Long-term prediction by DNA methylation of high-grade cervical intraepithelial neoplasia: Results of the ARTISTIC cohort

Methylation markers have shown potential for triaging high-risk HPV-positive (hrHPV+) women to identify those at increased risk of invasive cervical cancer (ICC). Our aim was to assess the performance of the S5 DNA methylation classifier for predicting incident high-grade cervical intraepithelial neoplasia (CIN) and ICC among hrHPV+ women in the ARTISTIC screening trial cohort. The S5 classifier, comprising target regions of tumour suppressor gene EPB41L3 and L1 and L2 regions of HPV16, HPV18, HPV31, and HPV33, was assayed by pyrosequencing in archived hrHPV+ liquid-based samples from 343 women with high-grade disease (139 CIN2, 186 CIN3, and 18 ICC) compared to 800 hrHPV+ controls. S5 DNA methylation correlated directly with increasing severity of disease and inversely with lead time to diagnosis. S5 could discriminate between hrHPV+ women who developed CIN3 or ICC and hrHPV+ controls (p <.0001) using samples taken on average 5 years before diagnosis. This relationship was independent of cytology at baseline. The S5 test showed much higher sensitivity than HPV16/18 genotyping for identifying prevalent CIN3 (93% vs. 61%, p = .01) but lower specificity (50% vs. 66%, p <.0001). The S5 classifier identified most women at high risk of developing precancer and missed very few prevalent advanced lesions thus appearing to be an objective test for triage of hrHPV+ women. The combination of methylation of host and HPV genes enables S5 to combine the predictive power of methylation with HPV genotyping to identify hrHPV-positive women who are at highest risk of developing CIN3 and ICC in the future.

DNA methylation testing with S5 for triage of high-risk HPV positive women

Methylation of host and viral genes is promising for triage of women with high-risk human papillomavirus infections (hrHPV). Using a population-based sample of hrHPV positive women with cervical biopsies within 12 months after cervical screening, the clinical value of the S5 methylation classifier (S5), HPV genotyping and cytology were compared as potential triage tests, for outcomes of cervical intraepithelial neoplasia (CIN) grade 3 or greater (CIN3+), CIN2+ and CIN2, and the area under the curve (AUC) calculated. S5 scores increased with histopathology severity (Ptrend  < .001). For CIN3+, the AUC was 0.780 suggesting S5 provides good discrimination between Collapse

Key Words

• DNA methylation
• cervical cancer
• high-risk HPV
• molecular markers
• triage

Collapse

MESH Headings

• DNA Methylation
• Early Detection of Cancer
• Female
• Human papillomavirus 16/genetics
• Human papillomavirus 18/genetics
• Humans
• Papillomaviridae/genetics
• Papillomavirus Infections/complications
• Papillomavirus Infections/diagnosis
• Papillomavirus Infections/genetics
• Triage
• Uterine Cervical Neoplasms/diagnosis
• Uterine Cervical Neoplasms/genetics
• Uterine Cervical Neoplasms/pathology
• Uterine Cervical Dysplasia/diagnosis
• Uterine Cervical Dysplasia/genetics
• Uterine Cervical Dysplasia/pathology

Collapse

Grants

• 21070 Cancer Research UK
• 27046 Cancer Research UK
• C27045/A27046 Cancer Research UK
• Cancer Research UK
• National Institute of Allergy and Infectious Diseases

Collapse

Affiliation(s)

Rachael Adcock Centre for Cancer Prevention, Wolfson Institute of Population HealthQueen Mary University of LondonLondonUK Center for HPV PreventionUniversity of New Mexico Comprehensive Cancer CenterAlbuquerqueNew MexicoUSA
Belinda Nedjai Centre for Cancer Prevention, Wolfson Institute of Population HealthQueen Mary University of LondonLondonUK
Attila T. Lorincz Centre for Cancer Prevention, Wolfson Institute of Population HealthQueen Mary University of LondonLondonUK
Dorota Scibior‐Bentkowska Centre for Cancer Prevention, Wolfson Institute of Population HealthQueen Mary University of LondonLondonUK
Rawinder Banwait Centre for Cancer Prevention, Wolfson Institute of Population HealthQueen Mary University of LondonLondonUK
Norah Torrez‐Martinez Center for HPV PreventionUniversity of New Mexico Comprehensive Cancer CenterAlbuquerqueNew MexicoUSA
Michael Robertson Center for HPV PreventionUniversity of New Mexico Comprehensive Cancer CenterAlbuquerqueNew MexicoUSA
Jack Cuzick Centre for Cancer Prevention, Wolfson Institute of Population HealthQueen Mary University of LondonLondonUK
Cosette M. Wheeler Center for HPV PreventionUniversity of New Mexico Comprehensive Cancer CenterAlbuquerqueNew MexicoUSA
New Mexico HPV Pap Registry Steering Committee

Collapse

Clinical performance of methylation as a biomarker for cervical carcinoma in situ and cancer diagnosis: A worldwide study

The shift towards primary human papillomavirus (HPV)-based screening has necessitated the search for a secondary triage test that provides sufficient sensitivity to detect high-grade cervical intraepithelial neoplasia (CIN) and cancer, but also brings an improved specificity to avoid unnecessary clinical work and colposcopy referrals. We evaluated the performance of the previously described DNA-methylation test (S5) in detecting CIN3 and cancers from diverse geographic settings in high-, medium- and low-income countries, using the cut-off of 0.80 and exploratory cut-offs of 2.62 and 3.70. Assays were performed using exfoliated cervical specimens (n = 808) and formalin-fixed biopsies (n = 166) from women diagnosed with cytology-negative results (n = 220), CIN3 (n = 204) and cancer stages I (n = 245), II (n = 249), III (n = 28) and IV (n = 22). Methylation increased proportionally with disease severity (Cuzick test for trend, P < .0001). S5 accurately separated women with negative-histology from CIN3 or cancer (P < .0001). At the 0.80 cut-off, 543/544 cancers were correctly identified as S5 positive (99.81%). At cut-off 3.70, S5 showed a sensitivity of 95.77% with improved specificity. The S5 odds ratios of women negative for cervical disease vs CIN3+ were significantly higher than for HPV16/18 genotyping at all cut-offs (all P < .0001). At S5 cut-off 0.80, 96.15% of consistently high-risk human papillomavirus (hrHPV)-negative cancers (tested with multiple hrHPV-genotyping assay) were positive by S5. These cancers may have been missed in current primary hrHPV-screening programmes. The S5 test can accurately detect CIN3 and malignancy irrespective of geographic context and setting. The test can be used as a screening and triage tool. Adjustment of the S5 cut-off can be performed considering the relative importance given to sensitivity vs specificity.

Adjunctive testing by cytology, p16/Ki-67 dual-stained cytology or HPV16/18 E6 oncoprotein for the management of HPV16/18 screen-positive women

High-risk human papillomavirus type 16/18 (HPV16/18) genotyping is unable to accurately discriminate nonprogressive infections from those that will progress to cervical cancer. Our study aimed to assesses if additional testing either with liquid-based cytology (LBC) or the putative progression markers p16/Ki-67 and HPV16/18 E6 oncoprotein (E6) can improve the efficiency of HPV16/18 genotyping for triaging high-risk HPV (hrHPV)-positive women through better cancer risk stratification. Women attending colposcopy after positive HPV16/18 genotyping results within the Forwarding Research for Improved Detection and Access for Cervical Cancer Screening and Triage (FRIDA) hrHPV-based screening study in Tlaxcala, Mexico, underwent further testing with LBC, p16/Ki-67 dual-stained (DS) cytology and E6. We calculated measures of test performance for detecting histologically confirmed cervical intraepithelial neoplasia grade 2 or higher (CIN2+) and grade 3 or higher (CIN3+). A number of 475 (64.3%) of 739 HPV16/18-positive women had complete results for all tests. Triage positivity rates were 14.1%, 18.5% and 24.4%, for LBC, E6 and DS, respectively. Compared with LBC, DS had higher sensitivity (24.4% vs 60.0%) although lower specificity (87.0% vs 79.3%) for CIN3+ (P < .001), whereas E6 had a sensitivity of 37.8% and a specificity of 83.5%. No invasive cancer was missed by DS or E6, but 75% were in normal cytology. DS test was associated with nearly 75% reduction of colposcopy referrals compared with the direct referral of all HPV16/18-positive women, giving the least number of colposcopies (n = 4.3) per CIN3+ detected. We show that adjunctive testing of HPV16/18-positive women with DS may greatly reduce unnecessary colposcopy referrals within HPV-based screening employing HPV16/18 genotyping while retaining acceptable sensitivity for CIN2+ and CIN3+.

A Randomized Comparison of Different Vaginal Self-sampling Devices and Urine for Human Papillomavirus Testing-Predictors 5.1

BACKGROUND

Human papillomavirus (HPV)-based screening is rapidly replacing cytology as the cervical screening modality of choice. In addition to being more sensitive than cytology, it can be done on self-collected vaginal or urine samples. This study will compare the high-risk HPV positivity rates and sensitivity of self-collected vaginal samples using four different collection devices and a urine sample.

