Clustering patterns of type-type combination in multiple genotypes infections of human papillomavirus in cervical adenocarcinoma.

Coinfections with multiple types of human papillomavirus (HPV) occur in cervical adenocarcinoma (ADC). However, it remains unclear the clustering patterns of multiple types in HPV coinfections and relevant factors in ADC. A total of 718 paraffin-embedded ADC specimens were collected in China and tested for HPV genotypes using SPF10-INNO-LIPA. The prevalence of HPV coinfections and clustering patterns by geographical regions, histological subtypes and ages were assessed. Type-specific attribution of HPV to ADC adjusted by HPV coinfections were calculated. The prevalence of HPV coinfections was found to be 8.4% in ADC cases with slight variation by geographic regions between 2.2% and 12.5%. The 88.3% of all HPV multiple infections in ADC were two types of HPV coinfections with predominant combination of HPV 16 and HPV 18. The attribution to ADC was 88.0% for HPV 16/18 targeted by bivalent and quadrivalent vaccine and 96.8% for HPV 16/18/31/33/45/52/58 targeted by nonavalent vaccine. Clustering patterns of multiple types were related with histological categories and age at diagnosis. In conclusion, HPV coinfections are uncommonly prevalent in ADC cases with slight variation by geographic regions and distinct clustering patterns of multiple types by histological subtypes and ages at diagnosis. The high attribution of carcinogenic HPV types to ADC predicts potential protection of HPV vaccine against ADC.