Human papillomavirus E7 serology and association with p16 immunohistochemistry in squamous cell carcinoma of the head and neck

• Serum from a cancer biorepository was analyzed for the presence of HPV E7 antibodies.
• HPV E7 seropositivity is correlated with positive tumor HPV DNA and p16 expression.
• HPV E7 seropositivity is correlated with squamous cell carcinoma of the oropharynx.

BackgroundHuman papillomavirus (HPV)-positive oropharyngeal cancer is associated with improved survival and treatment response as compared to HPV-negative cancers. P16 overexpression is widely accepted as a surrogate marker for HPV positivity.MethodsA total of 92 serum samples from 75 head and neck squamous cell carcinoma (HNSCC) patients were examined for HPV16 and 18 E7 antibodies by ELISA. Available tissue was tested for HPV–DNA by PCR, and p16 immunohistochemistry was obtained from a deidentified database.ResultsOf 75 HNSCC patients, 25 were HPV E7 seropositive. Seropositivity was strongly associated with cancers of the oropharynx, and correlated with positive p16 immunohistochemistry (IHC) and HPV–DNA. Post-treatment serum was available in a limited subset of patients, revealing a decrease in antibody titers following response to treatment.ConclusionsHPV E7 seropositivity correlated with positive tumor HPV–DNA and p16 expression, and was strongly associated with cancers of the oropharynx. E7 serology warrants further study as a potential biomarker in HPV-positive HNSCC.