Background: HPV-related oropharyngeal SCC represents a distinct subgroup of head and neck tumours. We analyse the expression of cytokeratin 7, a junctional biomarker with a SEQIKA fragment which stabilises HPV-16 E7 transcripts, in oropharyngeal SCCs. Methods: Archived tumour specimens and epidemiological data were collected from patients with oropharyngeal SCC over ten years. Briefly, DNA was extracted from tissue blocks and HPV testing carried out using SPF10 HPV PCR and INNO-LiPA HPV Genotyping. Immunohistochemical staining for CK7 and p16ink4a was performed on the Ventana BenchMark Ultra Immunostainer. Analysis was by light microscopy using the H score. CK7 expression was correlated with epidemiological data, p16ink4a positivity and HPV status using SPSS. Results: CK7 expression was observed specifically and uniformly in the tonsillar crypt epithelium of normal tonsils and tumour specimens. There were 226 cases of oropharyngeal SCC, with 70 demonstrating both HPV and p16 positivity. Of 216 cases evaluated for CK7, 106/216 demonstrated some positivity while H score >60 was seen in 55 of these. CK7 H score >60 was significantly associated with tonsillar subsite and HPV and p16 positivity. Conclusions: An association between CK7 and HPV has been demonstrated. CK7-expressing tonsillar crypt cells potentially represent an oropharyngeal subsite susceptible to HPV-related SCC. Impact: Along with the cervix and anorectum, specific oropharyngeal expression of CK7 in a site predisposed to HPV-related tumours may suggest a role for CK7 in the pathogenesis of this subgroup of tumours. Further research is warranted to characterise the association between CK7 and HPV-related HNSCC.
- Received July 31, 2016.
- Revision received November 29, 2016.
- Accepted December 6, 2016.
- Copyright ©2017, American Association for Cancer Research.