Head and neck cancer patients who have a human papillomavirus (HPV) infection detectable with a blood-based biomarker have a better prognosis compared with HPV-negative patients, according to a study published in JAMA Oncology.
The researchers used a serum blood test for two specific HPV antibodies—the HPV16 E6 and E7 proteins.
"These data are among the first to demonstrate a convincing relationship between HPV16 and improved patient survival for tumors of the larynx and oral cavity,” wrote study authors led by Heather H. Nelson, MPH, PhD, of the division of epidemiology and community health at the University of Minnesota in Minneapolis.
The researchers analyzed the 5-year survival rates of 1,054 patients as part of a population-based study and analyzed the patients’ blood serum samples. Patients were enrolled at teaching hospitals in Boston and the data were collected between 1999 and 2003, and then between 2006 and 2011.
Testing positive for antibodies to the two HPV proteins was associated with improved overall survival (hazard ratio [HR], 0.33; P < .001). The authors did not find any evidence that the magnitude of immune response—assessed by antibody titer levels—affected survival outcome.
Seropositivity was associated with improved patient survival across all head and neck cancer types—larynx (HR, 0.29), oral cavity (HR, 0.45), and oropharynx (HR, 0.26). The associations with positive serotype were similar regardless of smoking or drinking exposure (HR for low exposure of 0.52, and 0.51 for heavy exposure).
Among the 162 patients with both p16 immunohistochemical measures and HPV serology, both measures were associated with survival among oropharynx patients (HR for serology, 0.16; HR for p16 measures, 0.16). Only serology was associated with outcome when considering all head and neck cancer cases (HR for serology, 0.49; HR for p16, 0.65).
Patients with the worst prognosis were those who were HPV-negative and were current smokers.
While prior studies have demonstrated that antibodies could predict outcome in HPV-positive patients with cancer of the oropharynx, the new study now shows that these antibodies are also important in other forms of head and neck cancer.
Current clinical trials are assessing whether head and neck cancer patients who test positive for HPV could be treated less aggressively.
A limitation of the study, noted by the authors, is that the presence of anti-HPV protein antibodies was not directly compared to the presence of HPV RNA or DNA.