Prophylactic vaccination against human papillomaviruses to prevent vulval and vaginal cancer and their precursors

Epidemiology of HPV-associated cancers past, present and future: towards prevention and elimination

Cervical cancer is the first cancer deemed amenable to elimination through prevention, and thus lessons from the epidemiology and prevention of this cancer type can provide information on strategies to manage other cancers. Infection with the human papillomavirus (HPV) causes virtually all cervical cancers, and an important proportion of oropharyngeal, anal and genital cancers. Whereas 20th century prevention efforts were dominated by cytology-based screening, the present and future of HPV-associated cancer prevention relies mostly on HPV vaccination and molecular screening tests. In this Review, we provide an overview of the epidemiology of HPV-associated cancers, their disease burden, how past and contemporary preventive interventions have shaped their incidence and mortality, and the potential for elimination. We particularly focus on the cofactors that could have the greatest effect on prevention efforts, such as parity and human immunodeficiency virus infection, as well as on social determinants of health. Given that the incidence of and mortality from HPV-associated cancers remain strongly associated with the socioeconomic status of individuals and the human development index of countries, elimination efforts are unlikely to succeed unless prevention efforts focus on health equity, with a commitment to both primary and secondary prevention.

Use of concept mapping to inform a participatory engagement approach for implementation of evidence-based HPV vaccination strategies in safety-net clinics

BACKGROUND

Multiple evidence-based strategies (EBS) for promoting HPV vaccination exist. However, adolescent HPV vaccination rates remain below target levels in communities at high risk for HPV-associated cancers and served by safety-net clinics. Participatory engaged approaches are needed to leverage the expertise of community and clinical partners in selecting EBS relevant to their local context. We engaged concept mapping as a method to inform the adoption and adaptation of EBS that seeks to empower implementation partners to prioritize, select, and ultimately implement context-relevant EBS for HPV vaccination.

METHODS

Using 38 EBS statements generated from qualitative interviews and national HPV vaccine advocacy sources, we conducted a modified concept mapping activity with partners internal to safety-net clinics and external community members in two study sites of a larger implementation study (Greater Los Angeles and New Jersey), to sort EBS into clusters and rate each EBS by importance and feasibility for increasing HPV vaccination within safety-net clinics. Concept mapping findings (EBS statement ratings, ladder graphs and go-zones) were shared with leaders from a large federally qualified health center (FQHC) system (focusing on three clinic sites), to select and implement EBS over 12 months.

RESULTS

Concept mapping participants (n=23) sorted and rated statements, resulting in an eight-cluster solution: 1) Community education and outreach; 2) Advocacy and policy; 3) Data access/quality improvement monitoring; 4) Provider tracking/audit and feedback; 5) Provider recommendation/communication; 6) Expanding vaccine access; 7) Reducing missed opportunities; and 8) Nurse/staff workflow and training. The FQHC partner then selected to intervene on eight of 17 EBS statements in the "go-zone" for action, with three from "reducing missed opportunities," two from "nurse/staff workflow and training," and one each from "provider tracking/audit and feedback," "provider recommendation/communication," and "expanding vaccine access," which the research team addressed through the implementation of three multi-level intervention strategies (e.g., physician communication training, staff training and workflow assessment, audit and feedback of clinic processes).

CONCLUSIONS

Concept mapping provided a powerful participatory approach to identify multilevel EBS for HPV vaccination relevant to the local safety-net clinic context, particularly when several strategies exist, and prioritization is necessary. This study demonstrates how a clinic system benefited directly from the ratings and prioritization of EBS by multilevel clinic and community partners within the broader safety-net clinic context to identify and adapt prioritized solutions needed to advance HPV vaccine equity.

Lower incidence of vaginal cancer after cervical human papillomavirus screening - long-term follow-up of Finnish randomized screening trial

OBJECTIVE

Around 70% of vaginal cancers and 40-50% of vulvar cancers are attributable to human papillomavirus (HPV). Globally the burden of these diseases is estimated to grow due to the increasing HPV prevalence and rapidly aging global population. We aimed to examine if HPV screening for cervical cancer has an additional beneficial effect in preventing vaginal and vulvar cancers. To assess this, we used long-term follow-up data from the Finnish randomized HPV screening trial.

