In one of the first studies to detect cancer using RNA in saliva, researchers were able to differentiate patients with head and neck cancer from healthy subjects based on biomarkers found in their saliva, according to an article in the Dec. 15 issue of the journal Clinical Cancer Research.
Researchers at the University of California Los Angeles’ Jonsson Comprehensive Cancer Center reported in the March 2004 issue of Journal of Dental Research that people have about 3,000 clinically distinct types of RNA in their saliva. This discovery led to a novel clinical approach called salivary transcriptome diagnostics.
In a study to evaluate this diagnostic approach’s value, researchers collected unstimulated saliva from 32 subjects with cancers of the mouth, tongue, larynx and pharynx and 32 matched control subjects. When they extracted RNA from the saliva samples, they discovered that 1,679 genes were expressed at significantly different levels in the test subjects’ saliva than in the control subjects’ saliva.
Study results also showed that a combination of four RNA biomarkers provided a detectable signature for head and neck cancer. Researchers conducted a blinded second saliva screening and identified the signature in test subjects with 91 percent sensitivity and specificity.
"We will follow up with a larger cohort of about 200 patients in the near future," said senior author David Wong, D.M.D., D.M.Sc. "This study will hopefully allow us to distinguish in saliva between the various stages of the cancer and ultimately push our accuracy up to as close to 100 percent as possible."
