Detection of human papillomavirus DNA by in situ DNA hybridization and polymerase chain reaction in premalignant and malignant oral lesions

The sensitivity of detection of human papillomavirus (HPV) DNA in premalignant and malignant oral lesions by in situ hybridization (ISH) and polymerase chain reaction (PCR) were compared. With both methods HPV DNA was found in 4 of 24 cases of epithelial dysplasia, 4 of 14 cases of verrucous hyperplasia, and 1 of 10 cases of squamous cell carcinoma. The 10 cases of smokeless tobacco keratoses and 3 cases of verrucous carcinoma that we examined were all negative for HPV DNA. The PCR for the E6 open reading frame of HPV-16 correctly identified all cases that were positive by ISH. Only a single case that was positive by PCR was negative by ISH for HPV DNA. However, the PCR demonstrated the presence of HPV-16 infection in one case, which had hybridized most intensely with the probe for types 31/33/35 in the ISH. This discrepancy probably is due to the high degree of cross-hybridization in the ISH assay. PCR appears to be an effective technique for identifying HPV-16 DNA sequences in biopsy material from premalignant and malignant oral lesions.