Alyssa M. Cornall

Very Low Prevalence of Vaccine Human Papillomavirus Types Among 18- to 35-Year Old Australian Women 9 Years Following Implementation of Vaccination

Introduction A quadrivalent human papillomavirus vaccination program targeting females aged 12-13 years commenced in Australia in 2007, with catch-up vaccination of 14-26 year olds through 2009. We evaluated the programs impact on HPV prevalence among women aged 18-35 in 2015. Methods HPV prevalence among women aged 18-24 and 25-35 was compared with prevalence in these age groups in 2005-2007. For women aged 18-24, we also compared prevalence with that in a postvaccine study conducted in 2010-2012. Results For the 2015 sample, Vaccination Register-confirmed 3-dose coverage was 53.3% (65.0% and 40.3% aged 18-24 and 25-35, respectively). Prevalence of vaccine HPV types decreased from 22.7% (2005-2007) and 7.3% (2010-2012), to 1.5% (2015) (P trend < .001) among women aged 18-24, and from 11.8% (2005-2007) to 1.1% (2015) (P = .001) among those aged 25-35. Conclusions This study, reporting the longest surveillance follow-up to date, shows prevalence of vaccine-targeted HPV types has continued to decline among young women. A substantial fall also occurred in women aged 25-35, despite lower coverage. Strong herd protection and effectiveness of less than 3 vaccine doses likely contributed to these reductions.

Human papillomavirus prevalence in unvaccinated heterosexual males following a national female vaccination program

Background In Australia, high uptake of the quadrivalent human papillomavirus (4vHPV) vaccine has led to reductions in the prevalence of human papillomavirus (HPV) genotypes 6, 11, 16, and 18 in women and girls aged ≤25 years. We evaluated the impact of the program impact on HPV prevalence in unvaccinated male subjects. Methods Sexually active heterosexual male subjects aged 16-35 years were recruited in 2014-2016. Participants provided a self-collected penile swab sample for HPV genotyping (Roche Linear Array) and completed a demographic and risk factor questionnaire. Results The prevalence of 4vHPV genotypes among 511 unvaccinated male subjects was significantly lower in those aged ≤25 than in those aged >25 years: 3.1% (95% confidence interval, 1.5%-5.7%) versus 13.7% (8.9%-20.1%), respectively (P < .001); adjusted prevalence ratio, 0.22 (.09-.51; P < .001). By contrast, the prevalence of high-risk HPV genotypes other than 16 and 18 remained the same across age groups: 16.8% (95% confidence interval, 12.6%-21.9%) in men aged ≤25 years and 17.9% (12.4%-25.0%) in those aged >25 years (P = .76); adjusted prevalence ratio, 0.98, (.57-1.37; P = .58). Conclusions A 78% lower prevalence of 4vHPV genotypes was observed among younger male subjects. These data suggest that unvaccinated men may have benefited from herd protection as much as women from a female-only HPV vaccination program with high coverage.

Looking beyond human papillomavirus (HPV) genotype 16 and 18: Defining HPV genotype distribution in cervical cancers in Australia prior to vaccination

Australia has implemented a high‐coverage HPV vaccination program but has not, to date, established the distribution of HPV types that occur in cervical cancers in Australia. This information is important for determining the potential for cervical cancer prevention with both current and broader spectrum HPV vaccines. We analysed 847 cervical cancers diagnosed 2005 to 2015 in tertiary centres in the three most populous Australian states with resolution of specimens containing multiple HPV types using laser‐capture microdissection. Archived FFPE tissue was reviewed by specialist pathologists, sandwich sectioned, and initially whole‐tissue sections genotyped for HPV. Samples were first genotyped using SPF10‐LiPA25 (version 1). Negative samples were screened with DNA ELISA kit HPV SPF10, followed by genotyping with SPF+ LiPA if ELISA positive. If still negative, samples were tested on a qPCR assay targeting the E6 region of HPV16, 18, 45 and 33. Of the 847 cancers (65.1% squamous, 28.7% adenocarcinoma, 4.3% adenosquamous, 2.0% other), 92.9% had HPV detected. Of the HPV‐positive cancers, 607 of 787 (77.1%) contained HPV16 or 18, 125 of 787 (15.9%) contained HPV31/33/45/52 or 58, and 55 (7.0%) another HPV type. There was a strong correlation between HPV type and age, with younger women most likely to have HPV16/18 detected and least likely HPV negative. Our findings indicate that cervical cancers diagnosed in Australia more frequently contain HPV16/18 than in international series. This could be due to cervical screening in Australia increasing the proportion of adenocarcinomas, in which types 18 and 16 more strongly predominate, due to prevention of squamous cancers.