METHODS

A total of 620 women referred for colposcopy were invited to provide an initial stream urine sample collected with the Colli-Pee device and take two vaginal self-samples, using either a dry flocked swab (DF) and a wet dacron swab (WD), or a HerSwab (HS) and Qvintip (QT) device. HPV testing was performed by the BD Onclarity HPV Assay.

RESULTS

A total of 600 vaginal sample pairs were suitable for analysis, and 505 were accompanied by a urine sample. Similar positivity rates and sensitivities for CIN2+ and CIN3+ were seen for DF, WD, and urine, but lower values were seen for QT and HS. No clear user preferences were seen between devices, but women found urine easiest to collect, and were more confident they had taken the sample correctly. The lowest confidence in collection was reported for HS.

CONCLUSIONS

Urine, a DF swab, and WD swab all performed well and were well received by the women, whereas the Qvintip and HerSwab devices were less satisfactory.

IMPACT

This is the first study to compare five self-sampling methods in the same women taken at the same time. It supports wider use of urine or vaginal self-sampling for cervical screening.

Effective methylation triage of HPV positive women with abnormal cytology in a middle-income country

The S5-methylation test, an alternative to cytology and HPV16/18 genotyping to triage high-risk HPV-positive (hrHPV+) women, has not been widely validated in low-middle-income countries (LMICs). We compared S5 to HPV16/18 and cytology to detect cervical intraepithelial neoplasia Grade 2 or worse (CIN2+) and CIN3+ in hrHPV+ women selected from a randomized pragmatic trial of 2661 Colombian women with an earlier-borderline abnormal cytology. We included all hrHPV+ CIN2 and CIN3+ cases (n = 183) age matched to 183 Collapse

Key Words

• DNA methylation
• HPV test
• biomarkers
• cervical cancer
• triage

Collapse

MESH Headings

• Adult
• Aged
• Atypical Squamous Cells of the Cervix/pathology
• Atypical Squamous Cells of the Cervix/virology
• Colombia
• DNA Methylation
• Early Detection of Cancer/methods
• Female
• Genes, Viral/genetics
• Humans
• Middle Aged
• Papillomavirus Infections/complications
• Papillomavirus Infections/diagnosis
• Sensitivity and Specificity
• Uterine Cervical Neoplasms/diagnosis
• Uterine Cervical Neoplasms/pathology
• Uterine Cervical Neoplasms/virology
• Uterine Cervical Dysplasia/diagnosis
• Uterine Cervical Dysplasia/pathology
• Uterine Cervical Dysplasia/virology

Collapse

Grants

• 16891 Cancer Research UK
• 27046 Cancer Research UK
• C569/A10404 Cancer Research UK

Collapse

Affiliation(s)

Arianis Tatiana Ramírez Infection and Cancer Group, School of Medicine and Corporación Académica para el Estudio de Patologías Tropicales, Universidad de Antioquia, Medellín, Colombia
Gloria Inés Sánchez Infection and Cancer Group, School of Medicine and Corporación Académica para el Estudio de Patologías Tropicales, Universidad de Antioquia, Medellín, Colombia
Belinda Nedjai Centre for Cancer Prevention, Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine, Queen Mary University of London, London, UK
María Cecilia Agudelo Infection and Cancer Group, School of Medicine and Corporación Académica para el Estudio de Patologías Tropicales, Universidad de Antioquia, Medellín, Colombia
Adam R Brentnall Centre for Cancer Prevention, Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine, Queen Mary University of London, London, UK
Kate Cuschieri Queen's Medical Research Institute of The University of Edinburgh, Edinburgh, UK
Kelly Melisa Castañeda Infection and Cancer Group, School of Medicine and Corporación Académica para el Estudio de Patologías Tropicales, Universidad de Antioquia, Medellín, Colombia
Jack Cuzick Centre for Cancer Prevention, Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine, Queen Mary University of London, London, UK
Attila T Lorincz Centre for Cancer Prevention, Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine, Queen Mary University of London, London, UK

Collapse

Methylation of HPV 16 and EPB41L3 in oral gargles: Associations with oropharyngeal cancer detection and tumor characteristics

Oropharyngeal cancer (OPC) incidence is increasing significantly among men and often requires intensive therapy causing significant morbidity. Early detection of OPC is needed, when monotherapy can be safely delivered with less treatment-associated morbidity, while maintaining high cure rates. We conducted a study of 101 pretreatment male OPC cases matched 1:1 to 101 disease-free controls for age and smoking history. Oral gargles were collected from cases and controls with additional biopsies or aspirates from cases. The HPV SPF10 -LiPA25 PCR assay was utilized for HPV genotyping. Methylation of three CpG sites (438, 427 and 425) in the EPB41L3 gene and methylation status of the L1 (6,367, 6,389), L2 (4,257, 4,262, 4,266, 4,269, 4,275, 4,282) and E2 (3,412, 3,415, 3,417, 3,433, 3,436) CpG sites of HPV 16 positive specimens was assessed by pyrosequencing. Significant correlations were observed between tumor and oral specimens for all methylation biomarkers (p < 0.01). EPB41L3 and HPV 16 L1, L2 and E2 methylation were significantly (p < 0.0001) higher among cases than controls, regardless of early vs. late disease. When HPV 16 genes and EPB41L3 methylation status were combined in a logistic regression analysis, a sensitivity of 70.3% and a specificity of 90.9% were observed for the detection of OPC from an oral gargle. Our data suggest that methylation biomarkers measured in oral gargles may have utility in identifying OPC early. Future studies are needed to replicate these findings and to inform additional biomarkers that can maximize specificity and sensitivity for early OPC detection.

Comparison of HPV-16 and HPV-18 Genotyping and Cytological Testing as Triage Testing Within Human Papillomavirus-Based Screening in Mexico

IMPORTANCE

Triage tests enhance the efficiency cervical cancer screening based on human papillomavirus (HPV), but the best approach for maximizing programmatic effectiveness is still uncertain, particularly in a real-world scenario.

OBJECTIVE

To compare the clinical performance of 6 triage strategies based on liquid-based cytology (LBC) and HPV-16 and HPV-18 genotyping individually or in combination as sequential triage tests to detect cervical intraepithelial neoplasia (CIN) grade 2 or higher among women with high-risk HPV.

DESIGN, SETTING, AND PARTICIPANTS

This diagnostic study of routine cervical cancer screening was conducted at 100 primary health centers in Tlaxcala, Mexico. Women aged 30 to 64 years were recruited from August 1, 2013, to February 24, 2016, as part of the Forwarding Research for Improved Detection and Access for Cervical Cancer Screening and Triage study. Six triage scenarios for referral to colposcopy were examined: (1) LBC testing that found atypical squamous cells of undetermined significance (ASC-US) or worse, (2) positive results in HPV-16 genotyping, (3) positive results in HPV-18 genotyping, (4) positive results in HPV-16/HPV-18 genotyping, (5) positive results in HPV-16 genotyping or, if genotyping results were negative, reflex LBC testing that found ASC-US or worse, and (6) positive results in HPV-16/HPV-18 genotyping or, if genotyping results were negative, reflex LBC testing that found ASC-US or worse. Data were analyzed from October 2017 to August 2018.

EXPOSURES

Liquid-based cytological testing with simultaneous HPV-16 and HPV-18 genotyping. Women whose HPV genotyping results were positive for HPV-16 or HPV-18 or whose LBC results found ASC-US or worse and a random set of negative and normal results were referred to colposcopy with histologic analysis used for disease confirmation.

MAIN OUTCOMES AND MEASURES

Clinical performance of each test strategy for detection of CIN grade 2 or higher. Secondary outcomes included resource utilization of each triage scenario, measured by the number of tests performed, the referral rate for colposcopy, and the numbers of colposcopies per CIN grade 2 or higher detected.

RESULTS

A total of 36 212 women (median [interquartile range] age, 40 [35-47] years) were screened, and 4051 women (11.2%) had high-risk HPV. Of these women, 1109 (24.6%) were found to have HPV-16, HPV-18, or ASC-US or worse. Further histologic testing detected CIN grade 2 or higher in 110 of 788 women (14.0%) who underwent follow-up colposcopy. Sensitivity and specificity for 3 main triage strategies were 42.9% and 74.0% for LBC; 58.3% and 54.4% for HPV-16/HPV-18 genotyping; and 86.6% and 34.0% for HPV-16/HPV-18 genotyping with reflex LBC. The referral rate to colposcopy was 29% for HPV-16/HPV-18 with reflex LBC, which was 2-fold higher than the referral rate of 12% for LBC.

CONCLUSIONS AND RELEVANCE

Triage of women with high-risk HPV with HPV-16/HPV-18 genotyping with reflex LBC was significantly associated with improvement in detection of CIN grade 2 or higher compared with LBC alone. The benefit of disease prevented may outweigh the cost of increasing requirements for colposcopy services in settings with limited adherence to follow-up after a positive screening result.

