Epidemiology of cervical intraepithelial neoplasia: the role of human papillomavirus

Factors associated with the persistence of human papillomavirus after surgery in patients with cervical cancer

OBJECTIVE

To determine the rate of human papillomavirus (HPV) persistence after surgery in patients with cervical cancer, and to analyze the factors associated with HPV persistence and viral load after surgery.

METHODS

Medical records of women who underwent surgery for treatment of cervical cancer between 1 January 2018 and 30 June 2019 at Obstetrics and Gynecology Hospital of Fudan University in Shanghai, China, were retrospectively analyzed. Patients with persistent HPV infection after 2 years of follow-up were identified. Univariate and multivariate analyses were employed to determine the impact of various factors including patient age, menopausal status, parity, and surgical margin status on HPV persistence. The Wilcoxon test was used to analyze the factors that influenced postoperative HPV viral load.

RESULTS

Altogether, 607 women were eligible for the final analysis. The persistence rates of HPV at 6 months, 1 year, and 2 years after surgery were 17.3, 13.7, and 10.2 %, respectively. In univariate analysis, the factors that were predictive of the persistence of HPV infection were old age, postmenopausal status, and positive vaginal incision margin with cancer. In multivariate analysis, the significant independent predictive factors were postmenopausal status and positive vaginal incision margin with cancer (P < 0.05, odds ratio (OR) = 2.289, 95 % confidence interval (CI): 1.262-4.150 and OR = 3.271, 95 % CI: 1.253-8.537, respectively). A vaginal lesion with cancer or squamous intraepithelial lesion (SIL) and positive vaginal incision margin influenced HPV viral load at 6 months after surgery (P < 0.05).

CONCLUSIONS

Postmenopausal patients and those with positive vaginal incision margin with cancer are at an increased risk of HPV persistence after surgical treatment for cervical cancer. Vaginal lesions with cancer or SILs and positive vaginal incision margin are risk factors for high HPV viral load after surgery.

A Brief Overview of Oncogenes and Signal Transduction Pathways in Gynecological Cancer

Gynecological cancer is the cancer that originates in the female reproductive system. According to the anatomical location of the cancer, it is distinguished into cervical, uterine, vaginal, ovarian, and vulvar cancer. Oncogenes and tumor catalytic genes play a key role in the genesis and development of gynecological cancer. This article presents the signaling pathways and expression of oncogenes that take place in the carcinogenesis of the female reproductive system.

Cervical Cancer and Its Precursors: A Preventative Approach to Screening, Diagnosis, and Management

Cervical cancer affects the cells lining the cervix, most commonly occurring in the cells of the transformation zone. Screening for cervical cancer looks to detect preinvasive disease, allowing for intervention before invasive disease develops. an assessment of individual risk factors, Selection of screening method depends on patient age, her screening history and results, and resources available. Screening has resulted in well-documented declines in cervical cancer incidence and mortality in the United States. Guidelines continue to evolve as new data emerge. Although cervical cancer prevention strategies include interventions directed toward limiting number of sexual partners, condom use, and reduction in cigarette smoking, vaccination represents the most direct targeted strategy.

Human Papilloma Virus Persistence after Cone Excision in Women with Cervical High Grade Squamous Intraepithelial Lesion: A Prospective Study

Background. Persistent human papillomavirus (HPV) infection is a necessary event in cervical cancer tumorigenesis. Our objectives were to estimate the rate of HPV infection persistence after large loop excision of the transformation zone (LEEP) in patients with high grade squamous intraepithelial lesions (HSIL) and to investigate if HPV persistence is type related. Methods. We conducted a prospective study on 89 patients with HSIL treated with LEEP. DNA HPV was performed before surgery and at 6, 12, and 18 months after LEEP. Results. Four patients were excluded from the study. The HPV persistence in the remaining 85 patients was 32.95% (6 months), 14.12% (12 months), and 10.59% (18 months). Type 16 had the highest persistence rate, 23.5% (6 months), 11.8% (12 months), and 8.2% (18 months). Coinfection was found to be 54.12% before LEEP and 18.8% (6 months), 4.7% (12 months), and 3.5% (18 months) after LEEP. The rate of coinfections including type 16 was 46.83% of all coinfections. Coinfection including type 16 was not correlated with higher persistence rate compared to infection with type 16 only. Conclusions. HPV infection is not completely eradicated by LEEP in patients with HSIL lesion on PAP smear. HPV persistence after LEEP is influenced by HPV type. HPV type 16 has the highest persistence rate.

