Oral squamous cell carcinoma (mouth cancer) and oropharyngeal squamous cell carcinoma (throat cancer) often go undetected in the early stages. More than 70% of oral cancers are detected in stages III or IV when the five-year survival rate drops to less than 50%. If they’re diagnosed early, the survival rate rises to 84%. 

Early diagnosis of mouth and throat cancer has been difficult because it relies on a visual exam, typically by a dentist, but these cancers often have little to no symptoms in the early stages. Likewise, many people don’t have regular dental visits and the thoroughness of screenings varies by providers, especially in less developed nations, where oral cancer rates tend to be the highest.

If cancer is suspected, patients typically need to undergo an invasive biopsy, which runs the risk of hematomas and bleeding, and there’s an increased risk of metastasis if cancer cells are released into the bloodstream during the procedure.

Several diagnostic tools are available to help providers determine if a biopsy is needed, but there is no consensus on which are the most effective, and their accuracy is not high enough, ranging from about 80% to 88% accurate.

The research team, which includes Salomon Amar, D.D.S., Ph.D., provost for Biomedical Research at Touro University and Nevenka Dimitrova, Ph.D., adjunct associate professor of pathology, microbiology and immunology, at New York Medical College, in Valhalla, New York, was looking for an easier, more sensitive screening tool. They collaborated with Viome Life Sciences Inc. to develop a microbial and gene expression test called CancerDetect for Oral & Throat Cancer™, which simply uses saliva.

The study included people at higher risk of these cancers—those over 50 years of age or those who have a history of tobacco use. The saliva test results (negative or positive) were compared with the diagnoses of lesions that were discovered during a biopsy. The study found that the test had a 90% sensitivity (true positive rate) for oral cancer and 84.2% for throat cancer, at a specificity of 94% (true negative rate). The test was equally accurate for early-stage and later-stage cancers.

“This test has the potential to be used for early screening in primary care settings and in secondary care centers, reducing the number of unnecessary biopsies under some scenarios,” the authors wrote.

The non-invasive test, which has been fast-tracked by the Food and Drug Administration (FDA), offers important advantages over existing diagnostic tests because of its high sensitivity and specificity. “It has the potential to identify patients for additional follow-up before their disease has progressed to be apparent in visual/tactile exams,” they wrote.

The American Cancer Society estimates about 54,000 new cases of oral cancer, leading to 11,230 deaths in the U.S. in 2022. In South/Southeast Asia, oral cancer is one of the top three cancers, and about half of all oral cancers occur in Asia.