Cobas HPV Genotyping of FNA Sample Supernatant and Frozen Section Scrapings of Suspected Head and Neck Cancer

Abstract

The human papillomavirus (HPV) status of squamous cell carcinomas (SCCs) of the head and neck is relevant for therapy planning, staging, and follow-up. Immunohistochemistry (IHC) for p16 is a surrogate marker of HPV status in oropharyngeal SCC, but not at other head and neck sites. We tested if the cobas HPV test was feasible and superior to p16-IHC on fine-needle aspiration (FNA) supernatants and frozen section (FS) scrapings of suspected SCC. A 500 μL aliquots of postcentrifugation supernatant CytoRich Red media of FNA cellblock specimens and scrapings of FS suspended in SurePath media vials were tested with the cobas HPV test and compared with p16-IHC and/or HPV in situ hybridization (ISH) performed on cellblock and/or resections. Twenty-nine (n=29) FNAs were tested for a cobas HPV test, p16, and/or HPV-ISH. The mean collection to testing time was 6.3 days (range: 0 to 24 d). Cobas yielded valid results in all cases; p16-IHC could not be interpreted in 4 (13%) cellblocks; correlation was performed on subsequent resections. Cohen κ correlation for cobas versus p16-IHC/HPV-ISH on FNA samples was 0.9, perfect agreement, sensitivity 100%, specificity 92.3%, positive predictive value 94.1%, negative predictive value 100%. Thirty-four (n=34) scrapings from FS were tested for cobas, p16, and/or HPV-ISH. The mean collection to testing time was 10.4 days (range: 1 to 28 d). Cohen κ correlation for cobas versus p16-IHC/HPV-ISH on FS scrapings was 1, perfect agreement. Sensitivity, specificity, positive predictive value, and negative predictive value was 100%. Cobas genotype was HPV-16 in 87%, HPV-18 in 3%, and HPV-other in 10%. Cobas HPV test in FNA supernatant and FS scrapings outperformed or was equivalent to p16-IHC and provided genotyping information.