Human papillomavirus infection and other risk factors for cervical neoplasia: a case-control study

Disparities in Cervical Cancer Incidence and Mortality: Can Epigenetics Contribute to Eliminating Disparities?

Screening for uterine cervical intraepithelial neoplasia (CIN) followed by aggressive treatment has reduced invasive cervical cancer (ICC) incidence and mortality. However, ICC cases and carcinoma in situ (CIS) continue to be diagnosed annually in the United States, with minorities bearing the brunt of this burden. Because ICC peak incidence and mortality are 10-15 years earlier than other solid cancers, the number of potential years of life lost to this cancer is substantial. Screening for early signs of CIN is still the mainstay of many cervical cancer control programs. However, the accuracy of existing screening tests remains suboptimal. Changes in epigenetic patterns that occur as a result of human papillomavirus infection contribute to CIN progression to cancer, and can be harnessed to improve existing screening tests. However, this requires a concerted effort to identify the epigenomic landscape that is reliably altered by HPV infection specific to ICC, distinct from transient changes.

Gender, Ethnic, and Acculturation Differences in Sexual Behaviors: Hispanic and Non-Hispanic White Adults

Hispanics have an increased prevalence of sexually transmitted diseases (STDs). To describe the prevalence of sexual behaviors of Hispanics, we conducted surveys of randomly selected residents in census tract areas and members of a health maintenance organization (n = 2,596). Hispanic men were more likely to start sexual intercourse at an earlier age and reported lower rates of condom use than non-Hispanic White men. Hispanic women reported having a higher number of children, less use of barrier contraception, fewer lifetime sexualpartners, andfewer STDs than non-Hispanic White women. Less-acculturated Hispanic men reported a younger age for theirfirst sexual intercourse and a lower frequency of condom use than did more highly acculturated Hispanic men. Highly acculturated Hispanic women reporteda highernumberof lifetime sexual partners than did less-acculturated women. Gender differences, mediated by marital status, age, and education, were more significantly associated with sexual behavior than ethnicity.

Prevalence of human papillomavirus genotypes in northern Taiwanese women

The prevalence of Human Papillomavirus (HPV) in the general population of northern Taiwan is described. A total of 343 consecutive cervical swabs from women visiting the medical center for routine gynecologic care were included. Cervical cell cytology was examined by the Papanicolaou (Pap) test, and a PCR-based hybridization gene chip analysis was used to identify HPV genotypes. The HPV prevalence in the overall population was 32.4%. When divided into two groups according to cytology, 20.9% of women with normal cytology were HPV positive while 75.3% of women with abnormal cytology were HPV positive. Among positive samples, 68.5% were single type infections while 31.5% harbored multiple HPV types. A total of 32 types of HPV were identified; the leading five were HPV16 (5.8%), HPV58 (5.3%), HPV53 (4.1%), HPV52 (3.8%), and HPV18 (2.3%). Our results constitute baseline data and may provide important implications for future prophylactic programs. The relatively high prevalence of HPV 58, 53, and 52 among northern Taiwanese women has important implications for vaccine development.

Molecular Microbiological Testing

The application of molecular testing methods in the clinical laboratory has dramatically improved our ability to diagnose infectious diseases. Nucleic acid techniques, such as plasmid profiling, various methods for generating restriction fragment length polymorphisms and the polymerase chain reaction (PCR) are making increasing inroads into clinical laboratories. However, the clinical usefulness of molecular testing will only be maximized to its fullest benefit by appropriate and careful studies correlating clinical findings with assay results.

Replication and assembly of human papillomaviruses

Human papillomaviruses (HPVs) are small dsDNA tumor viruses, which are the etiologic agents of most cervical cancers and are associated with a growing percentage of oropharyngeal cancers. The HPV capsid is non-enveloped, having a T=7 icosahedral symmetry formed via the interaction among 72 pentamers of the major capsid protein, L1. The minor capsid protein L2 associates with L1 pentamers, although it is not known if each L1 pentamer contains a single L2 protein. The HPV life cycle strictly adheres to the host cell differentiation program, and as such, native HPV virions are only produced in vivo or in organotypic "raft" culture. Research producing synthetic papillomavirus particles--such as virus-like particles (VLPs), papillomavirus-based gene transfer vectors, known as pseudovirions (PsV), and papillomavirus genome-containing quasivirions (QV)--has bypassed the need for stratifying and differentiating host tissue in viral assembly and has allowed for the rapid analysis of HPV infectivity pathways, transmission, immunogenicity, and viral structure.

Molecular detection and genotyping of human papillomavirus in cervical carcinoma biopsies in an area of high incidence of cancer from Moroccan women

Cervical cancer is a leading cause of cancer-related deaths in developing countries, and the human papillomavirus (HPV) is linked etiologically to cervical cancer. Eighty nine cervical carcinoma biopsies collected from women visiting the Oncologic Center in Casablanca (Centre Hospitalier Universitaire Ibn Rochd, Morocco) for cervical cancer symptoms, were screened for HPV DNA by polymerase chain reaction amplification with subsequent typing by hybridization with specific oligonucleotides for HPV types 16, 18, 31, 33, 45, and 59. Using very high stringency hybridization the HPV types could be easily distinguished. After preliminary clinical sorting, 92% (82/89) of the samples were found to be HPV-positive. Among the samples infected by a single HPV, type 16 was the most frequent 36.6% (30/82) of the positive samples, followed by HPV 18; 19.5% (16/82). Double or even multiple infections by the different HPV types were also detected (35.5% of the positive samples); dual infections were the more frequent, with the following combinations of HPVs: HPV16/HPV18 (21% of the positives samples) and HPV16/HPV45 (8.5%).

High-risk and multiple human papillomavirus (HPV) infections in cancer-free Jamaican women

Background

Vaccines, that target human papillomavirus (HPV) high risk genotypes 16 and 18, have recently been developed. This study was aimed at determining genotypes commonly found in high-risk and multiple-HPV infections in Jamaican women. Two hundred and fifty three (253) women were enrolled in the study. Of these, 120 pregnant women, aged 15–44 years, were recruited from the Ante Natal Clinic at the University Hospital of the West Indies and 116 non-pregnant, aged 19–83, from a family practice in Western Jamaica. Cervical cell samples were collected from the women and HPV DNA was detected using Polymerase Chain Reaction and Reverse Line Hybridization. HPV genotypes were assessed in 236 women. Data were collected from January 2003 to October 2006.

Results

HPV DNA was detected in 87.7% (207/236) and of these 80.2% were positive for high-risk types. The most common high-risk HPV types were: HPV 45 (21.7%), HPV 58 (18.8%), HPV 16 (18.4%), HPV 35 (15.0%), HPV 18 (14.5%), HPV 52 (12.0%) and HPV 51(11.1%). Other high-risk types were present in frequencies of 1.4% – 7.2%.

Multivariate regression analyses showed that bacterial vaginosis predicted the presence of multiple infections (OR 3.51; CI, 1.26–9.82) and that alcohol use (OR 0.31; CI, 0.15–0.85) and age at first sexual encounter (12–15 years: OR 3.56; CI, 1.41–9.12; 16–19 years, OR 3.53, CI, 1.22–10.23) were significantly associated with high risk infections. Cervical cytology was normal in the majority of women despite the presence of high-risk and multiple infections.

Conclusion

HPV genotype distribution in this group of Jamaican women differs from the patterns found in Europe, North America and some parts of Asia. It may be necessary therefore to consider development of other vaccines which target genotypes found in our and similar populations. HPV genotyping as well as Pap smears should be considered.

