HPV-associated head and neck cancers are becoming increasingly common, and diagnosing these cancers often involves invasive tissue biopsies that are not always effective at catching the disease early. The increase in cases and importance of beginning treatment early have made fast, accurate and accessible diagnostic tools even more crucial for combatting these cancers. A recent study testing the efficacy of a novel blood test developed by researchers at the Massachusetts Eye and Ear Infirmary and Massachusetts General Hospital showed that this less invasive and less expensive method could potentially replace tissue biopsies when combined with a physical exam and routine imaging to diagnose HPV-associated head and neck cancers.
Because these cancers are driven by the human papillomavirus, the liquid biopsy method can be used to detect levels of cell-free viral DNA in the blood. This specific type of DNA, also referred to as circulating tumor HPV DNA, is only found in the blood when HPV-associated cancer is present, making it an advantageous diagnostic marker for this type of cancer. Blood was collected from 70 patients with a new, assumed diagnosis of HPV-associated head and neck cancer and 70 control participants from the hospital and infirmary, and analyzed with custom droplet digital PCR (ddPCR) assays targeting certain HPV genotypes. The subjects also underwent routine imaging and a physical exam.
The results showed that the new test had a 98.4% sensitivity for identifying a positive result and a 98.6% specificity for detecting a negative result, which is even more accurate than standard methods. When the liquid biopsy was combined with imaging and physical exam findings, diagnostic sensitivity was 95.1% and diagnostic specificity was 98.6%. Notably, the results could be delivered much faster than with a typical tissue biopsy, with the average time from first presentation to diagnosis being just 15 days with the blood test and about 41 days on average with standard methods. The liquid biopsy was also 38% less expensive than standard methods, with an average estimated savings of more than $6,000 per patient. This study was published in Clinical Cancer Research, a journal of the American Association for Cancer Research.
“Liquid biopsy is an extremely promising approach to improve diagnosis for patients and to provide more essential information to surgeons faster,” said study co-author Mark A. Varvares, the chief of otolaryngology-head and neck surgery at Mass Eye and Ear. “The ability to shorten the time from presentation to diagnosis will have significant impact on expediting the initiation of treatment, which will improve outcomes and decrease patient anxiety. Sending a tube of blood into the lab when a patient first arrives can considerably cut down on time to diagnosis and lead to faster care.”
Due to the results of the recent study, the research team has now designed a clinical trial to validate the findings and use the liquid biopsy method to personalize care and make real time decisions for patients. The trial is scheduled to open for patients in 2022.
Photo: Study co-author Daniel L. Faden, MD, a head and neck surgical oncologist and investigator in the Mike Toth Head and Neck Cancer Research Center at Mass Eye and Ear, and assistant professor of otolaryngology–head and neck surgery at Harvard Medical School. Credit: Mass Eye and Ear