Chapter 5: Updating the natural history of HPV and anogenital cancer

Preventing cervical cancer: the Pap test and the HPV vaccine

Women look to their internists and other primary care physicians to provide preventive health care. Periodic Pap tests are as much a part of a woman's ongoing health care as periodic lipid assessments, mammograms, screening for colon cancer, or any of the other recommended screening assessments. This article provides primary care physicians with the information needed to perform Pap tests at the appropriate intervals, or if not set up to do Pap tests themselves, to make the appropriate referrals. Also provided is the necessary information to counsel women with abnormal Pap tests who may need colposcopy or other follow-up evaluation. Finally, the role of the HPV vaccine in the prevention of cervical cancer is summarized.

Human papillomavirus genotyping by multiplex pyrosequencing in cervical cancer patients from India

Cervical cancer is a leading cause of cancer-related deaths among women in India. Human papillomavirus (HPV) infection is the causative agent of cervical cancer; and infection with the high-risk genotypes, predominantly HPV16 and 18,is the biggest risk factor. Vaccines targeting HPV16 and 18 have been found to confer protection in large- scale clinical trials.HPV genotyping has traditionally been carried out to screen the population "at risk" using indirect methods based on polymerase chain reaction (PCR) using consensus primers combined with various DNA hybridization techniques,and often followed by the sequencing of candidate products.Recently,a high-throughput and direct method based on DNA sequencing has been described for HPV genotyping using multiplex pyrosequencing. We present a pilot study on HPV genotyping of cervical cancer and non-malignant cervical samples using multiplex pyrosequencing. Using genomic DNA from cell lines,cervical biopsies,surgical tissues or formalin-fixed,paraffin- embedded tissue samples,we could successfully resolve 6 different HPV types out of the 7 tested,with their prevalence found to be in agreement with earlier reports. We also resolved coinfections with two different HPV types in several samples. An HPV16 genotype with a specific and recurrent sequence variation was observed in 8 cancer samples and one non-malignant sample. We find this technique eminently suited for high-throughput applications,which can be easily extended to large sample cohorts to determine a robust benchmark for HPV genotypes prevalent in India.

Persistent human papillomavirus infection and cervical neoplasia: a systematic review and meta-analysis

Detection of persistent cervical carcinogenic human papillomavirus (HPV) DNA is used as a marker for cervical cancer risk in clinical trials. The authors performed a systematic review and meta-analysis of the association between persistent HPV DNA and high-grade cervical intraepithelial neoplasia (CIN2-3), high-grade squamous intraepithelial lesions (HSIL), and invasive cervical cancer (together designated CIN2-3/HSIL+) to evaluate the robustness of HPV persistence for clinical use. MEDLINE and Current Contents were searched through January 30, 2006. Relative risks (RRs) were stratified by HPV comparison group. Of 2,035 abstracts, 41 studies were eligible for inclusion in the meta-analysis. Over 22,500 women were included in calculation of RRs for persistent HPV DNA detection and cervical neoplasia. RRs ranged from 1.3 (95% confidence interval: 1.1, 1.5) to 813.0 (95% confidence interval: 168.2, 3,229.2) for CIN2-3/HSIL+ versus <CIN2-3/HSIL+; 92% of RRs were above 3.0. Longer durations of infection (>12 months), wider testing intervals, CIN2-3/HSIL+, and use of an HPV-negative reference group were consistently associated with higher RRs. Thus, HPV persistence was consistently and strongly associated with CIN2-3/HSIL+, despite wide variation in definitions and study methods. The magnitude of association varied by duration of persistence and testing interval. Precise definition and standardization of HPV testing, sampling procedure, and test interval are needed for reliable clinical testing. These findings validate HPV persistence as a clinical marker and endpoint.

Behavior in early adolescence and risk of human papillomavirus infection as a young adult: results from a population-based study

OBJECTIVE

The goal of this study was to determine the utility of a risk factor-based approach to human papillomavirus catch-up vaccination.

METHODS

Data from waves I and III of the National Longitudinal Study of Adolescent Health were examined to determine the association between adolescent characteristics and future human papillomavirus infection. Analysis was restricted to 3181 female subjects who were >12 years of age when risk factors were assessed in wave I (1994-1995) and who underwent human papillomavirus testing as young adults in wave III (2001-2002). The main outcome of interest was a positive test result for >or=1 of 4 human papillomavirus types (human papillomavirus-6, -11, -16, or -18) targeted by the human papillomavirus vaccine currently available in the United States. Separate analyses were performed for sexually active and virginal adolescents. Poststratification sampling weights were used to generate nationally representative estimates.

RESULTS

Although nearly one half (43%) of the female adolescents were sexually active in wave I, adolescent sexual activity status was not associated with future detection of vaccine-specific human papillomavirus infection. Furthermore, for both virginal and sexually active adolescents, none of the assessed risk factors was associated with increased odds of future vaccine-specific human papillomavirus infection in multivariate models. Similar results were obtained when all high-risk human papillomavirus types were assessed as the outcome measure.