Cervical screening program and the psychological impact of an abnormal Pap smear: a self-assessment questionnaire study of 590 patients

PURPOSE

Invasive cervical cancer is today the fourth most common cancer of women in western civilization. Screening programs have led to a continuously decrease. Nevertheless, both screening and a positive test result are known to be associated with a negative psychological impact. Screening programs in European countries differ and thus psychological impact might as well. The aim of this study was to evaluate the psychological impact of women with an abnormal Pap smear in a German cohort.

METHODS

Between July 2013 and May 2014, a self-assessment questionnaire was distributed to 595 patients that were referred to a special clinic for cervical dysplasia for further evaluation of an abnormal Pap smear. Patients were recruited in five different centers.

RESULTS

Most patients (45.9 %) were informed about the test result via phone call by their doctor. 68.8 % of the patients felt anxious and 26.3 % even felt panic. After having talked to their physician, 51.4 % of our cohort still felt worried and only 24.4 % felt reassured. Concerning disease management, 48.4 % underwent a control Pap smear in 6 months. The preferred information source was the physician (63.9 %). Compared to the results in other European countries, our study cohort showed differences concerning age distribution, patients living in a partnership, number of children and especially disease management.

CONCLUSION

Cancer screening itself and abnormal test results have an impact on patient's feelings. To reduce the psychological impact, patients need to be better informed about the risks and benefits of cancer screening programs and in case of cervical cancer screening about the meaning of an abnormal test result. Our results underline the importance of a trustful physician-patient relationship in that matter.

Distribution of cervical intraepithelial neoplasia on the cervix in Chinese women: pooled analysis of 19 population based screening studies

Background

Controversy remains whether a pattern of cervical intraepithelial neoplasia exists on the cervix. Our study aims at determining if the prevalence of histologically proven lesions differs by cervical four-quadrant location or by 12 o'clock surface locations of diagnosis.

Methods

We conducted a retrospective, histopathological study of 19 different population based cervical cancer screening studies from 1999 to 2010 by Cancer Hospital of Chinese Academy of Medical Sciences. The Institutional Review Board for human research subjects at CHCAMS approved all of the studies. During the colposcopy procedure, participant received either 4-quadrant biopsy or directed biopsy with/without endocervical curettage. Data of all samples were stratified by the methods of sampling. Kruskal-Wallis test was used to determine overall distribution of normal/CIN1, CIN2 and CIN3+ on the cervix.

Results

In total, 53,088 cervical samples were included in distribution analysis. 66.9 % samples were obtained by random biopsy, 16.1 % were by directed biopsy, and 17.0 % were by endocervical curettage. 95.9%of the biopsied samples were diagnosed as normal/CIN1, 2.0 % were CIN2, and 2.1 % were CIN3 + . CIN2 and CIN3+ were most often found in quadrants 2 and 3 (χ_KW² = 46.6540, p < 0.0001) and at the 4- and 7-o'clock positions by directed biopsy (OR_CIN2 = 2.572, 1.689, OR_CIN3+ = 3.481, 1.678, respectively), and at the 5-, 6-, 7-, 9- and 12-o’clock positions by random biopsy. CIN3+ was least often found at the 11-o’clock position by directed biopsy (OR = 0.608).

Conclusions

Our results suggest a predisposition of specific locations on the cervix to CIN occurrence. Quadrants 2 and 3, especially the 4- and 7-o’clock positions should be preferentially targeted during biopsy. The decision for random biopsy should be reconsidered in future studies.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1494-4) contains supplementary material, which is available to authorized users.

The incidence of human papillomavirus infection following treatment for cervical neoplasia: a systematic review

OBJECTIVE

To systematically review the published literature in order to estimate the incidence and describe the variability of human papillomavirus (HPV) infection in women following treatment for cervical neoplasia.

