Source: jcp.bmj.com
Authors: Selvam Thavaraj et al.

Background:
Oncogenic human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (SCC) is a subtype of head-and-neck cancer with a distinct clinical and prognostic profile. While there are calls to undertake HPV testing for oropharyngeal SCCs within the diagnostic setting and for clinical trials, there are currently no internationally accepted standards.

Methods:
142 tonsil SCCs were tested using p16 immunohistochemistry (IHC), high-risk HPV DNA in situ hybridisation (ISH) and HPV DNA polymerase chain reaction (PCR; GP5+/6+ primers).

Results:
There were high levels of agreement between pathologists for p16 IHC and HPV ISH scoring; however, around 10% of HPV ISH cases showed some interobserver discrepancy that was resolved by slide review. The combination of p16 IHC and HPV ISH classified 53% of the samples as HPV-positive, whereas the combination of p16 IHC and HPV PCR classified 61% of the samples as HPV-positive. By employing a three-tiered, staged algorithm (p16 IHC/HPV ISH/HPV PCR), the authors were able to classify 98% of the cases as either HPV-positive (p16 IHC+/HPV DNA+; 62%) or HPV-negative (p16 IHC−/HPV DNA−; 35%).

Conclusions:
The current study suggests that using a combination of p16 IHC/HPV ISH/HPV PCR, in a three-tiered, staged algorithm, in conjunction with consensus reporting of HPV ISH, leads to less equivocal molecular classification. In order to ensure consistent reporting of this emerging disease, it is increasingly important for the head-and-neck oncology community to define the minimum requirements for assigning a diagnosis of ‘HPV-related’ oropharyngeal SCC in order to inform prognosis and for stratification in clinical trials.

Authors:
1. Selvam Thavaraj1,
2. Angela Stokes1,
3. Eliete Guerra2,
4. Jon Bible3,
5. Eugene Halligan3,
6. Anna Long4,
7. Atuora Okpokam4,
8. Philip Sloan4,5,
9. Edward Odell1,
10. Max Robinson5

Authors’ affiliations:

1. Oral Pathology, Department of Clinical and Diagnostic Sciences, King’s College London Dental Institute, London, UK
2. Oral Pathology, Department of Dentistry, Faculty of Health Science, University of Brasilia, Brasilia, Brazil
3. GSTS Pathology, Department of Infection, Virology Section, St Thomas’ Hospital, London, UK
4. Department of Cellular Pathology, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne, UK
5. Centre for Oral Health Research, School of Dental Sciences, Newcastle University, Newcastle Upon Tyne, UK

Source: J Clin Pathol 2011;64:308-312 Published Online First: 23 February 2011 doi:10.1136/jcp.2010.088450