HPV16 detection in oral rinses for oropharyngeal cancer

HPV infection is responsible for the majority of oropharyngeal carcinomas in the United States. In 10 percent to 25 percent of patients with HPV-positive tumors, the cancer will progress after treatment and earlier diagnoses of progressive or recurrent disease may result in earlier treatment and better outcomes. HPV16 DNA in oral exfoliated cells is detected in as many as two-thirds of HPV-positive cancers before treatment and persists in a small subset of patients after treatment.

Gypsyamber D'Souza, Ph.D., of the Johns Hopkins Bloomberg School of Public Health, Baltimore, and coauthors examined HPV DNA detection in oral rinses after treatment for HPV-related oropharyngeal cancer with disease recurrence and survival to understand the implications for prognosis.

The study included 124 patients with new HPV-related oropharyngeal caner who had one or more posttreatment oral rinses.

The authors found oral HPV16 DNA was common at diagnosis (67 of 124 participants). However, it was detected in only six patients after treatment, including five patients with persistent oral HPV16 DNA that was also detected at diagnosis.

Although infrequent, the detection of persistent oral HPV16 DNA in posttreatment oral rinses was associated with worse disease-free survival and overall survival. All five patients with persistent oral HPV16 DNA developed recurrent disease and three died of the disease. In contrast, only 9 of 119 patients without persistent oral HPV16 DNA developed recurrent disease.

The authors note that the conclusions of their study are limited by the infrequency of persistent oral HPV16 DNA detection and the small number of deaths and recurrences.

"Our data suggest that persistent HPV16 DNA detection in posttreatment oral rinses, although uncommon, is associated with poor prognosis and may be predictive of disease recurrence, in particular local recurrence. Therefore, HPV16 DNA detection in oral rinses is a potentially useful tool for long-term tumor surveillance for the growing population of HPV-OPC (human papillomavirus-related oropharyngeal carcinoma) survivors," the study concludes.

Commentary: Not Just Spitting in the Wind

In a related commentary, Julie E. Bauman, M.D., M.P.H., and Robert L. Ferris, of the University of Pittsburgh, write: "Human papillomavirus-specific biomarkers in OPSCC [oropharyngeal squamous cell carcinoma] may be used to improve clinical outcomes, and this pioneering study demonstrates an association between persistent oral HPV16 DNA detection and recurrence. ... Meanwhile, the high negative predictive value of oral rinse HPV16 DNA detection raises the promise of deintensifying surveillance visits and/or costly imaging, particularly if on a prospective trial."