Methylation estimates the risk of precancer in HPV-infected women with discrepant results between cytology and HPV16/18 genotyping

BACKGROUND

Vigilant management of women with high-risk human papillomavirus (hrHPV) is necessary in cancer screening programs. To this end, we evaluated the performance of S5 (targeting DNA methylation in HPV16, HPV18, HPV31, HPV33, and human gene EPB41L3) to predict cervical intraepithelial neoplasia grade 2 or higher (CIN2+) in a sample of hrHPV-infected women referred to colposcopy in the FRIDA Study, a large screening trial in Mexico. A nested case-control sample with women referred to colposcopy either by atypical squamous cells of undetermined significance or higher (ASCUS+) in cytology and/or positive for HPV types 16 or 18 was tested by S5. Seventy-nine cases of CIN2+ were age-matched to 237 controls without a diagnosis of CIN2+ (

RESULTS

The S5 classifier separated women with CIN2+ from

CONCLUSIONS

S5 testing on hrHPV-positive women significantly increased diagnostic information compared to triage by HPV16/18 plus cytology and appears to have clinical utility as an additional test to substantially lessen burdens on colposcopy.

TRIAL REGISTRATION

The FRIDA Study is registered in ClinicalTrials.gov , number NCT02510027.

Collapse

Key Words

• Cervical cancer
• Cervical intraepithelial neoplasia
• DNA methylation
• EPB41L3
• Human papillomavirus
• S5 classifier
• Triage

Collapse

MESH Headings

• Adult
• Area Under Curve
• Case-Control Studies
• Clinical Trials as Topic
• Colposcopy
• DNA Methylation
• DNA, Viral/genetics
• Early Detection of Cancer/methods
• Epigenesis, Genetic
• Female
• Genotype
• Human papillomavirus 16/genetics
• Human papillomavirus 18/genetics
• Humans
• Mexico
• Microfilament Proteins/genetics
• Middle Aged
• Papillomavirus Infections/complications
• Papillomavirus Infections/genetics
• Sensitivity and Specificity
• Sequence Analysis, DNA
• Triage
• Uterine Cervical Neoplasms/diagnosis
• Uterine Cervical Neoplasms/genetics
• Uterine Cervical Neoplasms/virology
• Uterine Cervical Dysplasia/diagnosis
• Uterine Cervical Dysplasia/genetics
• Uterine Cervical Dysplasia/virology

Collapse

Grants

• 21070 Cancer Research UK
• 27046 Cancer Research UK
• P30 CA016672 NCI NIH HHS
• C569/A10404 Cancer Research UK
• Instituto Mexicano del Seguro Social
• Secretaría de Salud
• Consejo Nacional de Ciencia y Tecnología
• Instituto Nacional de Salud Publica

Collapse

Affiliation(s)

Rubí Hernández-López Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Cuernavaca, Morelos México Centro de Investigación en Políticas, Población y Salud, Universidad Nacional Autónoma, Ciudad de México, México
Attila T. Lorincz Wolfson Institute of Preventive Medicine, Centre for Cancer Prevention, Queen Mary University of London, London, UK
Leticia Torres-Ibarra Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Cuernavaca, Morelos México
Caroline Reuter Wolfson Institute of Preventive Medicine, Centre for Cancer Prevention, Queen Mary University of London, London, UK
Dorota Scibior-Bentkowska Wolfson Institute of Preventive Medicine, Centre for Cancer Prevention, Queen Mary University of London, London, UK
Rhian Warman Wolfson Institute of Preventive Medicine, Centre for Cancer Prevention, Queen Mary University of London, London, UK
Belinda Nedjai Wolfson Institute of Preventive Medicine, Centre for Cancer Prevention, Queen Mary University of London, London, UK
Indira Mendiola-Pastrana Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Cuernavaca, Morelos México
Leith León-Maldonado Centro de Investigación en Políticas, Población y Salud, Universidad Nacional Autónoma, Ciudad de México, México Cátedra-CONACYT, Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Cuernavaca, Morelos México
Berenice Rivera-Paredez Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Cuernavaca, Morelos México Centro de Investigación en Políticas, Población y Salud, Universidad Nacional Autónoma, Ciudad de México, México
Paula Ramírez-Palacios Unidad de Investigación Epidemiológica y en Servicios de Salud, Delegación Morelos, Instituto Mexicano del Seguro Social, Cuernavaca, Morelos México
Eduardo Lazcano-Ponce Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Cuernavaca, Morelos México
Jack Cuzick Wolfson Institute of Preventive Medicine, Centre for Cancer Prevention, Queen Mary University of London, London, UK
Jorge Salmerón Centro de Investigación en Políticas, Población y Salud, Universidad Nacional Autónoma, Ciudad de México, México

Collapse

Evaluation of a validated methylation triage signature for human papillomavirus positive women in the HPV FOCAL cervical cancer screening trial

Human papillomavirus (HPV)-based cervical cancer screening requires triage of HPV positive women to identify those at risk of cervical intraepithelial neoplasia grade 2 (CIN2) or worse. We conducted a blinded case-control study within the HPV FOCAL randomized cervical cancer screening trial of women aged 25-65 to examine whether baseline methylation testing using the S5 classifier provided triage performance similar to an algorithm relying on cytology and HPV genotyping. Groups were randomly selected from women with known HPV/cytology results and pathology outcomes. Group 1: 104 HPV positive (HPV+), abnormal cytology (54 CIN2/3; 50 Collapse

Key Words

• cervical cancer
• cervical cancer screening
• colposcopy triage
• human papillomavirus
• methylation

Collapse

MESH Headings

• Adult
• Aged
• Case-Control Studies
• Cell Biology
• Early Detection of Cancer/methods
• Europe
• Female
• Human papillomavirus 16/genetics
• Human papillomavirus 16/pathogenicity
• Human papillomavirus 18/genetics
• Human papillomavirus 18/pathogenicity
• Humans
• Methylation
• Middle Aged
• Papillomavirus Infections/complications
• Papillomavirus Infections/genetics
• Risk
• United States
• Uterine Cervical Neoplasms/diagnosis
• Uterine Cervical Neoplasms/etiology
• Uterine Cervical Neoplasms/genetics

Collapse

Grants

• 16891 Cancer Research UK
• C569/A10404 Cancer Research UK

Collapse

Affiliation(s)

Darrel A. Cook BC Centre for Disease ControlVancouverBritish ColumbiaCanada BC Cancer AgencyVancouverBritish ColumbiaCanada
Mel Krajden BC Centre for Disease ControlVancouverBritish ColumbiaCanada Lower Mainland Pathology and Laboratory MedicineVancouverBritish ColumbiaCanada Faculty of MedicineUniversity of British ColumbiaVancouverBritish ColumbiaCanada
Adam R. Brentnall Wolfson Institute of Preventive Medicine, Centre for Cancer Prevention, Queen Mary University of LondonLondonUnited Kingdom
Lovedeep Gondara BC Cancer AgencyVancouverBritish ColumbiaCanada
Tracy Chan Lower Mainland Pathology and Laboratory MedicineVancouverBritish ColumbiaCanada
Jennifer H. Law Lower Mainland Pathology and Laboratory MedicineVancouverBritish ColumbiaCanada
Laurie W. Smith BC Cancer AgencyVancouverBritish ColumbiaCanada
Dirk J. van Niekerk BC Cancer AgencyVancouverBritish ColumbiaCanada Lower Mainland Pathology and Laboratory MedicineVancouverBritish ColumbiaCanada Faculty of MedicineUniversity of British ColumbiaVancouverBritish ColumbiaCanada
Gina S. Ogilvie BC Centre for Disease ControlVancouverBritish ColumbiaCanada Faculty of MedicineUniversity of British ColumbiaVancouverBritish ColumbiaCanada
Andrew J. Coldman BC Cancer AgencyVancouverBritish ColumbiaCanada Faculty of MedicineUniversity of British ColumbiaVancouverBritish ColumbiaCanada
Rhian Warman Wolfson Institute of Preventive Medicine, Centre for Cancer Prevention, Queen Mary University of LondonLondonUnited Kingdom
Caroline Reuter Wolfson Institute of Preventive Medicine, Centre for Cancer Prevention, Queen Mary University of LondonLondonUnited Kingdom
Jack Cuzick Wolfson Institute of Preventive Medicine, Centre for Cancer Prevention, Queen Mary University of LondonLondonUnited Kingdom
Attila T. Lorincz Wolfson Institute of Preventive Medicine, Centre for Cancer Prevention, Queen Mary University of LondonLondonUnited Kingdom

Collapse

Human Papillomavirus Research: Where Should We Place Our Bets?

