PAPILLOMAVIRUSES IN HEAD AND NECK DISEASE - PATHOPHYSIOLOGY AND POSSIBLE REGULATION

Human papillomaviruses (HPVs) are etiologic agents of both benign and malignant epithelial tumors. More than 60 different types of viruses a re known, each associated with tissue site and lesion type specificiti es and differing probabilities of malignant progression. HPVs type 6 a nd type 11 cause benign papillomas of mucosal squamous epithelium in t he aerodigestive tract, with only rare conversion to malignancy. HPV 1 6 is the most frequently detected HPV in the genital tract, inducing f lat lesions with a significant risk of malignant conversion. In the ae rodigestive tract, HPV 16 is found only rarely in benign lesions but i s detected in 5-20% of squamous carcinomas. In the aerodigestive tract , HPVs frequently cause latent infection, i.e., viral DNA present in t issue but no evidence of clinical or histologic disease. Approximately 10% of the general population may have latent infections. Regulation and activation of latent infections are not well understood, although it is clear that viral functions are tightly regulated by the state of differentiation of the squamous host cell. Control of viral transcrip tion may be the key to prevention of viral activation, and thus contro l of disease. Among the possible agents under investigation are retino ids, growth factors, anti-sense RNA which interferes with viral expres sion, and estrogen metabolites. All of these agents modulate either vi ral expression or cell differentiation or both. It is hoped that in th e near future one or more of these agents will be useful in preventing HPV-associated disease. (C) 1993 Wiley-Liss, Inc.