CONCLUSIONS

Behavioral risk factors assessed during adolescence are inadequate predictors of future infection with vaccine-type human papillomavirus. A risk factor-based approach to human papillomavirus catch-up vaccination is unlikely to be an effective implementation strategy.

Age at sexual initiation and number of sexual partners in the female Spanish population Results from the AFRODITA survey

OBJECTIVES

The AFRODITA study was designed to describe patterns relating to the number of lifetime sexual partners (SP) and age at first sexual intercourse (AFSI) by geographic region in a representative sample of Spanish women.

STUDY DESIGN

A representative sample of the female Spanish population was obtained using the Access Panel Technique. Postal questionnaires were sent to 11,086 women aged 18-70 years. Data were collected on AFSI, number of sexual partners, contraceptive methods, cervical cancer screening and socio-demographic characteristics.

RESULTS

The average AFSI was 20.9 years. AFSI below the age of 19 years was reported by 30.8% of the women. Among sexually active women, 70.6% reported being monogamous and 6.4% reported > or = 5 lifetime sexual partners. Younger age at interview was strongly related to earlier AFSI and to higher number of lifetime sexual partners. Women younger than 25 were 39 times more likely to have an AFSI before age 18 than women over age 55. The percentage of women aged less than 25 reporting two or more sexual partners was four times higher than that of women 56 and older. In the multivariate analysis, having two or more sexual partners was independently associated with young age, early AFSI, having ever used oral contraceptives, living in an urban area, having had a screening Pap test in the last 3 years, having a sexually transmitted infection and nuliparity.

CONCLUSIONS

This study confirms important changes in the sexual behaviour of Spanish women. Younger cohorts show a younger age at sexual initiation and higher number of sexual partners. These are key factors that may induce changes in the human papillomavirus (HPV) prevalence and the cervical cancer incidence in Spain.

Conservative management of adolescents with abnormal cytology and histology

Adolescents remain vulnerable to human papilloma virus (HPV) infection because of certain physiologic characteristics inherent in this age group and common sexual behaviors, including lack of condom use. The commonness of HPV in this age group also results in frequent abnormal cytology. Fortunately, most of the infections are transient, with frequent clearance of HPV and the lesion. Current strategies for adolescents with abnormal cytology include conservative management, avoiding invasive procedures. For cytologic atypical squamous cells of undetermined significance or squamous intraepithelial lesions (SIL), management can be obtaining cytology only at 1-year intervals for up to 2 years before referral for colposcopy is necessary. For biopsy-proven cervical intraepithelial neoplasia (CIN) I, management is similar with yearly cytology indefinitely or until high-grade-SIL or CIN II/III develops. CIN II in adherent adolescents can be managed with 6-month cytology and colposcopy.

Type-dependent integration frequency of human papillomavirus genomes in cervical lesions

Chromosomal integration of high-risk human papillomavirus (HR-HPV) genomes is believed to represent a significant event in the pathogenesis of cervical cancer associated with progression from preneoplastic lesions to invasive carcinomas. This hypothesis is based on experimental data suggesting that integration-dependent disruption of HR-HPV E2 gene functions is important to achieve neoplastic transformation and on clinical data gathered by analyzing lesions induced by human papillomavirus (HPV) 16 and 18 that revealed integrated viral genome copies in the vast majority of cervical cancer cells. However, a substantial fraction of cervical cancers is associated with other HR-HPV types for which virtually no data concerning their integration status have been reported so far. Here, we compared integration frequencies of the five most common oncogenic HPV types (HPV16, 18, 31, 33, and 45) in a series of 835 cervical samples using a specific mRNA-based PCR assay (Amplification of Papillomavirus Oncogene Transcripts). Most precancerous lesions displayed exclusively episomal viral genomes, whereas 62% of the carcinomas had integrated viral genomes. However, the frequency of integrated HR-HPV genomes showed marked differences for individual HR-HPV types. HPV16, 18, and 45 were found substantially more often in the integrated state compared with HPV types 31 and 33. The analysis of the median age of patients with high-grade precancerous lesions and invasive cancers suggests that precancers induced by HPV types 18, 16, and 45 progress to invasive cervical cancer in substantially less time compared with precancers induced by HPV types 31 and 33. These findings suggest that integration of oncogenic HPV genomes in cervical lesions is a consequence rather than the cause of chromosomal instability induced by deregulated HR-HPV E6-E7 oncogene expression. Distinct HR-HPV types apparently provoke chromosomal instability in their host cells to a different extent than is reflected by their integration frequencies in advanced lesions and the time required for CIN 3 lesions to progress to invasive cancer.

Appropriate Use of Cervical Cancer Vaccine

Human papillomavirus (HPV) is a necessary, though not sufficient, cause of cervical cancer. Two vaccines have been developed that prevent two HPV types associated with 70% of cervical cancers. One of the vaccines (a quadrivalent vaccine) also prevents two HPV types associated with 90% of genital warts. Both HPV vaccines have shown very good efficacy and safety. This review summarizes the guidelines for use of the quadrivalent vaccine published by the Advisory Committee on Immunization Practices, presents data on vaccine efficacy and safety, and gives an overview of the findings of cost-effectiveness studies. In addition, we summarize the research on the attitudes of parents and health care providers toward HPV vaccine and critically evaluate controversial and challenging issues surrounding HPV vaccination, including concerns about sexual disinhibition and potential obstacles to vaccine distribution and uptake.