BACKGROUND

Massive strides have been made with respect to primary and secondary prevention of human papillomavirus (HPV)-associated disease as a result of prophylactic vaccination and cervical screening based on molecular HPV testing. However, cervical cancer continues to be an important clinical and societal burden. Additionally, other HPV-associated cancers, for which there are no screening programmes, are rising. Finally, the optimal combination of vaccination and screening strategies will require careful thinking. Considering this unprecedented and important time, we were keen to solicit the views of the expert community to determine what they perceived were the key priorities for HPV research. Our objective was to identify consensus and key priorities for HPV-based research through provision of a questionnaire disseminated to a multidisciplinary group of key opinion leaders (KOLs).

SUMMARY

A structured survey composed of 46 HPV research "categories" was sent to 73 KOLs who were invited to "rank" the categories according to priority. The invitees represented clinical and public health disciplines as well as basic scientists. Scores were weighted according to the number of responses. Invitees also had the opportunity to comment on barriers to the research and suggest other research areas that required attention not reflected in the survey. We received 29 responses in total; overall, the 3 highest-ranked categories were "optimal cervical screening in low and middle-income countries (LMICs)," "primary disease prevention in LMICs" and "impact of vaccine on HPV infection and associated disease." "HPV and the microbiome" and "mechanisms of transformation" were the highest-ranked categories with respect to basic research. Consistent barriers to research were around governance on the use of samples and data and funding, particularly in an era of vaccination. Key Messages: Research to support the management of disease in LMICs is clearly perceived as a priority in the international community in addition to other diverse areas which necessitate an improved basic understanding of viral mechanisms and interactions. International, multidisciplinary efforts which articulate the broader HPV research agenda will be important when seeking funding in addition to international endeavours to support the efficient use of existing samples and cohorts to facilitate such research.

Molecular progression to cervical precancer, epigenetic switch or sequential model?

The evolution of precancerous cervical lesions is poorly understood. A widely held model of cervical intraepithelial neoplasia grade 3 (CIN3) development is sequential progression from normal through CIN1 and CIN2 to CIN3. Another hypothesis, the "molecular switch" model, postulates that CIN3 can evolve directly from human papillomavirus (HPV)-infected normal epithelium without progressing through CIN1 and CIN2. To shed light on this process, we compared DNA methylation of selected human biomarkers and HPV types in two groups of CIN1: CIN1 that were near or adjacent to CIN3 (adjacent-CIN1) and CIN1 that were the principal lesions with no CIN3 detected (principal-CIN1). 354 CIN (CIN1 and CIN3) and normal tissue areas were dissected and typed for HPV from 127 women who underwent loop electrosurgical excision procedures (LEEP). Methylation of genes EPB41L3 and the viral regions of HPV16-L1/L2, HPV18-L2, HPV31-L1, and HPV33-L2 were determined by a highly accurate quantitative pyrosequencing of bisulfite converted DNA. There was a significant trend of increased methylation with disease grade comparing normal to CIN1 and CIN3 (p < 0.0001). Adjacent-CIN1 predominantly shared the same HPV types as the CIN3, however, methylation differed substantially between adjacent-CIN1 and CIN3 (p = 0.008). In contrast diagnostically principal-CIN1 had an indistinguishable methylation distribution compared to adjacent-CIN1 (EPB41L3: p = 0.49; HPVme-All: p = 0.11). Our results suggest that progression from normal epithelium to CIN1 or CIN3 is usually promoted by the same HPV type but occurs via distinct DNA epigenotypes, thus favoring the "molecular switch" model.

Role of quantitative p16INK4A mRNA assay and digital reading of p16INK4A immunostained sections in diagnosis of cervical intraepithelial neoplasia

Visual interpretation of cervical biopsies is subjective and variable, generally showing fair to moderate inter-reader agreement in distinguishing high from low grade cervical intraepithelial neoplasia (CIN). We investigated the performance of two objective p16 quantitative tests in comparison with visual assessment: (i) p16-mRNA assay and (ii) digital analysis of sections stained for p16 protein. The primary analysis considered 232 high-risk human papilloma virus positive (HPV+) samples from diagnostic cervical specimens. A p16 RT-qPCR (p16-mRNA assay) was run on mRNA extracted from formalin-fixed paraffin-embedded sections. Two p16 immunohistochemistry (IHC) readings, a visual read by a histopathologist (Visual IHC) and a digital read of a high-resolution scan (Digital IHC), were done on adjacent sections. The worst reviewed CIN grade (agreed by at least two histopathologists) from up to two biopsies and a loop excision was taken, with CIN2/3 as the primary endpoint. Visual IHC attained a specificity of 70% (95%CI 61-77) for 85% (95%CI 77-91%) sensitivity. The four-point Visual IHC staining area under the curve (AUC) was 0.77 (95%CI 0.71-0.82), compared with 0.71 (95%CI 0.64-0.77) for p16-mRNA and 0.67 (95%CI 0.60-0.74) for Digital IHC. Spearman rank-order correlations were: visual to p16-mRNA 0.41, visual to digital 0.49 and p16-mRNA to digital: 0.22. The addition of p16-mRNA assay to visual reading of p16 IHC improved the AUC from 0.77 to 0.84 (p = 0.0049). p16-mRNA testing may be complementary to visual IHC p16 staining for a more accurate diagnosis of CIN, or perhaps a substitute in locations with a lack of skilled pathologists.

Methylation of HPV and a tumor suppressor gene reveals anal cancer and precursor lesions

We studied DNA methylation patterns of human papillomavirus (HPV) and tumor suppressor gene EPB41L3 in 148 anal and perianal biopsies to determine whether high levels of methylation would be associated with anal intraepithelial neoplasia (AIN). The most prevalent HPV type was HPV16, detected in 54% of the 30 benign biopsies, 33% of the 43 low-grade AIN (lgAIN), 82% of the 59 high grade AIN (hgAIN) and 4 of the 5 anal cancers. A methylation score was developed (0.561*HPV16me+0.439*EPB41L3) which had increasing values with severity of disease: the mean was 8.1% in benign, 13.2% in lgAIN, 22.3% in hgAIN and 49.3% in cancers (p < 0.0001). The methylation score as a triage classifier at a cut-off of 8.8 gave a sensitivity of 90.6% (95% CI: 82.8, 96.9), specificity of 50.7% (95% CI: 39.7, 61.6) and area under the curve of 0.82 (95% CI: 0.75-0.89) for separating hgAIN and cancer from benign and lgAIN biopsies. We conclude that methylation of HPV16 and EPB41L3 show highly significant association with increasing severity of AIN and cancer and may be useful as biomarkers in anal disease.

Virtues and Weaknesses of DNA Methylation as a Test for Cervical Cancer Prevention

Epigenetics is the study of heritable and non-heritable genetic coding that is additive to information contained within classical DNA base pair sequences. Differential methylation has a fundamental role in the development and outcome of malignancies, chronic and degenerative diseases and aging. DNA methylation can be measured accurately and easily via various molecular methods and has become a key technology for research and healthcare delivery, with immediate roles in the elucidation of disease natural history, diagnostics and drug discovery. This review focuses on cancers of the lower genital tract, for which the most epigenetic information exists. DNA methylation has been proposed as a triage for women infected with human papillomavirus (HPV) and may eventually directly complement or replace HPV screening as a one-step molecular diagnostic and prognostic test. Methylation of human genes is strongly associated with cervical intraepithelial neoplasia (CIN) and cancer. Of the more than 100 human methylation biomarker genes tested so far in cervical tissue, close to 20 have been reported in different studies, and approximately 10 have been repeatedly shown to have elevated methylation in cervical cancers and high-grade CIN (CIN2 and CIN3), most prominently CADM1, EPB41L3, FAM19A4, MAL, miR-124, PAX1 and SOX1. Obtaining consistent performance data from the literature is quite difficult because most methylation studies used a variety of different assay methodologies and had incomplete and/or biased clinical specimen sets, varying assay thresholds and disparate target gene regions. There have been relatively few validation studies of DNA methylation biomarkers in large population-based screening studies, but an encouraging development more recently is the execution of well-designed studies to test the true performance of the markers in real-world settings. Methylation of HPV genes, especially HPV16, HPV18, HPV31, HPV33 and HPV45, in disease progression has been a major focus of research. Elevated methylation of the HPV16 L1 and L2 open reading frames, in particular, is associated with CIN2, CIN3 and invasive cancer. Essentially all cancers have high levels of methylation for human genes and for driver HPV types, which suggests that quantitative methylation tests may have utility in predicting CIN2 and CIN3 that are likely to progress. It is still early in the process of development of methylation biomarkers, but already they are showing strong promise as a universal and systematic approach to molecular triage, applicable to all cancers, not just cancer of the cervix. DNA methylation testing is better than HPV genotyping triage and is competitive with or complementary to other approaches such as cytology and p16 staining. Genome-wide studies are underway to systematically expand methylation classifier panels and find the best combinations of biomarkers. Methylation testing is likely to show big improvements in performance in the next 5 years.

