• 2/15/2005
  • England
  • BBC News World Edition

Saliva tests could be used to detect tumours such as breast cancer, researchers believe.

A small study on 32 patients with head and neck cancers showed promising results using a test that checks for genetic signs of cancer in saliva.

The University of California Los Angeles researchers now plan a much larger study they told the journal Clinical Cancer Research. UK cancer experts said there was a need for simple, non-invasive cancer tests.

Spit test

Researchers have been looking at ways to pick up cancer in samples of urine, faeces and saliva for some time as an alternative to blood tests.

Some have focused on detecting proteins produced by cancers. Dr David Wong and his team at UCLA’s Jonsson Comprehensive Cancer Center decided instead to look at the genetic messenger for such proteins, called RNA.

They recruited 32 patients with cancers of the mouth, tongue and throat and 32 healthy volunteers of the same age and sex. By testing saliva samples, the scientists were able to spot which of the study participants had cancer correctly nine times out of 10.

Dr Wong said their results were good, but not good enough.

“Although we were able to identify the head and neck cancer patients with 91% sensitivity and accuracy, we missed one out of 10. “With a larger study, we will move that accuracy closer to 100%,” he said.

Future hope

His team is currently recruiting 200 patients with oral cancer to this end.

“We now hope to demonstrate the utility of saliva for systemic diagnosis of other diseases such as breast cancer,” he added.

Rates of oral cancer are increasing in the UK, especially among women and young adults, and the risk is highest for people who smoke and drink alcohol.

Dr Kat Arney of Cancer Research UK said: “Early detection of cancer can greatly increase a person’s chances of survival. “The use of RNA to detect cancer is a potential advance in technology, particularly using a non-invasive saliva test.

“The UCLA team have produced some promising early results, and it will be important to see if this test proves to be reliable in a larger number of patients.”

Dr Nick Coleman from the Medical Research Council’s Cancer Cell Unit in Cambridge, said: “It is a good type of approach to take. We need to do it [cancer testing] with as little inconvenience as possible to people so they are more likely to use screening services. The study was small so it needs to be looked at in a larger numbers of people.”

“The authors mention using it to find breast cancer. Whether it would work to find cancers in other parts of the body is anybody’s guess.”

A spokeswoman from CancerBACUP said: “Different cancers require different tests to make a diagnosis and it may be a number of years before we see biochemical saliva tests as part of general cancer detection.”