Serum HPV Antibody Levels May Be a Biomarker for Recurrent HPV-associated Oropharyngeal Cancer
Among patients treated for oropharyngeal cancers linked to human papillomavirus (HPV) infection, at least 1 HPV-infection antibody could help identify those patients at risk for a recurrence of the cancer. These study findings were published in Cancer Prevention Research.1
The recent increase in incidence of oropharyngeal cancers in the United States is due to HPV infections, according to the National Cancer Institute. Approximately 80% of these cancers now are accounted for by HPV infections.
Overall survival rates are higher for people with HPV-positive tumors of the throat, base of the tongue, and tonsils. However, more than 25% of HPV-positive cancers recur, and most often within the first 2 years after treatment.
"There are currently no reliable tests available to detect early recurrence, so we hope to find a biological marker that could help identify those most at risk," said Carole Fakhry, MD, MPH, associate professor of otolaryngology-head and neck surgery at the Johns Hopkins University School of Medicine and member of the Johns Hopkins Kimmel Cancer Center, in Baltimore, Maryland.
This retrospective analysis examined serum from 60 patients with HPV-positive oropharyngeal cancer to determine levels of 4 antibodies to HPV: E6, E7, E1, and E2. These were examined at pretreatment, early posttreatment (6 months or less after treatment), and late posttreatment (more than 6 months after treatment).
The average level of most of these antibodies was lower after treatment. Patients with high levels of the E6 antibody before undergoing treatment were 7 times more likely to have their cancer return than those with lower levels. Among the 60 patients, 6 cases of recurring cancers were identified within an average follow-up of 4.4 years after treatment.
Fakhry and her colleagues reasoned that levels of the E6 antibody should fall after a patient is treated, and so increasing levels of E6 might indicate a greater risk of the cancer returning.
"Potentially, a low-risk patient may need less stringent surveillance while a high-risk patient may require more intense imaging," Fakhry explained. "But this is far away from clinical practice, as we would really need to understand whether this hypothetical approach [with E6] would improve lead time to diagnosis of recurrence and survival outcomes."
This study is a promising start to identify which patients are most at risk for recurrence. More studies are needed to confirm the usefulness of E6 as a biomarker.
1. Fakhry C, Qualliotine JR, Zhang Z, et al. Serum antibodies to HPV16 early proteins warrant investigation as potential biomarkers for risk stratification and recurrence of HPV-associated oropharyngeal cancer. Cancer Prev Res. 2016;9(2):135-141.