A novel DNA methylation score accurately predicts death from prostate cancer in men with low to intermediate clinical risk factors

Clinically aggressive disease behavior is difficult to predict in men with low to intermediate clinical risk prostate cancer and methylation biomarkers may be a valuable adjunct for assessing the management of these patients. We set to evaluate the utility of DNA methylation to identify high risk disease in men currently considered as low or intermediate risk. DNA was extracted from formalin-fixed paraffin-embedded transurethral prostate resection tissues collected during the years 1990-96 in a watchful-waiting cohort of men in the UK. The primary end point was death of prostate cancer, assessed by reviewing cancer registry records from 2009. Methylation was quantified by pyrosequencing assays for six genes (HSPB1, CCND2, TIG1, DPYS, PITX2, and MAL) with established biomarker value in prostate cancer. A novel prognostic methylation score was developed by multivariate Cox modelling using the six methylation biomarkers in 385 men with low-and-intermediate clinical risk variables and its prognostic value compared to two previously defined clinically-derived risk scores. Methylation score was the most significant variable in univariate and bivariate analysis in men with low-to-intermediate CAPRA risk score. When combined with CAPRA score the hazard ratio was 2.02; 95% confidence interval, 1.40-2.92. For a methylation score sensitivity of 83% the specificity was 44%, while the maximum achieved sensitivity by CAPRA was 68% at a specificity of 44%. The derived methylation score is a strong predictor of aggressive prostate cancer that could have an important role in directing the management of patients with low-to-intermediate risk disease. The estimated areas under the curve (AUC) at 10 years of follow-up were 0.62 (95% CI: 0.51, 0.70) and 0.74 (95% CI: 0.65, 0.82) for CAPRA, and combined (CAPRA + methylation) risk score (CRS) respectively.

Validation of a DNA methylation HPV triage classifier in a screening sample

High-risk human papillomavirus (hrHPV) DNA tests have excellent sensitivity for detection of cervical intraepithelial neoplasia 2 or higher (CIN2+). A drawback of hrHPV screening, however, is modest specificity. Therefore, hrHPV-positive women might need triage to reduce adverse events and costs associated with unnecessary colposcopy. We compared the performance of HPV16/18 genotyping with a predefined DNA methylation triage test (S5) based on target regions of the human gene EPB41L3, and viral late gene regions of HPV16, HPV18, HPV31 and HPV33. Assays were run using exfoliated cervical specimens from 710 women attending routine screening, of whom 38 were diagnosed with CIN2+ within a year after triage to colposcopy based on cytology and 341 were hrHPV positive. Sensitivity and specificity of the investigated triage methods were compared by McNemar's test. At the predefined cutoff, S5 showed better sensitivity than HPV16/18 genotyping (74% vs 54%, P = 0.04) in identifying CIN2+ in hrHPV-positive women, and similar specificity (65% vs 71%, P = 0.07). When the S5 cutoff was altered to allow equal sensitivity to that of genotyping, a significantly higher specificity of 91% was reached (P < 0.0001). Thus, a DNA methylation test for the triage of hrHPV-positive women on original screening specimens might be a valid approach with better performance than genotyping.

Methylation of viral and host genes and severity of cervical lesions associated with human papillomavirus type 16

Methylation of human papillomavirus (HPV) and host genes may predict cervical cancer risk. We examined the methylation status of selected sites in HPV16 and human genes in DNA extracted from exfoliated cervical cell samples of 244 women harboring HPV16-positive cancer or cervical intraepithelial neoplasia (CIN) or negative for intraepithelial lesions or malignancy (NILM). We quantified the methylation of CpG sites in the HPV16 L1 gene (CpG 6367 and 6389) and in the human genes EPB41L3 (CpG 438, 427, 425) and LMX1 (CpG 260, 262, 266, 274) following bisulfite treatment and pyrosequencing. Receiver operating characteristic (ROC) curves were used to analyze the diagnostic utility of methylation level for the different sites and for a joint predictor score. Methylation in all sites significantly increased with lesion severity (p < 0.0001). Area under the curve (AUC) was highest among the CIN2/3 vs. cancer ranging from 0.786 to 0.853 among the different sites. Site-specific methylation levels strongly discriminated CIN2/3 from NILM/CIN1 and cancer from CIN2/3 (range of odds ratios [OR]: 3.69-12.76, range of lower 95% confidence bounds: 1.03-4.01). When methylation levels were mutually adjusted for each other EPB41L3 was the only independent predictor of CIN2/3 vs. NILM/CIN1 contrasts (OR = 9.94, 95%CI: 2.46-40.27). High methylation levels of viral and host genes are common among precancerous and cancer lesions and can serve as independent risk biomarkers. Methylation of host genes LMX1 and EPB41L3 and of the viral HPV16 L1 sites has the potential to distinguish among precancerous lesions and to distinguish the latter from invasive disease.

HPV33 DNA methylation measurement improves cervical pre-cancer risk estimation of an HPV16, HPV18, HPV31 and \textit{EPB41L3} methylation classifier

BACKGROUND

Persistent infection %by with high risk human papillomavirus (hrHPV) types causes cervical cancer but most women who test positive are at very low risk of neoplasia. Strategies are needed which can retain high sensitivity of hrHPV testing but reduce the number of false-positives. We showed previously that a combination DNA methylation triage assay for HPV types 16, 18 and 31 and human gene EPB41L3 was useful to identify high grade cervical lesions.

OBJECTIVE

Assess whether measurement of DNA methylation in HPV type 33 can improve the previous classifier.

METHODS

A London colposcopy referral group of 1493 women of whom 556 (37%) had histologically-confirmed CIN (cervical intraepithelial neoplasia) 2 or 3 that included 114 HPV33 positive women with methylation measured for three L2 CpGs 5557, 5560 and 5566. Discrimination performance was assessed for the new classifier S5, built by adding HPV33 to the earlier classifier.

RESULTS

HPV33 methylation measurement improved prediction among HPV33 positive women. Receiver operating characteristic analyses showed an area under the curve (AUC) for HPV33 methylation of 0.68 (95% CI 0.57-0.78). The earlier risk score was significantly improved by HPV33 methytlation (AUC = 0.82 vs 0.80; P < 0.001). For 90% sensitivity the specificity for CIN2/3 was 49% (95% CI 46-52%).

CONCLUSIONS

Measurement of HPV33 DNA methylation contributes independent diagnostic information to EPB41L3 and HPV16, HPV18 and HPV31, and is superior to genotyping. Other HPV and human methylation target regions might be useful to further improve S5.

DNA methylation gene-based models indicating independent poor outcome in prostate cancer

BACKGROUND

Prostate cancer has a variable clinical behaviour with frequently unpredictable outcome. DNA methylation plays an important role in determining the biology of cancer but prognostic information is scanty. We assessed the potential of gene-specific DNA methylation changes to predict death from prostate cancer in a cohort of untreated men in the UK.

METHODS

This was a population-based study in which cases were identified from six cancer registries in Great Britain. DNA was extracted from formalin-fixed paraffin wax-embedded transurethral prostate resection tissues collected during 1990-96 from men with clinically-localised cancer who chose not to be treated for at least 6 months following diagnosis. The primary end point was death from prostate cancer. Outcomes were determined through medical records and cancer registry records. Pyrosequencing was used to quantify methylation in 13 candidate genes with established or suggested roles in cancer. Univariate and multivariate Cox models were used to identify possible predictors for prostate cancer-related death.

RESULTS

Of 367 men, 99 died from prostate cancer during a median of 9.5 years follow-up (max = 20). Univariately, 12 genes were significantly associated with prostate cancer mortality, hazard ratios ranged between 1.09 and 1.28 per decile increase in methylation. Stepwise Cox regression modelling suggested that the methylation of genes HSPB1, CCND2 and DPYS contributed objective prognostic information to Gleason score and PSA with respect to cancer-related death during follow-up (p = 0.006).

CONCLUSION

Methylation of 13 genes was analysed in 367 men with localised prostate cancer who were conservatively treated and stratified with respect to death from prostate cancer and those who survived or died of other causes. Of the 13 genes analysed, differential methylation of HSPB1, CCND2 and DPYS provided independent prognostic information. Assessment of gene-methylation may provide independent objective information that can be used to segregate prostate cancers at diagnosis into predicted behavioural groups.

Cancer diagnostic classifiers based on quantitative DNA methylation

Epigenetic change is part of the carcinogenic process and a deep reservoir for biomarker discovery. Reversible methylation of cytosines is noteworthy because it can be measured accurately and easily by various molecular methods and DNA methylation patterns are linked to important tumourigenic pathways. Clinically relevant methylation changes are known in common human cancers such as cervix, prostate, breast, colon, bladder, stomach and lung. Differential methylation may have a central role in the development and outcome of most if not all human malignancies. The advent of deep sequencing holds great promise for epigenomics, with bioinformatics tools ready to reveal large numbers of new targets for prognosis and therapeutic intervention. This review focuses on two selected cancers, namely cervix and prostate, which illustrate the more general themes of epigenetic diagnostics in cancer. Also discussed is differential methylation of specific human and viral DNA targets and laboratory methods for measuring methylation biomarkers.

