Expanded strain coverage for a highly successful public health tool: Prophylactic 9-valent human papillomavirus vaccine.

Human papillomavirus is considered the causative factor for cervical cancer, which accounts for approximately 5% of the global cancer burden and more than 600,000 new cases annually that are attributable to HPV infection worldwide. The first-generation prophylactic HPV vaccines, Gardasil® and Cervarix®, were licensed approximately a decade ago. Both vaccines contain the most prevalent high-risk types, HPV16 and 18, which are associated with 70% of cervical cancer. To further increase the type coverage, 5 additional oncogenic HPV types (31, 33, 45, 52 and 58) were added to the existing Gardasil-4 to develop a 9-valent HPV vaccine (9vHPV), Gardasil 9®, increasing the potential level of protection from ∼70% to ∼90%. The efficacy of the vaccine lies primarily in its ability to elicit type-specific and neutralizing antibodies to fend off the viral infection. Therefore, type-specific and neutralizing murine monoclonal antibodies (mAbs) were used to quantitate the antigenicity of the individual vaccine antigens and to measure the antibody levels in the serum samples from vaccinees in a type- and epitope-specific manner in a competitive immunoassay. Assays for 9vHPV are extended from the proven platform used for 4vHPV by developing and adding new mAbs against the additional types. In Phase III clinical trials, comparable safety profile and immunogenicity against the original 4 types were demonstrated for the 9vHPV vaccine, and these were comparable to the 4vHPV vaccine. The efficacy of the 9vHPV vaccine was established in trials with young women. Immunobridging for younger boys and girls was performed, and the results showed higher immunogenicity in the younger age group. In a subsequent clinical trial, the 2-dose regimen of the 9vHPV vaccine used among girls and boys aged 9-14 y showed non-inferior immunogenicity to the regular 3-dose regimen for young women (aged 16-26 years). Overall, the clinical data and cost-effectiveness analysis for the 9vHPV vaccine support its widespread use to maximize the impact of this important, life-saving vaccine.

Longitudinal assessment of DNA methylation changes during HPVE6E7-induced immortalization of primary keratinocytes.

High-risk human papillomavirus (hrHPV)-induced immortalization and malignant transformation are accompanied by DNA methylation of host genes. To determine when methylation is established during cell immortalization and whether it is hrHPV-type dependent, DNA methylation was studied in a large panel of HPVE6E7-immortalized keratinocyte cell lines. These cell lines displayed different growth behaviors, i.e., continuous growth versus crisis period prior to immortalization, reflecting differential immortalization capacities of the 7 HPV-types (16/18/31/33/45/66/70) studied. In this study, cells were monitored for hypermethylation of 14 host genes (APC, CADM1, CYGB, FAM19A4, hTERT, mir124-1, mir124-2, mir124-3, MAL, PHACTR3, PRDM14, RASSF1A, ROBO3, and SFRP2) at 4 different stages during immortalization. A significant increase in overall methylation levels was seen with progression through each stage of immortalization. At stage 1 (pre-immortalization), a significant increase in methylation of hTERT, mir124-2, and PRDM14 was already apparent, which continued over time. Methylation of ROBO3 was significantly increased at stage 2 (early immortal), followed by CYGB (stage 3) and FAM19A4, MAL, PHACTR3, and SFRP2 (stage 4). Methylation patterns were mostly growth behavior independent. Yet, hTERT methylation levels were significantly increased in cells that just escaped from crisis. Bisulfite sequencing of hTERT confirmed increased methylation in immortal cells compared to controls, with the transcription core and known repressor sites remaining largely unmethylated. In conclusion, HPV-induced immortalization is associated with a sequential and progressive increase in promoter methylation of a subset of genes, which is mostly independent of the viral immortalization capacity.

The immunohistochemical assessment of HPV related adenocarcinoma: pathologic and clinical prognostic significance.

