Researchers and clinicians also wonder if blood tests for oropharyngeal cancer are, or will soon be, accurate and reliable enough to definitively diagnose head and neck cancer. “The question is, can it be good enough to diagnose a cancer without having to take a biopsy in clinic or go to the operating room?” Dr. Glazer said. That could be a huge advantage, given the fact that “a lot of head and neck cancer patients aren’t the healthiest, and tumors could involve risky areas within the airway, so taking a biopsy isn’t always the safest procedure to do,” Dr. Glazer said. “Drawing a blood sample may be a cheaper, quicker, safer way to make a diagnosis.”
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December 2022According to a recently published study in the International Journal of Cancer, circulating tumor HPV DNA may be detectable in the blood years before HPV-positive head and neck squamous cell carcinoma (HNSCC) is usually diagnosed. The study examined prediagnostic plasma samples of 12 HNSCC patients; the samples were collected 19, 34, and 43 months before cancer diagnosis. Circulating tumor HPV-16 CAN was detected in three of the 10 patients (30%) who were eventually diagnosed with HPV-16–positive tumors, including three of seven patients (43%) with HPV-16–positive oropharynx cancer (Int J Cancer. 2022;151:1081–1085). Additional clinical trials are currently underway.
The utility of early diagnosis is also a subject of speculation. “We can hypothesize that finding cancer earlier may make a difference, but that certainly hasn’t been proven yet,” Dr. Zevallos said. “Does detection of a cancer signal seven months earlier have any meaningful impact on survival? Is there a downside for the patient in knowing that a cancer is going to manifest, but you can’t do anything about it?”
Even as researchers work to answer these questions, other researchers are exploring additional diagnostic avenues. Both Summit Biolabs in Aurora, Col., and Naveris have developed saliva tests to detect head and neck cancer, and clinical trials to date have found that the tests can detect HPV-associated cancers with high accuracy (Onco’Zine. News Release. June 6, 2021). Dr. Zevallos and his team are also investigating liquid biopsies of surgical drain fluids.
Within the field, we now have proof of concept that if you can determine a patient’s inflammation category and then block that pathway with a very highly specific antibody, you can actually modify the disease. —Benjamin Bleier, MD
“The idea of using the surgical drain as a window into the body has never really been tapped; drain fluid is typically treated as a biowaste,” Dr. Zevallos said. “We’ve measured the amount of tumor DNA in a drain immediately after surgery all the way through 48 hours after surgery, and what we’ve found is that, in the majority of cases, patients will clear the tumor DNA. The ones who don’t clear it are of interest to us.” Continued detection of exosomes in the surgical drain fluid may suggest remaining cancer.