Identification of a novel human papillomavirus type 16 E1 gene variant with potentially reduced oncogenicity

The human papillomavirus (HPV) 16 genome has been studied extensively, although no study has focused on the E1 gene that is implicated in viral DNA replication. After analyzing the E1 region of HPV 16 genomes in 429 cervical samples, 11.2% were found to contain a 63 nucleotides duplication in this region. Sequence analysis of the E6 and the E7 regions has shown that all samples containing this duplication were related to E6-G350 variant of the HPV 16 (Chi square test, P = 0.0012). A comparison of cervical lesion severity of the examinees having regular or variant E1 genes has shown that the variant group had a significantly (Fischer's exact test, P = 0.0401) lower percentage of high grade disease cases, suggesting that this particular duplication might reduce the oncogenic potential of HPV 16, and also might clarify the differences of E6-G350 variant oncogenicity observed in European populations. Albeit, a decreased incidence of high grade cervical lesions can be linked to the prevalence of multiple HPV infection, the additional decrease of those cases with the variant E1 gene versus those without (10.5% and 18.6%, respectively) can only be ascribed to the effect of this particular HPV variant. Further research is needed to clarify the biology of these HPV 16 E1 variants.

Evaluation of different techniques for identification of human papillomavirus types of low prevalence

Human papillomaviruses (HPVs) have been recognized as etiologic factors in a variety of diseases. Due to the large number of HPV types, methods for HPV genotyping are difficult to standardize. Despite this fact, several methods exist, and some of them are available commercially. In this study, we evaluated the Roche Diagnostics linear array (LA) HPV genotyping assay, the Innogenetics INNO-LiPA (line probe assay [LiPA]), and two noncommercial reverse line blot (RLB) assays based on either primers GP5+ and GP6+ (GP) or newly designed broad-spectrum primers BSGP5+ and BSGP6+ (BS). The reliabilities of these assays were tested with a wide spectrum of HPV types less prevalent in cervical samples. This is the first study to compare the performance of the most widely used HPV genotyping methods with selected samples positive for low-prevalence HPV types. We focused on interassay agreement, both overall and type specific, in cases with single and/or multiple HPV infections. Interassay agreement was moderate in cases of single HPV infections and poor in cases of multiple HPV infections. The LA and the BS-based RLB assays found a higher rate of cases positive for multiple HPV types than LiPA and the GP-based RLB assay. The weakest capability in detecting multiple HPV infections was observed for LiPA. The use of only one assay in epidemiological and clinical studies might lead to biased conclusions. Therefore, a universally evaluated and agreed upon HPV typing assay or a combination of current assays is needed for possible clinical applications, and knowledge of their limitations is advised.

Epidemiologic modeling of cervical dysplasia with molecular and cytopathological markers

OBJECTIVES

Conventional cervical screening is insufficient at identifying patients who are likely to progress from cervical dysplasia to carcinoma. Traditional epidemiologic studies have identified potential factors to aid in the discrimination between those lesions likely to progress from those likely to regress; however, there is still much to be learned. To examine the role of traditional epidemiologic factors in conjunction with molecular markers of human papillomavirus activity, we studied a group of women attending colposcopy clinics in Houston, TX, and Vancouver, BC, between October 2000 and July 2003.

METHODS

Quantitative real-time PCR was used to measure mRNA expression of the human papillomavirus E7 gene, and quantitative cytology was used to gather information about the DNA index and chromatin features of the cells from these women. Logistic regression was used to establish predictor variables for histologic grade based on the epidemiologic risk factors and the molecular markers.

RESULTS

The most predictive factors were mRNA level, DNA index, parity, and age. The ROC curve for the individual logits indicated excellent discrimination.

CONCLUSION

In accordance with other authors, these results suggest that molecular markers of the malignant process should be included in analyses looking to predict the progression potential of cervical lesions.

Absolute quantitative real-time polymerase chain reaction for the measurement of human papillomavirus E7 mRNA in cervical cytobrush specimens

Background

Few reports of the utilization of an accurate, cost-effective means for measuring HPV oncogene transcripts have been published. Several papers have reported the use of relative quantitation or more expensive Taqman methods. Here, we report a method of absolute quantitative real-time PCR utilizing SYBR-green fluorescence for the measurement of HPV E7 expression in cervical cytobrush specimens.

Results

The construction of a standard curve based on the serial dilution of an E7-containing plasmid was the key for being able to accurately compare measurements between cervical samples. The assay was highly reproducible with an overall coefficient of variation of 10.4%.

Conclusion

The use of highly reproducible and accurate SYBR-based real-time polymerase chain reaction (PCR) assays instead of performing Taqman-type assays allows low-cost, high-throughput analysis of viral mRNA expression. The development of such assays will help in refining the current screening programs for HPV-related carcinomas.

Lower red blood cell folate enhances the HPV-16-associated risk of cervical intraepithelial neoplasia

OBJECTIVE

We previously reported that higher circulating concentrations of folate are independently associated with a lower likelihood of becoming positive for high-risk human papillomaviruses (HR-HPVs) and of having a persistent HR-HPV infection and a greater likelihood of becoming HR-HPV negative (Cancer Res 2004;64:8788-93). In the present study conducted in the same study population, we tested whether circulating folate concentrations modify the risk of cervical intraepithelial neoplasia (CIN) > or =2 associated with specific types of HR-HPV.

METHODS

Multiple logistic regression models were used to assess associations (odds ratio with 95% confidence intervals) across HR-HPV, folate, and rigorously reviewed cervical histology of each subject.

RESULTS

HPV-16-positive women with low red blood cell folate were significantly more likely to be diagnosed with CIN > or =2 than were HPV-16-negative women with higher red blood cell folate (odds ratio 9, 95% confidence interval 3.3-24.8).

CONCLUSION

To our knowledge, this is the first study reporting an independent association of folate with risk of having CIN > or =2 in a population tested extensively for HR-HPV and CIN that also adequately controlled for several other micronutrients and known risk factors for CIN. Our findings suggest that improving the folate status in HR-HPV-infected women may reduce the risk of CIN and thus the risk of cervical cancer. Folate supplementation should be tested as a means of reducing the risk of developing CIN > or =2 in women exposed to HR-HPV, especially HPV-16.

Cyclooxygenase-2 Inhibition Attenuates Antibody Responses against Human Papillomavirus-Like Particles

Vaccination to generate protective humoral immunity against infectious disease is becoming increasingly important due to emerging strains of virus, poorly immunogenic vaccines, and the threat of bioterrorism. We demonstrate that cyclooxygenase-2 (Cox-2) is crucial for optimal Ab responses to a model vaccine, human papillomavirus type 16 virus-like particles (HPV 16 VLPs). Cox-2-deficient mice produce 70% less IgG, 50% fewer Ab-secreting cells, and 10-fold less neutralizing Ab to HPV 16 VLP vaccination compared with wild-type mice. The reduction in Ab production by Cox-2(-/-) mice was partially due to a decrease in class switching. SC-58125, a structural analog of the Cox-2-selective inhibitor Celebrex reduced by approximately 70% human memory B cell differentiation to HPV 16 VLP IgG-secreting cells. The widespread use of nonsteroidal anti-inflammatory drugs and Cox-2-selective inhibitory drugs may therefore reduce vaccine efficacy, especially when vaccines are poorly immunogenic or the target population is poorly responsive to immunization.

Human papillomavirus infections with multiple types and risk of cervical neoplasia

BACKGROUND

Besides an established role for certain human papillomavirus (HPV) genotypes in the etiology of cervical cancer, little is known about the influence of multiple-type HPV infections on cervical lesion risk. We studied the association between multiple HPV types and cervical lesions among 2,462 Brazilian women participating in the Ludwig-McGill study group investigation of the natural history of HPVs and cervical neoplasia.

METHODS

Cervical specimens were typed by a PCR protocol. The cohort's repeated-measurement design permitted the assessment of the relation between the cumulative and concurrent number of HPV types and any-grade squamous intraepithelial lesions (SIL) and high-grade SIL (HSIL).

