Human papillomavirus 6/11, 16 and 18 in oral carcinomas and benign oral lesions.

We have examined 118 oral squamous cell carcinomas, 72 oral leukoplakias, 12 cases of cheilitis and 65 of oral lichen planus for the presence of human papillomavirus (HPV) 6/11, 16 and 18 DNA by PCR/Southern blot hybridization. HPV DNA were found in 51/118 carcinomas (43.2%), in 16/72 (22.2%) leukoplakias, 3/12 (25.0%) cheilitic lesions and 10/65 (15.4%) lichen planus cases. These differences were even stronger when analyzing separately for the high-risk types HPV 16 and 18 as compared to low-risk types 6/11. HPV 16 and 18 DNA were present in 41/118 (34.7%) oral carcinomas, 12/72 (16.7%) leukoplakias, 2/12 (16.7%) cheilitic lesions and 6/65 (9.2%) lichen planus. In contrast to this, oral carcinomas displayed the lowest HPV 6/11 detection rate (4.2%), compared with 11.1% for leukoplakias, 8.3% for cheilitic lesions and 7.7% in lichen planus. These results indicate a successive increase of the detection rate of HPV 16 and 18 from low level in non or questionably preneoplastic lesions (lichen planus) to preneoplastic lesions (leukoplakia and cheilitis) and to oral carcinoma. In conclusion, our results suggest an association of oral carcinogenesis and infection with the high-risk HPV types 16 and 18.