METHODS

Between 2003 and 2008, over 236,000 women were individually randomized (1:1) to primary HPV or cytology screening in Southern Finland. We followed this cohort up to the year 2020. To compare the study arms, we calculated site-specific and pooled incidence rate ratios (IRRs) and mortality rate ratios (MRRs) for vaginal and vulvar cancers using Poisson regression.

RESULTS

During 3,5 million person-years of follow-up, the IRR for vaginal cancer in the HPV arm compared to the cytology arm was 0.40 (95% CI 0.17-0.88) and the corresponding MRR was 0.74 (95% 0.21-2.24). The corresponding IRR for vulvar cancer was 0.73 (95% 0.50-1.08) and the MRR was 0.64 (95% 0.23-1.62). The pooled IRR was 0.67 (95% 0.47 ̶ 0.95) and MRR 0.67 (95% 0.31 ̶ 1.37).

CONCLUSION

We found lower incidence of vaginal cancers with HPV screening compared to cytology screening. To validate our results, we recommend analyzing data on vaginal and vulvar cancers also from other HPV screening studies.

Understanding Clinic and Community Member Experiences with Implementation of Evidence-Based Strategies for HPV Vaccination in Safety-Net Primary Care Settings

HPV vaccination rates remain below target levels among adolescents in the United States, which is particularly concerning in safety-net populations with persistent disparities in HPV-associated cancer burden. Perspectives on evidence-based strategies (EBS) for HPV vaccination among key implementation participants, internal and external to clinics, can provide a better understanding of why these disparities persist. We conducted virtual interviews and focus groups, guided by the Practice Change Model, with clinic members (providers, clinic leaders, and clinic staff) and community members (advocates, parents, policy-level, and payers) in Los Angeles and New Jersey to understand common and divergent perspectives on and experiences with HPV vaccination in safety-net primary care settings. Fifty-eight interviews and seven focus groups were conducted (n = 65 total). Clinic members (clinic leaders n = 7, providers n = 12, and clinic staff n = 6) revealed conflicting HPV vaccine messaging, lack of shared motivation to reduce missed opportunities and improve workflows, and non-operability between clinic electronic health records and state immunization registries created barriers for implementing effective strategies. Community members (advocates n = 8, policy n = 11, payers n = 8, and parents n = 13) described lack of HPV vaccine prioritization among payers, a reliance on advocates to lead national agenda setting and facilitate local implementation, and opportunities to support and engage schools in HPV vaccine messaging and adolescents in HPV vaccine decision-making. Participants indicated the COVID-19 pandemic complicated prioritization of HPV vaccination but also created opportunities for change. These findings highlight design and selection criteria for identifying and implementing EBS (changing the intervention itself, or practice-level resources versus external motivators) that bring internal and external clinic partners together for targeted approaches that account for local needs in improving HPV vaccine uptake within safety-net settings.

Vulvar Carcinoma: Standard of Care and Perspectives

PURPOSE

Treatment of vulvar carcinoma (VC) is challenging. The objectives of this review were to describe for clinicians the epidemiologic and clinical aspects of VC, the standard of care in terms of primary local treatment and systemic therapies, and the recent innovations and perspectives emerging from translational research in immuno-oncology.

DESIGN

We conducted a comprehensive review outlying the clinical aspects and biologic background of vulvar cancer, highlighting modern treatment strategies on the basis of a personalized approach.

RESULTS

Epidemiologic data showed a recent rise in incidence of VC, attributed to human papillomavirus. Surgery is the mainstay of primary treatment, but multimodal approaches are frequently required in the presence of adverse prognosis histopathologic factors. Chemoradiation is indicated when organ-sparing surgery is not feasible. However, inability to achieve high locoregional control rates in advanced cases and the morbidity associated with local treatments are still key issues. Recent clinical data showed the benefit of individualized strategies combining organ-sparing surgical strategies, less invasive lymph node staging procedures, and refinement in radiotherapy modalities. Among the most important research area, there is a sound rationale for testing modern systemic approaches such as immune checkpoint inhibitors in selected patients with recurrent and/or metastatic tumors. Although no specific data exist for VC, the role of supportive care and post-treatment rehabilitation strategies is also crucial.