RESULT

At individual visits, 1.9% to 3.2% of the women were infected with multiple HPVs. Cumulatively during the first year and the first 4 years of follow-up, 12.3% and 22.3% were infected with multiple types, respectively. HSIL risk markedly increased with the number of types [odds ratio (OR), 41.5; 95% confidence interval (95% CI), 5.3-323.2 for single-type infections; OR, 91.7; 95% CI, 11.6-728.1 for two to three types; and OR, 424.0; 95% CI, 31.8-5651.8 for four to six types, relative to women consistently HPV-negative during the first year of follow-up]. The excess risks for multiple-type infections remained after exclusion of women infected with HPV-16, with high-risk HPV types, or persistent infections, particularly for any-grade SIL. Coinfections involving HPV-16 and HPV-58 seemed particularly prone to increase risk.

CONCLUSION

Infections with multiple HPV types seem to act synergistically in cervical carcinogenesis. These findings have implications for the management of cervical lesions and prediction of the outcome of HPV infections.

Pre-invasive cervical disease and uterine cervical cancer in Brazilian adolescents: prevalence and related factors

The objective was to describe the prevalence and factors associated with uterine cervical cancer (CA) and high-grade squamous intraepithelial lesions (HSIL) in adolescents. A cross-sectional study was carried out with 702 sexually active adolescents treated at a general hospital in Rio de Janeiro, Brazil, from 1993 to 2002. Screening was performed by cytopathology and colposcopy and confirmation by biopsy. Exposure variables were socio-demographic characteristics and those related to reproductive health, habits, and sexual behavior. Adjusted odds ratios were estimated using multivariate logistic regression analysis. Based on histopathology, the prevalence of HSIL/CA was 3% (95%CI: 1.8-4.6). There was one case of invasive cancer. With each additional pregnancy, the odds of HSIL/CA increased by 2.2 (95%CI: 1.1-4.4). Age was also associated with this outcome, doubling the odds of acquiring this degree of disease with each year of age (OR = 2.0; 95%CI: 1.2-3.4). The prevalence of lesions suggests the importance of including sexually active adolescent females in cervical cancer screening programs aimed at early detection and treatment of these lesions.

Human papillomavirus typing with GP5+/6+ polymerase chain reaction reverse line blotting and with commercial type-specific PCR kits

BACKGROUND

Infection with human papillomavirus (HPV) is a necessary step in the progression to cervical cancer. Many methods for HPV testing are currently available, most developed to detect pools of HPV types.

OBJECTIVES

To evaluate the HPV typing by molecular methods and to compare commercial kits with an established laboratory method.

STUDY DESIGN

Eighty-four cervical samples found to be positive for HPV DNA by GP5+/6+-polymerase chain reaction-enzyme immunoassay-reverse line blotting (PCR-EIA-RLB) were re-tested with two commercial methods, INNO-LiPA and Amplisense HPV typing, able to identify the HPV type predicted by PCR-EIA-RLB in 76 and 67 samples, respectively.

RESULTS

The INNO-LiPA assay revealed HPV DNA in 75/76 samples (98.7%; 95% CI, 0.93-0.99) that would contain HPV types identifiable by this assay. The Amplisense HPV assay revealed HPV DNA in 58/67 samples (86.6%; 95% CI, 0.76-0.93) containing HPV types detectable by this assay. For samples with a single infection, the unweighted kappa for concordance of HPV typing was 0.87 (95% CI, 0.78-0.97) for PCR-EIA-RLB versus INNO-LiPA, 0.94 (95% CI, 0.87-0.99) for INNO-LiPA versus Amplisense HPV, and 0.82 (95% CI, 0.70-0.94) for PCR-EIA-RLB versus Amplisense HPV typing. PCR-EIA-RLB revealed 12 multiple infections, INNO-LiPA revealed 14, and Amplisense HPV revealed 5. The agreement among tests for samples with multiple infections was lower, giving kappa values of 0.44 (95% CI, 0.18-0.70) for PCR-EIA-RLB versus INNO-LiPA, 0.52 (95% CI, 0.19-0.85) for PCR-EIA-RLB versus Amplisense HPV and 0.43 (95% CI, 0.12-0.74) for INNO-LiPA versus Amplisense HPV.

CONCLUSIONS

In HPV-positive samples, the agreement among tests for HPV typing was high for single infections but markedly lower for infections with multiple HPV types.

HPV-induced carcinogenesis of the uterine cervix is associated with reduced serum ATRA level

OBJECTIVE

In uterine cervical cancer, certain oncogenic HPV types are considered as key etiologic factor. But the progression of HPV associated cervical precancerous lesions depends on many other factors such as oncogenes, immune system, anti-viral factors etc. This study is therefore focused on the effect of an important dietary anti-viral factor called All Trans Retinoic Acid (ATRA) on the development of HPV associated cervical cancer as it is found higher in poor socioeconomic people.

METHOD

We analyzed a total population of 130 including control subjects who have no complaints of uterine cervical lesions and the HPV-6/11, 16/18 infected cases of low grade squamous intraepithelial lesions [SIL], high grade squamous intraepithelial lesions [HSIL], and invasive cancers, for serum ATRA level. This study also focused to find out the association of serum ATRA level with the proliferation status in terms of proliferating cell nuclear antigen (PCNA) expression as it is an anti-proliferation agent and with the grades of cervical lesions, using SPSS statistical package.

RESULTS

The results showed a highly significant negative association for serum ATRA level with different stages of cervical lesions (F = 3.305; P = 0.000) by one-way ANOVA and with intensity of PCNA expression (r = -0.825; P < 0.01) by Pearson's correlation test. A highly significant association was observed for the PCNA expression with the grades of cervical lesions too (F = 37.89; P = 0.000). Further, we found from our data that all the invasive cancer cases were infected with HPV-16/18 and none with HPV-6/11. Hence, we analyzed the association of serum ATRA level with HPV-16/18 infected preinvasive cases in developing invasiveness, by Fisher's Exact Test, using Graph Pad Prism as shown in Table 1. The results show an odds ratio (OR) of 36.93 and a relative risk (RR) of 4.99 with an 95% interval being 2.896 to 8.603, which is significant at the level of P = 0.0001 for the reduced [<0.6 mug/ml] serum ATRA level in developing invasive cancer in HPV-16/18 infected preinvasive cases.

CONCLUSION

All these results suggest that the serum ATRA level highly influences the progression of cervical lesions to invasive cancer and can be therefore aimed as a marker for progression in combination with HPV-16/18, which helps to enhance the modalities of therapy towards cost effectiveness.

High prevalence of human papillomavirus infections in urine samples from human immunodeficiency virus-infected men

Infection with human immunodeficiency virus (HIV) and the resulting immunosuppression are associated with an increased risk for human papillomavirus (HPV) persistence and related malignancies. In the present study we investigated the prevalence of HPV in urine samples from 104 HIV-infected men with low CD4+ cell counts (<100 per mm(3)) and 115 urine samples from HIV-negative men. A high prevalence of HPV DNA (39.4%) was found in the HIV patients. Most of the HPV types were high risk (81.4%), with HPV 52 as the most prevalent type (12.5%), followed by HPV 18 (6.7%), HPV 35 (5.8%), and HPV 70 (4.8%). Multiple HPV genotypes were observed in 17 (41%) of the 41 HPV- and HIV-positive men. In contrast, only 11 (9.6%) HPV DNA-positive cases were observed among the 115 HIV-uninfected men, and 3 (27.3%) contained multiple genotypes. Quantitative analyses indicated that the HPV viral load, as measured in urine samples, is significantly higher in HIV-positive men compared to HIV-negative men. In the present study we show that urine samples are useful for detecting HPV DNA, there is a high prevalence of HPV in HIV-positive men, and the HPV viral load is substantially higher in HIV-positive than in HIV-negative men. More studies are needed to evaluate the risk and natural development of HPV-related malignancies in HIV-positive men.

