In a retrospective observational cohort study, a commercially available blood test used to evaluate tumor tissue–modified viral-HPV DNA demonstrated 100% specificity for both diagnosis of oropharyngeal cancer and surveillance for recurrence. Sensitivity was 91.5% for correctly identifying patients who have the disease and 88.4% for surveillance.
“A positive result appeared to confirm the presence of disease, [but] approximately 1 in 10 negative results in patients with pathologically confirmed HPV-associated oropharyngeal squamous cell carcinoma were falsely negative,” lead investigator Rocco Ferrandino, MD, with Mount Sinai, New York, said in an interview.
“Therefore, further workup should still be pursued when clinical suspicion for HPV-associated oropharynx cancer is high,” Dr. Ferrandino said.
The study was published online, in JAMA Otolaryngology–Head and Neck Surgery, to coincide with presentation at the annual meeting of the American Head and Neck Society in Montreal.
‘Remarkable promise’
The diagnosis of HPV-associated oropharyngeal cancer currently relies on a tissue-based biopsy of the primary site or a regional lymph node; however, there has been growing interest in the potential of liquid biopsy for diagnosis and surveillance.
The commercially available assay that was evaluated in the study uses a distinct method to identify and quantify a tumor-associated or tumor-modified pattern of DNA fragments that significantly increases the specificity for identifying an HPV-associated malignant tumor. However, evaluation of the assay has been limited to small cohort studies and clinical trials.
In the current study, Dr. Ferrandino and colleagues evaluated the performance of the assay used during routine clinical practice at their high-volume institution over a period of nearly 3 years.
The study included 163 patients in the diagnostic cohort and 290 in the surveillance cohort. In the diagnostic cohort, 152 had HPV-associated oropharyngeal cancer, and 11 had HPV-negative oropharyngeal cancer. The sensitivity of the assay in pretreatment diagnosis was 91.5% (139 of 152 tests), and the specificity was 100% (11 of 11 tests).
In the surveillance cohort of 290 patients, 591 tests were evaluated. A total of 23 patients developed pathologically confirmed recurrences over a median follow-up of 40.5 months. The assay demonstrated sensitivity of 88.4% (38 of 43 tests) and specificity of 100% (548 of 548 tests) in detecting recurrences.
The median lead time from positive test to pathologic confirmation was 47 days.
“The lead time provided by positive assay results may allow a window of opportunity for salvage treatment or for the application of adjuvant systemic therapy,” Dr. Ferrandino and colleagues explain.
“While these results are exciting and may support adjunctive use of circulating tumor DNA testing for diagnosis and surveillance, we really need more prospective and multicenter studies to validate these findings,” Dr. Ferrandino said in an interview.
In an accompanying commentary, Miriam Lango, MD, department of head and neck surgery, the University of Texas MD Anderson Cancer Center, Houston, said she agrees that a prospective clinical validation study is needed.
“Nevertheless, the use of this technology shows remarkable promise to transform the ability to identify and follow patients with HPV-related disease. Testing is likely to be increasingly used in routine clinical care, as it is commercially available,” Dr. Lango writes.
Still, she noted, “It is incumbent on us to establish evidence for strong and detailed surveillance guidelines to share among the cancer community.”
The study had no specific funding. Dr. Ferrandino and Dr. Lango have disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.