Although several epidemiologic studies have confirmed the association between high-risk human papillomavirus (hr-HPV) and adenocarcinoma of the cervix, there are few papers focusing on the molecular immunophenotype of the HPV related cervical adenocarcinoma and its precursor lesions. The present study is aimed to assess the immunohistochemical expression of p16, p53, cyclin D1, EGFR, and COX-2 in benign and malignant lesions of cervical glandular components, and consequently the identification of the relationship between these markers and the HPV L1 capsid protein. We investigated 7 cases of endocervical adenocarcinoma in situ (AIS), 8 cases of adenosquamous carcinoma, 15 cases of invasive adenocarcinoma of endocervical type, and 5 cases without malignant lesions (normal and/or benign endocervical epithelium). The tissue fragments underwent standard laboratory procedures for the histopathological and immunohistochemical exams. For each marker, the semi-quantitative assessment was performed using appropriate scoring systems. Our results showed that: (i) the combination of L1 capsid protein and p16 can predict the progression risk of precursor lesion of endocervical adenocarcinomas; (ii) p53 - COX2 - p16 co-assessment is useful as a panel of relevant biomarkers for L1 - p16 association; (iii) EGFR increases according to the progression in lesions severity; (iv) cyclin D1 is a reliable marker for the invasive capacity. Further studies are necessary to quantify the value of these markers, as prognostic factors in HPV related cervical adenocarcinoma.

Women's preferences regarding options for management of atypical, borderline or low-grade cervical cytological abnormalities: a review of the evidence.

OBJECTIVES: To review the evidence on women's preferences for and valuation of alternative management pathways following identification of low-grade cytological abnormalities as part of routine cervical cancer screening. The aim was to identify empirical studies evaluating women's preferences regarding alternative management pathways and to compare the impact of alternative elicitation methods on results. METHODS: A systematic review of the literature was conducted using the online bibliographic information service PubMed database. Empirical studies were identified that elicited general preferences, utilities or valuations based on willingness to pay (WTP) with respect to management of low-grade cytology results. Data were extracted on the methodology used and the empirical results. RESULTS: Where quality of life data were elicited directly from patients that were undergoing management of low-grade abnormalities utilizing direct elicitation techniques such as WTP, general preference questionnaires and the Euroqol, the studies tended towards a preference in favour of HPV testing (and colposcopy referral if HPV positive) rather than repeat cytology. In contrast, where studies included the general population and presented hypothetical scenarios of treatment pathways, and explicitly tried to incorporate assessment of process utility, the evidence indicated a slight tendency to favour repeat cytology. CONCLUSION: Consideration of patient preferences in the management of low-grade cytology is important for designing screening protocols. The reviewed studies indicate that potentially different conclusions may be drawn depending on the elicitation methodology and selection of participants in the research.

Epidemiology and burden of HPV infection and related diseases: implications for prevention strategies.

Human papillomavirus (HPV) infection is a necessary, although not sufficient cause of cervical cancer. Globally, HPV infection accounts for an estimated 530,000 cervical cancer cases (~270,000 deaths) annually, with the majority (86% of cases, 88% of deaths) occurring in developing countries. Approximately 90% of anal cancers and a smaller subset (<50%) of other cancers (oropharyngeal, penile, vaginal, vulvar) are also attributed to HPV. In total, HPV accounts for 5.2% of the worldwide cancer burden. HPVs 16 and 18 are responsible for 70% of cervical cancer cases and, especially HPV 16, for a large proportion of other cancers. Prophylactic vaccination targeting these genotypes is therefore expected to have a major impact on the burden of cervical cancer as well as that of other HPV-related cancers. Over the past 50 years, organized or opportunistic screening with Papanicolaou (Pap) cytology has led to major reductions in cervical cancer in most developed countries. However, due to lack of resources or inadequate infrastructure, many countries have failed to reduce cervical cancer mortality through screening. HPV DNA testing recently emerged as a likely candidate to replace Pap cytology for primary screening. It is less prone to human error and more sensitive than Pap in detecting high-grade cervical lesions. For countries with national vaccination programs, HPV testing may also serve as a low cost strategy to monitor long term vaccine efficacy. Introduction of well organized vaccination and screening programs should be a priority for all countries. Increased support from donors is needed to support this cause.

Human papillomavirus testing in the prevention of cervical cancer.