METHODS

Several scientific literature databases (e.g. PubMed, ISI Web of Science) were searched through January 31, 2012. Eligible articles provided data on (i) baseline HPV infection status within 6 months prior to or at time of treatment (pre-treatment); and (ii) HPV test results for women's first visit after treatment occurring within 36 months (post-treatment). We abstracted and summarized the post-treatment incidence of newly detected HPV genotypes that were not present at pre-treatment, overall and stratified by study and other population characteristics.

RESULTS

A total of 25 studies were included, reporting post-treatment HPV incidence in nearly 2000 women. Mean patient age ranged from 31 to 43 years (median 36). Most studies used cervical exfoliated cell specimens to test for HPV DNA (n=20; 80%), using polymerase chain reaction (n=21; 84%). Cervical neoplasia treatment included loop electrical excision procedure (n=11; 44%); laser conization (n=2; 8%); laser ablation, surgical conization, cryotherapy, alpha-interferon (n=1; 4% each); or multiple treatment regimens (n=8; 32%). Follow-up times post-treatment ranged from 1.5 to 36 months (median 6). More than half of studies (n=17; 68%) estimated the incidence of any HPV type following treatment, while 7 (28%) focused specifically on high-risk (HR) HPV. HPV incidence after treatment varied widely, ranging from 0 to 47% (interquartile range: 0%-15%) in up to 3 years of follow-up after treatment. Lower HPV incidence was observed among studies that included relatively younger women, used laser conization, focused on HR-HPV rather than overall HPV infection, and had a lower proportion of recurrent cervical disease.

CONCLUSIONS

These modest summary incidence estimates from the published literature can guide clinicians, epidemiologists and health economists in developing best practices for post-treatment cervical cancer prevention.

Genomic polymorphism of human papillomavirus type 52 in women from Northeast China

Human papillomavirus (HPV) 52 is an oncogenic HPV type prevalent in Asia. The aim of the study was to analyze HPV 52 genetic variations in women from Northeast China. To explore the intratypic variants of HPV 52, the genomic regions of L1, E6, E7 and long control region (LCR) of HPV 52, which have been identified in women from Northeast China by HPV GenoArray test, were analyzed. Twenty-five mutations were identified in the regions examined. Of the mutations found in the L1 gene, three novel nonsynonymous mutations of C5640T, A5641T and G5642A were located within the region that encodes the binding domain of neutralizing antibodies against HPV 52. Although four variations were identified in HPV 52 E6 and E7 genes, no significant association was found between the mutations and the cytological lesion of the patients. Eight mutations, including a novel CTT7681−7683 deletion, found in the LCR of HPV 52 encompassed the known transcription binding sites, which may possibly affect the transcription of the oncogenic genes of E6 and E7. The most prevalent HPV 52 variant in women from northeastern China belongs to clade L1-LN-A. The genetic variations of HPV 52, including three novel nonsynonymous mutations of C5640T, A5641T and G5642A in the L1 gene and a novel CTT7681−7683 deletion in the LCR, were first documented in strains from women in Northeast China. The statistical result showed no associations between the variants and the severities of the infected women. These findings provide new data regarding gene variations of HPV 52.

Identification of key amino acid residues that determine the ability of high risk HPV16-E7 to dysregulate major histocompatibility complex class I expression

High risk human Papillomavirus (HPV) types are the major causative agents of cervical cancer. Reduced expression of major histocompatibility complex class I (MHC I) on HPV-infected cells might be responsible for insufficient T cell response and contribute to HPV-associated malignancy. The viral gene product required for subversion of MHC I synthesis is the E7 oncoprotein. Although it has been suggested that high and low risk HPVs diverge in their ability to dysregulate MHC I expression, it is not known what sequence determinants of HPV-E7 are responsible for this important functional difference. To investigate this, we analyzed the capability to affect MHC I of a set of chimeric E7 variants containing sequence elements from either high risk HPV16 or low risk HPV11. HPV16-E7, but not HPV11-E7, causes significant diminution of mRNA synthesis and surface presentation of MHC I, which depend on histone deacetylase activity. Our experiments demonstrate that the C-terminal region within the zinc finger domain of HPV-E7 is responsible for the contrasting effects of HPV11- and HPV16-E7 on MHC I. By using different loss- and gain-of-function mutants of HPV11- and HPV16-E7, we identify for the first time a residue variation at position 88 that is highly critical for HPV16-E7-mediated suppression of MHC I. Furthermore, our studies suggest that residues at position 78, 80, and 88 build a minimal functional unit within HPV16-E7 required for binding and histone deacetylase recruitment to the MHC I promoter. Taken together, our data provide new insights into how high risk HPV16-E7 dysregulates MHC I for immune evasion.

