Detection of Human Papillomavirus and p53 Protein in Oral Verrucous Carcinomas ― Preliminary Report ―
Objective: To investigate coexpression of the human papillomavirus (HPV) and p53 protein in oral verrucous carcinomas (OVCs). Materials and Methods: Eight surgical specimens from five Japanese OVC patients who were treated in the Department of Oral Surgery of Kawasaki Medical School between 1975 and 1997 were studied using immunohistochemistry (IHC) and the consensus primer-mediated polymerase chain reaction (PCR). Results: None of OVCs was found to have p53 - immunoreactivity by IHC, and none of the cases was HPV-positive by the PCR. Of interest was a case of HPV-negative and p53-negative oral papilloma which turned into an HPV-negative and p53-negative OVC at the same site. Conclusions: It seems possible that the oral cavity may not be susceptible to HPV-induced verrucous carcinomas with p53 protein overexpression. Furthermore, detection of p53 expression by IHC is thought to have great potential as a biomarker of the proliferating cells. Therefore, p53 - negativity in OVCs as shown in this study may explain why OVC patients have significantly better survival than patients with oral squamous cell carcinomas, which often have a higher p53-positivity.