Breakthrough DNA Blood Test Detects Cancer Earlier to Help Patients Beat Head and Neck Cancer

A breakthrough in DNA blood testing now allows oncologists to detect certain head and neck cancers earlier and treat them more easily and cost effectively than ever before. “This is precision medicine,” says Bhisham Chera, MD, Professor of Radiation Oncology and Otolaryngology - Head and Neck Surgery, and Wendy and Keith Wellin Endowed Chair in Radiation Oncology at the Medical University of South Carolina (MUSC).

“Tumors cells release DNA just like normal cells. So, circulating tumor DNA (ctDNA) can be measured in the blood – it’s commonly referred to as a liquid biopsy.” Since 2016, Chera has worked with colleagues to develop a blood test for oropharyngeal cancers (OPCs) caused by the human papilloma virus (HPV-positive OPCs). That diagnostic test, called NavDx® (Naveris Inc.), recently became widely available and is already changing clinical standards of care. “The HPV virus infects epithelial cells and, over time, causes cancer,” says Chera. “When a cancer cell dies, the cancer degrades its DNA into fragments that get released into the bloodstream. This test can distinguish HPV DNA that’s from cancer cells as opposed to HPV DNA from non-cancerous cells. 

So, it’s only positive after HPV creates a cancer. You don’t get a positive result if you simply have an HPV infection.” This is good news for the estimated 46,000 Americans who are diagnosed with HPV-related cancers each year.[1] “Although our cure rate for HPV-OPC is pretty high – around 80% – nearly 20% of patients will experience a recurrence,” says Chera. “After the initial cancer is treated, traditional follow-up is with a physical exam – looking at the throat, palpating the neck, performing a xberoptic scope exam of the throat. You do a PET scan (positron emission tomography) three months after treatment ends with chest imaging every 6 months for patients at higher risk for recurrence. But basically, we rely on the physical exam, which we know leads to underdiagnosing of recurrences.”

Not only does traditional follow-up care often fail to catch recurrences early, it is also uncomfortable and expensive. The NavDx® test provides an alternative, cost-effective, highly accurate diagnostic tool for identifying patients who need further evaluation. “It identifies cancer recurrence in >90 to 95% of patients often sooner than traditional imaging,” says Chera. This includes HPV recurrences in distant parts of the body, which may be outside the area covered by traditional scans. “From the ctDNA in the blood, we can detect HPV-related cancer regardless of its location in the body. When you see the test is positive, you start looking more closely at the site of the original cancer. But if that suspected site is negative after work up, you know you have to look further, because if there’s HPV-positive ctDNA in the blood, there’s HPV-related cancer in the body.” The test is also useful for evaluating patients’ treatment response. “It’s not only positive at diagnosis, it also lets you see the ctDNA blood levels clear during treatment. You can watch in real time as the cancer-related DNA becomes undetectable,” says Chera. This invaluable information may allow oncologists to identify patients who can stop treatment early or reduce their treatment dose, as well as those who need to switch therapies or receive higher doses. This is the very definition of personalized, precision medicine. Many ongoing clinical trials are currently evaluating these potential applications.

Of course, there are substantial benefits when patients can receive less exposure to radiation or chemotherapy without sacrificing curative efficacy. “We don’t really know the exact correct dose of radiation or chemotherapy for each individual patient,” says Chera. “The standard for radiation is 7 weeks of treatment, but if we know the cancer is gone by seeing the ctDNA disappear from the bloodstream, we could potentially stop earlier. Patients will have fewer acute side effects and treatment will be less costly, plus their long-term quality of life will be better if we can reduce the dose or, for some, maybe omit chemotherapy or radiation after surgery altogether while still maintaining high cure rates.” It is also possible that NavDx® will have utility in other types of HPV-associated cancers such as cervical and anal cancer.

The NavDx® test represents a clinical care milestone in treating patients with HPV-related cancers. Chera and his colleagues at MUSC are opening clinical trials that will utilize the test in guiding treatment decisions. It’s one of the many ways that the team of physicians and researchers at MUSC’s Hollings Cancer Center is changing what’s possible for patients with head and neck cancers.

Conflict of Interest Statement

Dr. Chera is a co-inventor of intellectual property held by University of North Carolina regarding the ctHPVDNA detection methodology (US Patent 11,168,373), and is a scientific advisor with ownership interest in Naveris, Inc, a company that has licensed ctHPVDNA technology from University of North Carolina for commercialization [1] Centers for Disease Control and Prevention. Cancers Associated with Human Papillomavirus, United States—2014–2018. USCS Data Brief, no. 26. Atlanta, GA: Centers for Disease Control and Prevention, US Department of
Health and Human Services; 2021. Available at: www.cdc.gov/cancer/uscs/about/data-briefs/no26-hpv-assoc-cancers-UnitedStates-2014-2018.htm