Outcome of expectant management of cervical intraepithelial neoplasia grade 2 in women followed for 12 months

OBJECTIVE

To evaluate the outcome of CIN 2 diagnosed by colposcopy-directed biopsy in women followed without treatment for 12 months and to verify whether the regression and progression of this lesion are associated with the woman's age at diagnosis and age at first sexual intercourse.

STUDY DESIGN

Women diagnosed with CIN 2 by biopsy and with previous cervical smear showing LSIL were included in this cohort study and followed up for one year with cervical smear and colposcopy every three months. The rates of progression, persistence and regression of the CIN 2 were evaluated. The Kruskal-Wallis test was used to analyze the woman's age at diagnosis, age at first sexual intercourse and interval since the first sexual intercourse according to the CIN 2 outcome, assuming a significance level of 5%.

RESULTS

At the end of 12 months of follow-up the CIN 2 regression rate was 74% (31/42), progression rate to CIN 3 was 24% (10/42) and in one case CIN 2 persisted (2%). Among women who had regression, this event was detected in the first six months of follow-up in 26 of the 31 cases. There was no statistically significant association between the evolution of CIN 2 and the woman's age at diagnosis, age at first sexual intercourse and interval since first sexual intercourse. Women whose lesions were restricted to one quadrant were more likely to have CIN 2 regression at three-month follow-up compared with women with a lesion extending to one or more quadrants (OR: 6.50; 95% CI: 1.20-35.23).

CONCLUSIONS

The results of this study indicate that the majority of CIN 2 diagnosed by biopsy in women with previous Pap smear showing LSIL will regress in 12 months and therefore an expectant approach could be considered in these cases, not only for young women. Nevertheless these findings are not conclusive, and larger studies are required in order to certify when it is safe to adopt expectant management for CIN 2.

Successful photodynamic therapy with topical 5-aminolevulinic acid for five cases of cervical intraepithelial neoplasia

OBJECTIVES

Photodynamic therapy (PDT) is a minimally invasive treatment for cervical intraepithelial neoplasia. The purpose of this study was to assess the feasibility and effectiveness of PDT in patients with CIN and high-risk HPV infection.

METHODS

Five patients diagnosed CIN 2 or CIN 3 with human papillomavirus (HPV) infection were included. Each patient had gynecologic examination including cervical cytology, HPV DNA testing, colposcopy and biopsy. Two grams of 5-aminolevulinic acid (ALA) gel (118 mg/g) was topically applied to the cervix and covered with a special plastic cap for 3-4 h, followed by 20 min illumination of both ecto- and endo-cervical canal with red coherent light (wavelength 633 nm) using a PDT laser and a special light catheter. The PDT therapy was repeated with an interval of 1 week. Follow-up examination including biopsy and histology, colposcopy, HPV DNA testing were carried out after 3, 6 and 9 months.

RESULTS

Treatment could be accomplished in all cases and no severe side effect was encountered. All the CIN2 patients had a complete response for 9 months and one CIN3 HPV remained positive for 6 months after three or four treatments.

CONCLUSION

PDT seems to be a non-invasive, repeatable procedure for CIN and cervical HPV infection with minimal side effects and can be easily performed on outpatient basis.

Reasons for early interventions by gynaecologists in a clinical follow-up study on cervical intraepithelial neoplasia

OBJECTIVE

In a previous clinical follow-up study on psychosocial factors and cervical intraepithelial neoplasia (CIN), we had noticed a high percentage of early interventions to the cervix by gynaecologists, in discordance with the research protocol. The aim of the current study was to investigate the reasons for these interventions.