CONCLUSION

There are still insufficient studies dedicated to patients with VC. Public health programs for prevention, screening, and early diagnosis are required, and clinical research should be strengthened to provide high-quality clinical evidence and improve patients' oncologic and functional outcomes.

Understanding medical mistrust and HPV vaccine hesitancy among multiethnic parents in Los Angeles

Determinants of parental HPV vaccine hesitancy, including medical mistrust and exposure to negative vaccine information, are understudied in racial/ethnic minority communities where vaccine uptake is low. We conducted a cross-sectional survey (March 2021) among parents of adolescents, ages 9-17 years, from an academic enrichment program serving low-income, first-generation, underrepresented minority families in Los Angeles to understand determinants of parental HPV vaccine hesitancy. Parents completed self-administered surveys, including a 9-item HPV vaccine hesitancy scale, in either English, Spanish, or Chinese. Logistic regression was used to identify individual and interpersonal factors associated with parental hesitancy and adolescent HPV vaccination. One-fifth of parents (n = 357) reported high HPV vaccine hesitancy and > 50% reported concerns about safety or side effects. High medical mistrust was associated with high parental HPV vaccine hesitancy (adjusted-OR 1.69, 95% CI: 1.13, 2.37). Community-tailored and multilevel strategies to increase vaccine confidence are needed to improve HPV and other adolescent vaccinations.

Human microbiomes in cancer development and therapy

Colonies formed by bacteria, archaea, fungi, and viral groups and their genomes, metabolites, and expressed proteins constitute complex human microbiomes. An increasing evidences showed that carcinogenesis and disease progression were link to microbiomes. Different organ sources, their microbial species, and their metabolites are different; the mechanisms of carcinogenic or procancerous are also different. Here, we summarize how microbiomes contribute to carcinogenesis and disease progression in cancers of the skin, mouth, esophagus, lung, gastrointestinal, genital, blood, and lymph malignancy. We also insight into the molecular mechanisms of triggering, promoting, or inhibiting carcinogenesis and disease progress induced by microbiomes or/and their secretions of bioactive metabolites. And then, the strategies of application of microorganisms in cancer treatment were discussed in detail. However, the mechanisms by which human microbiomes function are still poorly understood. The bidirectional interactions between microbiotas and endocrine systems need to be clarified. Probiotics and prebiotics are believed to benefit human health via a variety of mechanisms, in particular, in tumor inhibition. It is largely unknown how microbial agents cause cancer or how cancer progresses. We expect this review may open new perspectives on possible therapeutic approaches of patients with cancer.

Plasma-Based Metabolomics Profiling of High-Risk Human Papillomavirus and their Emerging Roles in the Progression of Cervical Cancer

High-risk human papillomavirus (HR-HPV) is the main etiological factor for cervical cancer. Accumulating evidence has suggested the active role of metabolites in the initiation and progression of cancers. This study explored the plasma metabolic profiles of HPV-16 positive (HPV16 (+)), HPV-18 positive (HPV18 (+)), and HPV negative (CTL) individuals using a nontargeted metabolomics approach. C8 ceramide-1-Phosphate (d18 : 1/8 : 0) was found to inhibit cervical cancer cell proliferation and migration in vitro, evidenced by CCK8 experiments, a cell migration test, RT-qPCR, and western blotting. The underlying mechanism demonstrated that C8 inhibited proliferation and migration in cervical cancer cells via the MAPK/JNK1 signaling pathway. These findings may contribute to the clinical treatment of HR-HPV-induced cervical cancer by intervening in its initiation and progression.

Impact of the cervical cancer awareness months on public interest in Japan: A Google Trends analysis, 2012–2021

The immunization and screening rates for human papillomavirus in Japan are lower than those in other countries. We aimed to evaluate the impact of cervical cancer awareness months on public attention using Google Trends analysis. Between 2012 and 2021, we analyzed the trends in relative search volumes (RSVs) for “Shikyuu-keigan” (cervical cancer in English) in Japan, during the cervical cancer awareness month (CCAM) in January and cervical cancer prevention awareness enhancement month (CCPAEM) in November. We performed a joinpoint regression analysis to identify a statistically significant trend change point. Additionally, we compared the mean RSVs of each awareness month with the rest of the year. Significant trend change points were observed, but none were found in CCAM and CCPAEM periods. Comparison of mean RSVs among CCAM, CCPAEM, and the rest of the months did not suggest any significant increases in RSVs during these awareness periods. In conclusion, CAM and CCPAEM did not raise public interest in cervical cancer in Japan. Although the results are based on internet users, the findings might suggest a need to develop a more effective and attractive approach to achieve the 90-70-90 targets of cervical cancer prevention by 2030.