Strong evidence now supports the adoption of cervical cancer prevention strategies that explicitly focus on persistent infection with the causal agent, human papillomavirus (HPV). To inform an evidence-based transition to a new public health approach for cervical cancer screening, we summarize the natural history and cervical carcinogenicity of HPV and discuss the promise and uncertainties of currently available screening methods. New HPV infections acquired at any age are virtually always benign, but persistent infections with one of approximately 12 carcinogenic HPV types explain virtually all cases of cervical cancer. In the absence of an overtly persistent HPV infection, the risk of cervical cancer is extremely low. Thus, HPV test results predict the risk of cervical cancer and its precursors (cervical intraepithelial neoplasia grade 3) better and longer than cytological or colposcopic abnormalities, which are signs of HPV infection. The logical and inevitable move to HPV-based cervical cancer prevention strategies will require longer screening intervals that will disrupt current gynecologic and cytology laboratory practices built on frequent screening. A major challenge will be implementing programs that do not overtreat HPV-positive women who do not have obvious long-term persistence of HPV or treatable lesions at the time of initial evaluation. The greatest potential for reduction in cervical cancer rates from HPV screening is in low-resource regions that can implement infrequent rounds of low-cost HPV testing and treatment.

Human papillomavirus vaccines: new tools for accelerating cervical cancer prevention in developing countries.

Despite the available knowledge and tools to prevent cervical cancer, it remains the second most common cancer in women, with four-fifths of the cases occurring in developing countries. Projections are for a 90% increase in global cervical cancer cases by 2020 if no additional public-health interventions are implemented. Prophylactic human papillomavirus (HPV) vaccines, which have proven immunogenicity, safety and efficacy, are now commercially available; and coupled together with quality screening have the potential to dramatically accelerate reductions in cervical cancer mortality rates and save millions of women's lives. The current cost of the new HPV vaccines and new screening technologies, however, are a major barrier to their widespread implementation. There is an urgent need for HPV vaccines and new technologies for effective screening to become more available and affordable, especially to poor communities everywhere.

A multi-type HPV transmission model.

A prophylactic quadrivalent (types 6/11/16/18) vaccine against oncogenic and warts-causing genital Human papillomavirus (HPV) types was approved by the US Food and Drug Administration in 2006. This paper presents a nonlinear, deterministic, age-structured, mathematical model of the transmission dynamics of HPV and disease occurrence in a US population stratified by gender and sexual activity group. The model can assess both the epidemiologic consequences and cost effectiveness of alternative vaccination strategies in a setting of organized cervical cancer screening in the United States. Inputs for the model were obtained from public data sources, published literature, and analyses of clinical trial data. The results suggest that a prophylactic quadrivalent HPV vaccine can: (i) substantially reduce the incidence of disease, (ii) increase survival among females, (iii) improve quality of life for both males and females, (iv) be cost-effective when administered to females age 12-24 years, and (v) be cost-effective when implemented as a strategy that combines vaccination of both females and males before age 12 vaccination with a 12 to 24 years of age catch-up vaccination program.

Knowledge and interest of Turkish women about cervical cancer and HPV vaccine.

OBJECTIVE: We aimed to evaluate the knowledge and interest level of Turkish women about HPV, HPV vaccines and cervical cancer using a questionaire. METHOD: A 25-item questionnaire was distributed to women in three different cities located in separate sociocultural locations. RESULTS: At the closure of the study 143 women responded and returned the survey. Of the participants 62.2% (89) had a university degree, 36.4% (52) a high school education, and 1.4% (2) had lower school degrees; 98.5% of the women would consent to have their daughter vaccinated for HPV and 94.7% would consent to have their son vaccinated if vaccine provided prevention against cancer and related diseases. However in both cases women gave importance to the "cost" - unless vaccine could be free. On logistic regression analyses none of the variables (i.e., questions) in the survey predicted women's willingness to accept the vaccine for themselves or their children. CONCLUSIONS: Women in Turkey would be willing to have themselves and their children receive HPV vaccine against cervical cancer and related diseases.

Reducing the health burden of HPV infection through vaccination.

Human papillomavirus (HPV), a sexually transmitted infection and the etiologic cause of genital warts and cervical cancer, is highly prevalent in sexually active men and women. Although cervical screening procedures have significantly reduced the disease burden associated with HPV infection, they are expensive and abnormal results cause significant emotional distress. Therefore, prevention may be an effective strategy for reducing the economic, psychosocial, and disease burden of HPV infection. Multivalent vaccines are now in clinical development. A bivalent vaccine that protects against HPV 16 and 18, and a quadrivalent vaccine which protects against HPV types 6, 11, 16, and 18, have been shown to significantly reduce the occurrence of incident and persistent HPV infections in phase 2 clinical trials; phase 3 trials are currently underway. HPV vaccines will be most effective when administered prior to initiation of sexual activity, and vaccination campaigns should aggressively target preadolescent and adolescent populations.