Identification of ZDHHC14 as a novel human tumour suppressor gene

Genomic changes affecting tumour suppressor genes are fundamental to cancer. We applied SNP array analysis to a panel of testicular germ cell tumours to search for novel tumour suppressor genes and identified a frequent small deletion on 6q25.3 affecting just one gene, ZDHHC14. The expression of ZDHHC14, a putative protein palmitoyltransferase with unknown cellular function, was decreased at both RNA and protein levels in testicular germ cell tumours. ZDHHC14 expression was also significantly decreased in a panel of prostate cancer samples and cell lines. In addition to our findings of genetic and protein expression changes in clinical samples, inducible overexpression of ZDHHC14 led to reduced cell viability and increased apoptosis through the classic caspase-dependent apoptotic pathway and heterozygous knockout of ZDHHC14 increased [CORRECTED] cell colony formation ability. Finally, we confirmed our in vitro findings of the tumour suppressor role of ZDHHC14 in a mouse xenograft model, showing that overexpression of ZDHHC14 inhibits tumourigenesis. Thus, we have identified a novel tumour suppressor gene that is commonly down-regulated in testicular germ cell tumours and prostate cancer, as well as given insight into the cellular functional role of ZDHHC14, a potential protein palmitoyltransferase that may play a key protective role in cancer.

A DNA methylation classifier of cervical precancer based on human papillomavirus and human genes

Testing for high-risk (hr) types of human papillomavirus (HPV) is highly sensitive as a screening test of high-grade cervical intraepithelial neoplastic (CIN2/3) disease, the precursor of cervical cancer. However, it has a relatively low specificity. Our objective was to develop a prediction rule with a higher specificity, using combinations of human and HPV DNA methylation. Exfoliated cervical specimens from colposcopy-referral cohorts in London were analyzed for DNA methylation levels by pyrosequencing in the L1 and L2 regions of HPV16, HPV18, HPV31 and human genes EPB41L3, DPYS and MAL. Samples from 1,493 hrHPV-positive women were assessed and of these 556 were found to have CIN2/3 at biopsy; 556 tested positive for HPV16 (323 CIN2/3), 201 for HPV18 (73 CIN2/3) and 202 for HPV31 (98 CIN2/3). The prediction rule included EPB41L3 and HPV and had area under curve 0.80 (95% CI 0.78-0.82). For 90% sensitivity, specificity was 36% (33-40) and positive predictive value (PPV) was 46% (43-48). By HPV type, 90% sensitivity corresponded to the following specificities and PPV, respectively: HPV16, 38% (32-45) and 67% (63-71); HPV18, 53% (45-62) and 52% (45-59); HPV31, 39% (31-49) and 58% (51-65); HPV16, 18 or 31, 44% (40-49) and 62% (59-65) and other hrHPV 17% (14-21) and 21% (18-24). We conclude that a methylation assay in hrHPV-positive women might improve PPV with minimal sensitivity loss.

DNA methylation of PITX2 predicts poor survival in men with prostate cancer

AIM

We investigated if methylation of candidate genes can be useful for predicting prostate cancer (PCa) specific death.

PATIENTS & METHODS

Methylation of PITX2, WNT5a, SPARC, EPB41L3 and TPM4 was investigated in a 1:2 case-control cohort comprising 45 men with cancer of Gleason score ≤ 7 who died (cases), and 90 men who were alive or died of other causes with survival time longer than the cases (controls). A univariate conditional logistic regression model was fitted by maximizing the likelihood of DNA methylation of each gene versus the primary end point.

RESULTS

A 10% increase in methylation of PITX2 was associated with PCa related death with OR 1.56 (95% CI: 1.17-2.08; p = 0.005).

CONCLUSION

Our study strengthens prior findings that PITX2 methylation is useful as a biomarker of poor outcome of PCa and in addition we also suggest that it may be particularly useful in men with low Gleason score.

New technologies and procedures for cervical cancer screening

The clearly higher sensitivity and reproducibility of human papillomavirus (HPV) DNA testing for high-grade cervical intraepithelial neoplasia (CIN) has led to widespread calls to introduce it as the primary screening test. The main concern has been its lower specificity, due to the fact that it cannot separate transient from persistent infections, and only the latter are associated with an increased risk of high-grade CIN and cancer. Thus, even proponents of HPV testing generally only recommend it for women over the age of 30 years (or in some cases 35 years). If HPV testing is to reach its full potential, new approaches with better specificity are needed, either as triage tests for HPV positive women or, if the high sensitivity of HPV DNA testing can be maintained, as alternate primary screening modalities. Approaches that may useful in this regard, especially as triage tests, include HPV typing, methylation (and consequent silencing) of host and viral genes, and new cytologic methods, such as p16(INK4a) staining, which attempt to identify proliferating cells. At an earlier stage of development are direct methods based on detection of HPV E6 or E7 proteins. Recent progress and current status of these methods is discussed in this chapter. The current status of visual inspection (VIA and VILI) methods is also surveyed and progress on self-sampling is reviewed. This article forms part of a special supplement entitled "Comprehensive Control of HPV Infections and Related Diseases" Vaccine Volume 30, Supplement 5, 2012.

HPV16 L1 and L2 DNA methylation predicts high-grade cervical intraepithelial neoplasia in women with mildly abnormal cervical cytology

DNA methylation changes in human papillomavirus type 16 (HPV16) DNA are common and might be important for identifying women at increased risk of cervical cancer. Using recently published data from Costa Rica we developed a classification score to differentiate women with cervical intraepithelial neoplasia grade 2 or 3 (CIN2/3) from those with no evident high-grade lesions. Here, we aim to investigate the performance of the score using data from the UK. Exfoliated cervical cells at baseline and 6-months follow-up were analyzed in 84 women selected from a randomized clinical trial of women undergoing surveillance for low-grade cytology. Selection of women for the methylation study was based on detectable HPV16 in the baseline sample. Purified DNA was bisulfite converted, amplified and pyrosequenced at selected CpG sites in the viral genome (URR, E6, L1 and L2), with blinding of laboratory personnel to the clinical data. The primary measure was a predefined score combining the mean methylation in L1 and any methylation in L2. At the second follow-up visit, 73/84 (87%) women were HPV16 positive and of these 25 had a histopathological diagnosis of CIN2/3. The score was significantly associated with CIN2/3 (area under curve = 0.74, p = 0.002). For a cutoff with 92% sensitivity, colposcopy could have been avoided in 40% (95% CI 27–54%) of HPV16 positive women without CIN2/3; positive predictive value was 44% (32–58%) and negative predictive value was 90% (71–97%). We conclude that quantitative DNA methylation assays could help to improve triage among HPV16 positive women.

Quantitative DNA methylation and recurrence of breast cancer: a study of 30 candidate genes

BACKGROUND

The need for new prognostic factors in breast cancer is ever increasing as breast cancer management evolves. Aberrant DNA methylation plays a pivotal role in cancer development and progression; DNA methylation-based biomarkers may provide independent prognostic information. We used pyrosequencing to investigate the prognostic potential of quantitative DNA methylation of a large set of candidate genes in a Korean single-institution series of operable breast cancer.

METHODS

Absolute DNA methylation in 20 candidate genes from an initial set of 30 genes was measured by pyrosequencing of bisulfite converted DNA in 121 fresh frozen breast cancer cases. Survival analyses used continuous and categorized (quintile-based) gene methylation data with time to recurrence (TTR) as an endpoint. Prognostic abilities of gene-only and risk-score models were explored.

RESULTS

Median follow-up was 5.1 years; 25 recurrences (21%) were observed. Nodal status, methylation of TWIST1, SLIT2 (both as continuous and categorized variables) and APC, HLA-A, NKX2-5, SERPINB5, SFN (as categorized variables) were significantly prognostic; grade showed a prognostic trend. A multivariate model containing nodal status, grade and TWIST1 was a best fit (p< 0.001) in stepwise regression; risk-score based on this model separated patients into 3 distinct risk-groups (p< 0.001). A gene-only model based on TWIST1 and SFN also classified patients into distinct risk-groups (p=0.009).

CONCLUSIONS

This study shows that accurate quantitative measurement of DNA methylation by pyrosequencing identifies a small set of genes with independent prognostic potential in breast cancer. These genes complement the current clinico-pathological prognostic factors and appear to be potential biomarkers that warrant further validation.

Methylation of HPV18, HPV31, and HPV45 genomes and cervical intraepithelial neoplasia grade 3

BACKGROUND

Persistent infections with carcinogenic human papillomavirus (HPV) types are the necessary cause of cervical cancer. We recently demonstrated that the HPV16 genome is strongly methylated in cervical precancer compared with transient infections. However, the extent of methylation in other HPV types and its role in progression to cancer is poorly understood.