Anal HPV detection in men who have sex with men living with HIV who report no recent anal sexual behaviours: baseline analysis of the Anal Cancer Examination (ACE) study

Objectives Men who have sex with men (MSM) living with HIV are at high risk of infection with high-risk human papillomavirus (HPV), the cause of anal cancer. We assess whether anal HPV DNA detection is related to recent anal sexual activity, what types of anal sexual activity or the persistence of HPV genotypes. Methods We analysed anal swabs taken at the baseline of a 2-year prospective anal cancer screening study of MSM living with HIV from four HIV clinics in Melbourne, Australia. Anal HPV detection was stratified by age and anal sexual behaviours. Results 281 anal swabs were included in the analysis. The majority (80%, 95% CI 75 to 84) of men were positive for any HPV; 59% (95% CI 53 to 65) were positive for high-risk HPV (hr-HPV) genotypes; and 31% (95% CI 26 to 36) men were positive for HPV 16 and/or 18 with no significant differences according to age groups (p>0.261). In men who reported no receptive anal sexual activity in the last six months (22%), hr-HPV was found in 53% (95% CI 41 to 65) for no anal sexual activity versus. 60% (95% CI 54 to 67) for anal sexual activity (p=0.320). HPV 16 and/or 18 was found in 26% (95% CI 16 to 38) for no anal sexual activity versus. 32% (95% CI 27 to 39) for anal sexual activity (p=0.320). Conclusions Anal HPV in MSM living with HIV is detected in the majority of men throughout all age groups. Anal HPV detection remains high even in men reporting no anal sexual activity in the preceding six months.

High reproducibility of histological diagnosis of human papillomavirus-related intraepithelial lesions of the anal canal

Summary In a natural history study of anal human papillomavirus (HPV) infection and HPV-related lesions, we examined the reproducibility of histological high-grade squamous intraepithelial lesion (HSIL). Three expert anogenital pathologists share the reporting of histological specimens from the Study of the Prevention of Anal Cancer (SPANC), utilising Lower Anogenital Squamous Terminology (LAST) criteria. In total, 194 previously reported biopsies were randomly chosen within diagnostic strata [50 HSIL–anal intraepithelial neoplasia (AIN) 3; 45 HSIL–AIN 2; 49 ‘flat’ low-grade squamous intraepithelial lesion (LSIL); 50 ‘exophytic’ LSIL; and 50 negative for squamous intraepithelial lesion] and reviewed by each of these three pathologists. Consensus was defined as agreement between at least two review diagnoses, using a binary classification of HSIL and non-HSIL, or if consensus was not obtained in this way, it was achieved through a multiheader microscope session by the three pathologists. We found very high agreement between original and consensus diagnoses (Kappa = 0.886) and between each pathologists review and consensus (Kappas = 0.926, 0.917 and 0.905). Intra-observer agreement for the three pathologists was 0.705, 1.000 and 0.854. This high level of diagnostic reproducibility indicates that the findings of SPANC should be robust and provide reliable information about HPV-related anal canal disease.

