title: Investigating a cluster of vulvar cancer in young women: a cross-sectional study of genital human papillomavirus prevalence.
abstract: BACKGROUND
  Vulvar cancer is a relatively rare malignancy, which occurs most often in postmenopausal women. We have previously identified a geographic cluster of vulvar cancer in young Indigenous women living in remote communities in the Arnhem Land region of Australia. In this population, we investigated the prevalence of oncogenic human papillomavirus (HPV) infection in anogenital samples (vulvar/vaginal/perianal area and cervix) and compared the overall, type-specific and multiple infection prevalence between sites.
  
  
  METHODS
  A cross-sectional survey of 551 Indigenous women aged 18-60 years was undertaken in 9 Arnhem Land communities. Women were consented for HPV detection and genotyping collected by a combined vulvar/vaginal/perianal (VVP) sweep swab and a separate PreservCyt endocervical sample collected during Pap cytology screening. HPV DNA testing was undertaken using PCR with broad spectrum L1 consensus PGMY09/11 primers with genotyping of positive samples by Roche Linear Array. The primary outcomes were the prevalence of cervical and VVP high-risk (HR) HPV.
  
  
  RESULTS
  The prevalence of VVP HR-HPV was 39%, which was significantly higher than the cervical HR-HPV prevalence (26%, p<0.0001). HPV-16 was the most common genotype detected in both sites (VVP 11%, cervical 6%). HPV-16 infection peaked in women aged <20 years; however, there was a marked decline in cervical HPV-16 prevalence with age (p=0.007), whereas following an initial decline, the prevalence of VVP HPV-16 remained constant in subsequent age-groups (p=0.835).
  
  
  CONCLUSIONS
  In this population experiencing a cluster of vulvar cancer, the prevalence of cervical oncogenic HPV infection was similar to that reported by studies of other Australian women; however there was a significantly higher prevalence of vulvar/vaginal/perianal infection to cervical. The large discrepancy in HPV prevalence between anogenital sites in this population may represent more persistent infection at the vulva. This needs further investigation, including the presence of possible environmental and/or genetic factors that may impair host immunity.
authors.affiliation: Discipline of Obstetrics & Gynaecology, The University of Adelaide, Adelaide, SA 5005, Australia. alice.rumbold@adelaide.edu.au
authors.forename: Alice R
authors.initials: AR
authors.lastname: Rumbold
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Tan
authors.forename: John R
authors.initials: JR
authors.lastname: Condon
authors.forename: Debbie
authors.initials: D
authors.lastname: Taylor-Thomson
authors.forename: Maria
authors.initials: M
authors.lastname: Nickels
authors.forename: Sepehr N
authors.initials: SN
authors.lastname: Tabrizi
authors.forename: Margaret L J
authors.initials: ML
authors.lastname: Davy
authors.forename: Margaret M
authors.initials: MM
authors.lastname: O'Brien
authors.forename: Christine M
authors.initials: CM
authors.lastname: Connors
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Zardawi
authors.forename: Jim
authors.initials: J
authors.lastname: Stankovich
authors.forename: Suzanne M
authors.initials: SM
authors.lastname: Garland
mesh_terms: D000293:Adolescent; D000328:Adult; D001003:Anal Canal / Q000821:virology; D001315:Australia / Q000453:epidemiology; D003430:Cross-Sectional Studies; D004279:DNA, Viral / Q000235:genetics / Q000302:isolation & purification; D005260:Female; D005838:Genotype; D006801:Humans; D027383:Papillomaviridae / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D030361:Papillomavirus Infections / Q000453:epidemiology* / Q000821:virology*; D016133:Polymerase Chain Reaction; D044382:Population Groups; D015995:Prevalence; D014621:Vagina / Q000821:virology; D014844:Vulva / Q000821:virology; D014846:Vulvar Neoplasms / Q000453:epidemiology* / Q000821:virology*; D055815:Young Adult
chemical_list: D004279:DNA, Viral