Bladder cancer

What is bladder cancer?

The bladder is the bag of muscle that gathers urine produced by the kidneys. It can be found in the lower abdomen.

Bladder cancer is the sixth most common cancer in the UK, with 10,300 cases diagnosed each year. It has one of the highest survival rates of any cancer, with more than half of patients alive five years after diagnosis.

Bladder cancer symptoms

Most bladder cancers are transitional cell carcinomas, which start in the cells that line the bladder. Some aren't detected until they have spread through this lining into the muscle beyond.

The appearance of blood in the urine is the most common clue to bladder cancer, occurring in up to 80 per cent of those affected. However, the blood is often in microscopic amounts so may only picked up during urine tests.

Other symptoms may not appear until the cancer has developed further, and include the need to pass urine suddenly and often, or pain when passing urine.

It should be emphasised that all these symptoms are typical of urinary tract infections, which are much more common than bladder cancer. There is no need to panic if you develop these problems, but see your GP for further investigations.

Even if there is a tumour present, it may be benign rather than a malignant cancer.

The National Institute for Health and Clinical Excellence (NICE) recommends GPs refer patients to a specialist within two weeks if they have:

• Blood in the urine but no symptoms to suggest a urine infection
• Blood in the urine and a urinary tract infection has been ruled out
• Blood with recurring or persistent infections of the urine in someone over 40

Bladder cancer causes

Bladder cancer was one of the first cancers to be linked to a specific cause. In 1895, it was recognised that exposure to certain dyes increased the risk.

These days, many other risk factors have been identified, including:

• Ethnic background - caucasians are most at risk
• Smoking - smokers appear to be two to three times more likely to develop bladder cancer. Chemicals from cigarette smoke are filtered by the body into the urine and then passed to the bladder where they are in contact with the lining cells
• Radiotherapy and chemotherapy used to treat other cancers
• Exposure to a number of different chemicals, such as arylamines once used in the manufacture of rubber and plastics but now banned in the UK, polycyclic hydrocarbons, paint and printing inks. Scientists have found links with certain occupations and perhaps the chemicals used there. Increased risk appears to affect workers in the rubber, chemical and leather industries
• Repeated bladder infections increase the risk of a type of cancer called squamous cell carcinoma, especially among smokers or when there are bladder stones
• Parasitic infections such as bilharzia or schistosomiasis are a major cause in the developing world

Bladder cancer is more common in men, perhaps because in the past more men smoked or were exposed to industrial chemicals.

Bladder cancer is usually slow growing and therefore found most often in older people.

Despite these discoveries, researchers still don’t know exactly why and how the disease first develops.

Diagnosing bladder cancer

As with other cancers, investigating bladder cancer includes a process known as staging to work out how far the tumour has spread, which treatment should be used and what the long-term outlook is likely to be.

To check for a cancer, a doctor will carry out a full physical examination, which will probably include a rectal exam using a gloved finger to check for unusual lumps that may indicate a tumour.

A cytoscopy will probably be used to confirm diagnosis. This involves inserting a very thin and flexible telescopic probe up the urethra - the tube through which urine is passed. This is an uncomfortable procedure but not usually painful. The probe allows the doctor to look for signs of disease or another cause for the symptoms, such as bladder stones. The probe can also remove a tissue sample (biopsy) for examination under a microscope.

If this confirms cancer, further tests such as CT scans, MRI or other x-rays may be carried out to check the spread of the disease.

Because bladder cancer often bleeds and blood is seen in the urine, it tends to reveal itself fairly early. About 75 per cent of bladder cancers are diagnosed before they have spread very far and are therefore at a stage where they can often be successfully treated with surgery or other treatments.

Bladder cancer treatments

Treatment depends how far the cancer has spread.

Superficial bladder cancers (sometimes called papillary bladder cancers) form little growths on the inside of the bladder that can usually be removed very easily during surgery. However, some spread further and faster through the bladder tissues. These are more of a threat and may need more intensive treatment.

A treatment called BCG, better known as a vaccine against TB, seems to work against bladder cancer cells, possibly because it seems to stimulate the cells of the immune system to attack and kill cancer cells, but its use is still predominantly experimental.

About 50 per cent of superficial bladder cancer will return, but most can be controlled quite easily with further surgery.

If the cancer is confined to the lining of the bladder, a simple procedure called transurethral resection (TUR) can be carried out. This is similar to cytoscopy, except the probe is used to burn away cancer cells with an electric current. This is normally carried out under anaesthetic. The patient may have pain when passing urine for a short time afterwards, and some blood in the urine.

In about 20 per cent of cases the cancer has invaded deeper into the tissues by the time of diagnosis, and in five per cent it will have spread further to another part of the body. These tumours are more difficult to treat. If the cancer has spread into the bladder muscle, a bigger operation may be needed.

If the cancer isn't particularly fast-spreading and aggressive, and is confined to only one part of the bladder wall, then a partial or segmental cystectomy could be carried out. This involves removing part of the bladder, and allows the patient to urinate normally once recovered.

However, if the cancer has spread, a more radical cystectomy is carried out. The entire bladder is removed, along with any nearby organs that the cancer cells may have spread to.

In such cases, the patient no longer has anywhere to store urine. The surgeon creates an opening in the patient's side, called a stoma, which allows a bag to be attached. A piece of the patient's own small intestine can be used as the tube carrying the urine to the stoma.

Modern surgical techniques may allow a replacement bladder to be fashioned in some patients, giving back a degree of urinary control, and doctors are constantly improving these.

Radiotherapy may be recommended, either as the first treatment or to kill any cancer cells that remain after surgery. This is either targeted on the pelvic area or given as a radioactive implant that is placed into the bladder.

In some cases chemotherapy can be targeted directly at the bladder via a catheter, which helps to prevent some of the unpleasant side effects. However, if the cancer is widely spread, standard chemotherapy may be used.

Immunotherapy - harnessing the immune system to fight bladder cancer - is also widely used in some cases of superficial cancer.

Only about 25 per cent of those with a local spread of the cancer will survive more than three years, and far fewer when the tumour has spread to other organs. Unfortunately, it's very difficult to predict who will be cured by treatment and when the cancer might recur.

As with all cancers, there are a number of research trials underway to look for more effective combinations of treatment, as well as trials of urine tests which might help to easily detect bladder cancer.