Human papillomavirus infection: biology, epidemiology, and prevention

Over the past several decades, knowledge of the biology and epidemiology of human papillomavirus (HPV) infection has increased tremendously. However, there are still many unanswered questions concerning the interaction of the virus with its host. The virus has been identified as a necessary causal agent for cervical squamous neoplasia and has been linked to the development of neoplasia in several other mucosal sites. The viral oncogenes E6 and E7 are the major players in the virus' scheme to evade the immune system and use the host cell replication machinery to survive. Many risk factors for infection with HPV have been identified; however, the focus now centers on identifying risk factors for persistence of the infection as it is likely that transient infections play a very small role in the overall development of clinical disease. Prevention measures to date have centered around screening programs, mostly for cervical cancer, including the perfection of screening techniques and inclusion of molecular testing for HPV into screening regimens. The development of prophylactic and therapeutic vaccines has also increased as primary prevention measures appear to have the best hope for long-term effects on cancer incidence.

Prevalence of high-risk human papillomavirus (HR-HPV) types 16 and 18 in healthy women with cytologically negative Pap smear

OBJECTIVE

To study the prevalence of high-risk human papillomavirus (HR-HPV) types 16 and 18 in healthy women with negative Pap smears in identifying women with underlying cervical squamous intra-epithelial (SIL) lesions.

METHODS

A total of 3300 women who were attending the Gynecology OPD of Lok Nayak Hospital, one of the major government tertiary hospitals in New Delhi, were screened during a 1-year study period, and 2079 (63%) of them were found to have cytologically negative Pap smear with inflammation and the rest (37%) also had negative Pap report but without inflammation. Hundred and sixty of these sexually active women aged between 20 and 60 years were randomly selected, and were investigated by colposcopy and a guided biopsy was done wherever required. HPV types 16 and 18 DNA was detected in scraped cervical cells from all women using type-specific primers in polymerase chain reaction (PCR).

RESULTS

The high-risk HPV (type 16 and 18) prevalence by PCR was found to be 10% (16/160). Histopathological findings were obtained in 123 women, out of which 15 had LSIL and four had HSIL. High-risk HPV types 16/18 could be detected in nine out of these 19 (47.3%) squamous intra-epithelial lesions (p < 0.00008) which includes two out of the four women (50%) having HSIL, while only seven out of 104 (6.7%) of the subjects with normal (negative) Pap reports (p = 0.03) had infection of high-risk HPV.

CONCLUSION

The results indicate that about 10% of women who show a negative Pap smear, but have inflammation are positive for high-risk HPV types 16/18 and about 15% harbor squamous intra-epithelial lesions. It is suggested that high-risk HPV detection can be utilized as an adjunct to routine cytology screening programs to identify 'high risk' women who have concurrently negative Pap smears but may harbor oncogenic HPV infection and/or more likely to develop CIN lesions.

Semiquantitative analysis of human papillomavirus DNA in cervical intraepithelial neoplasia by a differential polymerase chain reaction

A differential polymerase chain reaction (PCR), which takes account of both the human papillomavirus (HPV) type and the amount of viral DNA, was applied to 100 cervical intraepithelial neoplasias (CIN) in order to improve the characterisation of the lesions. One hundred women with cytological smears suggestive of CIN I-III and a colposcopically guided punch biopsy were studied. DNA was phenol-extracted and a consensus PCR with L1 primers and a type-specific PCR for HPV-16 and-18 E6 were performed in parallel. The different sensitivity of the PCR methods allowed a semiquantitative analysis of viral DNA. HPV analysis was possible in all 100 very small cervical punch biopsies. Of the lesions 79% were HPVpositive. The percentage of HPV-16-positive lesions increased significantly (P < 0.001) with the degree of severity of CIN (CIN I: 46%, CIN II: 63%, CIN III: 85%). The percentage of CIN with a high viral load increased also with the grade of CIN (CIN I: 8%, CIN II: 33%, CIN III: 44%). Cytologically positive lesions (Pap IIID or IVa) had significantly more frequently (p < 0.02) a high viral load: 39% vs. 10% of cytologically false negative lesions. In conclusion, type-specific PCR had a very high sensitivity in the detection of HPV-DNA also in cytologically false negative CIN. The addition of the less sensitive consensusPCR allowed a semiquantitative analysis of the viral copy number. The higher amount of viral DNA in cytologically positive lesions, which may correspond to a higher rate of proliferation, reflects a possible role of the viral load in the progression of CIN. In clinical practice, differential HPVPCR could help to improve the management of CIN.

Detection of high-risk human papillomavirus E6 and E7 oncogene transcripts in cervical scrapes by nested RT-polymerase chain reaction

The oncogenic potential of the high-risk human papillomavirus (HPV) genotypes (types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66 and 68) depends on the expression of the two viral oncogenes E6 and E7. Thus, the detection of HPV E6/E7 oncogene transcripts could serve as a factor in the evaluation of a risk of development of cervical intraepithelial neoplasia (CIN) and its progression to cervical cancer. A nested RT-PCR assay for the detection of E6/E7 oncogene transcripts of all known high-risk HPV genotypes was established. In the study described, 779 high-risk HPV-DNA-positive cervical scrapes exhibiting all grades of CIN, including non-dysplastic cervical mucosa (CIN 0), were examined. Spliced E6/E7 oncogene transcripts of all the high-risk HPVs were detected in numerous samples, with an overall detection rate of 47%. In 227 cases with agreement between the cytologic and histologic findings, the prevalence increased with lesion severity: CIN 0, 18%; CIN I, 58%; CIN II, 77%; CIN III, 84%. Multiple transcriptionally active high-risk HPVs were detected in 12% (33/279) of patients with multiple high-risk HPV infections. This work sets the stage for a prospective follow-up study currently being undertaken to evaluate the prognostic relevance of the detection of high-risk HPV E6/E7 oncogene transcripts for the persistence of a high risk HPV infection, and the possible evolution and further development of a CIN. Future applications of the assay described may include the monitoring of women in studies investigating antiviral treatment or vaccination.

Comparison of human papillomavirus genotypes in high-grade squamous intraepithelial lesions and invasive cervical carcinoma: evidence for differences in biologic potential of precursor lesions

High-grade squamous intraepithelial lesions of the cervix are heterogeneous in their invasive potential. Comparison of human papillomavirus types between invasive cervical carcinoma and high-grade squamous dysplasia may provide insight into this biological variability. Liquid-based Pap specimens from 55 high-grade intraepithelial lesions and 47 invasive cervical carcinomas were analyzed by reverse line blot for 27 human papillomavirus types designated high, intermediate, or low risk. Human papillomavirus DNA was present in all high-grade intraepithelial lesions (23 different types) and in 94% (13 types) of invasive carcinomas. High-risk types were present in 81% of invasive carcinomas compared to 58% of high-grade intraepithelial lesions. Severe dysplasias harbored more (79%) high-risk human papillomaviruses as compared to moderate dysplasias (37%). In 40% of high-grade dysplasia cases (59% of moderate dysplasias; 21% of severe) and 13% of invasive carcinomas, intermediate-risk genotypes were identified in the absence of high-risk HPV types. Human papillomavirus 16 was the most common type in all categories, including 47% of high-grade squamous dysplasias (26% moderate; 68% severe) and 61% of invasive carcinomas. Both high-risk type (P=0.0004) and type 16 (P=0.0007) human papillomaviruses were positively associated with increasing severity of diagnosis. The heterogeneous nature of high-grade squamous dysplasias as compared to invasive carcinoma is evident by the wider spectrum of associated human papillomavirus types. Likewise, moderate dysplasia appears to be more heterogeneous in viral type than severe dysplasia. Moderate cases were more often associated with intermediate-risk types, while high-risk types were more prevalent in severe dysplasias and invasive cancers. Moderate dysplasia cases harboring viral types infrequently found in cancers may have a low risk for progression. Human papillomavirus genotyping of high-grade squamous intraepithelial lesions may be important in assessing risk for progression to invasion.

A phase II trial of interleukin-12 in patients with advanced cervical cancer: clinical and immunologic correlates. Eastern Cooperative Oncology Group study E1E96

PURPOSE

The ability to mount lymphoproliferative responses to peptides derived from the human papillomavirus (HPV) E6 and E7 oncoproteins has been associated with regression of dysplastic lesions of the uterine cervix and loss of associated HPV infection. Interleukin-12 (IL-12) is a potent immunopotentiator of T-cell function, and has been shown in phase I clinical trials to be tolerable.