Front-to-back & dabbing wiping behaviour post-toilet associated with anal neoplasia & HR-HPV carriage in women with previous HPV-mediated gynaecological neoplasia

BACKGROUND Anal cancer is a human papillomavirus (HPV)-mediated neoplasia of the anal squamous epithelium. Anal cancer is much more common among women, particularly those with a previous high-grade gynaecological neoplasia. METHODS Cross-sectional study of women with a previous HPV-mediated gynaecological neoplasia in Tasmania, Australia. Women presenting for follow-up gynaecological care had anal swab samples taken for anal cytology by Hologic Liquid ThinPrep, followed by HPV genotyping. Women with abnormal anal cytology were invited for high-resolution anoscopy. Potential risk factors, including post-toilet wiping behaviours, were queried by questionnaire while clinical covariates were extracted from medical records. Covariates of anal outcomes evaluated by log-binomial and log-multinomial regression. RESULTS From 163 women enrolled in the study, 65 (39.9%) had abnormal cytology, with 46 (28.2%) being high-grade. Of the 50 women with abnormal anal cytology having high-resolution anoscopy, 32 (64.0%) had abnormal histology with 13 (26.0%) being high-grade. Of the 123 women tested for HR-HPV DNA, 48 (39.0%) had HR-HPV detected, the most common genotypes being 16 and 51 (14/123, 11.4% for both). In addition to some known anal cancer risk factors, we found front-to-back wiping was associated with significantly increased (Prevalence ratio (PR) range: 1.99-3.60) prevalence of cytological and histological abnormality and HR-HPV carriage/co-carriage, while dabbing post-toilet was significantly associated with decreased prevalences (PR range: 0.50-0.62). CONCLUSIONS Post-toilet wiping behaviours were significantly associated with the prevalence of anal cytological, histological and HR-HPV carriage outcomes. This suggests a biologically plausible mechanism for HR-HPV introduction and the higher frequencies of anal neoplasia in women.

Vaccine-preventable anal human papillomavirus in Australian gay and bisexual men

Objective HPV causes ~90% of anal cancer and HPV16 is the type most commonly associated with anal cancer. Gay and bisexual men (GBM) are at greatly increased risk. We investigated patterns of vaccine-preventable anal HPV in older GBM. Methods The Study of the Prevention of Anal Cancer (SPANC) is an ongoing, prospective cohort study of HIV-positive and HIV-negative Australian GBM. Participants completed questionnaires and underwent an anal swab for HPV genotyping using Roche Linear Array. We analysed baseline data from SPANC by HPV type, mean number of types, stratified by age and HIV status. Results Anal HPV results from 606 (98.2%) of 617 participants (median age 49 years, 35.7% HIV-positive) showed 525 (86.7%) had ≥1 HPV type and 178 (29.4%) had HPV16. Over one third of participants (214, 35.3%) had no nonavalent vaccine-preventable types detected. Two (0.3%) participants had all quadrivalent types and none had all nonavalent vaccine types. HIV-positive participants (p<0.001) and younger participants (p=0.059) were more likely to have more vaccine-preventable HPV types detected. Conclusion Anal HPV was highly prevalent in this largely community-based GBM cohort. Vaccine-preventable HPV16 was detected in approximately one third of participants. These findings suggest that the potential efficacy of HPV vaccination of older GBM should be explored.

The performance of human papillomavirus biomarkers in predicting anal high-grade squamous intraepithelial lesions in gay and bisexual men.