STUDY DESIGN

We retrospectively analysed the study records of the clinical study, concerning the follow-up of 98 patients with a CIN 1 or 2 lesion for 2.25 years by colposcopy and cervical smears. We recorded the number of early interventions that had occurred in the clinical study as well as the reasons for these interventions. A distinction was made between acceptable and unacceptable reasons for early intervention.

RESULTS

During follow-up, 39 out of 98 women (40%) had undergone intervention in discordance with the protocol. No acceptable reason for these interventions was found for 67% of these patients (26/39). In the majority of these cases either no reason for the intervention had been given, or the gynaecologist had feared for progression of the CIN lesion.

CONCLUSION

Gynaecologists tend to intervene during follow-up of CIN, partly out of fear for progression. This tendency may complicate follow-up studies on CIN.

The influence of smoking and other cofactors on the time to onset to cervical cancer in a southern European population

Cervical cancer is a complex and multifactorial disease. Although there are substantial data supporting the causative role of persistent human papillomavirus (HPV) infection in the development of cervical cancer, the complete course of the disease has never been completely understood. Several risk cofactors have been suggested with controversial results. Portugal has the highest incidence of squamous cell carcinoma (SCC) within western Europe and there are no known studies regarding the role of cofactors in SCC. The aim of our study was to evaluate the role of smoking, sexual behaviour, reproductive and contraceptive history, in the time-to-onset (TTO) of severe cervical lesions (HGSIL/SCC) in the Portuguese population. We verified that age of first sexual intercourse under 18 years (odds ratio (OR) 2.8), pregnancy (OR 2.9), first pregnancy under 21 years (2.6), number of pregnancies (OR 2.3-5.4) and parity (OR 1.9-5.7) are risk factors in the development of cervical neoplasia. Smoke exposure index (SEI) was significantly different (P=0.002) between cases and controls. Our results regarding time-to-onset demonstrate that smoking (P<0.001, log rank test), number of sexual partners (P<0.001, log rank test) and use of oral contraceptives (P<0.001, log rank test) are important determinants in the earlier onset of severe cervical lesions. Using this approach, our findings may help to clarify the role of smoking and other cofactors in the persistence and progression of cervical lesions.

Immunohistochemical expression of DNA mismatch repair (MMR) system proteins (hMLH1, hMSH2) in cervical preinvasive and invasive lesions

The purpose of our study was to analyze the immunohistochemical expression of two MMR system proteins at different steps of neoplastic progression within the squamous cervical epithelium. We compared cases showing normal histologic appearance with those affected by low and high-grade squamous intraepithelial lesions and invasive cervical carcinoma. We investigated formalin-fixed and paraffin-embedded tissue specimens obtained from 83 selected patients (55 with preinvasive neoplastic lesions and 28 with invasive squamous cervical carcinoma) for the expression of hMSH2 and hMLH1 at the immunohistochemical level. We also included 30 patients with histologically normal cervix as a control group. Epithelial cells of CIN lesions showed a significant increase in the expression of both hMLH1 and hMSH2 proteins compared to non-neoplastic squamous epithelium (p < 0.0001). The cases of invasive carcinoma showed a positivity for hMLH1 protein that was statistically lower than that for non-neoplastic cells (p = 0.0009) and that for cases with CIN (p < 0.0001). Positivity for hMSH2 protein was higher than that for normal epithelium (p = 0.0007), but lower than that for preinvasive lesions (p = 0.0001). Preinvasive lesions showed increased expression of both proteins if compared with normal esocervical epithelium. Neoplastic stromal invasiveness is associated with a significant loss of hMLH1 function.

Human papillomavirus and cervical cancer: issues for biobehavioral and psychosocial research

There is now overwhelming evidence that high-risk, sexually transmitted types of human papillomavirus (HPV) are the main causal agent in cervical cancer. Biobehavioral and psychosocial research is uniquely capable of addressing many of the issues raised by HPV and its link with cervical cancer. In this article we review current findings in this area and identify issues for future research. The first of the three sections explores issues associated with the introduction of HPV testing for the detection and management of cervical abnormalities and the impact of growing public awareness of the sexually transmitted nature of cervical cancer. The implications for public understanding of cervical cancer, psychosocial issues associated with screening, and the potential impact on screening uptake are discussed. The second section addresses the role of biobehavioral factors in the persistence and progression of HPV infection as well as possible interventions to minimize the risk of persistence. Finally, primary prevention of HPV is discussed.

