Can a mouthwash test help predict head and neck cancer recurrence?

For years, mouthwash has been marketed as an essential hygiene product to prevent bad breath, even though it offers minimal, if any, health benefits.

But what if a mouthwash-based test for biomarkers could help doctors predict disease recurrence in head and neck cancer patients?

That futuristic scenario appears closer to reality after a new study by researchers from the Sylvester Comprehensive Cancer Center at the University of Miami Miller School of Medicine, UC San Diego Health and collaborating cancer centers.

Their conclusions, published on August 15 in the journal JAMA Otolaryngology – Head and Neck Surgerycould improve how doctors predict and detect the recurrence of these cancers.

“Our study suggests that detecting biomarkers in saliva collected from a mouthwash after initial treatment offers an opportunity to easily assess the risk of recurrence,” said Elizabeth Franzmann, MD, a head and neck surgeon at Sylvester and co-corresponding author of the study. “Elevated levels of either biomarker were associated with disease recurrence.”

Men are more sensitive

Head and neck cancers account for nearly 4% of all cancers in the United States and are most commonly diagnosed in people over age 50, according to the National Cancer Institute. Men are twice as likely to be diagnosed with the disease.

The main treatment options include surgery and radiation therapy, which can affect speech, swallowing and appearance, seriously affecting the patient’s quality of life. These effects can be even more severe after a recurrence.

Additionally, recurrence isn’t always easy to detect. “It can be very difficult to determine whether what you’re seeing is simply post-treatment changes or whether the cancer has recurred,” says Joseph Califano III, MD, director of the Hanna and Mark Gleiberman Head and Neck Cancer Center at the University of California, San Diego, and a co-corresponding author of the study. “Good biomarkers could help eliminate some of the uncertainty.”

Franzmann, whose research lab focuses on finding an inexpensive, noninvasive screening test for these cancers, stressed the importance of early detection of recurrences.

“These patients are suffering terribly,” she said. “The more we can minimize these effects by detecting recurrences at an early stage, the better we can reduce patient morbidity and mortality.”

Assessment of the risk of recidivism

Previously, Franzmann and his team had studied how biomarkers in mouthwashes could assess the risk of developing oral or oropharyngeal tumors, the most common types of head and neck cancer. They found a link with two key biomarkers: CD44, a tumor-initiating molecule, and total protein levels.

In this new study, the researchers investigated whether these two biomarkers could predict recurrence in patients who had already been diagnosed. Their clinical trial evaluated the effects of CD44 and total protein levels in more than 160 patients at multiple cancer centers. Patients were given mouthwash samples to use up to 18 months after their initial treatment.

To measure the presence of biomarkers, the researchers used laboratory tests and experimental lateral flow tests, a technology similar to pregnancy tests and COVID-19 stick-based tests.

“Our laboratory analyses showed an association between biomarker levels and subsequent recurrence,” Franzmann said. “Compared to patients with normal protein levels three months after treatment, patients with approximately twice the total protein had an estimated 65% higher risk of recurrence.”

She added that patients whose CD44 levels were three times the normal level had an estimated 62% higher risk of recurrence.

Focus on rapid tests

The study also generated preliminary data on a rapid point-of-care test to measure these biomarkers, the results of which should help accelerate its development.

“It would be really helpful to have a test that is inexpensive, feasible, and can be done while the patient is in the office,” Franzmann said. “That’s where we’re focusing.”

She and her colleagues emphasized that while more research is needed, biomarkers hold great promise for refining risk prediction in patients with head and neck cancers. Better risk prediction, in turn, has the potential to save lives by reducing the need for harsh and invasive treatments. We thank Vigilant Biosciences for its contribution to this work.