Management of Early-Stage Vulvar Cancer

Simple Summary

Vulvar cancer is a rare gynecological malignancy that affects mainly postmenopausal women. Recently, however, an alarming increase in the rates among young women has been observed due to human papillomavirus infection. The standard treatment for vulvar cancer is surgery with or without radiotherapy as adjuvant treatment. In recent decades, sentinel lymph node biopsy has been included as part of the surgical treatment. Thus, our objective was to review and discuss the advances found in the literature about early-stage vulvar cancer. For this, we searched PubMed for publications in the English language. Relevant articles, such as the GROINS-V studies, and the GOG protocols, are presented in this review exhibiting the evolution of early-stage vulvar cancer treatment and the decrease in surgical morbidity rates.

Abstract

Vulvar cancer is a rare gynecological malignancy since it represents 4% of all cancers of the female genital tract. The most common histological type is squamous cell carcinoma (90%). This type can be classified into two clinicopathological subtypes according to the etiology. The first subtype is associated with persistent human papillomavirus infection and is usually diagnosed in younger women. The second subtype is associated with lichen sclerosus condition, and in most cases is diagnosed in postmenopausal women. Currently, an increase in first subtype cases has been observed, which raised the concern about associated mortality and treatment morbidity among young women. Vulvar cancer treatment depends on histopathology grade and staging, but surgery with or without radiotherapy as adjuvant treatment is considered the gold standard. In recent decades, sentinel lymph node biopsy has been incorporated as part of the treatment. Therefore, we sought to review and discuss the advances documented in the literature about vulvar cancer focusing on the treatment of early-stage disease. Relevant articles, such as the GROINS-V studies and the GOG protocols, are presented in this review. Additionally, we discuss key points such as the evolution of treatment from invasive surgery with high morbidity, to more conservative approaches without compromising oncologic safety; the role of sentinel lymph node mapping in the initial staging, since it reduces the complications caused by inguinofemoral lymphadenectomy; the recurrences rates, since local recurrence is common and curable, however, groin-associated, or distant recurrences have a poor prognosis; and, finally, the long-term follow-up that is essential for all patients.

Factors associated with intention of human papillomavirus vaccination among Chinese college students: implications for health promotion

Human papilloma virus (HPV) is the most common reproductive tract virus. Most HPV infections occur during adolescence or young adulthood, and thus college students are one of the main target populations of HPV vaccination. However, data on knowledge of HPV and HPV vaccine as well as the intention to be vaccinated among Chinese college students were limited. The purpose of this study was to address this gap by investigating a sample of college students from four universities and analyzing the factors influencing their intention. College students (N = 343) filled in a survey comprised of demographic information, HPV and vaccine knowledge, and vaccination intention between September 2018 and January 2019. A descriptive statistical analysis was conducted to describe students' HPV-related knowledge and vaccination intention. Logistic regression analysis was used to determine the predictors of HPV vaccination intention. The participants had low levels of HPV and HPV vaccine-related knowledge, as well as modest intention to be vaccinated. Significant differences were identified in gender, years of study, and perceived susceptibility of HPV infection. Students who perceived higher risk of HPV infection (OR = 6.659, p = .001), had higher level knowledge of HPV vaccine (OR = 2.697, p < .001), in junior (OR = 0.186, p = .006) and senior year (OR = 0.276, p = .015) had greater intention to get HPV vaccinated. The findings suggest that multiple-level efforts are continuously needed to target Chinese college students to increase their HPV vaccine knowledge and vaccination awareness to reduce HPV-related disease burden among this population.

