Population-based evaluation of type-specific HPV prevalence among women in British Columbia, Canada

Detection and Genotyping of Papillomavirus by Real-Time PCR in Iraqi Patients

Background: Cervical cancer (CC) is linked to human papillomavirus (HPV). Globally, the prevalence and genotype distribution differ significantly. Objectives: The goal of this study was to find HPV 14, 16, 18, and 45 genotypes in urogenital swabs by using a real-time PCR amplification test for quantitative genotyping of HPV DNA types 16, 18, and 45 and for simultaneous quantitative detection of HPV DNA types 31, 33, 35, 39, 51, 52, 56, 58, 59, 66, and 68, for a total of 14 HPV genotypes. Methods: This case-control study included 86 cervical swabs from Iraqi women referred by the Al-Yarmook teaching hospital in Baghdad, Iraq. The ages of cases varied from 23 to 70 years and specimens were obtained between March 2020 and March 2021. The DNA was extracted for molecular assay. Fourteen HPV genotypes were detected using real-time PCR (16, 18, 45, 31, 33, 35, 39, 51, 52, 56, 58, 59, 66, and 68). The detection protocol was based on the commercial Kit V31-100/F FRT as follows. For each sample reaction, 10х(N+1) μL of PCR-mix-1-FRT HPV 14 was added into a new tube. Then, 5.0х(N+1) μL of PCR-mix-2 buffer and 0.5х(N+1) μL of TaqF DNA polymerase were added. The tubes were vortexed. Finally, the prepared tubes added 10 μL of DNA samples from test or control samples. The statistical analysis was conducted using the statistical package for SPSS and Excel 2016 software. Results: Genotype 16 had the highest frequency, followed by genotypes 45 (22%), 18 (14%), 35 and 59 (6%), 52 and 58 (4%), and 31 (2%), while genotypes 33, 39, 51, 56, 66, and 68 had the lowest frequency (1%). Conclusions: The real-time PCR was efficient for detecting and genotyping HPV-DNA and could help in earlier detection and clinical care of HPV-infected patients by reducing costs and workload.

Association Between Human Papillomavirus Infection Among Pregnant Women and Preterm Birth

IMPORTANCE

Preterm birth remains a leading cause of perinatal mortality and lifelong morbidity worldwide. The cause of most preterm births is unknown, although several infectious processes have been implicated.

OBJECTIVE

To assess whether human papillomavirus (HPV) infection, a frequent infection among women of childbearing age, is associated with preterm birth.

DESIGN, SETTING, AND PARTICIPANTS

The prospective HERITAGE cohort study was conducted at 3 academic hospitals in Montreal, Québec, Canada, among 899 pregnant women recruited between November 8, 2010, and October 16, 2016. Follow-up was completed on June 15, 2017. Statistical analysis was conducted from February 6, 2020, to January 21, 2021.

EXPOSURES

Vaginal HPV DNA detection in the first and third trimesters of pregnancy and placental HPV infection.

MAIN OUTCOMES AND MEASURES

The main outcome was preterm birth (defined as a live birth or stillbirth between 20 weeks and 0 days and 36 weeks and 6 days of gestation). The association between HPV DNA detection and preterm birth was measured using logistic regression. Odds ratios (ORs) and 95% CIs were adjusted by inverse probability of treatment weights of the propensity score.

RESULTS

The study included 899 women (mean [SD] age, 31.3 [4.6] years [range, 19-47 years]) with singleton pregnancies. A total of 378 women (42.0%) had HPV DNA detected in vaginal samples collected during the first trimester, and it was detected in 91 of 819 placentas (11.1%) at delivery. Fifty-five participants experienced preterm birth (38 spontaneous and 17 medically indicated). Persistent vaginal HPV-16/18 detection was significantly associated with all preterm births (adjusted OR [aOR], 3.72; 95% CI, 1.47-9.39) and spontaneous preterm births (aOR, 3.32; 95% CI, 1.13-9.80), as was placental HPV infection (all preterm births: aOR, 2.53; 95% CI, 1.06-6.03; spontaneous preterm births: aOR, 2.92; 95% CI, 1.09-7.81). Results were similar when restricting the analysis to participants without a history of cervical intraepithelial neoplasia treatment.

