Investigating a cluster of vulvar cancer in young women: a cross-sectional study of genital human papillomavirus prevalence
1 Discipline of Obstetrics & Gynaecology, The University of Adelaide, Adelaide, SA 5005, Australia
2 Epidemiology and Health Systems Division, Menzies School of Health Research, PO Box 41096, Casuarina, NT 0811, Australia
3 Clinical Microbiology and Infectious Diseases, Royal Women’s Hospital, and Department of Obstetrics and Gynaecology, University of Melbourne, Royal Women’s Hospital, Cnr of Flemington Road and Grattan Street, Parkville, VIC 3052, Australia
4 WHO HPV LabNet Regional Reference Laboratory - Western Pacific Region, Melbourne, VIC, Australia
5 Health Services Division, Northern Territory Department of Health, PO Box 40596, Casuarina, NT 0811, Australia
6 Infectious Diseases and Microbiology Group, Murdoch Children’s Research Institute, Bio 21 Institute, Level 1 Building 404, 30 Flemington Rd, Parkville, Victoria 3052, Australia
7 Surgical and Specialties Service, Royal Adelaide Hospital, North Tce, Adelaide, SA 5000, Australia
8 Department of Obstetrics and Gynaecology, Cairns Base Hospital, The Esplanade, Cairns, QLD 4870, Australia
9 Discipline of Anatomical Pathology, University of Newcastle, Manning Health Campus, PO Box 649, Taree, NSW, 2430, Australia
10 Biostatistics Group, Menzies Research Institute Tasmania, University of Tasmania, Medical Sciences Building 1, 17 Liverpool Street, Private Bag 23, Hobart, TAS 7000, Australia
BMC Infectious Diseases 2012, 12:243 doi:10.1186/1471-2334-12-243Published: 5 October 2012
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.
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.
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).
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.