High-risk human papillomavirus in nasopharyngeal carcinoma

Background Human papillomavirus (HPV), a cause of oropharyngeal carcinoma, has also been implicated as an etiologic agent in nasopharyngeal carcinomas. Methods We performed p16 immunohistochemistry and in situ hybridization for Epstein-Barr virus (EBV) and HPV on 45 carcinomas of the nasopharynx. Results Thirty-four (76%) carcinomas were EBV-positive/HPV-negative, 7 (16%) were EBV-negative/HPV-negative, and 4 (9%) were EBV-negative/HPV-positive. HPV was more likely to be detected in carcinomas from white patients than non-white patients (16% vs 0%; p =.03). Of the 3 patients with HPV-positive carcinomas and available staging information, all were found to have extension into the oropharynx. All HPV-positive carcinomas were p16 positive, but none of the HPV-negative carcinomas were p16 positive (p <.001). Conclusion HPV can be detected in a subset of carcinomas involving the nasopharynx, but many of these may represent extension from an oropharyngeal primary. P16 immunohistochemistry is a reliable marker for separating EBV-related and HPV-related carcinomas of Waldheyer's ring.