[High-risk HPV types in oral and laryngeal papilloma and leukoplakia]

Juvenile and adult laryngeal papillomas (JLP and ALP) and oral papillomas (OP) are important benign tumors of the head and neck. Laryngeal leukoplakia (LL) may be a precancerous lesion. The etiology of the papillomas is associated with human papillomavirus infection (HPV). The important noxes for the development of laryngeal leukoplakias are nicotine, alcohol, and HPV. Adult laryngeal papillomas and OP can also undergo malignant conversion. Today, there is no marker known to distinguish in progressive lesions and in those which show a regression. Different types of HPV were detected in head and neck cancer too. There is a important similarity to the genesis of cervical cancer. The 77 known HPV types were divided into benign types, e.g., 6 and 11, and those with oncogene potential, e.g., 16, 18, 31, 33, and 35. The detection of oncogene HPV may be a sensitive marker for prognosis of primary benign lesions.

In this study, the presence of HPV genomes 6, 11, 16, 18, 31, 33, and 35 in 17 JLP, 27 ALP, 15 OP, and 11 LL was examined. DNA extracted from archived samples embedded in paraffin was amplified using the E6 specific polymerase chain reaction (PCR). The products were visualized by electrophoresis, and positive identification was achieved by Southern blot analysis and hybridization to specific biotinylated oligonucleotide.

Our data show the presence of HPV 6/11 in all JLP (17 of 17), in all ALP (27 of 27), in 13 of 15 (87%) OP, and in seven of 11 (63%) LL. The "malignant" types HPV 16, 18, and 33 were found in six of 27 (22%) of the ALP, in three of 15 (20%) of the OP, and in four of 11 (36%) of the LL. the dominant type was HPV 16, HPV 31 and 35 were not detectable. Three ALP, one OP, and the four LL of the cases with oncogene HPV showed histologic features of moderate dysplasia.

The role of HPV in malignant transformation of infected cells remains unclear. It is well known that the carcinogenesis must depend on promoters such as alcohol, tobacco, and metabolites of chronic inflammations. All patients with positive biopsies confirming HPV 16, 18, or 33 must receive special care to prevent the development of a carcinoma.