Saliva test for oral and throat cancers

Saliva can be used to diagnose whether someone has oral cancer, and may also be a reliable indicator of other cancers and diseases.

Research at the University of California at Los Angeles has provided the first proof that RNA biomarkers in saliva can be used to detect cancer inexpensively, says Dr David Wong, chairman of oral biology and medicine at the university.

His exploratory study, published in Clinical Cancer Research, shows that oral cancer was identified in nine out of 10 cancer patients.

Saliva is already used to diagnose certain diseases, including HIV, which is detected from protein antibodies.

"This is a new direction, using a non-invasive fluid to look for disease signatures, particularly in cancer," Dr Wong said, adding that new technology to analyse genes rapidly made this possible.

His team worked backwards from saliva samples taken from oral cancer patients to identify a combination of four RNA biomarkers, from the 3000 found in saliva, that provided a signature for cancers of the mouth, tongue, larynx and pharynx.

RNA is the information carrier for genetic material. While DNA contains the instructions for producing proteins, RNA molecules carry the instructions into the cell's machinery.

- REUTERS