Cancer of the Uterine Cervix

HEALTH ISSUE: Cervical cancer is one of the most common malignant diseases of women; it is diagnosed in almost half a million women every year and half as many die from it annually. In Canada and other industrialized countries, its incidence has decreased due to cytology screening. However, invasive cases still occur, particularly among immigrant groups and native Canadian women. Although incidence of squamous cell carcinomas has decreased, the proportion of adenocarcinomas has increased because Pap cytology is ineffective to detect these lesions. KEY FINDINGS: In Canada, cervical cancer will cause an estimated 11,000 person-years of life lost. In most Canadian provinces, early detection is dependent on opportunistic screening. Primary prevention can be achieved through health education (sexual behavior modification) and vaccination to prevent infection from Human Papillomavirus (HPV). The initial results from vaccination trials are encouraging but wide scale use is more than a decade away. DATA GAPS AND RECOMMENDATIONS: Most cases of cervical cancer occur because the Pap smear was either false negative, was not done or not done often enough. Appropriate recommendations and guidelines exist on implementation of cytology-based programs. However, most Canadian women do not have access to organized screening. Further research is needed to 1) evaluate automated cytology systems; 2) define appropriate management of precursor lesions and 3) deliver definitive evidence of HPV testing efficacy in long-term follow-up studies with invasive cancer as an outcome and 4) provide Canadian data to justify augmenting or modifying current programs to use HPV testing in secondary triage of equivocal Pap smears.

The Epidemiology of Cervical Cancer

Cervical cancer is one of the most common neoplastic diseases affecting women, with a combined worldwide incidence of almost half a million new cases annually, second only to breast cancer. Basic and epidemiologic research conducted during the past 15-20 years have provided overwhelming evidence for an etiologic role for infection with certain types of sexually-transmitted human papillomavirus (HPV) as the primary cause of cervical cancer. The relative risks of cervical cancer following HPV infection as ascertained in case-control and cohort studies are among the highest in cancer epidemiology. The available evidence indicates that the HPV-cervical cancer association satisfies all relevant causal criteria for public health action. Other cervical cancer risk factors, such as smoking, parity, use of oral contraceptives, diet, other infections, and host susceptibility traits must be understood in the context of mediation of acquisition of HPV infection or in influencing events of the natural history of cervical neoplasia that occur following the establishment of a persistent HPV infection. Virtually all cervical carcinoma specimens contain HPV DNA, which suggests that HPV infection is a necessary cause of cervical neoplasia. This is the first instance in which a necessary cause has been demonstrated in cancer epidemiology--a realization that has obvious implications for primary and secondary prevention of this neoplastic disease.

Prevalence of specific types of human papillomavirus and cervical squamous intraepithelial lesions in consecutive, previously unscreened, West-African women over 35 years of age

Previous studies among women worldwide have demonstrated that infection with specific types of human papillomaviruses (HPV) is central to the pathogenesis of cervical neoplasia. There is little data, however, concerning the prevalence of specific HPV types and the association of each type with cervical neoplasia among women in sub-Saharan Africa, who remain at very high risk of cervical cancer. We studied 2,065 consecutive patients aged 35 years or older, presenting to community health clinics in Dakar and Pikine, West Africa, who had not been screened previously for cytologic abnormalities or HPV. Cytologic diagnosis and HPV detection were accomplished using a ThinPrep Pap and a polymerase chain reaction-based reverse-line strip assay, respectively. Odds ratios (OR) and associated 95% confidence intervals (CI) were estimated using polynomial logistic regression. Cytologic abnormalities were found in 426 women (20%), including 254 (12%) with atypical squamous cells of undetermined significance, 86 (4%) with low-grade squamous intraepithelial lesions, 66 (3%) with high-grade squamous intraepithelial lesions (HSIL) and 20 (1%) with invasive cancer. HPV infection was detected in 18%. Among women with negative cytologic findings, the prevalence of high risk but not low risk HPV types increased with age. HPV16 (2.4%) and HPV58 (1.6%) were the most frequently detected HPV types in this population, as well as being the most strongly associated with risk of HSIL/cancer (HPV16: OR = 88, 95% CI = 39-200; HPV58: OR = 51, 95% CI = 16-161). These data suggest that in addition to HPV16, HPV58 should be considered in the strategic planning of vaccination against cervical cancer in this geographic region.

