Application of the Roche Cobas® HPV 4800 in Formalin-Fixed, Paraffin-Embedded Samples for Head and Neck Squamous Cell Carcinomas.

Testing for high risk human papillomavirus (HR-HPV) status is standard of care in squamous cell carcinomas of the oropharynx as well as cervical lymph node squamous cell carcinomas of unknown primary origin. DNA or RNA in-situ hybridization (ISH) and p16 immunohistochemistry, widely used currently for HPV detection are operator-dependent. In addition, DNA ISH has a relatively low sensitivity, and p16 is not entirely specific for HR-HPV infection. In this study, we examined the performance of the cobas® HPV genotyping assay in formalin-fixed, paraffin-embedded (FFPE) samples of head and neck squamous cell carcinoma. FFPE samples from head neck and other anatomic sites tested by ISH and p16 for HR-HPV at ARUP Laboratories were selected for this study. Samples were deparaffinized, stained and micro-dissected for tumor contents followed by tissue lysis, then tested with cobas® for HR-HPV. All the samples were also tested by HPV Linear Array for confirmation. All (N = 18) high risk HPV positive specimens tested by cobas® were confirmed as positive by the Linear Array test. All the specimens tested as negative by cobas® were tested as negative (N = 5) or positive only for low risk HPV (N = 3) by Linear Array, as cobas® only detects HR HPV. Limits of detection for HPV16 and 18 were established at 160-320 and 320-1600 copies, respectively. Our data suggest that cobas® HR-HPV genotyping is a viable option for detection of HR-HPV in formalin-fixed, paraffin-embedded samples from head and neck and other anatomic sites and has been validated for clinical use.