The Usability of p16 Immunohistochemical Staining as a Screening Test of Human Papillomavirus Infection in Head and Neck Squamous Cell Carcinoma / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: Although human papillomavirus (HPV) infection has been recognized as having an important role in the pathogenesis of head and neck squamous cell carcinoma (HNSCC), there is no simple and reliable screening test of HPV infection in HNSCC to date. In the present study, we investigated the usability of p16 immunohistochemical staining as a screening test for HPV infection in HNSCC. SUBJECTS AND METHOD: Paraffin blocks were obtained from 45 tonsil SCC patients, who underwent surgery as an initial treatment between 1995 and 2004. Paraffin blocks were also obtained from 20 normal controls. Expression of p16 was investigated immunohistochemically and these results were compared with results of HPV genotyping and the real-time polymerase chain reaction (PCR) assay of viral oncoprotein to validate p16 staining as a reliable diagnostic tool of HPV infection. RESULTS: The expression of p16 was found to be significantly different between tonsil SCC (32/45, 71.1%) and normal control tissues (0/20, 0%)(p<0.05). Among the 45 patients, HPV genotyping and real-time PCR assay were performed in 21 of the 32 p16 (+) patients and in 6 patients of the 13 p16 (-) patients. HPV-16 was detected in 18 (85.7%) out of the 21 p16 (+) patients and in 2 (33.3%) out of the 6 p16 (-) patients. The p16 expression and HPV-16 status was significantly correlated (p<0.05). The two patients who had HPV-16 infection but did not have p16 expression showed an episomal infection or very low viral copy number each. CONCLUSION: The p16 expression may be an useful marker of HPV infection in HNSCC and may be used as a screening test for HPV infection in HNSCC.