Serum HPV16 E7 Oncoprotein Is a Recurrence Marker of Oropharyngeal Squamous Cell Carcinomas.

Despite improved prognosis for many HPV-positive head and neck squamous cell carcinomas (HNSCCs), some cases are still marked by recurrence and metastasis. Our study aimed to identify novel biomarkers for patient stratification. Classical HPV markers: HPV-DNA, p16 and HPV mRNA expression were studied in HNSCC ( = 67) and controls ( = 58) by qPCR. Subsequently, ELISA tests were used for HPV16 L1 antibody and HPV16 E7 oncoprotein detection in serum at diagnosis and follow-up. All markers were correlated to relapse-free survival (RFS) and overall survival (OS). HPV-DNA was found in HNSCCs (29.85%), HPV16-DNA in 95% of cases, HPV16 E7 mRNA was revealed in 93.75%. p16 was overexpressed in 75% of HPV-positive HNSCC compared to negative samples and controls ( < 0.001). Classical markers correlated with improved OS ( < 0.05). Serological studies showed similar proportions of HPV16 L1 antibodies in all HNSCCs ( > 0.05). Serum E7 oncoprotein was present in 30% HPV-positive patients at diagnosis ( > 0.05) and correlated to HNSCC HPV16 E7 mRNA ( < 0.01), whereas it was associated to worse RFS and OS, especially for oropharyngeal squamous cell carcinoma (OPSCC) ( < 0.01). Detection of circulating HPV16 E7 oncoprotein at diagnosis may be useful for stratifying and monitoring HPV-positive HNSCC patients for worse prognosis, providing clinicians a tool for selecting patients for treatment de-escalation.