Management of precursor lesions of cervical carcinoma: history, host defense, and a survey of modalities

Before the initiation of screening and treatment for cervical cancer precursors, approximately 3% to 4% of women were destined to eventually develop cervical cancer. During the last 50 years the rate of cervical cancer incidence and mortality has decreased by more than 75% primarily because of the widespread availability of cervical cytologic screening and of treatment for documented cervical precancer. Successful screening of the entire population and appropriate treatment of lesions could theoretically reduce this risk to one tenth of the risk of an unscreened population [7,28]. The relatively recent understanding of the etiology of cervical cancer precursor lesions and of the immune response to them has given new direction to management options that incorporate healthy habits and dietary measures as part of traditional ablative or excisional treatment options. As we look to the future we can expect that new markers that more specifically identify individuals at-risk for cervical precancer and cancer will be developed and take precedence in cervical screening. At the same time, treating the cause of these lesions, rather than the result, should provide less traumatic and more successful therapies. To this end, harnessing the immune system through immune response modifiers and HPV vaccines seems to be on the horizon, as do new chemopreventative approaches. Of all human cancers, only cervical cancer, once the second most common cancer among women, stands on the threshold of being virtually eliminated.

Human papillomaviruses: into the new millennium

Human papillomaviruses (HPV) are newsworthy in this new millennium. Numerous articles have appeared in the lay press ranging in style and quality from informative essays to sensationalized exposes. Women, sensitized by confusing information, are asking obstetricians hard questions about HPV transmission and prevention, partner notification, the need for HPV testing, and methods of treatment. These questions are difficult because none of the answers are clear cut. This article provides the practicing gynecologist and obstetrician a concise and accurate summary of clinically important issues surrounding HPV. Current knowledge about HPV virology, epidemiology, testing, and the prospects for vaccination and other prevention measures is summarized.

Human papillomavirus infection, cervical dysplasia and invasive cervical cancer in Honduras: a case-control study

A substantial body of evidence has confirmed human papillomavirus (HPV) infection as the central etiological agent in human cervical carcinogenesis. In Honduras, cervical cancer is the most common cancer among women, with a high annual incidence. We conducted a population-based, case-control study of 229 patients with different grades of CIN and invasive cervical cancer and 438 matched controls. A structured questionnaire was used to investigate known and probable risk factors for cervical cancer. Cervical scrapes were tested for the presence of different HPV types using a general primer-mediated PCR followed by PCR-based sequencing. HPV DNA was detected in 87% of all cancer in situ and invasive cancer cases, and 95% of invasive cases could be attributed to high-risk types. In control women, 39% were positive for HPV DNA sequences. HPV 16 prevalence ranked highest in all stages of cervical dysplasias, invasive cancers and controls. A statistically significant association with HPV was observed for CIN II, CIN III and invasive cancer, showing an upward trend to more severe lesions and being more pronounced for HPV 16 and related types. The OR for HPV 16- and 18-related invasive cancer cases was 14.88 (95% CI 5.12-43.25) and 74.66 (95% CI 7.77-717.62), respectively. Our results confirm a central role of HPV as the cause of cervical cancer in Honduras and provide information as to the type distribution of HPVs in the country.

