Types of human papillomavirus revealed in cervical adenocarcinomas after DNA sequencing

In a collection of 173 cervical adenocarcinomas, the prevalence of HPV in relation to the age of women and the distribution of the various oncogenic types of HPV were evaluated. The tumour material was analysed by PCR of the HPV L1 gene followed by direct DNA sequencing and/or the polymerase chain reaction and single-strand conformation polymorphism (PCR-SSCP) technique for the identification and typing of HPV. In 68% (117/173) of the adenocarcinomas, HPV was present. A significant correlation was observed between the prevalence of HPV and age: in women younger than 40 years, HPV was present in 88%, whereas in women 60 years and older, it was found in only 39% (p<0.001). Among the HPV-positive tumours, type 18 predominated (52%) followed by type 16 (35%) and type 45 (7.7%) while other oncogenic types of HPV (31 and 59) were rarely found. HPV 16 was relatively more frequent in older women but this observation was not significant (p=0.06). HPV-typing by PCR and direct DNA sequence analysis is more specific than analysis by PCR-SSCP, especially among the less frequently occurring types of HPV. Our results further show that the prevalence of HPV in women with cervical adenocarcinomas is age-related and that the most frequently occurring types of HPV are 18, followed by 16 and 45. We have concluded that the oncogenic role of HPV in cervical squamous carcinomas and adenocarcinomas is, in some respects, discrepant.