CONCLUSIONS AND RELEVANCE

The study's results suggest that persistent HPV-16/18 infection is associated with an increased risk of preterm birth, independent of cervical treatment. Future studies should investigate the association of HPV vaccination and vaccination programs with the risk of preterm birth.

High-risk HPV prevalence among women undergoing cervical cancer screening: Findings a decade after HPV vaccine implementation in British Columbia, Canada

BACKGROUND

British Columbia (BC) introduced a publicly funded, school-based human papillomavirus (HPV) immunization program in 2008 with the quadrivalent vaccine. In 2010/2011, a baseline evaluation of HPV prevalence was conducted among women undergoing cervical cancer screening. After 10 years of publicly funded HPV vaccination, HPV-type prevalence was re-evaluated.

METHODS

From August 2017 to March 2018, 1107 physicians were invited to return cytobrushes used during routine Pap screening to the Cervical Cancer Screening Laboratory for HPV testing. Only age or year of birth was collected. Specimens were screened for high-risk HPV (hrHPV) and positive samples were genotyped. HPV type prevalence was compared for females 15-22 yrs (those eligible for the school-based vaccination) and 23+ yrs (ineligible for school-based vaccination) for the 2010/2011 and the 2017/2018 data.

RESULTS

There were 3309 valid samples received for testing; of these, 3107 were included in the analysis. The overall hrHPV prevalence was 12.2% (95% CI 11.3-13.3) in 2010/11, and 12.0% (95% CI 10.9-13.2) in 2017/18. For the 15-22 age group, the prevalence for any hrHPV was 26.8% (95% CI 23.1-30.8) in 2010/11 and 25.4% (95% CI 15.3-37.9) in 2017/18. For those aged 15-22, HPV16 prevalence in 2010/11 was 8.8% (95% CI 6.5-11.5) and in 2017/18 was 6.3% (95% CI 1.8-15.5), with corresponding figures for HPV18 3.7% (95% CI 2.3-5.7) and 0% (95% CI 0.0-5.7), respectively. For all hrHPV types, there were no statistically significant differences between the 2010/11 and 2017/18 periods.

CONCLUSIONS

This study illustrates the prevalence of hrHPV in BC over time in women undergoing cervical cancer screening, where an indication of a decline in HPV16/18 is seen in vaccine eligible women.

A health economic model to estimate the costs and benefits of an mRNA vs DNA high-risk HPV assay in a hypothetical HPV primary screening algorithm in Ontario, Canada

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Using an mRNA HPV test in cervical screening can reduce costs and avoid procedures.

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This could benefit both the healthcare system and women by optimizing resource use.

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These results can inform choices in cervical screening programs in Canada.

This study models the impact of using two different types of high-risk (HR) human papillomavirus (HPV) tests: mRNA (Aptima) and DNA (Hybrid Capture 2) as part of a hypothetical primary HPV screening program in Ontario, Canada. Outcomes were the costs of the screening program, and number of colposcopies, HPV tests and cytology tests. Results were estimated for one cohort going through the screening algorithm. A decision tree model was adapted from a published UK study, with inputs drawn from published Canadian data for the probabilities through the model, costs, demographic, and screening data from Ontario. Sensitivity and scenario analyses explored uncertainty in the model inputs and assumptions. Results indicated that screening using an mRNA test could yield cost savings of CAD $4,007,266 (95% credibility interval [CI]: −7,866,251 – 8,035) compared to using a DNA test, with 10,639 (95% CI: 10,170 – 11,094) fewer women undergoing unnecessary colposcopies, and reductions in unnecessary HR-HPV and cytology tests. The HR-HPV test comprised the largest percentage of the costs saved, and the probability of being HPV positive in the first year had the biggest impact on results. These results indicate that the choice of HR-HPV test is important when implementing a primary HPV screening program to avoid unnecessary resource use and cost, which will benefit both women and healthcare providers.

High frequency of HPV genotypes 59, 66, 52, 51, 39 and 56 in women from Western Mexico

BACKGROUND

Human papillomavirus infection is an important factor associated with cervical cancer (CC) development. The prevalence and genotype distribution vary greatly worldwide. Examining local epidemiological data constitutes an important step towards the development of vaccines to prevent CC. In this work, we studied the prevalence of HPV genotypes in women from Western Mexico with the COBAS 4800 and/or Linear Array Genotyping Test (LA).

