[Demonstration and organizational structure of the DNA of human papillomaviruses in laryngeal and hypopharyngeal carcinomas].

Thirty biopsy specimens from various histological types of human carcinomas of the larynx and hypopharynx were analysed for the presence of human papillomavirus (HPV) DNA: DNA from the individual specimens were tested for the presence of homologous sequences to HPV genotypes 1, 2, 4, 8, 9, 10, 11, 13, 16 and 18. One squamous cell carcinoma of the hypopharynx (postcricoideal area) contained multiple copies of DNA hybridizing under stringent conditions with HPV 16 DNA. The latter DNA has been found to be frequently associated with human genital cancer. HPV 16 DNA was found mostly episomally as oligomeric circles of 7.9 kbp size, and as larger rear-ranged circular molecules. Integration of the viral DNA in the host cell DNA seems quite likely. Integration and rearrangement of viral DNA into cellular DNA may play a role in the induction and maintenance of the transformed state. The presence of sequences reacting under semistringent conditions with HPV DNA was observed in two additional biopsy specimens of this study. This could suggest that additional laryngeal cancers are associated with papilloma virus infections.