Heterologous administration of HPV16 E7 epitope-loaded nanocomplexes inhibits tumor growth in mouse model

The nanostructured complexes can result in enhanced vaccine efficacy by facilitating the distribution and uptake of antigens by antigen-presenting cells (APCs), thereby stimulating immune responses. Here, we hypothesized that either directly coating of nanoadjuvants including aluminum phosphate (AlPO₄) and adenovirus (Ad) with a modified HPV16 E7 MHC-I specific epitope, RAHYNIVTF_49-57, or mixing the CpG oligodeoxynucleotide (CpG-ODN) with the cationic epitope to form nanocomlexes, and their combinational therapy would enhance their anti-tumor effects in a TC-1 mouse model. The positively-charged HPV16 E7 epitope was attracted to the oppositely-charged adjuvants by electrostatic interaction to generate epitope/adjuvant nanocomplexes. We showed that coating the nanosized adjuvants with the cationic epitope increased the particles' surface charge without significant change in their size. We then tested the cellular immunogenicity and therapeutic efficacy of nanocomplexes by measuring IL-10 and IFN-γ production, the expression of CD107a as a marker of CTL response, and tumor growth inhibition. The nanocomplexes were administered either in homologous or heterologous prime-boost regimens, and heterologous immunizations including Ad/Pep-CpG/Pep, CpG/Pep-Ad/Pep, Ad/Pep-Alum/Pep, and Alum/Pep-Ad/Pep induced significantly higher levels of IL-10, IFN-γ, and CD107a-expressing CD8 T cells compared with homologous administrations. Furthermore, the tumor growth was significantly suppressed in mice receiving nanostructured complexes in the heterologous immunizations. Our study highlights the potential of the heterologous prime-boost administration of the epitope-coated nanostructures as an effective immunization strategy.

Cancer of the vulva: 2021 update

Vulvar cancer is an uncommon gynecological malignancy primarily affecting postmenopausal women. There is no specific screening and the most effective strategy to reduce vulvar cancer incidence is the opportune treatment of predisposing and preneoplastic lesions associated with its development. While vulvar cancer may be asymptomatic, most women present with vulvar pruritus or pain, or have noticed a lump or ulcer. Therefore, any suspicious vulvar lesion should be biopsied to exclude invasion. Once established, the most common subtype is squamous cell carcinoma. Treatment of vulvar cancer depends primarily on histology and surgical staging. Treatment is predominantly surgical, particularly for squamous cell carcinoma, although concurrent chemoradiation is an effective alternative, particularly for advanced tumors. Management should be individualized and carried out by a multidisciplinary team in a cancer center experienced in the treatment of these tumors.

A useful update for trainees and specialists regarding the diagnosis, staging, treatment, and some controversies in the management of vulvar neoplasms.

Genetic Predisposition to Persistent Human Papillomavirus-Infection and Virus-Induced Cancers

Human papillomaviruses (HPVs) are the most common sexually transmitted pathogens worldwide and among the more than 200 identified HPV types, approximately 15 high risk (HR-HPV) types are oncogenic, being strongly associated with the development of cervical cancer, anogenital cancers and an increasing fraction of head and neck squamous cell carcinomas (HNSCC). HPV-associated cervix cancer accounts for 83% of HPV-attributable cancers, and more than two-thirds of those cases occur in developing countries. Despite the high frequency of HPV infections, in most cases, the virus is cleared by the host immune response and only a small proportion of infected individuals develop persistent infections that can result in malignant transformation, indicating that other elements, including biological, genetic and environmental factors may influence the individual susceptibility to HPV-associated cancers. Previous studies have quantified that heritability, in the form of genetic variants, common in the general population, is implicated in nearly 30% of cervical cancers and a large number of studies conducted across various populations have identified genetic variants that appear to be associated with genes that predispose or protect the host to HPV infections thereby affecting individual susceptibility to HPV-associated cancers. In this article, we provide an overview of gene association studies on HPV-associated cancers with emphasis on genome-wide association study (GWAS) that have identified novel genetic factors linked to HPV infection or HPV-associated cancers.

The impact of HPV vaccination beyond cancer prevention: effect on pregnancy outcomes

While the benefits of human papillomavirus (HPV) vaccination relating to cervical cancer prevention have been widely documented, recent published evidence is suggestive of an impact on adverse pregnancy outcomes (APOs) in vaccinated mothers and their infants, including a reduction in rates of preterm births and small for gestational age infants. In this review, we examine this evidence and the possible mechanisms by which HPV vaccination may prevent these APOs. Large-scale studies linking HPV vaccination status with birth registries are needed to confirm these results. Potential confounding factors to consider in future analyses include other risk factors for APOs, and historical changes in both the management of cervical precancerous lesions and prevention of APOs. If confirmed, these additional benefits of HPV vaccination in reducing APO rates will be of global significance, due to the substantial health, social and economic costs associated with APOs, strengthening the case for worldwide HPV immunization.

