Human papillomavirus 16 physical status and the TP53 Codon 72 polymorphism in Japanese HPV-positive oropharyngeal cancer patients

Background: In human papillomavirus (HPV)-induced carcinogenesis, the arginine (Arg) allele of the TP53 codon 72 polymorphism binds more efficiently to the HPV E6 oncoprotein than the proline (Pro) allele. We investigated the physical status of HPV-16 DNA and the TP53 codon 72 polymorphism in oropharyngeal squamous cell carcinoma (OPSCC). Methods: Tumor samples from 70 p16-positive OPSCC patients were tested for HPV-16 physical status by examining the E2 and E6 open reading frames. The TP53 codon 72 polymorphism was screened by direct sequencing. Results: Of 70 patients, 53 were E6 positive, 29 had integrated forms of HPV-16 DNA, and 24 had mixed or episomal forms. Furthermore, 44 carried the Arg/Arg or Arg/Pro genotype, 3 carried the Pro/Pro genotype, and in 6 patients we were unable to obtain sequencing data. Conclusions: HPV-16 physical status was heterogeneous in our OPSCC patients. Most OPSCC patients had the TP53 Arg/Arg or Arg/Pro genotype.