METHODS

We analyzed whole-genome methylation patterns of the three next most carcinogenic HPV genotypes: HPV31 (closely related to HPV16), and two other closely related types, HPV18 and HPV45. DNA was extracted from cervical cytology specimens from 92 women with precancer and 96 women infected with HPV31, HPV18, or HPV45, but who had no cytological or histological abnormalities. After bisulfite modification, genome-wide pyrosequencing was performed covering 80-106 sites. We calculated differences in median methylation, odds ratios, areas under the curve, and Spearman rank correlation coefficients for methylation levels between different sites. All statistical tests were two-sided.

RESULTS

For all three HPV types, we observed strongly elevated methylation levels at multiple CpG sites in the E2, L2, and L1 regions among women with cervical intraepithelial neoplasia grade 3 compared with women with transient infections. We observed high correlation of methylation patterns between phylogenetically related types. The highest areas under the curve were 0.81 for HPV31, 0.85 for HPV18, and 0.98 for HPV45. Differential methylation patterns in cervical intraepithelial neoplasia grade 3 patients with multiple infections suggest that methylation can clarify which of the infections is causal.

CONCLUSIONS

Carcinogenic HPV DNA methylation indicates transforming HPV infections. Our findings show that methylation of carcinogenic HPV types is a general phenomenon that warrants development of diagnostic assays.

Clinical human papillomavirus detection forecasts cervical cancer risk in women over 18 years of follow-up

PURPOSE

To describe the long-term (≥ 10 years) benefits of clinical human papillomavirus (HPV) DNA testing for cervical precancer and cancer risk prediction.

METHODS

Cervicovaginal lavages collected from 19,512 women attending a health maintenance program were retrospectively tested for HPV using a clinical test. HPV positives were tested for HPV16 and HPV18 individually using a research test. A Papanicolaou (Pap) result classified as atypical squamous cells of undetermined significance (ASC-US) or more severe was considered abnormal. Women underwent follow-up prospectively with routine annual Pap testing up to 18 years. Cumulative incidence rates (CIRs) of ≥ grade 3 cervical intraepithelial neoplasia (CIN3+) or cancer for enrollment test results were calculated.

RESULTS

A baseline negative HPV test provided greater reassurance against CIN3+ over the 18-year follow-up than a normal Pap (CIR, 0.90% v 1.27%). Although both baseline Pap and HPV tests predicted who would develop CIN3+ within the first 2 years of follow-up, only HPV testing predicted who would develop CIN3+ 10 to 18 years later (P = .004). HPV16- and HPV18-positive women with normal Pap were at elevated risk of CIN3+ compared with other HPV-positive women with normal Pap and were at similar risk of CIN3+ compared with women with a low-grade squamous intraepithelial Pap.

CONCLUSION

HPV testing to rule out cervical disease followed by Pap testing and possibly combined with the detection of HPV16 and HPV18 among HPV positives to identify those at immediate risk of CIN3+ would be an efficient algorithm for cervical cancer screening, especially in women age 30 years or older.

Elevated methylation of HPV16 DNA is associated with the development of high grade cervical intraepithelial neoplasia

We explored the association of human papillomavirus type 16 (HPV16) DNA methylation with age, viral load, viral persistence and risk of incident and prevalent high grade CIN (CIN2+) in serially collected specimens from the Guanacaste, Costa Rica cohort. 273 exfoliated cervical cell specimens (diagnostic and pre-diagnostic) were selected: (1) 92 with HPV16 DNA clearance (controls), (2) 72 with HPV16 DNA persistence (without CIN2+) and (3) 109 with CIN2+. DNA was extracted, bisulfite converted and methylation was quantified using pyrosequencing assays at 66 CpGs across the HPV genome. The Kruskal-Wallis test was used to determine significant differences among groups, and receiver operating characteristic curve analyses were used to evaluate how well methylation identified women with CIN2+. In diagnostic specimens, 88% of CpG sites had significantly higher methylation levels in CIN2+ after correction for multiple tests compared with controls. The highest area under the ROC curve (AUC) was 0.82 for CpG site 6457 in L1, and a diagnostic sensitivity of 91% corresponded to a specificity of 60% for CIN2+. Prospectively, 17% of CpG sites had significantly higher methylation in pre-diagnostic CIN2+ specimens (median time of 3 years before diagnosis) versus controls. The strongest pre-diagnostic CpG site was 6367 in L1 with an AUC of 0.76. Age-stratified analyses suggested that women older than the median age of 28 years have an increased risk of precancer associated with high methylation. Higher methylation in CIN2+ cases was not explained by higher viral load. We conclude that elevated levels of HPV16 DNA methylation may be useful to predict concurrently diagnosed as well as future CIN2+.

Absolute quantitation of DNA methylation of 28 candidate genes in prostate cancer using pyrosequencing

Aberrant DNA methylation plays a pivotal role in carcinogenesis and its mapping is likely to provide biomarkers for improved diagnostic and risk assessment in prostate cancer (PCa). We quantified and compared absolute methylation levels among 28 candidate genes in 48 PCa and 29 benign prostate hyperplasia (BPH) samples using the pyrosequencing (PSQ) method to identify genes with diagnostic and prognostic potential.

RARB, HIN1, BCL2, GSTP1, CCND2, EGFR5, APC, RASSF1A, MDR1, NKX2-5, CDH13, DPYS, PTGS2, EDNRB, MAL, PDLIM4, HLAa, ESR1 and TIG1 were highly methylated in PCa compared to BPH (p < 0.001), while SERPINB5, CDH1, TWIST1, DAPK1, THRB, MCAM, SLIT2, CDKN2a and SFN were not. RARB methylation above 21% completely distinguished PCa from BPH. Separation based on methylation level of SFN, SLIT2 and SERPINB5 distinguished low and high Gleason score cancers, e.g. SFN and SERPINB5 together correctly classified 81% and 77% of high and low Gleason score cancers respectively. Several genes including CDH1 previously reported as methylation markers in PCa were not confirmed in our study. Increasing age was positively associated with gene methylation (p < 0.0001).

Accurate quantitative measurement of gene methylation in PCa appears promising and further validation of genes like RARB, HIN1, BCL2, APC and GSTP1 is warranted for diagnostic potential and SFN, SLIT2 and SERPINB5 for prognostic potential.

The Promise and the Problems of Epigenetics Biomarkers in Cancer

Epigenetics plays an important role in tissue differentiation and phenotypic changes are associated with extensive modifications in epigenetic patterns such as DNA methylation (DNAme), histone methylation and acetylation marks, and micro RNAs. From a diagnostic perspective, DNAme is one of the more tractable epigenetic changes; differentially affecting a large number of genes. Variations can be measured accurately, on any given set of CG sites, by sequencing bisulfite converted DNA. The promise of DNAme is that biomarkers can be found in every kind of gene from rare unstable cell-cycle enzymes to highly expressed structural proteins. Almost any kind of biological specimen is amenable and the changes can be measured in tissue biopsies, scrapes, aspirates, urine, blood and other fluids. To date, hundreds of differentially methylated genes have been identified in cancer that can potentially function as biomarkers. The most common kind of change, studied, is CpG island methylation of tumor suppressor genes that modifies transcription. Despite a great many candidates, few of the DNAme markers have been adequately validated for routine clinical use. Important current limitations of epigenetic biomarkers are that assays are diverse; gene lists are large; comparative data are few, and disagreements in published papers are frequent.

A long-term prospective study of type-specific human papillomavirus infection and risk of cervical neoplasia among 20,000 women in the Portland Kaiser Cohort Study

BACKGROUND

Human papillomavirus (HPV) DNA testing is more sensitive than cytology for detection of cervical intraepithelial neoplasia grade 3 and cancer (≥CIN3). Adding HPV testing to cytology is recommended for women ≥30 but long-term prospective studies of HPV testing are rare.

METHODS

Beginning in 1989-1990, ~20,000 women in a prepaid health maintenance organization (median age = 34) were followed passively by recommended annual cytology. We tested archived cervicovaginal lavage specimens collected at enrollment, primarily by MY09-MY11 PCR-based methods, for carcinogenic HPV types. We calculated positive and negative predictive values for the entire study period, and Kaplan-Meier estimates of cumulative probability for ≥CIN3, up to 18 years of follow-up.

RESULTS

We observed 47 cases of invasive cervical cancer during the study period, and 156 cases of CIN3. Predictive values and Kaplan-Meier analyses yielded the same conclusions. In women 30 and older, the reassurance against ≥CIN3 following a single negative HPV test was long-lasting (cumulative probability = 0.7% during follow-up). In this age group, a single HPV test (positive vs. negative, hazard ratio of 8.5, 95% CI = 4.8-15.1) provided greater long-term risk stratification than a single cytologic result (abnormal vs. normal, HR = 2.9, 95% CI = 1.2-6.6). The risk for ≥CIN3 was higher for HPV16 than for the average of the other carcinogenic types (hazard ratio = 2.7).

CONCLUSION AND IMPACT

The data from this cohort study show the long-term predictive value of HPV testing, particularly in women ≥30, and a possible role for distinguishing particularly carcinogenic types like HPV16.