EXPERIMENTAL DESIGN

Patients were required to have measurable metastatic, recurrent or inoperable cervical carcinoma. Patients could have had one prior adjuvant regimen and one prior regimen for advanced disease. Treatment consisted of IL-12 administered at 250 ng/kg IV as a rapid push in the outpatient setting daily x 5 every 21 days. Whole blood samples were acquired twice before treatment then approximately every 3 weeks to assess lymphoproliferative response in vitro to HPV type 16 (HPV 16) E4, E6, and E7 peptides. These responses were correlated with demographics and with clinical outcome.

RESULTS

Thirty-four patients were enrolled; 29 were evaluable. Over half had received cisplatin-based chemotherapy. The most common serious toxicities were hematologic or hepatic, and all were reversible. There was one partial responder (3%). The median survival was 6.5 months (95% CI: 5.8, 11.5 months). Eighteen of 29 eligible patients had evaluable laboratory data both pre- and post-therapy. There was a statistically significant increase in lymphoproliferative responses for HPV 16 E4, E6, and E7 peptides (P=0.020, 0.020, 0.043). There was a significant association between change in lymphoproliferative response to HPV 16 E6 peptides and number of cycles of treatment administered (P=0.048). There was no correlation between change in lymphoproliferative response to any peptide with age, performance status, race, prior chemotherapy, time from diagnosis to treatment, or with overall survival.

CONCLUSIONS

IL-12 treatment was associated with improved lymphoproliferative responses to HPV 16 E4, E6, and E7 peptides. This is the first clinical trial to demonstrate induction of cell-mediated immune (CMI) responses to specific antigens (peptides) following treatment with IL-12 in women with cervical cancer. This improvement in immune response was not associated with enhanced objective response or survival.

Can Human Papillomavirus DNA Testing Substitute for Cytology in the Detection of High-Grade Cervical Lesions?

Context.—High-risk human papillomaviruses (HPVs) are causal factors of cervical carcinomas.

Objective.—To evaluate the sensitivity and efficiency of HPV DNA testing in comparison with conventional cytology for detection of cervical intraepithelial neoplasia (CIN) and cancer.

Design.—Both testing procedures were administered to 593 women, aged 14 to 88 years (average, 41.7 years), who were referred for abnormal cytology from January 2000 through December 2001 at Korea University Guro Hospital (Seoul, Korea). After histologic confirmation by either colposcopically directed biopsy or endocervical curettage, the efficiency of the detection methods for high-grade cervical lesion was evaluated for the following 3 data sets: HPV DNA testing, conventional cytology, and the 2 tests combined.

Results.—The sensitivity, specificity, and positive predictive, and negative predictive values for the detection of CIN 2 or higher were 92.4%, 52.4%, 49.3%, and 93.2% for HPV DNA testing; 76.3%, 65.8%, 52.8%, and 84.7% for cytology; and 97.8%, 36.7%, 49.2%, and 97.3% for the combined tests. Among the 151 patients diagnosed with CIN 2 or CIN 3, 137 patients (90.7%) were HPV positive, 116 patients (76.8%) were proven to have abnormal cytology, and 147 patients (97.6%) were positive for either HPV DNA testing or cytology. The sensitivity values for HPV DNA testing and cytology were 97.9% (46/47) and 74.5% (35/47), respectively, for invasive cervical cancer detection, and the combined tests showed 100% (47/47) sensitivity. Depending on the patient's age and the grade of the cervical lesion, HPV DNA testing proved to be significantly more sensitive than cytology for the primary detection of cervical abnormalities (P &lt; .001).

Conclusion.—Human papillomavirus DNA testing for the detection of high-grade cervical lesions was more sensitive than cytology alone. In addition, the screening sensitivity can be further improved by combining cytology with HPV DNA testing. This approach is especially beneficial in detecting cancer precursors in women older than 60 years.

Risk factors for squamous intraepithelial lesions (SIL) of the cervix among women residing at the US-Mexico border

It is now well established that cervical cancer is caused by oncogenic human papillomavirus (HPV) infections that commonly infect women worldwide. What remains to be understood are the factors that contribute to cervical cancer in the presence of HPV infection. We conducted a case-control analysis of women recruited at the US-Mexico border to simultaneously evaluate factors associated with 3 cytologic outcomes: atypical squamous cells of undetermined significance or atypical glandular cells of undetermined significance (ASCUS/AGUS), low grade squamous intraepithelial lesions (LSIL) and high grade squamous intraepithelial lesions (HSIL). A cross-sectional binational study of 2059 women ages 15-79 years was conducted between 1997 and 1998. A significant difference in the distribution of cytologic categories by country was observed (3.0% vs. 0.7% HSIL among Mexican vs. US women, respectively). The only factors independently associated with all 3 cytologic outcomes were HPV infection and viral load. A linear increase in risk with increasing viral load was observed for each of the 3 outcome variables, with the strength of this association increasing with cytology abnormality. In addition to HPV infection, parity and Mexico as a country of residence appear to be associated with LSIL and HSIL, respectively. Factors associated with cytologic outcomes in analyses limited to women with HPV infection were similar to results obtained in models where HPV infection was included as a covariate. Future work is needed to evaluate the predictive value of HPV viral load utilizing more specific and quantitative measures.

Co-overexpression of p53 and bcl-2 proteins in HPV-induced squamous cell carcinoma of the uterine cervix

OBJECTIVE

The aim of this study was to analyze aberrant expression of both apoptotic protein p53 and antiapoptotic protein bcl-2 in squamous cell carcinoma (SCC) of the uterine cervix with HPV infection and its significance as a marker for progression of cervical lesions.

METHODS

One hundred and five cervical lesions and 20 normal (age matched) cervical epithelium from patients with complaints other than cervical lesions were investigated immunocytochemically for aberrant expression of p53 and bcl-2 using the streptavidin-biotin-peroxidase method with respective monoclonal antibodies. HPV status was also anlayzed using type-specific primers for HPV 16/18 and HPV 6/11 by polymerase chain reaction (PCR). The statistical correlation analysis was carried out using Spearman's correlation test and univariate analysis by the SPSS system.

RESULTS

An abnormal nuclear expression of tumor-suppressor protein p53 and cytoplasmic expression of bcl-2 were observed using immunocytochemistry in biopsies of cervical lesions but not in normal subjects. The intensity of immunoreactivity for both p53 and bcl-2 proteins varied between different histopathological grades of cervical lesions and the correlation analysis showed a highly significant positive correlation for their expression level with different stages from mild dysplasia to invasive cancer with r = 0.88842; P = 0.00001 and r = 0.86929; P = 0.00001, respectively. A highly significant positive correlation was also observed between the expression of both p53 and bcl-2 proteins and HPV infection. The current study indicates a very good significant direct correlation (r = 0.83925; P = 0.00001) between p53 expression and bcl-2 expression in the study population, suggesting the co-overexpression of these proteins in HPV-associated cervical cancer.

CONCLUSIONS

From the observations it is suggested that the immunodetection of both p53 and bcl-2 proteins in squamous cell carcinoma of the uterine cervix can be used as an independent diagnostic marker for cervical cancer associated with HPV infection. The highly significant association of these proteins with HPV infection suggests that the high-risk HPV infection may be responsible for the co-overexpression of p53 and bcl-2 in cervical cancer even though both of them are antagonistic in their function. This study thus helps to understand the molecular mechanism underlying cervical carcinogenesis and which in turn may improve the therapeutic approach.

