Oncogenic human papillomavirus (HPV) is a causative agent in a subgroup of head and neck carcinomas, particularly tonsillar squamous cell carcinomas (TSCC). This study was undertaken because controversial data exist on the physical status of HPV-DNA and the use of p16INK4A overexpression as surrogate HPV marker, and to examine the impact of HPV and tobacco consumption on the clinical course of TSCC. Tissue sections of 81 TSCC were analyzed by HPV 16-specific fluorescence in situ hybridization (FISH) Head and neck squamous cell carcinomas (HNSCC) account for 4% of all malignancies in the Western world, for up to 50% of all malignancies in Southeast Asian countries and for 6.5% of all annual cancer cases worldwide.1 HNSCC is associated with severe disease-and treatment-related morbidity and because treatment has not improved greatly in recent years, the 5-year survival rate remains 50%. HNSCC develop in various anatomical defined regions, including the oral cavity, larynx and pharynx. These organ-specific tumors each show specific clinical presentations and outcome, and are treated by different strategies. 2,3 The median age at presentation is 60 years and approximately two-third of patients are male. Well-known risk factors in the etiology of HNSCC are cigarette smoking combined with alcohol consumption in Western countries, or with betel quid chewing in Asia. A history of tobacco use is present in 90% of patients who develop oral cavity cancers.
2,3Despite these evident associations, the exact mechanisms by which these factors cause tumor initiation and progression are not fully understood. Furthermore, the fact that most tobacco and alcohol users do not develop HNSCC and that in recent years more often individuals without a history of these traditional risk factors have been witnessed, 4 underlines the complexity of HNSCC pathogenesis and a role for additional factors in the disease process.Increasing evidence suggests that human oncogenic papillomaviruses (HPVs), known to cause uterine cervical and other anogenital cancers, may also be of importance in the pathogenesis of HNSCC. 5 The strongest association has been found for oropharyngeal carcinomas, especially tonsillar carcinomas.6-11 Sero-positive patients for HPV 16 or with a history of HPV-related anogenital cancer also show increased risk rates of developing oropharyngeal cancer.12,13 The prevalence of HPV-exhibiting HNSCC, however, varies broadly amongst several studies (2-76%) due to differences in the population, combination of histological subsites, type and number of specimens analyzed, and detection methods used. 7,14 Thus, besides determining the presence of HPV DNA it has been suggested to better define the biological association of oncogenic HPV with these tumors, e.g., by means of assessing the viral copy number per cell, the viral oncoprotein E6/E7 expression levels, perturbation of pRb-dependent cell cycle control, or the physical status of the virus (episomal or integrated). 15 In this way, several reports have shown that HPV 16 is predomi...