Human papillomavirus infections in laryngeal cancer

Although the association and clinical significance of human papillomavirus (HPV) infections with a subset of head and neck cancers, particularly for oropharyngeal carcinoma, has recently been well documented, the involvement of HPV in laryngeal cancer has been inadequately evaluated. Herein we review the currently known associations of HPV infections in diseases of the larynx and their potential for oncogenicity. Using several methods of detection, HPV DNA has been detected in benign (papillomatosis), indolent (verrucous carcinoma), and malignant (squamous cell carcinoma) lesions of the larynx. Consistent with the known oncogenic risk of HPV infections, common HPV types associated with laryngeal papillomatosis include low-risk HPV types 6 and 11, with high-risk HPV types 16 and 18 more commonly present in neoplastic lesions (verrucous carcinoma and squamous cell carcinoma). Although a broad range of prevalence has been noted in individual studies, approximately 25% of laryngeal squamous cell carcinomas harbor HPV infections on meta-analysis, with common involvement of high-risk HPV types 16 (highest frequency) and 18. Preliminary results suggest that these high-risk HPV infections seem to be biologically relevant in laryngeal carcinogenesis, manifested as having viral DNA integration in the cancer cell genome and increased expression of the p16 protein. Despite this knowledge, the clinical significance of these infections and the implications on disease prevention and treatment are unclear and require further investigation.