• Posted January 22, 2024

'Brush Biopsy' Could Be Easy Dental Office Cancer Screen

A newly developed “brush biopsy” allows dentists to screen for the most common form of mouth cancer, a new study reports.

Dentists use a small brush to gently collect cells from potentially cancerous lesions inside the mouth, researchers write in the journal Cancer Medicine.

The sample is then analyzed for genetics related to oral squamous cell carcinoma.

Up to now, surgical biopsies have been required to diagnose mouth cancer, an extra referral step that some patients don't take until their cancer has progressed to a more advanced, harder-to-treat stage, researchers said in background notes.

“So many patients get lost; they don't follow up,” co-researcher Guy Adami, an associate professor of oral medicine and diagnostic sciences at the University of Illinois-Chicago, said in a news release. “We've tried to keep our focus mainly on early Stage 1 and 2 cancers, so it actually works with the cancers that you want to detect.”

The diagnostic system looks for small segments of genetic material called microRNA that regulate how genes function, also called genetic expression.

The test relies on an expression signature of 40 microRNA sequences that can distinguish between a tumor and normal tissue with higher than 90% accuracy.

Importantly, the test works using epithelial cells, which constitute the outermost layer of cells in a person's mouth.

These cells can be collected with less than a minute of gentle brushing by a dentist or a nurse, with no numbing required.

The brush is then stored in a tube of solution and sent off to a lab for analysis, with results returning in days.

“We were the first to observe that brush biopsy samples actually work quite well when you use microRNA,” Adami said. “All you need is a good light and the brushes.”

The brush biopsy is an improvement over surgical biopsy because the surgery often collects a mix of cell types, making analysis more complicated. In addition, the surgery risks spreading cancerous cells to other parts of the mouth.

It's also better than blood tests because it focuses on a single suspected cancer site, so doctors know exactly where to treat if cancer is discovered.

“If you compare what we do, which is site-specific targeting of tissue, to the other tests out there, they don't have a targeting of where the tumors actually are,” co-researcher Dr. Joel Schwartz, a professor of oral medicine and diagnostic sciences with the University of Illinois-Chicago, said in a news release. “That makes it harder to start treatment rapidly after detection.”

By making screening easier to perform, researchers hope their test will reduce health inequities in patient groups who don't receive regular dental care or have a higher incidence of mouth cancer.

For example, Black men have a dramatically lower survival rate for mouth cancer than other racial and ethnic groups, researchers noted. The test could help catch their mouth cancers before they become advanced and hard-to-treat.

Adami and Schwartz have patented the test and formed a company called Arphion Diagnostics to commercialize it. They remain on the lookout for business partners to help bring the test into dental clinics.

The technology also might be used to diagnose other oral diseases, if researchers unlock the unique microRNA signatures of those illnesses.

“There are 600 different diseases that occur in the mouth, and a number of these have already been characterized with microRNAs,” Schwartz said. “We could use the same approach and really have a profound impact on these kinds of disease.”

More information

The American Cancer Society has more about mouth cancer.

SOURCE: University of Illinois-Chicago, news release, Jan. 17, 2024