METHODS

The samples analysed in this study represent a population from Western Mexico, which includes six different states. Our approach was first to test for HPV in cervical samples from women who attended their health clinic for routine gynaecological studies (open-population, n = 3000) by utilizing COBAS 4800. Afterwards, 300 of the HPV-positive samples were randomly selected to be genotyped with LA; finally, we genotyped samples from women with cervical intraepithelial neoplasia grade 1 (CIN 1, n = 71) and CC (n = 96) with LA. Sociodemographic data of the diverse groups were also compared.

RESULTS

The overall HPV prevalence among the open-population of women as determined by COBAS 4800 was 12.1% (n = 364/3000). Among the HPV-positive samples, single infections (SI) with HPV16 were detected in 12.4% (n = 45/364), SI with HPV18 were detected in 1.4%, and infection with at least one of the genotypes included in the high-risk HPV pool was detected in 74.5% of the cases. LA analysis of the samples showed that in addition to HPV genotypes 16 and 18, there was a high prevalence of HPV genotypes 59, 66, 52, 51, 39 and 56 in women from Western Mexico. With respect to the sociodemographic data, we found statistically significant differences in the number of pregnancies, the use of hormonal contraceptives and tobacco intake.

CONCLUSIONS

Our data indicate that there is a high prevalence of HPV genotypes which are not covered by the vaccines currently available in Mexico; therefore, it is necessary to include HPVs 59, 66, 51, 39 and 56 in the design of future vaccines to reduce the risk of CC development. It is also essential to emphasize that the use of hormonal contraceptives and tobacco smoking are risk factors for CC development in addition to the presence of HPV.

Cervical Intraepithelial Neoplasia Rates in British Columbia Women: A Population-Level Data Linkage Evaluation of the School-Based HPV Immunization Program

BACKGROUND

To understand real-world human papillomavirus (HPV) vaccine impact, continuous evaluation using population-based data is critical. We evaluated the early impact of the school-based HPV immunization program on cervical dysplasia in women in British Columbia, Canada.

METHODS

Data linkage was performed using records from provincial cervical screening and immunization registries. Precancerous outcomes were compared between unvaccinated and HPV-vaccinated women born 1994-2005. Incidence rate, relative rate (RR), and vaccine effectiveness (VE), using unadjusted and adjusted Poisson regression of cytology (HSIL) and histopathology (CIN2, CIN3, and CIN2+) outcomes, were compared across vaccination status groups.

RESULTS

Women who received a complete series of vaccine on schedule between age 9 and 14 years had an adjusted RR = 0.42 (95% confidence interval [CI], 0.31-0.57) for CIN2+ over 7 years of follow-up compared to unvaccinated women, resulting in a VE of 57.9% (95% CI, 43.2%-69.0%). Adjusted RR for HSIL was 0.53 (95% CI, .43-.64), resulting in a VE of 47.1% (95% CI, 35.6%-56.7%).

CONCLUSION

Women vaccinated against HPV have a lower incidence of cervical dysplasia compared to unvaccinated women. Immunization between 9 and 14 years of age should be encouraged. Continued program evaluation is important for measuring long-term population impact.

Conservative management of CIN2: National Audit of British Society for Colposcopy and Cervical Pathology members' opinion

There is no doubt that organised cervical screening programmes have significantly reduced the rates of cervical cancer by detection and treatment of high-grade cervical intraepithelial neoplasia (CIN2, CIN3). National UK guidelines do not differentiate between CIN2 and CIN3 as separate entities and recommend treatment for both, although a degree of uncertainty exists regarding the natural history of CIN2. This national survey of British Society for Colposcopy and Cervical Pathology members aimed to assess attitudes towards conservative management (CM) of CIN2 in the UK and identify potential selection criteria. In total, 511 members responded (response rate 32%); 55.6% offered CM for selective cases; 12.4% for all cases; 16.4% had formal guidelines. Most agreed age group was >40yrs (83%), HPV 16/18 positive (51.4%), smoking (60%), immuno-compromise (74.2%), and large lesion size (80.8%) were relative contraindications for CM. 75.9% favoured six-monthly monitoring, with 80.2% preferring excisional treatment for persistent high-grade disease. Many UK colposcopists manage CIN2 conservatively without formal guidelines. Potential selection criteria should be investigated by a multicentre study. Impact statement Although anecdotally some colposcopists manage many women with CIN2 conservatively, this National Audit of British Society for Colposcopy and Cytopathology members, we believe, is the first time this has been formally recorded. The survey assesses current attitudes towards conservative management (CM) of CIN2 and seeks to identify potential selection criteria that could be used to identify suitable women. It received over 500 responses and significantly, identified many colposcopists recommending CM of CIN2 for patients despite the lack of any formal guidance regarding this approach. The greater majority of respondents were keen to consider participating in a multicentre trial on CM of CIN2 targeting the UK screening population (25-64 years). The paper has international relevance as ACOG and ASCCP have recently changed their guidance for the management of CIN2 in younger women and now recommend CM with monitoring rather than first line ablative or excisional treatment due to concerns regarding overtreatment, especially in women who have not yet completed their family.