Human papillomavirus (HPV) profiles of vulvar lesions: possible implications for the classification of vulvar squamous cell carcinoma precursors and for the efficacy of prophylactic HPV vaccination

The term vulvar intraepithelial neoplasia (VIN) introduced in 1986 incorporates 3 grades of usual VIN (u-VIN I-III) and the differentiated VIN (d-VIN). Although u-VIN is etiologically associated with the human papillomavirus (HPV) infection, d-VIN represents an alternative HPV negative pathway of vulvar carcinogenesis. In 2004, the u-VIN I category was abandoned and u-VIN II and III were merged. Further, an alternative Bethesda-like terminology scheme presenting the term vulvar intraepithelial lesion was proposed recently. To analyze the impact of HPV profiles of vulvar precancerous lesions for their classification and to assess the presumable efficacy of the prophylactic HPV vaccination, 269 vulvar excisions representing lichen sclerosus, lichen simplex chronicus, condylomata acuminata, d-VIN, all grades of u-VIN and squamous cell carcinomas were subjected to the HPV typing by use of GP5+/6+ polymerase chain reaction and reverse line blot hybridization. The results showed different HPV profiles, and also differing frequency of multiple-type HPV infection and the age structure in patients with u-VIN II and III. The biologic heterogeneity within the u-VIN II category was also demonstrated. u-VIN I was distinguished as a rare disorder associated with high-risk HPV infection. We conclude that the original VIN terminology proposed in 1986 seems to be appropriate for the classification of vulvar squamous dysplastic lesions. The spectrum of HPV types found in vulvar squamous cell carcinomas indicates that the efficacy of HPV vaccination in preventing vulvar cancer might be diminished in the studied population, because the recently developed prophylactic vaccines are targeted against a limited number of HPV types.

Modelling the population-level impact of vaccination on the transmission of human papillomavirus type 16 in Australia

BACKGROUND

Vaccines are now available to prevent the development of cervical cancer from genital human papillomavirus (HPV) infection. The decision to vaccinate depends on a vaccine's cost-effectiveness. A rigorous cost-effectiveness model for vaccinated individuals is presented in a companion paper; this paper investigates the additional benefits the community might receive from herd immunity.

METHODS

A mathematical model was developed to estimate the impact of a prophylactic vaccine on transmission of HPV type 16 in Australia. The model was used to estimate the expected reduction in HPV incidence and prevalence as a result of vaccination, the time required to achieve these reductions, and the coverage required for elimination. The modelled population was stratified according to age, gender, level of sexual activity and HPV infection status using a differential equation formulation. Clinical trials show that the vaccine is highly effective at preventing persistent infection and pre-cancerous lesions. These trials do not, however, provide conclusive evidence that infection is prevented altogether. The possible modes of vaccine action were investigated to see how vaccination might change the conclusions.

RESULTS

The model predicts that vaccination of 80% of 12-year-old girls will eventually reduce HPV 16 prevalence by 60-100% in vaccinated and 7-31% in unvaccinated females. If 80% of boys are also vaccinated, reductions will be 74-100% in vaccinated and 86-96% in unvaccinated females. A campaign covering only 12-year-old girls would require 5-7 years to achieve 50% of the eventual reduction. With a catch-up campaign covering 13-26-year-olds, this delay would be reduced to only 2 years. Unrealistically high coverage in both sexes would be required to eliminate HPV 16 from the population. Under pessimistic assumptions about the duration of vaccine-conferred immunity, HPV 16 incidence is predicted to rise in some older age groups.

CONCLUSIONS

Mass vaccination with a highly effective vaccine against HPV 16 has the potential to substantially reduce the incidence and prevalence of infection. Catch-up vaccination offers the potential to substantially reduce the delay before the benefits of vaccination are observed. A booster vaccination might be required to prevent an increase in incidence of infection in women over 25 years of age.

Human papillomavirus and HPV vaccines: a review

Cervical cancer, the most common cancer affecting women in developing countries, is caused by persistent infection with "high-risk" genotypes of human papillomaviruses (HPV). The most common oncogenic HPV genotypes are 16 and 18, causing approximately 70% of all cervical cancers. Types 6 and 11 do not contribute to the incidence of high-grade dysplasias (precancerous lesions) or cervical cancer, but do cause laryngeal papillomas and most genital warts. HPV is highly transmissible, with peak incidence soon after the onset of sexual activity. A quadrivalent (types 6, 11, 16 and 18) HPV vaccine has recently been licensed in several countries following the determination that it has an acceptable benefit/risk profile. In large phase III trials, the vaccine prevented 100% of moderate and severe precancerous cervical lesions associated with types 16 or 18 among women with no previous infection with these types. A bivalent (types 16 and 18) vaccine has also undergone extensive evaluation and been licensed in at least one country. Both vaccines are prepared from non-infectious, DNA-free virus-like particles produced by recombinant technology and combined with an adjuvant. With three doses administered, they induce high levels of serum antibodies in virtually all vaccinated individuals. In women who have no evidence of past or current infection with the HPV genotypes in the vaccine, both vaccines show > 90% protection against persistent HPV infection for up to 5 years after vaccination, which is the longest reported follow-up so far. Vaccinating at an age before females are exposed to HPV would have the greatest impact. Since HPV vaccines do not eliminate the risk of cervical cancer, cervical screening will still be required to minimize cancer incidence. Tiered pricing for HPV vaccines, innovative financing mechanisms and multidisciplinary partnerships will be essential in order for the vaccines to reach populations in greatest need.