'With the best of reasons': cervical cancer prevention policy and the suppression of sexual risk factor information

Cervical cancer is a very common but largely preventable cancer. Despite considerable medical knowledge of risk and even causal factors, possible social-behavioural strategies for the primary prevention of cervical cancer have rarely been explored as a viable addition to cervical screening. We examine key policy documents and interview 18 key informants on cervical cancer prevention in New Zealand. Using a discourse analytic approach we identify and discuss two discourses (which we have labelled 'protectionism' and 'right to know') which inform positions on whether or not women should be provided with information regarding sexual risk factors for cervical cancer. Cervical cancer prevention policy in New Zealand, which largely reflects a protectionist discourse, suppresses sexual risk factor information and focuses exclusively on cervical screening. The right to know discourse informs an alternative position, which contends that women have a right to be informed about risk factors. We discuss these positions in relation to questions about women's rights, the principle of informed choice, and attempts to judge what is in women's 'best interests.'

Human cervical cancer-associated nuclear matrix proteins

The nuclear matrix is the nonchromatin protein structural component of the nucleus that governs nuclear shape and also exerts regulatory control over higher order gene organization. Recent studies have documented the presence of tumor-associated nuclear matrix proteins in several human cancers. We used high-resolution two-dimensional gel electrophoresis to compare nuclear matrix protein patterns in cervical carcinomas with those from normal cervical tissue. Tumors obtained from 20 patients undergoing hysterectomy for clinically localized cervical cancer were compared with normal cervical tissue. We have identified five polypeptides (CvC-1: Mr = 69,408 Da, pI = 5. 78; CvC-2: Mr = 53,752 Da, pI = 5.54; CvC-3: Mr = 47,887 Da, pI = 5. 60; CvC-4: Mr = 46,006 Da, pI = 5.07; and CvC-5: Mr = 44,864 Da, pI = 6.61) in the nuclear matrix from cervical carcinomas that were present in 20 of 20 cervical tumors but 0 of 10 normal tissues. These data extend similar findings of cancer-associated nuclear matrix proteins in other human cancers and suggest that nuclear matrix proteins may represent a new class of cancer markers that could aid the diagnosis or management of some types of cancer.

Exploring the possibility of sexual-behavioural primary prevention interventions for cervical cancer

Consistent causal and risk factors for cervical cancer indicate that primary prevention may be beneficial for cervical cancer prevention. However, social or behavioural primary prevention strategies are seldom discussed in the prevention literature. This paper uses thematic analyses of interviews with key informants involved with cervical cancer prevention policy development in New Zealand to explore the possibility of sexual-behavioural primary prevention. While many informants perceived primary prevention to be important, others were cautiously accepting or opposed to it. Many concerns were raised that highlighting a preventable (sexually transmitted) causal factor might lead to blame and stigma around cervical cancer and reduce participation in cervical screening. Much of the support for primary prevention depended on it being conducted (indirectly) in the context of young people's sexual health education. Positions on primary prevention appeared to be informed by common presumptions about what happens in the 'real world' and the commonality of human papilloma virus in the general population. We contend that the possible health benefits from sexual-behavioural strategies for cervical cancer primary prevention need further exploration.

The high risk human papillomaviruses and oral cancer: evidence for and against a causal relationship

Oncogenic human papillomaviruses (HPVs) have been detected in oral squamous cell carcinoma (SCC). HPV16 is the most frequently detected HPV type in oral SCC and is present in up to 22% of cases, either alone or in combination with other HPV types. HPV18 is present in up to 14% of cases. HPV16 and HPV18 are present together in approximately 6% of cases. However, HPV16 and 18 are also detected in normal oral mucosae (10% and 11% of subjects, respectively). These data suggest that high risk HPV infection may be a co-factor in oral carcinogenesis and that latent HPV infection of the oral mucosa is common. A role for HPV infection in oral carcinogenesis is supported by the ability of high risk HPVs to immortalize oral keratinocytes in vitro. Immortalization may involve (i) deactivation of pre-formed tumor-suppressor proteins by viral oncoproteins, (ii) blocking of tumor-suppressor gene transcription as a result of HPV oncogene insertion or (iii) stimulation of cellular oncogene transcription by the upstream insertion of HPV-derived transcription activating sequences. Hence, infection of oral keratinocytes with high risk HPV may be involved in the pathogenesis of some oral SCCs although the evidence implicating HPV in oral carcinogenesis is, at present, mainly circumstantial.