Scientists from Fox Chase Cancer Center in the United States say DNA from the disease can be found in urine.

They carried out tests on 50 people with the disease. They found cancer DNA in the urine of 44. The DNA disappeared when they patients were cured.

Speaking at the American Urological Association's annual meeting in San Francisco, they said the test may be a simple way to diagnose the disease.

Rates soaring

The number of people being diagnosed with kidney cancer has increased sharply over the past 20 years.

Almost 6,000 people in the UK are told they have the disease each year.

A simple urine test for kidney cancer would certainly be welcome Professor Nick James, Cancer Research UK

However, rates vary considerably between different countries.

They are much higher in affluent western countries than they are in developing countries.

Scientists suspect lifestyle choices, such as smoking and obesity, play an important role.

Like all cancers, a person's chances of beating it are highest if it is diagnosed and treated early.

However, those chances fall sharply if it is spotted late and if it has spread to other parts of the body.

The most common symptom of the disease is blood in the urine.

This latest study suggests urine also carries DNA from the cancer.

According to the scientists, the urine test was highly accurate. It was tested on people with the disease and people without.

'Remarkably accurate'

It did not give any "false-positives", which means the test did not suggest that any of the healthy volunteers had the disease.

The scientist said the test was also able to distinguish between different stages of the disease.

"The test appears to be remarkably accurate," said Dr Robert Uzzo, a surgeon at the hospital and one of those involved in the study.

He said the findings suggested a urine test could be used to identify patients with prostate cancer and also to track their progress during treatment.

"This step in our research further supports the accuracy of this potential screening test but also demonstrates the possibility of using urine to monitor the patient after treatment."

Professor Nick James from Cancer Research UK welcomed the study.

"The research is very interesting and a simple urine test for kidney cancer would certainly be welcome.

"This type of work is technically feasible because huge advances have been made in protein analysis techniques.