Association between esophageal squamous cell carcinoma and human papillomavirus detected by Hybrid Capture II assay

From July 1999 to July 2000, 40 patients from the Surgical Oncology and Gastroenterology Departments of Irmandade da Santa Casa de Misericórdia de Porto Alegre were enrolled in a prospective study in order to find the frequency of human papillomavirus DNA (HPV-DNA) in esophageal squamous cell carcinoma. They were compared to 10 normal individuals (controls). Digene Inc. (Digene Corporation, Gaithersburg MD, USA) Hybrid Capture II assay, a chemoluminescent method, was used in both groups. The samples were collected from the tumor group by endoscopic biopsy in 20 cases, and by surgical specimens in the other 20 cases; the control group all underwent endoscopic biopsies. The cut-off point in the analytical assay for HPV-DNA was 1.0 pg/mL. Digene Corp. Hybrid Capture II assay tests HPV-DNA and differentiates high and low-risk for malignization virus groups. Gender, age, location of the tumor in esophagus and degree of differentiation on histology were also analyzed. There was one positive case (1.14 pg/mL), a 2.5% frequency of low-risk HPV-DNA type in the esophageal squamous cell carcinoma group (CI 95%: 0.00-7.34%). This group of patients consisted of 30 male and 10 female individuals, similar to the distribution seen in large series of such patients from the Brazilian population. The mean age was 63 years. Endoscopic samples of 10 patients who underwent endoscopic biopsy procedure for aleatory reasons, with normal looking esophageal mucosa, were tested to detect HPV-DNA, as controls. There was one positive case (1.17 pg/mL) of high-risk HPV-DNA type, resulting in a 10% positive rate. HPV-DNA is rarely found in esophageal squamous cell carcinomas: we found a 2.5% frequency, with confidence interval of 0-7.34%; and this is in the same range of controls (10% frequency, with CI: 9.1-10.9%). Both patients had a viral load quite near the 1.0 pg/mL cut-off point.

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.

Human papillomavirus testing methods

Testing for human papillomavirus (HPV) relies exclusively on techniques of molecular biology using nucleic acid probes. Tests for HPV using nucleic acid probes have been commercially available since the late 1980s, but early tests were cumbersome, involving the use of nucleic acid probes labeled with radioactive phosphorus (32P). These early HPV tests did not achieve widespread use because they did not detect all oncogenic HPV genotypes. The current commercial HPV detection kit, Digene's Hybrid Capture 2 kit, detects virtually all high-risk oncogenic HPV types, as well as most low-risk nononcogenic HPV genotypes. The Hybrid Capture 2 test format is a proprietary nucleic acid hybridization signal amplification system owned by Digene Corporation. Virtually all test formats for DNA sequence analysis are amenable to applications intended to detect and perhaps quantify the various HPV genotypes. These methods can involve direct hybridization with complementary DNA probes, such as Southern blotting or in situ hybridization, signal amplification, such as the Hybrid Capture 2 method or target nucleic acid amplification, most notably the polymerase chain reaction (PCR). Polymerase chain reaction has been used for HPV detection, genotyping, and viral load determination. General or consensus primer-mediated PCR assays have enabled screening for a broad spectrum of HPV types in clinical specimens using a single PCR reaction. Following amplification using consensus primers, individual HPV genotypes are identified using a variety of methods. Using consensus primers in a test format known as real-time quantitative PCR (RQ-PCR), it is possible to generate viral load (concentration) data from reaction curves generated by monitoring PCR reaction kinetics in real time.

Meta-analysis of social inequality and the risk of cervical cancer

Previous studies of the relationship between socio-economic status and cervical cancer have been mainly based on record linkage of routine data, such as cancer registry incidence rates and regional measures of social class based on census data. These routine data are liable to substantial misclassification with respect to socio-economic status. Previous reports are also primarily from developed countries, whereas the major burden of cervical cancer is in developing countries. We have therefore pooled the data from previously reported case-control studies of cervical cancer or dysplasia, which contain individual-level information on socio-economic characteristics to investigate the relationship between cervical cancer, social class, stage of disease, geographical region, age and histological type. Based on 57 studies, we found an increased risk of approximately 100% between high and low social class categories for the development of invasive cervical cancer, and an increased risk of approximately 60% for dysplasia, including carcinoma in situ. Although the difference was observed in all countries, it was stronger in low/middle income countries and in North America than in Europe. No clear differences were observed between squamous cell carcinoma and adenocarcinoma, or between younger and older women. These results indicate that both cervical infection with human papillomavirus, which is linked to both female and male sexual behaviour, and access to adequate cervical cancer screening programmes are likely to be important in explaining the large cervical cancer incidence rates observed in different socio-economic groups, and that the importance of these factors may vary between different geographical regions.

Occurrence of cervical infection with multiple human papillomavirus types is associated with age and cytologic abnormalities

BACKGROUND

Few aspects of the occurrence of infections with multiple HPV types have been described. Since the immunity conferred by vaccines is type-specific, the epidemiology of such coinfections needs to be addressed.

GOAL

The goal of the study was to document the prevalence and incidence of infection with multiple HPV types and the distribution of HPV types in coinfections.

STUDY DESIGN

In a prospective cohort of 2075 Brazilian women, cervical specimens were collected for cytology and HPV detection. Information on potential risk factors was obtained by interview.

RESULTS

The prevalence of HPV coinfections was 3% among cytologically normal women, 10% among women with ASCUS, 23% among those with LSIL, and 7% among those with HSIL. The incidence rate of coinfection declined markedly with age (Ptrend<0.001). Some HPV types co-occurred less frequently than expected, namely, HPV 16 and 18 occurring with other oncogenic HPV types and HPV 6/11.

CONCLUSION

We have observed that occurrence of HPV coinfection was dependent both on age and on the presence of cytologic abnormalities. These results may have implications for vaccine development and for public health decisions about vaccination programs.

Cigarette smoking and cervical cancer: Part I: a meta-analysis

Cancer of the cervix is the third most common cancer among women worldwide and its etiology is not clearly understood. Human papillomavirus can be found in approximately 95% of cervical cancers, but it does not appear to be necessary or sufficient to induce malignancy. In 1977, Winkelstein suggested that cigarette smoking was a causative factor in the development of cervical cancer. We report a meta-analysis of cigarette smoking and cervical disease and conclude that the data support a role for cigarette smoking as a risk factor for cervical cancer. We propose a multifactorial hypothesis involving a virus-tar interaction as the etiology of cervical cancer.

Can cervical cancer screening be stopped at 50? The prevalence of HPV in elderly women

Although the relation between cervical cancer and the human papillomavirus (HPV) has been established beyond doubt, the introduction of HPV detection in cervical cancer screening is halted, primarily by the high rate of false positivity in relation to morbidity, since the majority of women infected with HPV will not develop lesions. To counteract overconsumption of cervical cancer screening in elderly women, we wanted to test the hypothesis that women of 50 years or older who are HPV-negative and have a cytologically normal smear might be encouraged to refrain from further screening. As a first step, the prevalence of high-risk HPV in a population of 1,936 women of 50 years and older was investigated. After an initial decline, a slightly higher prevalence can be seen with increasing age. There is a decrease in the prevalence of multiple infections with age, paralleled by an increase in single infections, especially of HPV type 16 in the eldest-age group. However, neither the decrease in multiple infections nor the increase in single infections is statistically significant. The data obtained in this study show that, even in the presence of a slight increase in the HPV prevalence in elderly women, approximately 94% of the elderly women can be withdrawn from the cervical cancer screening. However, a follow-up study will be necessary to determine the frequency of (re)infection as well as the course of an HPV infection in elderly women.

Active and passive smoking, high-risk human papillomaviruses and cervical neoplasia

Few studies have evaluated the role of passive smoke exposure and cervical neoplasia risk. We assessed the role of active and passive cigarette smoke exposure and risk of cervical squamous intraepithelial lesion (SIL) in a case-control study based in a South Carolina Health Department; 59 high-grade SIL (HSIL) cases, 313 low-grade SIL (LSIL) cases and 427 controls were recruited and interviewed. Passive cigarette smoke exposure was significantly (P < 0.05) associated with high grade SIL (adjusted odds ratio (aOR) = 2.2) and low-grade SIL (aOR = 1.4). Active smoking was associated with SIL only among White women (aOR = 1.8). High-risk human papillomaviruses (HR-HPVs) appear to interact with active cigarette smoking to increase HSIL risk. HSIL cases compared with LSIL cases were significantly more likely to be HR-HPV positive current smokers (aOR = 3.0; 95% CI: (1.2, 7.7)). These data suggest that active and perhaps passive smoke exposure may be important co-factors in HSIL development among HR-HPV positive women.