Background: We evaluate the performance of human papillomavirus (HPV) biomarkers in prediction of anal histological high-grade squamous intraepithelial lesions in gay and bisexual men (GBM) in Sydney, Australia. Design: Baseline analysis of a 3-year cohort study. Methods: The Study of the Prevention of Anal Cancer is natural history study of anal HPV infection in GBM aged at least 35 years. All participants completed cytological and histological assessments. Stored ThinPrep PreservCyt residua were tested for HPV genotyping (Linear Array and Cobas 4800) and viral load, E6/E7 mRNA expression (NucliSENS easyQ HPV v1) and dual cytology staining of p16INK4a/Ki 67 antibodies (CINtecPLUS). Performance of each biomarker was compared with liquid-based anal cytology. The hypothetical referral rates were defined as the proportion of men who had abnormal cytology or tested positive to each of the biomarkers. Results: The median age of the 617 participants was 49 years (range: 35–79), and 35.7% were HIV-positive. All biomarkers were strongly associated with the grade of HPV-associated anal lesions (P < 0.001 for all). High-risk HPV (HR-HPV) viral load with a 33% cut-off and HR-HPV E6/E7 mRNA had similar sensitivity to anal cytology (78.4 and 75.4 vs. 83.2%, respectively), improved specificity (68.0 and 69.4 vs. 52.4%, respectively) and lower referral rates (47.0 and 45.0 vs. 59.2%, respectively). Specificity was significantly higher in the HIV-negative for HR-HPV viral load (72.3 vs. 58.2%, P = 0.005). Conclusion: HR-HPV viral load and E6/E7 mRNA had similar sensitivity and higher specificity in predicting histological anal high-grade squamous intraepithelial lesion with lower referrals in GBM than anal cytology.

Genetic and Environmental Factors in Invasive Cervical Cancer: Design and Methods of a Classical Twin Study

BACKGROUND Persistent high-risk human papillomavirus (HPV) infection is a necessary prerequisite for development of cervical cancer and its precursor lesion, high-grade squamous intraepithelial lesion (HSIL). However, HPV infection is not sufficient to drive this process, and genetic and environmental factors may also play a role. METHODS/DESIGN The Cervical Cancer, Genetics and Environment Twin Study was established to investigate the environmental and genetic influences on variation in susceptibility to cervical pre-cancer in 25- to 69-year-old monozygotic (MZ) and dizygotic (DZ) twins recruited through the Australian Twin Registry. Reviews of Papanicolaou (Pap) screening histories were undertaken to identify individual women with a history of an abnormal Pap test. This was followed by detection of HPV in archival Pap smears of selected twin pairs to determine HPV persistence. Selected twin pairs also completed a detailed questionnaire on socio-demographic characteristics, sexual behavior, and HPV knowledge. In future analyses, under the assumptions of the classical twin design, case-wise concordance for persistent HPV infection and HSIL will be calculated for MZ and DZ twin pairs, and twin pairs (both MZ and DZ) who are discordant for the above outcomes will be used to assess the contributions of measured environmental risk factors. DISCUSSION The study examines factors related to HPV persistence and development of HSIL among female MZ and DZ twins. The results will contribute to our understanding of the natural history of cervical HPV infection and the relative contributions of genetic and environmental factors in disease progression.

Papillary Immature Metaplasia of the Anal Canal: A Low-grade Lesion That Can Mimic a High-grade Lesion.

In a natural history study of anal human papillomavirus (HPV) infection and HPV-related lesions among homosexual men in Sydney, Australia, we identified 15 examples of papillary immature metaplasia (PIM) in anal biopsy samples. PIM has previously been described in the cervix, but not in the anal canal. PIM is a form of exophytic low-grade squamous intraepithelial lesion (eLSIL) also known as condyloma. In contrast to the maturing keratinocytes and koilocytosis seen in conventional eLSIL, the slender papillary structures of PIM have a surface population of immature squamous cells. In our anal samples PIM was characterized by close proximity to conventional eLSIL, was negative for p16INK4A (p16) expression, and revealed the presence of a single low-risk HPV genotype (either 6 or 11) in laser capture microdissected lesions. The clinical significance of recognizing PIM lies in preventing misdiagnosis as high-grade squamous intraepithelial lesion, (the presumed precursor to anal cancer), due to the morphologic immaturity of the cell population. In routine practice, awareness of anal canal PIM and p16 immunostaining will prevent this. Further study of the natural history of anal canal PIM is needed.