Differences in age-specific HPV prevalence between self-collected and health personnel collected specimen in a cross-sectional study in Ghana

BACKGROUND

HPV infections are ubiquitous and particularly common among sexually active young women. However, there are regional and national variations in age-specific HPV prevalence, which have implications for cervical cancer control. Data on age-specific HPV prevalences for Ghana and most sub-Saharan countries are scanty. Therefore, this study primarily sought to determine the age-specific HPV prevalence among women in a Ghanaian community and to determine whether these prevalences determined with health-personnel and self-collected specimens were comparable.

METHODS

In this cross-sectional study, conducted between March 2012 and March 2013, cervical specimens were collected by self- and health-personnel collection from 251 women who were between the ages of 15 and 65 years. HPV present in these specimens were genotyped by a nested-multiplex PCR and Luminex fluoro-microspheres based method. Information on the demographic, sexual and reproductive characteristics of the women were also obtained. A Chi-square test of association was employed to determine the association of the distribution of age groups with each categorised sexual and reproductive characteristic and HPV risk type's status.

RESULTS

The age group distribution of the participants was significantly associated with overall (χ2 = 36.1; p = 0.001), high risk (χ2 = 26.09; p = 0.002) and low risk (χ2 = 21.49; p = 0.011) HPV prevalences. The age-specific HPV prevalence pattern for each of the HPV risk types, determined with self-collected specimen, showed three peaks (at 20-24 years; 40-44 years and ≥ 55 years), while those determined with health-personnel collected specimen, showed two peaks (at 20-24 years and ≥ 55 years) for each HPV risk type's prevalence pattern. The high risk HPV prevalences determined with self-collected specimen were often higher than those determined with health-personnel specimen for the age groups between 25 and 45 years, who are mostly targeted for screening by HPV testing. Additionally, there were interesting variations in patterns of age-specific HPV genotype-specific prevalence between the two specimen collection methods.

CONCLUSIONS

The usefulness of self-collected specimen for high risk HPV burden determination and the existence of a two peaked and three peaked age-specific HPV prevalences in Ghana have been clearly indicated.

HPV Vaccine Uptake Among Canadian Youth and The Role of the Nurse Practitioner

The human papillomavirus (HPV) infects approximately 550,000 Canadians annually. Cancers of the cervix, mouth, anus, throat and neck are caused by various strains of the virus. The virus also causes genital warts. The disease and economic burden of HPV is high. Primary prevention through vaccine administration prior to onset of sexual activity is evidenced as best practice. Two vaccines are available, Gardasil and Cervarix. Consistent with global practices in developed countries, these vaccines are currently publicly funded for females and provided in school-based clinics in all provinces and territories in Canada. Despite well-documented efficacy with minimal adverse effects, the uptake of these vaccines remains low in all countries, including Canada. Although HPV immunization rates have increased, they remain significantly below the rates of other vaccine-preventable diseases. This is puzzling since school-based clinics and public funding presumably increase vaccine access. Barriers explicated include family lack of knowledge about the vaccine, and attitudes that are not informed by science and epidemiology. There is evidence that a health provider's recommendation is the single biggest influence on uptake. However, not all providers are cognizant about emerging issues in this area, including controversies about universal coverage for boys as well as girls, new vaccines and more. Nurse practitioners are in a position to collaborate with public health agencies to expand knowledge and coverage across Canada.

