• 1/1/2007
  • London, England
  • Fionna McCrae
  • www.dailymail.co.uk

A quick and easy mouthwash test for hard-to-diagnose cancers of the head and neck is being developed by scientists.

The kit – which looks for telltale signs of the disease in cells from the inside of a person’s cheeks – has proved more than 80 per cent accurate at distinguishing healthy people from cancer sufferers.

Such a “gargle and spit” test could prove invaluable in diagnosing the cancers which affect more than 7,000 Britons a year – and kill 2,500.

High-profile sufferers of head and neck cancers have included the journalist, John Diamond, who suffered from throat cancer and George Harrison, who suffered both neck and throat cancer. They both died in 2001.

The cancers, which include mouth, nose, throat, ear and eye tumours, are hard to diagnose and difficult to treat. Many are not spotted until the cancer has spread and a third of patients die within a year of diagnosis.

Surgery can be disfiguring and lead to problems with speech, hearing or eating and just 40 per cent of sufferers are still alive five years after diagnosis. Early diagnosis would allow treatment to start at a time when it is most likely to be effective.

The test, being developed in the U.S., picks up important genetic changes linked to head and neck cancer. The researchers, from Johns Hopkins University in Baltimore, identified the abnormalities after studying the genetics of hundreds of cancer sufferers and healthy people.

The volunteers were asked to gargle with a salty mouthwash, to remove cells from the insides of their cheeks.

Examination of the DNA inside the cells revealed telltale differences between the cancer sufferers and the healthy people, with a clutch of seven genes proving to be particularly important.

Testing for these genes correctly ruled out the disease in 203 of 248 healthy volunteers – an accuracy of 82 per cent.

The same test also accurately diagnosed the cancer in 43 per cent of sufferers, the journal Cancer Clinical Research reports.

The researchers said the test, which is still several years from the market, is likely to be of most use in ruling out head and neck cancer in those at high risk of the disease, including heavy smokers and drinkers.

Dr Joseph Califano, a head and neck cancer specialist, said: “Few tests can be accurate 100 per cent of the time in identifying both normal and cancerous cells.

“Because head and neck cancers are not widespread, it makes more sense to screen those at high risk and focus on the test’s ability to accurately rule out healthy people.”

He added that a saliva test is easy to do, as well as being painless and cheap. Current diagnosis involves a biopsy, which is often taken under general anaesthetic and can mean an overnight stay in hospital.

It is not known how much the test will cost. However, similar tests for other diseases cost around £500.

The kit is just one of several to harness advances in genetics to diagnose disease. U.S. researchers are developing a blood test that can spot Alzheimer’s disease up to six years before patients start to show symptoms and last November the Icelandic biotechnology firm deCODE launched a mail order kit that can predict a person’s risk of developing 17 diseases, from obesity to cancer.

There are fears, however, that such kits could cause unnecessary worry and that insurance companies could cash in by hiking premiums for those with a higher-than-average probability of serious illness. Critics also argue that it is wrong predict the onset of diseases for which there is no cure.

Dr Alison Ross, of charity Cancer Research UK said of the mouthwash: “We know that screening to detect cancer early can save lives, and this study raises the possibility of a quick, easy diagnostic test for head and neck cancer.

“But much more research will be needed to find out whether it could successfully be developed into a reliable way of screening people at high risk of this disease, such as heavy smokers and those who drink alcohol excessively.”