The urinary bladder is a hollow sac like organ situated in the pelvis. Its major function is to store the urine produced by the kidneys before finally emptying it. Uncontrolled proliferation of normal cells lining the bladder wall can lead to cancer.
Though the exact cause of bladder cancer is unknown, there are certain well recognized risk factors. Smoking is one of the most important risk factors. Smokers have twice the risk of developing bladder cancer than non-smokers. People exposed to certain chemicals like aromatic amines, especially used in dyeing, rubber, leather and textile industries are also at an increased risk. Chronic irritation of the bladder wall due to any cause can lead to bladder cancer too.
Some of the common symptoms of bladder cancer are haematuria and recurrent urinary tract infection. However, it is important to realize that most of the early cancers may be totally asymptomatic .A patient with these symptoms should consult his doctor if the symptoms persist for more than two weeks.
The mainstay of diagnosis is cystoscopy and biopsy whereby a long tubular instrument is inserted into the urinary bladder and the entire bladder lining is inspected. If any tumour is seen, the urologist tries to resect as much tumour as possible. Any abnormal looking tissue is taken for biopsy and sent to the pathologist for examination under a microscope.
The pathologist will confirm any cancer if present, and the depth of penetration into the wall of the urinary bladder. Some of the other tests that the patient may have to undergo for diagnosis and staging are: urine for cytology, ultrasound, CT/MRI scan, and sometimes PET-CT and bone scan, if indicated. The purpose of doing these tests is to find out the stage of the cancer as the prognosis and treatment depends on the stage. Broadly speaking, there are four stages depending upon how deep the cancer has penetrated into the bladder wall, and whether it has spread into structures outside the bladder like lymph nodes, bone, liver etc.
There are three main modalities of treatment – surgery, radiotherapy, and chemotherapy, either alone or in combination. In early bladder cancers limited to the superficial layer of the bladder wall, immunological therapy is used. In this, the patient comes in for multiple sessions.
- Surgery is one of the most widely used treatments. In most of the locally advanced tumours, the surgery is called radical cystectomy where the entire bladder and some adjoining structures are also removed. This operation requires some form of urinary diversion for the urine to come out through a new pathway. In certain less advanced tumours, a partial cystectomy may be sufficient where only a part of the bladder will be removed.
- Radiotherapy alone or in combination with chemotherapy is an alternative to surgery where the patient wants to conserve his bladder. Radiotherapy is the use of high energy X-rays which are focused on the area to be treated without affecting the tolerance of surrounding normal structures. Today, there are a number of sophisticated treatment techniques like IMRT, IGRT etc. to achieve this aim using state of art linear accelerators.
- Chemotherapy is the use of medicines given intravenously. It is called systemic treatment as it can kill cancer cells anywhere in the body. Appropriate treatment in a good multidisciplinary hospital can result in curing more than 50 per cent of patients. If the cancer is diagnosed at an early stage, the results are muchetter.
The TNM (Tumour, Nodes, Metastasis) staging system categorizes bladder cancer using the following scale:
- Stage 0 – Noninvasive tumours that are only in the bladder lining
- Stage I – Tumour goes through the bladder lining, but does not reach the
- muscle layer of the bladder
- Stage II – Tumour goes into the muscle layer of the bladder
- Stage III – Tumour goes past the muscle layer into tissue surrounding the bladder
- Stage IV – Tumour has spread to neighboring lymph nodes or to distant sites
- (metastatic disease)
Bladder cancer is often confused with an easily treatable infection. It is not easier to treat, and if detected in the most advanced stages, it could even lead to removal of the bladder.