2006 consensus guidelines for the management of women with abnormal cervical screening tests

OBJECTIVE

To provide revised evidence-based consensus guidelines for managing women with abnormal cervical cancer screening test results.

PARTICIPANTS

A group of 146 experts, including representatives from 29 professional organizations, federal agencies, and national and international health organizations, met in Bethesda, MD, September 18-19, 2006, to develop the guidelines. MAJOR CHANGES IN GUIDELINES: The core recommendations for managing women with atypical squamous cells of undetermined significance and low-grade squamous intraepithelial lesions were changed minimally. Postcolposcopy management for women with these cytological abnormalities is now identical. Management recommendations for these conditions did change for "special populations," such as adolescents for whom a more conservative approach incorporating cytological follow-up for 2 years was approved. Core recommendations for managing women with high-grade squamous intraepithelial lesions and atypical glandular cells also underwent only minor modifications. More emphasis is placed on immediate "screen-and-treat" approaches when managing women with high-grade squamous intraepithelial lesion. Testing for high-risk human papillomavirus DNA is incorporated into the management of women with atypical glandular cells after their initial evaluation with colposcopy and endometrial sampling. The 2004 Interim Guidance for the use of human papillomavirus DNA testing as an adjunct to cervical cytology for screening in women 30 years and older was formally adopted with only very minor modifications.

CONCLUSIONS

The 2006 Consensus Guidelines reflect recent data from large clinical trials and advances in technology and are designed to assist clinicians of all subspecialties.

Cervical human papillomavirus (HPV) infection and HPV type 16 antibodies in South African women

There is a high incidence of cervical cancer in South African women. No large studies to assess human papillomavirus virus (HPV) infection or HPV type 16 (HPV-16) exposure have occurred in the region, a requirement for policy making with regards to HPV screening and the introduction of vaccines. Control women (n = 1,003) enrolled in a case control study of hormonal contraceptives and cervical cancer were tested for 27 cervical HPV types by reverse line blot analysis. The seroprevalence of HPV-16 immunoglobulin G (IgG) and IgA antibodies was assessed by a virus-like particle-based enzyme-linked immunoassay of 908 and 904 control women, respectively, and of 474 women with cervical cancer. The cervical HPV prevalence was 26.1%. The HPV-16 IgG seroprevalence was 44.4% and the HPV-16 IgA seroprevalence was 28.7% in control women, and these levels were significantly higher (61.8% and 52.7%, respectively) for women with cervical cancer (odds ratio [OR], 2.1 and 2.8, respectively). The cervical HPV prevalence showed an association with cervical disease, and the HPV-16 IgG prevalence decreased while the HPV-16 IgA prevalence increased with increasing age (P < 0.05). The prevalence of oncogenic HPV types (including HPV-16) decreased with age, whereas nononcogenic HPV types showed limited association with age. Multivariate analysis revealed cervical HPV infection to be associated with herpes simplex virus type 2 infection (OR, 1.7) and increasing years of education (OR, 1.9). HPV-16 IgG antibodies were inversely associated with current smoking status (OR, 0.6), and the presence of HPV-16 IgA antibodies was inversely associated with the use of alcohol (OR, 2.1) and inversely associated with the use of oral contraceptives (OR, 0.6). High levels of exposure to HPV, and particularly HPV-16, were evident in this population. The apparent increase of serum HPV-16 IgA with increasing age requires further investigation.

Identification and characterization of two novel human papillomaviruses (HPVs) by overlapping PCR: HPV102 and HPV106

Complete genomes of HPV102 (8,078 bp) and HPV106 (8,035 bp) were PCR amplified and cloned from cervicovaginal cells of a 49-year-old Hispanic female with reactive changes on her Pap test and a 42-year-old Hispanic female with a Pap test diagnosis of atypical squamous cells of unknown significance (ASCUS), respectively. The nucleotide sequence similarity of the complete L1 open reading frame (ORF) determined that HPV102 and HPV106 are most closely related to HPV83 (84.1 % identity) and HPV90 (83.5 % identity), respectively, placing them in the genital HPV groups, papillomaviruses species alpha3 and alpha15. HPV102 and HPV106 contain five early genes (E6, E7, E1, E2, and E4) and two late genes (L2 and L1), and both lack an E5 ORF. On the basis of phylogenetic analyses and available clinical information, these two novel HPV types expand the heterogeneity of HPVs detected in the lower genital tract.

