Scientists at the Imperial Cancer Research Fund say they have found that patients with high levels of vascular endothelial growth factor (VEGF) are at greater risk of developing bladder cancer.

The cancer affects thousands every year and is three times more common in men than in women. It mostly affects the elderly.

If caught early the chances of surviving it are much better.

Blood vessel growth

The scientists have measured VEGF levels in cancer patients' urine for the first time.

The growth factor stimulates the development of blood vessels to feed the tumour and allow it to spread.

Led by Professor Adrian Harris, Director of the Imperial Cancer's Medical Oncology Unit, the team studied 261 people with bladder cancer and compared them with people with no disease or other types of tumours.

The patients with bladder cancer had far higher levels of VEGF in their urine.

The scientists also found a link between the amount of VEGF in the urine and the likelihood of cancer recurring.

This could mean that the test could provide a simple, quick, safe and relatively cheap way of predicting if the cancer will recur.

Uncomfortable treatment

There are many different forms of bladder cancer and they behave in very different ways.

Some are easier to treat than others. Also, some patients respond well to treatment while in others the cancer keeps recurring.

Currently, these patients have to undergo regular check-ups.

This involves either a cystoscope tube being inserted in the urethra, which can be uncomfortable, or patients providing urine samples which are examined under the microscope in the laboratory.

The scientists say the VEGF test is more accurate than the lab tests.

Cancer treatments

Professor Harris says that, if VEGF is as important in the development of bladder cancer as the study suggests, it may be worth studying ways of inhibiting it.

This could lead to the development of new drugs which could help treat the cancer.

"Deprived of the growth-promoting substances the tumours need, and so of their capacity to make new blood vessels, tumours might be effectively starved into submission," he said.

It is not known what causes bladder cancer, but risk factors are thought to include smoking and exposure to some chemicals at work, including rubber.

Symptoms of the disease include blood in the urine and a burning feeling which does not go away after treatment with antibiotics.