Prospective clinical study comparing DNA flow cytometry and HPV typing as predictive tests for persistence and progression of CIN I/II

A cohort of 70 consecutive women at a university hospital colposcopy clinic with untreated CIN I and CIN II (CIN I/II) confirmed by cytology and histology was followed for 1 year in the setting of a prospective trial. In the lesions, the presence of DNA from HPV types was examined by restriction fragment length polymorphism (RFLP) analysis. Aneuploid cell lines were demonstrated by aneuploid histograms generated by high-resolution DNA flow cytometry. HPV type 16 infection and the existence of aneuploid cell lines proved to be significant risk factors for CIN I/II lesions to persist or progress to CIN III in the 1-year follow-up period in the same cohort of patients. The relative risks and 95% confidence intervals (CI) were 1.81 (1.44-2.76) for aneuploid cell lines and 1.74 (1.10-2.76) for HPV type 16 infection in CIN I/II lesions. As a predictive diagnostic test for CIN I/II lesions to persist or progress, the specificity and positive predictive value (PPV) for aneuploid histograms were 100% (CI, 73.5-100%) and 100% (CI, 86.8-100%), respectively. The low sensitivity of 27.3% (CI, 14.9-42.8%) restricted the clinical application of the test, leaving 32 of 44 women with persisting or progressing CINI/II with diploid histograms. HPV type 16 positivity by FRLP had a PPV of 68.4% (CI, 43.5-87.4%) as a prognostic test. Six of 19 HPV 16 infected women showed complete remission of their CIN lesion. A combination of the two tests did not provide any additional information.

Cost-effectiveness of monolayers and human papillomavirus testing compared to that of conventional Papanicolaou smears for cervical cancer screening: protocol of the study of the French Society of Clinical Cytology

The French Society of Clinical Cytology is conducting a study to compare the cost-effectiveness of monolayers and human papillomavirus (HPV) testing with that of conventional Papanicolaou (Pap) smears for cervical cancer screening. The protocol of this study is presented. It includes 3,000 women who will be evaluated by the three methods (conventional Pap smears, or monolayers with or without HPV testing) and by the reference method: colposcopy followed, in cases with abnormalities, by cervical biopsy. Efficacy or performance of the methods will be compared on the basis of sensitivity. Cost comparisons and cost-effectiveness modeling will be based on the costs associated with methods themselves and also the costs of "false positives." This will require specific collection of data concerning the costs of the three methods, as these costs have not previously been accurately documented. Patient recruiting and data collection started in September 1999 and will be complete in June 2000. The first results are expected to be available in spring 2001.

High-risk HPVs and risk of cervical neoplasia: a nested case-control study

The purpose of this nested case-control study was to estimate the risk of SIL development among a cohort of women providing cervical samples as part of their family planning visit at baseline in 1991-1992. All women had normal cervical cytology (N = 2905) at baseline and provided a cervical sample for subsequent HPV typing. Among this cohort, 426 women developed SIL (22 HSIL and 404 LSIL), 619 developed atypia, and 1860 remained cytologically normal. Two controls per case were sampled from those who remained normal. PCR-based methods with L1 consensus primers were used to assess high-risk HPV positivity. Having an oncogenic HPV type at baseline was associated with an almost fourfold increased risk of HSIL development (relative risk (RR) = 3.8; 95% CI, 1.5--9.0) and a 70% increased risk of LSIL development (RR = 1.7; 95% CI, 1.2--2.3%). The association between HPV positivity and SIL development was strongest in the first year of follow-up (RR = 9.2 for HSIL and 2.5 for LSIL development). The decline in HPV-associated SIL risk may be a function of having only one measure of HPV positivity (at baseline).

Molecular diagnostics of infectious diseases: state of the technology

In this review, the basic technologies and procedures currently used in clinical laboratories performing molecular diagnostics are described. Special emphasis on specimen processing has been made since it is one of the most challenging steps involved in molecular testing. Representative examples are given for each type of technology, especially tests that are currently available in the market. The types of hybridization-based and amplification-based procedures are detailed. Finally, current problems and future developments are discussed.

Sexual behaviour and smoking as determinants of cervical HPV infection and of CIN3 among those infected: a case-control study nested within the Manchester cohort

To distinguish risk factors for acquisition of cervical human papillomavirus (HPV) infection from the determinants of neoplasia among infected individuals we have conducted a three-arm case-control study nested within a large population-based cohort of women (the Manchester cohort) screened for HPV at entry using L1 consensus primer PCR. The study includes 181 HPV-positive controls who did not develop high-grade cervical intraepithelial neoplasia (CIN3) during follow-up, 203 HPV-negative controls, and 199 HPV-positive cases with histologically confirmed CIN3. Detailed information on sexual, reproductive and gynaecological history, oral contraceptive use and smoking was obtained at face-to-face interview. There was a striking division between risk factors for infection and those predictive of disease. Comparing the HPV-positive against the HPV-negative controls, the only risk factors for infection were number of sexual partners (OR for six or more = 3.89; 95% Cl = 1.99-7.62), a relatively recent new sexual relationship (OR for a new partner within the previous 2 years = 4.17; 95% Cl = 2.13-8.33), and a history of previous miscarriage (OR = 2.59; 95% Cl = 1.28-5.21). The determinants of CIN3 among infected women were, in contrast, early age at first intercourse (OR for 16 years old or less = 3.23; 95% Cl = 1.33-7.69), a long time since starting a new sexual relationship (OR for 6 years or more = 4.94; 95% Cl = 2.51-9.71), and cigarette smoking, with strong evidence for a dose- response (OR for current smoking habit 20+ per day = 2.57; 95% Cl = 1.49-4.45). Oral contraceptive use was not significantly associated with either HPV infection or CIN3.

Prediction of high-grade cervical intraepithelial neoplasia in cytologically normal women by human papillomavirus testing

Human papillomavirus (HPV) testing has been suggested for primary screening of cervical cancer. Prediction of future high-grade cervical lesions is crucial for effectiveness and cost. We performed a case control study in a retrospective cohort of women with at least two cervical smears, all but the last one being negative, from the organized cervical screening programme in Florence, Italy. We searched for high-risk HPV in all previous, archival, smears from cases (new histologically confirmed cervical intraepithelial neoplasia (CIN) grade II or worse) and in one previous smear from each control (last smear cytologically normal, matched by age and interval (latency) from last smear). We applied polymerase chain reaction (PCR), and the b-globin gene was used as a DNA preservation marker. High-risk HPV was identified in 71/92 (77.17%) previous smears from 79 cases and 17/332 controls (5.12%). The odds ratio (OR) was 63.76 (95% CI 30.57-132.96). Among cases the proportion of HPV-positive smears declined slightly with increasing latency. Among cases, HPV was found in 81.24% (95% CI 69.93-88.96%) of smears with latency < 4 years and in 67.80% (95% CI 47.72-82.93%) of those taken at longer intervals, up to 6 years. These findings suggest that testing for high-risk HPV allows predicting 80% of CINII/III 3 years before the cytological diagnosis and two thirds 6 years before. They also suggest that testing women negative for high-risk HPV at longer interval and strictly following-up women who are HPV positive could be an effective strategy for cervical cancer screening.

Public health paradoxes and the epidemiological impact of an HPV vaccine

BACKGROUND

our understanding of human papilloma virus (HPV) and cervical cancer has improved dramatically, with a vaccine against the viral infection being a real possibility in the near future.