Prevalence of genital human papillomavirus by age and race/ ethnicity among males

BACKGROUND

Genital and oral cancers are often caused by human papillomavirus (HPV) types that can be prevented through HPV vaccination. Since HPV is sexually transmitted, knowledge of penile prevalence of vaccine-type HPV among US males can help predict potential disparities in these cancers. This study examines penile HPV prevalence by age and race/ethnicity among males.

METHODS

This study was a secondary analysis of publicly available data from the National Health and Nutrition Examination Survey (NHANES). Using data from penile swab samples collected from males between 2013 and 2016, the prevalence of 4vHPV and 9vHPV vaccine types was examined across age groups and by race/ethnicity. Logistic regression models adjusting for demographics, sexual behavior and circumcision were examined to determine whether associations remained after accounting for confounders.

RESULTS

Among 2,548 males evaluated, HPV infection prevalence differed by race/ethnicity with black males exhibiting a higher prevalence of HPV. Examination of 4vHPV type prevalence by age group showed that 18-26 year old males had a lower prevalence compared to older age groups. After controlling for confounders, 4vHPV prevalence was only significantly elevated among 27-34-year old males, those who were single, and males with 3+ lifetime sex partners. In adjusted models, 9vHPV type prevalence remained elevated among black males compared to white males.

CONCLUSION

Variations in 9vHPV type prevalence between blacks and whites indicate future disparities in HPV-related genital cancers may continue in the US during the next decade. Revaccinating certain populations with the 9vHPV vaccine may be appropriate to help mitigate this.

The European response to the WHO call to eliminate cervical cancer as a public health problem

The age-standardised incidence of cervical cancer in Europe varies widely by country (between 3 and 25/100000 women-years) in 2018. Human papillomavirus (HPV) vaccine coverage is low in countries with the highest incidence and screening performance is heterogeneous among European countries. A broad group of delegates of scientific professional societies and cancer organisations endorse the principles of the WHO call to eliminate cervical cancer as a public health problem, also in Europe. All European nations should, by 2030, reach at least 90% HPV vaccine coverage among girls by the age of 15 years and also boys, if cost-effective; they should introduce organised population-based HPV-based screening and achieve 70% of screening coverage in the target age group, providing also HPV testing on self-samples for nonscreened or underscreened women; and to manage 90% of screen-positive women. To guide member states, a group of scientific professional societies and cancer organisations engage to assist in the rollout of a series of concerted evidence-based actions. European health authorities are requested to mandate a group of experts to develop the third edition of European Guidelines for Quality Assurance of Cervical Cancer prevention based on integrated HPV vaccination and screening and to monitor the progress towards the elimination goal. The occurrence of the COVID-19 pandemic, having interrupted prevention activities temporarily, should not deviate stakeholders from this ambition. In the immediate postepidemic phase, health professionals should focus on high-risk women and adhere to cost-effective policies including self-sampling.

Real-World Effectiveness of Human Papillomavirus Vaccination Against Vulvovaginal High-Grade Precancerous Lesions and Cancers

BACKGROUND

Vaccination against human papillomavirus (HPV) has proven to be effective against severe cervical lesions and genital warts, whereas no previous study has provided real-world data on the HPV vaccine effectiveness against high-grade vulvovaginal lesions.

METHODS

A cohort of all women age 17-26 years living in Denmark during 2006-2019 was followed in nationwide registers for individual-level information about HPV vaccination and first diagnoses of vulvar and vaginal high-grade squamous intraepithelial lesions (HSIL+) or worse. The cumulative incidence of vulvar and vaginal HSIL+, respectively, was estimated with the Aalen-Johansen estimator, and Cox proportional hazards regression was used to estimate hazard ratios (HRs) for vulvar and vaginal lesions separately, comparing women vaccinated at age 16 years or younger and at age 17-26 years with unvaccinated women.

