Contributor

Prof. A. Sklavounou

Department of Oral Pathology and Medicine School of Dentistry, University of Athens

Title

Human papillomavirus - related oral diseases: A focus on oral cancer.   

Summary

  The oral cavity is lined by stratified squamous epithelium which is ortho-or   parakeratinized depending on the anatomic site. Thus the histology of the oral mucosa resembles that of the uterine cervix, other lower genital tract or skin. On the basis of these morphological similarities one can anticipate the presence of both the mucosal and cutaneous human papillomavirus types in different epithelial lesions of the oral mucosa.

  Benign oral legions such as squamous cell papilloma, condyloma acuminatum, verruca vulgaris, focal epithelial hyperplasia have been shown to be linked with different HPV types. On the other hand HPV involvement in precancerous lesions and oral squamous cell carcinoma is a controversial issue.

  Current epidemiologic data have shown that overall 25% of head and neck cancers are HPV associated. The oncogenic HPV- 16 was the most prevalent genotype accounting for 86-90% of cases of oropharyngeal squamous cell carcinoma and 68% of oral squamous cell carcinoma and a causal significance was identified. Similarly high-risk HPV types 16,18 have also been detected in precancerous oral lesions and the frequency is 2-3 times greater than in normal mucosa suggesting that HPV is likely to act as an initiator of epithelial proliferation.

  It is apparent therefore that HPV is a significant independent risk factor for a distinct group of oral cancers.

  This subgroup of HPV-16 positive tumors are clinically and molecularly  distinct from HPV-negative tumors. They occur in non-smokers and light or non drinkers younger individuals under 60 years of age and they appear to have a better prognosis compared to HPV-negative tumors.

  Furthermore sexual behavior is associated with risk for this group of cancer, thus creating new opportunities for the primary prevention via HPV prophylactic vaccination of both women and men.