The Absence of Human Papillomavirus E6/E7 mRNA Transcripts in Squamous Cell Carcinomas of the Oral Tongue: HPV Is Not a Relevant Agent in Squamous Cell Carcinomas of the Oral Tongue Including Those That Are Non-Tobacco Related
Justin S Poling, Ryan Li, Xiao-Jun Ma, Yuling Luo, Son Bui, Wayne M Koch, William H Westra. Johns Hopkins Hospital, Baltimore, MD; Advanced Cell Diagnostics, Hayward, CA
Background: The human papillomavirus (HPV) is an important cause of many head and neck squamous cell carcinomas (SCCs), but its role in cancer of the lateral tongue remains controversial. Indeed, detection rates of HPV in SCCs of the oral tongue have varied from 0% to 100%, largely reflecting differences in detection methodologies. The suspicion of an HPV-related lateral tongue SCC may be heightened in young patients and in patients who have never smoked. A recently described RNA in-situ hybridization (ISH) method for detecting HPV E6/E7 mRNA is sensitive, specific, and allows for accurate detection of HPV in routinely processed formalin-fixed tissues.
Design: We evaluated 107 SCCs of the lateral tongue for the presence of HPV using p16 immunohistochemistry and an RNA in situ hybridization (ISH) assay targeting high risk HPV E6/E7 mRNA. The ISH was performed using the RNAScope VS system on Ventana's Discovery XT. The study population included 41 patients who had never smoked, and 9 patients under the age of 40.
Results: HPV E6/E7 mRNA transcripts were detected in only 1 of 107 (0.9%) SCCs. P16 expression was detected in 10 of 107 (9.3%) SCCs. The one HPV-positive SCC was also p16 positive, while 9 of 10 p16-positive SCCs were negative for HPV E6/E7.
Conclusions: HPV is not detected in the vast majority of lateral tongue SCCs. Accordingly, routine HPV testing is not necessary for SCCs of the lateral tongue, and even selective testing is unwarranted in those patients without traditional risk factors such as smoking. Furthermore, p16 staining is not a reliable marker of HPV positivity at this particular anatomic site.
Category: Head & Neck
Monday, March 4, 2013 9:30 AM
Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 195, Monday Morning