RESULTS

The cohort consisted of 514 537 women, of which 50.6% were vaccinated at baseline (<16 years), 31.8% were vaccinated during follow-up (17-26 years), and 17.6% remained unvaccinated. The cumulative incidence was less than 0.6‰ for vulvar HSIL+ and less than 0.2‰ for vaginal HSIL+. Adjusted analyses showed reduced HRs for both vulvar (HR = 0.22, 95% confidence interval = 0.13 to 0.38) and vaginal HSIL+ (HR = 0.16, 95% confidence interval = 0.04 to 0.55) for women vaccinated at age 16 years or younger compared with unvaccinated women. For women vaccinated at 17-26 years of age, the reductions in HRs were smaller for vaginal HSIL+ and close to 0 for vulvar HSIL+.

CONCLUSIONS

HPV vaccination before 17 years of age reduces the risk of vulvar and vaginal HSIL+ based on real-world data.

Geographic and temporal variations in the incidence of vulvar and vaginal cancers

Vulvar and vaginal cancers are relatively rare cancers, together responsible for less than 1% of the global cancer incidence among women in 2018. The majority of vaginal cancers and a lesser proportion of vulvar cancers are associated with HPV, with rising incidence rates of vulvar cancer observed in younger women, possibly due to an increased prevalence of high-risk HPV types. This report assesses recent international variations in the incidence rates of vulvar and vaginal cancer derived from high-quality data from population-based cancer registries in 68 countries, and further assesses time trends for selected longer-term series in eight countries (Australia, China, Colombia, India, Norway, Slovakia, the U.S., and the U.K.) over the period 1983 to 2012. We observed a 30-fold variation in the recorded incidence rates of vulvar cancer in contrast with the threefold variation for vaginal cancer. We also observed a rising incidence of vulvar cancer in Australia, Norway and the U.K., and Slovakia, with a more rapid rise in the rates seen in women aged < 60 years at diagnosis. The annual percentage change over the most recent decade varied from 1.7% in Norway to 4.1% in Slovakia. The increases are largely confined to younger women and are likely linked to generational changes in sexual behaviour (earlier age at sexual debut and increasing transmission of HPV among cohorts born 1940 to 1950 and thereafter. Vaginal cancer incidence rates, in contrast, were lower and more stable, despite the higher HPV-attributable fraction relative to vulvar cancer. Irrespective of the trends, an increasing number of women are predicted to be diagnosed worldwide with both cancer types in future decades as population ageing and growth continues. The promise of high-coverage HPV vaccination will likely counter this rising burden, but the impact may take a number of decades.

Vulvar intraepithelial neoplasia: Incidence and long-term risk of vulvar squamous cell carcinoma

The risk of vulvar squamous cell carcinoma (VSCC) in patients with high-grade vulvar intraepithelial neoplasia (VIN) is considered lower in high-grade squamous intraepithelial lesion (HSIL) compared to differentiated VIN (dVIN), but studies are limited. Our study investigated both the incidence of high-grade VIN and the cumulative incidence of VSCC in patients with HSIL and dVIN separately. A database of women diagnosed with high-grade VIN between 1991 and 2011 was constructed with data from the Dutch Pathology Registry (PALGA). The European standardized incidence rate (ESR) and VSCC risk were calculated, stratified for HSIL and dVIN. The effects of type of VIN (HSIL vs dVIN), age and lichen sclerosis (LS) were estimated by Cox regression. In total, 1148 patients were diagnosed with high-grade VIN between 1991 and 2011. Between 1991-1995 and 2006-2011, the ESR of HSIL increased from 2.39 (per 100 000 woman-years) to 3.26 and the ESR of dVIN increased from 0.02 to 0.08. The 10-year cumulative VSCC risk was 10.3%; 9.7% for HSIL and 50.0% for dVIN (log rank P < .001). Type of VIN, age and presence of LS were independent risk factors for progression to VSCC, with hazard ratios of 3.0 (95% confidence interval [CI] 1.3-7.1), 2.3 (95% CI 1.5-3.4) and 3.1 (95% CI 1.8-5.3), respectively. The incidence of high-grade VIN is rising. Because of the high cancer risk in patients with dVIN, better identification and timely recognition are urgently needed.