HPV-16 viral load in oropharyngeal squamous cell carcinoma using digital PCR.

CONCLUSIONS: We did not identify any strong associations between HPV-16 viral load and any of the clinical or lifestyle factors.

OBJECTIVE: The epidemiology of oropharyngeal SCC is changing, with an increasing proportion of HPV-positive cases seen in the last decade. It is known that a high viral load is linked to the development of cervical cancer, the relation between viral load and oropharyngeal SCC is less clear. We sought to determine HPV-16 viral load in HPV-positive oropharyngeal SCCs using highly sensitive digital PCR and to identify clinical and lifestyle factors associated with viral load.

SUBJECTS AND METHODS: We analysed 45 HPV-16 positive oropharyngeal SCCs diagnosed between 2013 and 2015. All patients completed a lifestyle questionnaire and clinical data were extracted from medical charts. Viral load was determined using digital PCR assays for HPV-L1 and RNAseP.

RESULTS: We found large variations in HPV-16 viral load from 1 to 930 copies per cell (median 34 copies per cell).