Immunohistochemical examination of p53 protein accumulation, analysis of the p53 gene using amplification of the exons 5-8 followed by TGGE, and PCR based HPV typing were carried out on 40 oral squamous cell carcinomas. 28 of 40 oral carcinomas (70%) contained DNA of the oncogenic HPV types 16 and 18. A p53 accumulation was present in 20 of 37 tumors (54%). Mutations of the p53 gene were detected in 15 of 39 carcinomas (38%). 15 of 20 oral carcinomas with abnormal p53 expression and 11/15 tumors with mutations of the p53 gene were HPV positive. Our results demonstrate a frequent occurrence of p53 abnormalities in HPV positive oral squamous cell carcinomas. This pattern is divergent from HPV related genital carcinomas and could reflect differences in the etiology of squamous cell carcinomas of different sites.