Molecular biology of cervical cancer

Cervical cancer is a virus-induced disease that is caused by the integration of high-risk infecting human papillomaviruses (HPV) in the host genome. For this reason, the carcinogenesis process of cervical cancer is associated to the expression of the viral oncogenic proteins E6 and E7. These proteins are capable of inactivating p53 and pRb, which induces a continuous cell proliferation with the increasing risk of accumulation of DNA damage that eventually leads to cancer. Moreover, cervical cancer can be prevented by prophylactic HPV vaccines; their molecular characteristics and mechanism of action are reviewed. Ultimately, new molecular targets for cervical cancer like proteasome, the EGFR family and IGF family are exposed.

2006 consensus guidelines for the management of women with abnormal cervical cancer screening tests

A group of 146 experts representing 29 organizations and professional societies met September 18-19, 2006, in Bethesda, MD, to develop revised evidence-based, consensus guidelines for managing women with abnormal cervical cancer screening tests. Recommendations for managing atypical squamous cells of undetermined significance and low-grade squamous intraepithelial lesion (LSIL) are essentially unchanged. Changes were made for managing these conditions in adolescents for whom cytological follow-up for 2 years was approved. Recommendations for managing high-grade squamous intraepithelial lesion (HSIL) and atypical glandular cells (AGC) also underwent only minor modifications. More emphasis is placed on immediate screen-and-treat approaches for HSIL. Human papillomavirus (HPV) testing is incorporated into the management of AGC after their initial evaluation with colposcopy and endometrial sampling. The 2004 Interim Guidance for HPV testing as an adjunct to cervical cytology for screening in women 30 years of age and older was formally adopted with only very minor modifications.

High-risk cervical epithelial neoplasia grade 1 treated by loop electrosurgical excision: follow-up and value of HPV testing

OBJECTIVE

This study was undertaken to evaluate the value of high-risk human papillomavirus (HPV) testing in the follow-up of cervical intraepithelial neoplasia grade 1/low-grade squamous intraepithelial lesion treated by loop electrosurgical excision procedure because of the risk criteria established by the American Society for Colposcopy and Cervical Pathology (ie, unsatisfactory colposcopy or positive endocervical curettage, persistence of cervical intraepithelial neoplasia grade 1/low-grade squamous intraepithelial lesion, or high-risk HPV infection for longer than 2 years and older than 40 years).

STUDY DESIGN

Seventy-seven women with cervical intraepithelial neoplasia grade 1/low-grade squamous intraepithelial lesion treated by loop electrosurgical excision procedure and followed-up with colposcopy, cytology, and high-risk HPV detection using Hybrid Capture II.

RESULTS

More than 67% (67.6%) of women had cervical intraepithelial neoplasia grade 1 in the specimen; 22% a cervical intraepithelial neoplasia grade 2-3; and 10.4% had no lesion. Pretreatment HPV testing was positive in 100% of cervical intraepithelial neoplasia grade 2-3, in 93.5% of cervical intraepithelial neoplasia 1, and in 14.3% of cases with no lesion (P < .01). Pretreatment high-risk HPV testing was positive in all cases eventually developing residual/recurrent disease. Fifty percent of women with pretreatment viral load more than 100 relative light units had residual/recurrent disease develop. Posttreatment high-risk HPV testing during the follow-up reached a sensitivity and negative predictive value of 100% for detecting residual/recurrent disease.

CONCLUSION

Patients with low-grade squamous intraepithelial lesion/cervical intraepithelial neoplasia grade 1 and risk factors have a significant risk of harboring a cervical intraepithelial neoplasia grade 2-3 lesion. A conservative approach should be considered when basal high-risk HPV test is negative. High pretreatment high-risk HPV loads should be considered a risk factor for developing residual/recurrent disease. Posttreatment Hybrid Capture II has an extremely high sensitivity for detecting recurrences.

Human papillomavirus (HPV) genotype distribution in invasive cervical cancers in France: EDITH study

Invasive cervical cancer (ICC) remains a significant cause of morbidity and mortality in France. Since human papillomavirus (HPV) is the necessary cause of ICC, the aim of this study was to assess the type-specific prevalence of HPV in ICC in France in order to locally evaluate the potential benefit of an HPV 16/18 L1 virus-like particles (VLP) vaccination. A total of 516 histological specimens collected in 15 centers were analyzed. Among them, 86% had a diagnosis of squamous cell carcinoma (SCC) whereas 14% were adenocarcinomas (ADC). HPV genotyping was performed using the INNO-LiPA assay allowing the specific detection of 24 HPV genotypes both high risk (HR) and low risk (LR). The overall HPV prevalence in ICC was 97%. The most prevalent genotypes were HPV 16 (73%) and HPV 18 (19%) followed by HPV 31 (7%), 33, 68, 45, 52 and 58 (4.1-2.3%). HPV 16 and/or 18 were associated with 82% of ICC, 10% being HPV 16 and 18 coinfections. While HPV 16 was the most prevalent type in both SCC (74%) and ADC (64%), HPV 18 was by far more prevalent in ADC (37%) compared to SCC (16%; p < 0.001). Multiple infections with at least two different HR HPV genotypes were observed in 22% of ICC. Given the high HPV 16/18 prevalence and taking into account possible production of crossneutralizing antibodies against other HPV types, HPV 16/18 L1 VLP vaccination would be expected to significantly reduce the burden of ICC in France.

