumour, or destroy it by heat treatment. Tumours may also be treated by drugs that are delivered directly into the bladder through a catheter.
If a tumour is large or has spread deep into the tissues of the bladder, abdominal surgery may be necessary to remove the tumour along with part or all of the bladder. If the whole bladder must be removed, urine will be diverted through an opening on the skin in the abdominal area by way of a passage constructed from a piece of intestine. Radiotherapy and chemotherapy may be used for tumours that would be difficult to treat with cystoscopy or surgery or where a person is too ill or frail for surgery.
What is the prognosis?
Bladder tumours that have been diagnosed at an early stage can usually be treated successfully. However, lifelong monitoring will be necessary because further bladder tumours may develop. Regular checkups should ensure that, if more papillomas develop, they can be treated before they have the chance to become more serious.
If you smoke, giving up will greatly reduce your risk of developing a bladder tumour. Once you have had a tumour treated, giving up smoking will reduce the risk of recurrence. If you work with high-risk chemicals or have done so in the past, you should see your doctor for regular checkups because tumours can develop many years after exposure to carcinogenic chemicals.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.
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