Bladder cancer Dr Trisha Macnair Bladder cancer has a place in medical history because it was one of the first to be linked to a specific cause. In 1895 several cases were described among people working in the chemical dye industry, and it was recognised that exposure to certain dyes increased the risk of the cancer.

In this article

Introduction Causes

Symptoms Diagnosis

Treatment

These days many other risk factors have been identified, providing some explanation for about 10,300 cases diagnosed every year (making it the sixth most common cancer in the UK).

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

Risk factors of cancer of the bladder include:

• Ethnic background - Caucasians are most at risk.
• Smoking - this triples the risk as 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).

Repeated bladder infections increase the risk of a type of cancer called squamous cell carcinoma (especially among smokers or when there are bladder stones) and parasitic infections such as bilharzia or schistosomiasis are a major cause in the developing world.

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

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, although the blood is often in microscopic amounts so it may only picked up when the urine is tested.

Other symptoms may not appear until the cancer has developed further, and include urgency and frequency – 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. Don’t panic if you develop these problems, but see your GP to get it investigated further.

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

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

About 90 per cent of bladder cancers are a type known as transitional cell cancer, which develop from the cells which line the inside of the bladder. Because of their location, these lining cells come into prolonged contact with potentially harmful chemicals excreted by the body, such as cigarette smoke. Transitional cell cancers may be superficial or invasive, and these different types need different treatment.

Superficial bladder cancers (sometimes called papillary bladder cancers) form little growths on the inside of the bladder and 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.

Other types of bladder cancer are much less common. They include squamous cell cancer (more common in developing countries where they are linked to parasitic worm infections), adenocarcinomas, and cancer which has spread to the bladder from nearby organs such as the cervix or bowel.

Like 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.

Because bladder cancer often bleeds into 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 at a stage where they can often be successfully treated with surgery or treatments placed into the bladder.

Treatments for cancer of the bladder include chemotherapy (anti-cancer drugs) or a treatment called BCG, better known as a vaccine against TB, but for reasons not fully understood, 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. About 50 per cent of superficial bladder cancer will return but most can be controlled quite easily with further surgery.

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.

Radiotherapy, chemotherapy, or surgery to remove the bladder may be recommended but 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 is 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.

This article was first published in October 2008.