Prevalence of human papillomavirus antibodies in young female subjects in England

Sera from 1483 female subjects in England aged 10–29 years were tested. The age-standardised seroprevalence was 10.7% (95% confidence intervals 9.0–12.3) for human papillomavirus (HPV) 6, 2.7% (1.8–3.6) for HPV 11, 11.9% (10.2–13.6) for HPV 16, 4.7% (3.5–5.8) for HPV 18, and 20.7% (18.6–22.7) for any of the four types.

Prophylactic human papillomavirus vaccines: potential for sea change

Persistent human papillomavirus (HPV) infection is the central cause in the development of anogenital warts, precancers and cancers of uterine cervix, and a major factor in the genesis of other malignancies of the lower anogenital and upper aerodigestive tracts. The burden of disease carries very high medical, financial and psychosocial costs. The role of prophylactic HPV vaccines in reducing the burden of disease is discussed in light of the results of multiple randomized, controlled trials conducted worldwide in thousands of young females. The review discusses some of the issues that are still unknown, with respect to long-term vaccine performance, challenges to be overcome to achieve universal, mass prophylactic HPV vaccination, as well as the potential impact of the vaccines on primary screening for, and management of, HPV-related anogenital infection and disease.

Virally mediated cervical cancer in the iatrogenically immunocompromised: applications for psychoneuroimmunology

Oncogenic or high-risk (HR) human papillomavirus (HPV) infection is implicated in the pathogenesis of a number of cancers, including cervical cancer. HPV infected individuals who are immunocompromised secondary to acquired (e.g., human immunodeficiency virus [HIV]) or iatrogenic (e.g., systemic lupus erythematosus [SLE] patients and organ and hematopoeitic stem cell transplant recipients undergoing immunosuppressive therapy) immune deficiency are particularly at risk for HPV-initiated cervical neoplasia and cancer. Psychoneuroimmunologic (PNI) research has demonstrated that psychosocial factors such as stress, pessimism, and sleep quality may play a role in the promotion of HPV-mediated cervical neoplasia in HIV-positive women. However, no research to our knowledge has examined PNI mechanisms of HPV-mediated cervical neoplasia and cancer in women who are undergoing iatrogenic immunosuppressive therapy for the treatment of autoimmune disease or the prevention of graft-rejection. This article reviews the PNI mechanisms that may underlie the promotion of HPV-mediated cervical neoplasia and applies this model to HPV-infected women who are iatrogenically immunosuppressed, an understudied population at-risk for cervical cancer. Female transplant recipients, one such group, may provide a unique paradigm in which to explore further PNI mechanisms of HPV-mediated cervical neoplasia.

Integration of human papillomavirus vaccination, cytology, and human papillomavirus testing

There is justifiable excitement about the recent introduction of prophylactic vaccines against human papillomavirus (HPV) types 16 (HPV-16) and HPV-18. Preventing these infections theoretically could avert approximately 70% of cervical cancer cases worldwide. In the U.S., numerous influential advocates are calling for universal vaccination of adolescent females. Given the promise of the vaccines, perhaps it is inevitable that vaccine introduction is proceeding before full consideration of how universal vaccination would affect existing, successful cervical cancer prevention programs. Determining the impact and cost effectiveness of the vaccines unavoidably will require time. Nevertheless, it is worth describing in broad terms for the readers of Cancer Cytopathology how successful, broad HPV vaccination of adolescent girls may affect cytology and HPV testing.

Identification of a novel human papillomavirus (HPV97) related to HPV18 and HPV45

Human papillomavirus (HPV) type 97 was identified and the genome was cloned from cervicovaginal cells of a Costa Rican woman with a normal Pap smear. The HPV97 L1 open reading frame (ORF) was most closely related to HPV45 (84% identity) and HPV18 (79% identity), placing it into the high-risk alpha7 species. Ectopic expression of the HPV97 E6 and E7 proteins significantly decreased steady state p53 and pRb levels using an in vitro cotransfection assay, respectively. These data suggest that HPV97 shares a most recent common ancestor with HPV18 and HPV45 and should be evaluated in cancer specimens from different geographic populations.