Comparison of the Roche cobas® 4800 and Digene Hybrid Capture® 2 HPV tests for primary cervical cancer screening in the HPV FOCAL trial

BACKGROUND

HPV FOCAL is a randomized trial (ISRCTN79347302, registered 20 Apr 2007) comparing high-risk (hr) HPV testing vs. liquid-based cytology (LBC) for cervical cancer screening of women aged 25-65. We compared the Digene Hybrid Capture® 2 High-Risk HPV DNA Test® (HC2) and the Roche cobas® 4800 HPV Test (COBAS) for primary screening.

METHODS

Women (n=6,172) were screened at baseline by HC2 and COBAS and by LBC 24 months later. We assessed HPV genotyping and reflex LBC for colposcopy triage of baseline HPV positive women.

RESULTS

Overall HC2/COBAS agreement was 96.1% (kappa 0.75) and positive agreement was 77.5%. Baseline CIN2 and CIN3+ rates based on HPV screening were 8.6/1,000 and 6.6/1,000 respectively; 24 month rates were 0.7/1,000 and 0.4/1,000 (LBC screening). HC2 and COBAS were concordant positive for 91% of round 1 CIN2 and 98% of CIN3+. CIN3+ was significantly associated with HPV 16 (Odds Ratio [OR] 5.11; 95% confidence interval [CI] 2.30, 11.37), but not HPV 18 (OR 2.62; 95% CI 0.73, 9.49), vs. non-HPV 16/18 HPV at baseline. There was no significant association between HPV genotype and CIN2. CIN3+ was significantly more likely for high-grade (OR 5.99; 95% CI 2.53, 14.18), but not low-grade (OR 0.54; 95% CI 0.20, 1.49), vs. negative LBC. No significant association was observed between LBC grade and CIN2. HPV 16 and 18 were associated with 33% of CIN2 and 68% of CIN3+ identified at baseline.

CONCLUSIONS

For hrHPV positive women, abnormal reflex LBC is appropriate for colposcopy triage. In addition, immediate referral of women with HPV 16/18 and normal cytology may allow for earlier detection of CIN2+ lesions which would not be detected until after follow-up testing.

Reduction in cervical intraepithelial neoplasia in young women in British Columbia after introduction of the HPV vaccine: An ecological analysis

We report on the rates of cervical intraepithelial neoplasia (CIN) in young women aged 15-22 years of age in British Columbia before and after the introduction of an HPV vaccine program. Rates of cervical intraepithelial neoplasia (CIN) 2+ for each age stratum (15-22) in the calendar years 2004-2012 for the province of British Columbia were obtained from the BC Cancer Agency's population-based cervical cancer program. Incidence rate ratios (IRR) of CIN2+ were described and compared before and after HPV vaccine program introduction in cohorts born in vaccine eligible years, and in non-vaccine eligible years using piece-wise Poisson regression analysis, and adjusted for age. Between 2004 and 2012, rates of CIN2 and CIN2+ in young women aged 15-22 years in the province of British Columbia have decreased overall. After the introduction of the HPV vaccine program, the age adjusted IRR for CIN2+ for young women aged 15-17 years decreased significantly from 0.91 (95% CI: 0.86-0.98 p < 0.01) to 0.36 (95% CI: 0.18-0.73 p < 0.01). During the same time period, no similar reduction was found in young women 18-22 years. After introduction of HPV vaccine program, IRR for CIN2+ in young women 15-17 was significantly reduced for CIN2+ (0.14; 95% CI: 0.04- 0.47; p < 0.01) and CIN2 (0.1; 95% CI: 0.02-0.54; p < 0.01). This ecological analysis shows a significant reduction in CIN2+ lesions in young women aged 15-17 years in British Columbia after the introduction of the HPV vaccine in young women despite vaccine uptake levels below 70%.