AIMS

the goal of an HPV vaccine would be to reduce the prevalence of infection and hence the risk of cervical abnormalities. However, questions arise as to how this would interact with an existing intervention, screening, which reduces the progress of cervical abnormalities to serious disease. Furthermore, will a vaccine against one genotype influence the other types within a population and will the patterns of infection and disease remain the same if the vaccine alters the timing and type of HPVs experienced within a population? What would a vaccine that only worked in one sex achieve and how widespread would the use of such a vaccine have to be?

CONCLUSION

the above-given questions can be addressed within a theoretical framework that describes the transmission dynamics of human papilloma virus.

Risk factors for pre-cancerous lesions of the cervix

Studies on risk factors for pre-cancerous lesions of the uterine cervix have shown strong association with sexual practice. Women with multiple sexual partners and intercourse at early age are at high risk. A role of male partners in further enhancing the risk has been identified. All these support the hypothesis relating to a sexually transmissible aetiological agent. An extensive review of the literature on the risk factors for pre-cancerous lesions of cervix has been carried out. The risk factors were grouped into genital, sexual, chemical, dietary and life factors. Human papilloma virus (HPV) is the major infectious aetiological agent associated with the development of pre-cancerous lesions of cervix. Other co-factors such as multiple sexual partners of the male as well as the female and early age of first intercourse are also involved at the critical aetiological step of progression from low-grade to high-grade lesions. The role of other infectious agents in terms of supportive or interactive effects is not clear. No independent effect for herpes simplex virus 2 on risk is observed. Other risk factors include cigarette smoking, oral contraceptive usage, certain nutritional deficiencies and poor personal hygiene. However, it is not clear whether these factors operate independently from HPV. There is no consistency in the independent effect of these factors on the development of low- to high-grade lesions of cervix. There is a similarity in the patterns of risk between pre-cancerous lesions of the cervix and cervical cancer. Monogamy, late commencement of sexual activity, personal hygiene and use of barrier contraceptive methods help towards primary prevention. In the long-term, primary prevention of cervical neoplasia through HPV immunization of population may be a possibility.

Smoking and oral contraceptives as risk factors for cervical carcinoma in situ

Human papillomavirus (HPV) is probably a necessary but definitely not a sufficient cause of cervical carcinoma. However, it remains unclear which factors, in addition to HPV, are important for the development of cervical carcinoma and its precursor lesions. To address this issue, we conducted a case-control study nested in a population-based cohort consisting of women participating in cytological screening in one Swedish county, any time during 1969 through 1995. Detailed information on sexual practice, smoking habits and oral contraceptive (OC) use were collected through telephone interviews with 422 case patients diagnosed with cervical carcinoma in situ and 422 control subjects. All cytological smears were analyzed for presence of HPV 16/18 by a polymerase chain reaction (PCR)-based method. Odds ratios (OR) were used as measures of relative risk. After multivariate adjustment, a 2-fold higher risk was observed among current smokers compared with never smokers [OR 1.94; 95% confidence interval (CI 1.32-2.85)], an association apparently confined to women younger than 45 years. Current use of OCs was associated with a 4-fold increased risk overall (OR 3.64; 95% CI 1.91-6.93) with a monotonic increase with increasing duration of use (p for trend < 0.001). The number of sexual partners was significantly, positively associated with risk among HPV 16/18-negative (p for trend < 0.005) but not among HPV 16/18-positive women. Our data confirm the association between smoking and cervical carcinoma in situ, which might be age-dependent. Our results further indicate a relation with OC use and the risk for cervical carcinoma in situ.

Cervical human papillomavirus deoxyribonucleic acid persists throughout pregnancy and decreases in the postpartum period

OBJECTIVE

Our goal was to determine the persistence of human papillomavirus infection of the cervix in a prospectively evaluated cohort of pregnant women observed from the first trimester until after delivery.

STUDY DESIGN

A group of 232 women were enrolled in the first trimester of pregnancy and had cervico-vaginal lavage specimens collected for detection of the deoxyribonucleic acid of human papillomavirus. They underwent sampling again in the third trimester (146 patients available) and at 4 to 12 weeks after delivery (83 patients available). Human papillomavirus deoxyribonucleic acid was detected by means of the Hybrid Capture assay.

RESULTS

In the first trimester of pregnancy, 31% of the patients had positive test results for human papillomavirus deoxyribonucleic acid, whereas 35.6% had positive results in the third trimester (P = 1.0). A comparison of first-trimester test results with postpartum results (paired data available from 83 patients) showed a decline from 39.8% positivity to 26.5% (P =.04). Comparing third-trimester results with postpartum results (paired data available from 74 patients) showed a decline from 35.1% to 25. 7% positivity (P =.12). When specimens positive for human papillomavirus were divided between those containing "high cancer risk" types (9 virus types often associated with dysplasia or malignancy) and "low cancer risk" types (5 types usually found in benign lesions), similar trends were seen, although not all comparisons were statistically significant.

CONCLUSION

The increased prevalence, during pregnancy, of detectable human papillomavirus deoxyribonucleic acid, which was previously reported (Fife et al, Am J Obstet Gynecol 1996;174:1487-93), persists at a similar level throughout pregnancy but declines in the postpartum period. This observation is most consistent with activation of the virus by the physiologic changes of pregnancy.

A population-based study of human papillomavirus deoxyribonucleic acid testing for predicting cervical intraepithelial neoplasia

OBJECTIVE

Our purpose was to determine the predictive values of primary or secondary screening for cervical human papillomavirus infection for cytologic detection of cervical intraepithelial neoplasia.

STUDY DESIGN

Most of the 254 women referred for colposcopy in Västerbotten County in Sweden during October 1993 through December 1995 and 320 age-matched women from the general population were screened for human papillomavirus deoxyribonucleic acid by nested general-primer polymerase chain reaction.

RESULTS

Ninety-six percent of women with high-grade cervical intraepithelial neoplasia had human papillomavirus, compared with 4% of women with normal findings (odds ratio 606; 95% confidence interval 137 to 5607). Thirty-seven percent of referred women and 48% of referred women >39 years old had mostly minor cytologic abnormalities with no human papillomavirus. The human papillomavirus-associated positive predictive value for cervical intraepithelial neoplasia was 76% in the colposcopy group and 11% in the general population, whereas the negative predictive value was >97% in both populations.

CONCLUSION

Testing for human papillomavirus deoxyribonucleic acid seems diagnostically useful among women referred for colposcopy.

The risk of invasive cervical cancer among Hispanics: evidence for targeted preventive interventions

BACKGROUND

Mass screening for cervical cancer has considerably reduced invasive cancer rates; however, Hispanic Americans have not fully benefited. This study examined the relationship of demographic, socioeconomic, and acculturation factors to diagnostic stage prior to preventive interventions in a large Hispanic community (San Diego, CA, 1988-1991).

METHODS

Age-adjusted incidence rates (IR) were estimated for three subareas: Hispanic community targeted with interventions, comparison Hispanic community, and remainder of county. Incident cases of cervical cancer in the California Cancer Registry were used to calculate incidence rate ratios (IRR) of in situ to invasive stage cancer and estimate differences in early detection between Hispanics and white non-Hispanics. Multiple logistic regression was used to examine the relationship of cancer stage to census-linked income, education, poverty status, foreign birth, and language spoken.

RESULTS

The in situ cervical cancer IR is significantly lower for Hispanics than for white non-Hispanics in all three regions (P < 0.05). The overall IRR is 3.65 (95% CI 3.19, 4.18) for white non-Hispanics compared with 1.09 (95% CI 0.86, 1.38) for Hispanics. Hispanics in census tracts in the highest versus remaining quartiles for percentage of language-isolated households are at greater risk for invasive stage (OR = 2.10, 95% CI 1.27, 3. 40). White non-Hispanic women residing in census tracts in the highest versus lowest quartile of adults with less than 12 years education are at greater risk for invasive stage (OR = 2.10, 95% CI 1.31, 3.38).

CONCLUSIONS

Results show efforts aimed at cervical cancer early detection for Hispanic women are needed and well targeted. White non-Hispanic women in low-education communities are also at risk. Population-based methods in this study can focus efforts in communities needing preventive interventions.