Prevalence of human papillomavirus types in invasive vulvar cancers and vulvar intraepithelial neoplasia 3 in the United States before vaccine introduction

Abstract

OBJECTIVE: The study aimed to determine the baseline prevalence of human papillomavirus (HPV) types in invasive vulvar cancer (IVC) and vulvar intraepithelial neoplasia 3 (VIN 3) cases using data from 7 US cancer registries. MATERIALS AND METHODS: Registries identified eligible cases diagnosed in 1994 to 2005 and requested pathology laboratories to prepare 1 representative block for HPV testing on those selected. Hematoxylin-eosin- stained sections preceding and following those used for extraction were reviewed to confirm representation. Human papillomavirus was detected using L1 consensus polymerase chain reaction (PCR) with PGMY9/11 primers and type-specific hybridization, with retesting of samples with negative and inadequate results with SPF10 primers. For IVC, the confirmatory hematoxylin-eosin slides were re-evaluated to determine histological type. Descriptive analyses were performed to examine distributions of HPV by histology and other factors. RESULTS: Human papillomavirus was detected in 121/176 (68.8%) cases of IVC and 66/68 (97.1%) cases of VIN 3 (p < .0001). Patients with IVC and VIN 3 differed by median age (70 vs 55 y, p = .003). Human papillomavirus 16 was present in 48.6% of IVC cases and 80.9% of VIN 3 cases; other high-risk HPV was present in 19.2% of IVC cases and 13.2% of VIN 3 cases. Prevalence of HPV differed by squamous cell carcinoma histological subtype (p