Clinical evaluation of a GP5+/6+-based luminex assay having full high-risk human papillomavirus genotyping capability and an internal control

The LMNX genotyping kit HPV GP (LMNX) is based on the clinically validated GP5+/6+ PCR, with a genotyping readout as an alternative for the more established enzyme immunoassay (EIA) detection of 14 targeted high-risk human papillomavirus (HPV) types. LMNX is additionally provided with an internal control probe. Here, we present an analysis of the clinical performance of the LMNX using a sample panel and infrastructure provided by the international VALGENT (Validation of Genotyping Tests) project. This panel consisted of cervical specimens from approximately 1,000 women attending routine screening, "enriched" with 300 women with abnormal cytology. Cases were defined as women classified with cervical intraepithelial neoplasia (CIN) grade 2+ (CIN2+) (n = 102) or CIN3+ (n = 55) within the previous 18 months. Controls were women who had normal cytology results over two subsequent screening rounds at a 3-year interval (n = 746). The GP5+/6+-PCR EIA (EIA) was used as a comparator assay and showed sensitivities of 94.1% and 98.2% for CIN2+ and CIN3+, respectively, with a clinical specificity of 92.4% among women aged ≥ 30 years. The LMNX demonstrated clinical sensitivities of 96.1% for CIN2+ and of 98.2% for CIN3+ and a clinical specificity of 92.6% for women aged ≥ 30 years. The LMNX and EIA were in high agreement (Cohen's kappa = 0.969) for the detection of 14 hrHPVs in aggregate, and no significant difference was observed (McNemar's P = 0.629). The LMNX internal control detected 0.6% inadequate specimens. Based on our study results, we consider the LMNX, similarly to the EIA, useful for HPV-based cervical cancer screening.

Clinical prediction based on HPV DNA testing by hybrid capture 2 (HC2) in combination with liquid-based cytology (LBC)

Primary screening by HPV DNA testing is an effective method for reducing cervical cancer and has proven more sensitive than cytology. To advance this approach, many molecular methods have been developed. Hybrid capture 2 provides semi-quantitative results in ratios of relative light units and positive cutoff values (RLU/ PC). Twenty-five thousand and five patients were included in this study to analyze the correlation between the ratio of RLU/PC and stage of cervical dysplasia. The results show that the RLU/PC ratios ranged from 0-3500 while almost normal cases, ASC-US and ASC-H, had values below 200. Of those samples negative for cytology markers, 94.6% were normal and their RLU/PC ratios were less than 4. With an RLU/PC ratio greater than 4 and less than or equal to 300, the percentages in all age groups were normal 53.6%, LSIL 20.2%, ASC-US 17.2%, HSIL 6.13%, ASC-H 2.72%, and AGC 0.11%, respectively. In contrast, 64.0% of samples with a RLU/ PC ratio greater than 300 and less than or equal to 3500 were LSIL. These results should contribute to cost effective cervical cancer management strategies. Further studies of associations with particular HPV genotypes would be useful to predict the risk of progression to cancer.

Incidence of ano-genital and head and neck malignancies in women with a previous diagnosis of cervical intraepithelial neoplasia

OBJECTIVE

The objective of this study was to determine if women with a history of Cervical Intraepithelial Neoplasia grades 2 and 3 (CIN2 and CIN3) are at increased long-term risk for developing non-cervix HPV-related malignancies.

MATERIAL AND METHODS

Women diagnosed with CIN2 or CIN3 between 1980 and 2005 were identified from the British Columbia (BC) Cancer Agency Cervical Cancer Screening Program's database. These patients' records were then cross-referenced with the BC Cancer Registry for diagnosis of vulvar, vaginal, anal or head and neck (HN) cancers during the period subsequent to their diagnosis of CIN. Standardized incidence ratios (SIR) were generated according to expected rates of each cancer.

RESULTS

54,320 women with a diagnosis of CIN2 or CIN3 were identified between 1985 and 2005. The crude incidence rate for non-cervix HPV-related cancers was 35.4 per 100,000 person-years (8.6 for vagina, 17.6 for vulva, 3.7 for anal canal and 5.5 for HN). The SIR was 1.9 (95% CI 1.3-2.7) for all non-cervix cancers, 6.7 (95% CI: 3.0-12.8) for vagina, 2.9 (95% CI: 1.7-4.6) for vulva, 1.8 (95% CI: 0.4-4.7) for anal canal, and 0.6 (95% CI: 0.2-1.4) for HN. There were statistically significant increases in anal cancers for years 5-9 and in HN cancers for years 0.5-5.

CONCLUSION

BC women with a history of CIN2 or CIN3 are at relatively high risk of developing non-cervical HPV-related malignancies. The findings of this study suggest that interventions such as vaccination against high-risk HPV or long-term screening for these other cancers should be evaluated.