Immune concept of human papillomaviruses and related antigens in local cancer milieu of human cervical neoplasia

It is presently the right time for clarifying human papillomavirus (HPV)-associated cellular immunity and clinical implications before global HPV vaccination programs begin. Infection with oncogenic HPV associates with the progression of cervical neoplasia. Both cellular and humoral immune responses are essential for the clearance of HPV-associated cervical lesions. There is increasing evidence that the immune system plays a pivotal role in determining the outcome of HPV infection. Viruses and associated neoplastic cells are proposed to have evolved mechanisms to avoid immune attack. T-cell-mediated immune responses against oncogenic HPV are believed to play a central role in cervical carcinogenesis. The presence of HPV-specific cytotoxic T lymphocytes (CTL) in a majority of human cervical cancer patients provides an approach for further study of their functional role in modulating this malignancy. Tumor-infiltrating lymphocytes (TIL) develop as manifestations of the recognition and defense against malignant cells by the host immune system. Cancer cells may overcome immune surveillance, either by downregulating the proliferation of HPV-specific CTL, or altering the effector compositions of immune cells against HPV infections. TIL in the tumor microenvironment can be functionally inhibited and lose the ability of clonal proliferation as a result of depressed expression of IL-2Ralpha. The upregulation of inhibitory signaling relates to the modulation of the virus- and/or tumor-specific immune responses. Alteration of host genetic susceptibility may also lead to abnormal immune response as a general genomic instability resulting from virus persistence. Induction of HPV-specific immune responses is anticipated as an intimate point for the treatment of cervical neoplasia.

Hawaii cohort study of serum micronutrient concentrations and clearance of incident oncogenic human papillomavirus infection of the cervix

The degree to which the resolution of human papillomavirus (HPV) infection parallels exposure to other factors, particularly those related to nutritional status, is a relatively unexplored area of research. We established a cohort of women for long-term follow-up to examine the association of serum retinol, carotenoid, and tocopherol concentrations with the clearance of incident cervical HPV infection. Interviews and biological specimens were obtained at baseline and at 4-month intervals. At each visit, a cervical cell specimen for HPV DNA analysis and cytology and a fasting blood sample to measure micronutrient levels were collected. A Cox proportional hazards model was used to study the relationship between clearance of 189 incident (type-specific) oncogenic HPV infections and the levels of 20 serum micronutrients among 122 women. Higher circulating levels of trans-zeaxanthin, total trans-lutein/zeaxanthin, cryptoxanthin (total and beta), total trans-lycopene and cis-lycopene, carotene (alpha, beta, and total), and total carotenoids were associated with a significant decrease in the clearance time of type-specific HPV infection, particularly during the early stages of infection (<or=120 days). HPV clearance time was also significantly shorter among women with the highest compared with the lowest serum levels of alpha-tocopherol and total-tocopherol, but significant trends in these associations were limited to infections lasting <or=120 days. Clearance of persistent HPV infection (lasting >120 days) was not significantly associated with circulating levels of carotenoids or tocopherols. Results from this investigation support an association of micronutrients with the rapid clearance of incident oncogenic HPV infection of the uterine cervix.

Quadrivalent vaccine against human papillomavirus to prevent high-grade cervical lesions

BACKGROUND

Human papillomavirus types 16 (HPV-16) and 18 (HPV-18) cause approximately 70% of cervical cancers worldwide. A phase 3 trial was conducted to evaluate a quadrivalent vaccine against HPV types 6, 11, 16, and 18 (HPV-6/11/16/18) for the prevention of high-grade cervical lesions associated with HPV-16 and HPV-18.

METHODS

In this randomized, double-blind trial, we assigned 12,167 women between the ages of 15 and 26 years to receive three doses of either HPV-6/11/16/18 vaccine or placebo, administered at day 1, month 2, and month 6. The primary analysis was performed for a per-protocol susceptible population that included 5305 women in the vaccine group and 5260 in the placebo group who had no virologic evidence of infection with HPV-16 or HPV-18 through 1 month after the third dose (month 7). The primary composite end point was cervical intraepithelial neoplasia grade 2 or 3, adenocarcinoma in situ, or cervical cancer related to HPV-16 or HPV-18.

RESULTS

Subjects were followed for an average of 3 years after receiving the first dose of vaccine or placebo. Vaccine efficacy for the prevention of the primary composite end point was 98% (95.89% confidence interval [CI], 86 to 100) in the per-protocol susceptible population and 44% (95% CI, 26 to 58) in an intention-to-treat population of all women who had undergone randomization (those with or without previous infection). The estimated vaccine efficacy against all high-grade cervical lesions, regardless of causal HPV type, in this intention-to-treat population was 17% (95% CI, 1 to 31).

CONCLUSIONS

In young women who had not been previously infected with HPV-16 or HPV-18, those in the vaccine group had a significantly lower occurrence of high-grade cervical intraepithelial neoplasia related to HPV-16 or HPV-18 than did those in the placebo group. (ClinicalTrials.gov number, NCT00092534 [ClinicalTrials.gov].).

