Human Papilloma virus in oral carcinogenesis and Its routes of transmission
Rashmi Jaiswal and Manoj Pandey
World Journal of Epidemiology and Cancer Prevention 2012, 1:1
Introduction: Head and neck cancer include lesions at several subsites within the oral cavity, oropharynx, larynx, hypopharynx. The major known risk factors for the oral squamous cell carcinoma (OSCC) are smoking and alcohol. Recent reports have indicated Human Papilloma Virus (HPV) as a possible causal organism. HPV appears to be an independent risk factor for OSCC irrespective of tobacco or alcohol consumption.
Material and methods: A detailed search of the Medline and Cochrane data base was made. Title and abstract of each article was reviewed by two authors independently. Relevant articles were identified and reviewed systematically for route of transmission of HPV to the oral cavity, and its relationship with tobacco, alcohol and other risk factors.
Results: The most common site observed for the oral HPV infection is tonsil. The association is found in upto 50% of the cases and in most HPV-16 is identified. The chief oncoprotein of HPV-16 encoded by E6 and E7 genes have been reported to play a major role in HPV carcinogenesis by targeting tumor suppressor gene p53 and pRB respectively. Reports suggest oro-genital contact as one of the suspected mode of transmission, beside autoinfection from unwashed infected hands and deep mouth kissing. The perinatal vertical transmission is also reported.
Conclusions: There is not enough evidence to suggest s to what could be the mode of transmission of HPV to oral cavity and its relationship with other risk factors. Further researches on oral sexual behaviors in oral HPV transmission are required.