Characterization and experimental transmission of an oncogenic papillomavirus in female macaques

Cervical cancer is one of the leading causes of cancer mortality in women worldwide, yet few suitable animal models currently exist for study of this disease. Virtually all cases of cervical cancer in women are caused by specific types of genital human papillomavirus (HPV). In this study, we investigated naturally occurring genital PVs in female cynomolgus macaques (Macaca fascicularis) without breeding contact for at least 3.5 years. Exfoliated cervicovaginal cells from 19 of 54 animals tested positive for at least one PV. Seven different PVs were identified, including four novel genotypes and two genotypes (RhPV-d and RhPV-a) previously identified in rhesus macaques (Macaca mulatta). Four PV types were associated with cervical intraepithelial neoplasia (CIN), which resembled human CIN by endoscopy, cervical cytology, histology, and immunohistochemistry. The presence of CIN was highly associated with PV infection (P<0.0001). The most prevalent virus type was RhPV-d, which was identified in 60% of animals with CIN. An RhPV-d genome sequenced from a high-grade CIN lesion was found to be phylogenetically related to the highly oncogenic HPV16. Transfer of cervical cytobrush samples from donor animals naturally carrying RhPV-d resulted in new infections in 4 of 12 previously virus-free animals and abnormal cytology and histology in 1 of 4 infected animals after 18 weeks of infection. Experimental transmission was confirmed by E1/\E4 reverse transcription-PCR products and RhPV-d sequence identity with the donor variant. These findings identify key similarities between macaque and human oncogenic PVs which should prove useful in the study of viral persistence, carcinogenesis, and therapeutic development.

[Prevention of cervical cancer (II): prophylactic HPV vaccination, current knowledge, practical procedures and new issues]

Despite the considerable success of early screening for prevention of cervical cancer, Pap smears have not fulfilled the hopes that it would lead to a large-scale reduction of this cancer's incidence. Screening appears to be useful for a tiny portion of the world population, although a relatively large portion must put up with its limitations and disadvantages. Human papilloma viruses (HPV) 16 and 18 are responsible for two thirds of all cervical cancers worldwide. The condylomata (condyloma acuminatum), or genital warts, induced by HPV 6 and 11 are frequent among the young and difficult to manage. The extent and burden of HPV infection are considerable, as is the psychological and emotional impact of the diseases associated with it. Because cancer of the cervix is the final consequence of chronic HPV infection, it can be prevented by vaccination. A prophylactic vaccine to protect against the precancerous and cancerous lesions associated with HPV should save lives, reduce expensive diagnostic and therapeutic interventions, and have substantial individual and collective benefits. Clinical trials of anti-HPV vaccines for the prevention of cervical cancer and condyloma have shown remarkable results and an efficacy unequaled in the history of vaccination against infectious diseases. Vaccine efficacy has been shown only in young girls never exposed to the virus and only for the lesions associated with the specific viral types in the vaccine. Preliminary data indicate that the vaccination is effective in women who have previously eliminated naturally the virus. It has no therapeutic effects on existing lesions or in healthy virus carriers. Practical questions remain to be resolved. If the vaccination is left to individual initiative and vaccination coverage is insufficient, there will be no perceptible reduction in the frequency of cervical cancer. Vaccination policies will not be identical in poor countries, where the disease represents one of the leading causes of mortality among women, and in the rich countries, where screening programs have considerably reduced the frequency of this cancer. Current planning calls for the introduction of systematic vaccination of young girls aged 9-15 years, with progressive "catch-up" vaccination of the cohorts of young women aged 16-26 years. Nonetheless mathematical models and immunogenicity results indicate a possible benefit for individual vaccination of adults. This approach must still be assessed in the clinical trials underway. Because the vaccine does not protect against all types of HPV associated with cervical cancer, screening must be continued according to the conditions currently set. Vaccination and screening, which are complementary and synergistic, now constitute the new standards for prevention of this disease.

Imiquimod et autres immunomodulateurs en gynécologie

Immunomodulators have been used for some time in various medical specialities, but have only recently been used in gynaecology. The first drug in this therapeutic class, Immiquimod (Aldara), has been shown to be effective in treating lesions induced by Human Papillomavirus (HPV) such as genital warts or cervical and vulvar dysplasia, by stimulating the immune system of an infected individual. Thanks to its ease of use and its few side effects, Imiquimod would appear to be, in the future, the treatment of choice for these types of viral infections, alone or in association with therapeutic vaccines or physical abative therapies as a prevention of relapses. This review aims at summarizing and clarifying the mechanism of action of the different immunomodulators, their indications and their effectiveness in gynecologic practice.

Chapter 30: HPV vaccines and screening in the prevention of cervical cancer; conclusions from a 2006 workshop of international experts

The finding that cervical cancer only occurs in women infected with specific, "high-risk" types of the human papillomavirus (HPV) has led to the development of novel, non-cytology-based cervical cancer prevention strategies. We now have sensitive molecular methods for detecting HPV that dramatically improve our ability to detect high-grade cervical cancer precursor lesions. Perhaps more importantly, prophylactic HPV vaccines have been developed that are protective against cervical cancer precursors caused by HPV 16 and 18. In the Spring of 2006, over 100 experts in HPV, cervical cancer screening, and vaccination worked together to define how best to incorporate HPV DNA testing and the HPV vaccines into cervical cancer prevention efforts. In this summary, we summarize the opinions of this expert group on how these advances can be introduced to provide the maximum benefit to women and to reduce the global burden of cervical cancer.