Mouthwash as a low-cost and safe specimen transport medium for human papillomavirus DNA testing of cervicovaginal specimens

The usefulness of mouthwash as a transport medium for cervical specimens for carcinogenic human papillomavirus (HPV) DNA testing has not been evaluated. Two cervical specimens were collected from each of 34 patients, with one placed in mouthwash (Scope, Proctor and Gamble, Inc.) and the other in a liquid cytology medium commonly used for HPV DNA testing in alternating order. Paired specimens were tested by a PCR assay for carcinogenic HPV and a PCR HPV genotyping assay for 37 HPV types at 0, 3, and 6 weeks after collection; the results of the HPV genotyping assay were categorized into HPV risk groups according to cancer risk (HPV-16 > HPV-18 > other carcinogenic HPV types > noncarcinogenic HPV types > negative). After 4 months of storage, specimens were tested using a second, non-PCR test for carcinogenic HPV. We observed a >or=94% total agreement and kappa values of >or=0.88 between media at each time point for PCR-detected carcinogenic HPV. We observed a >or=74% total agreement, >or=0.62 unweighted kappa, and >or=0.75 linearly weighted kappa between media at each time point for PCR-detected HPV cancer risk category. Finally, we observed an 88% total agreement and kappa of 0.77 between media for carcinogenic HPV detection using a second test after 4 months of storage. We suggest that mouthwash might be used as a low-cost, safe, nonflammable storage and transport medium for cervical specimens for HPV DNA testing in cervical cancer screening programs.

Cross-sectional comparison of an automated hybrid capture 2 assay and the consensus GP5+/6+ PCR method in a population-based cervical screening program

In this cross-sectional study, clinical performances of the hybrid capture 2 assay using an automated instrument (i.e., rapid capture system) (hc2-RCS) and the high-risk human papillomavirus GP5+/6+ PCR-enzyme immunoassay (EIA) test were compared using cervical scrape specimens from 8,132 women that participated in a population-based screening trial. The hc2-RCS test scored significantly more samples positive (6.8%) than the GP5+/6+ PCR-EIA (4.8%) (P < 0.0005). This could be attributed largely to a higher positivity rate by the hc2-RCS test for women with cytologically normal, borderline, or mild dyskaryosis. A receiver operator characteristics analysis of the semiquantitative hc2-RCS results in relation to different cytology categories revealed that these differences are owing to differences in assay thresholds. For women classified as having moderate dyskaryosis or worse who also had underlying histologically confirmed cervical intraepithelial neoplasia grade 3 or cervical cancer (> or =CIN3), the hc2-RCS scored 97% (31/32) of samples positive, versus 91% (29/32) by GP5+/6+ PCR-EIA. However, this difference was not significant (P = 0.25). After increasing the hc2-RCS cutoff from 1.0 to 2.0 relative light units/cutoff value of the HPV16 calibrator (RLU/CO), no additional CIN3 lesions were missed by hc2-RCS, but the number of test-positive women with normal, borderline, or mild dyskaryosis was significantly decreased (P < 0.0005). However, at this RLU/CO, the difference in test positivity between hc2-RCS and the GP5+/6+ PCR-EIA was still significant (P = 0.02). The use of an RLU/CO value of 3.0 revealed no significant difference between hc2-RCS and GP5+/6+ PCR-EIA results, and equal numbers of smears classified as > or =CIN3 (i.e., 29/32) were detected by both methods. In summary, both assays perform very well for the detection of >or =CIN3 in a population-based cervical screening setting. However, adjustment of the hc2-RCS threshold to an RLU/CO value of 2.0 or 3.0 seems to produce an improved balance between the clinical sensitivity and specificity for > or =CIN3 in population-based cervical screening.

Cervical HPV DNA detection as a predictor of a recurrent SIL diagnosis among untreated women

OBJECTIVES

This study was conducted to test whether patient history of untreated cervical intraepithelial neoplasia (CIN) 1 or low-grade squamous intraepithelial lesions (LGSIL) modifies the interpretation of a positive HPV DNA result with regards to subsequent squamous intraepithelial lesions (SIL).

METHODS

Seventy-three women with recurrent SIL were compared to 105 controls who remain cytologically normal during follow up. Cervical samples collected at enrollment were assayed for HPV DNA in the subject and control groups.

RESULTS

Women with and without a history of LGSIL who tested positive for HPV DNA were at a similarly increased risk of having (recurrent) LGSIL as compared to controls. However, in women with a history of LGSIL, HPV DNA appeared to be less predictive for high-grade squamous intraepithelial lesions (HGSIL) than in women without a history of disease.

CONCLUSIONS

Past history of untreated CIN1 or LGSIL does not modify the predictive value of a positive HPV DNA test for subsequent LGSIL. The observed difference of the predictive value of a positive HPV DNA test for the risk of recurrent HSIL compared to incident HSIL should be pursued.

The elevated 10-year risk of cervical precancer and cancer in women with human papillomavirus (HPV) type 16 or 18 and the possible utility of type-specific HPV testing in clinical practice

BACKGROUND

Human papillomavirus (HPV) types 16 and 18 cause 60%-70% of cervical cancer worldwide, and other HPV types cause virtually all remaining cases. Pooled HPV testing for 13 oncogenic types, including HPV16 and 18, is currently used in clinical practice for triage of equivocal cytology and, in conjunction with Pap tests, is an option for general screening among women 30 years of age and older. It is not clear to what extent individual identification of HPV16 or HPV18 as an adjunct to pooled oncogenic HPV testing might effectively identify women at particularly high risk of cervical cancer or its immediate precursor, cervical intraepithelial neoplasia 3 (CIN3).

METHODS

From April 1, 1989, to November 2, 1990, a total of 20 810 women in the Kaiser Permanente health plan in Portland, OR, enrolled in a cohort study of HPV and cervical neoplasia. Women were tested for 13 oncogenic HPV types by Hybrid Capture 2 (HC2), and those women with a positive HC2 test were tested for HPV16 and 18. Enrollment Pap smear interpretation and HPV test results were linked to histologically confirmed CIN3 and cervical cancer (> or = CIN3) occurring during 10 years of cytologic follow-up. We calculated cumulative incidence rates with 95% confidence intervals for each interval up to 122 months using Kaplan-Meier methods.

RESULTS

The 10-year cumulative incidence rates of > or = CIN3 were 17.2% (95% confidence interval [CI] = 11.5% to 22.9%) among HPV16+ women and 13.6% (95% CI = 3.6% to 23.7%) among HPV18+ (HPV16-) women, but only 3.0% (95% CI = 1.9% to 4.2%) among HC2+ women negative for HPV16 or HPV18. The 10-year cumulative incidence among HC2- women was 0.8% (95% CI = 0.6% to 1.1%). A subanalysis among women 30 years of age and older with normal cytology at enrollment strengthened the observed risk differences.

CONCLUSIONS

HPV screening that distinguishes HPV16 and HPV18 from other oncogenic HPV types may identify women at the greatest risk of > or = CIN3 and may permit less aggressive management of other women with oncogenic HPV infections.

Semiquantitative Human Papillomavirus Type 16 Viral Load and the Prospective Risk of Cervical Precancer and Cancer

We examined whether higher human papillomavirus type 16 (HPV16) viral load predicted risk of cervical intraepithelial neoplasia 3 (CIN3) or cancer (together termed > or =CIN3) within a cohort of 20,810 women followed for 10 years with cytologic screening. Semiquantitative viral load for HPV16 was measured on baseline cervicovaginal specimens using a type-specific hybridization probe test with signal amplification. An increased risk of > or =CIN3 associated with higher HPV16 viral load was found only among cytologically negative women in early follow-up, suggesting that these cases were related to the detection of prevalent lesions missed at baseline. Women with higher HPV16 viral load were more likely to undergo ablative treatment during follow-up than those with lower viral load (P(trend) = 0.008), possibly diminishing any additional risk for > or =CIN3 attributable to higher HPV16 viral loads.

A novel filtration-based processing method of liquid cytology specimens for human papillomavirus DNA testing by hybrid capture II

We evaluated a more efficient method of processing liquid-based cervical cytology specimens for human papillomavirus (HPV) DNA testing by Hybrid Capture II (HCII). Aliquots were made from 701 specimens in the following sequence: 4.0, 2.0, 1.0, 0.5, and 1.5 mL. The 4.0-mL aliquot was processed by the standard method (STP), and half of the processed material was tested by HCII. Other aliquots were processed with a new, filtration-based processing method (NPM). The 2.0-mL NPM aliquot had HCII test performance most similar to the STP, ie, similar HCII positivity (P = .4) and good test agreement (kappa = 0.85, 95% confidence interval [CI], 0.80-0.89). The 194 cytologic negatives had greater positivity by STP (P = .04) compared with the 2.0-mL aliquot processed by NPM; between-method agreement was modest (kappa = 0.54, 95% CI, 0.36-0.72). A lower positive cut point for the 2.0-mL NPM aliquot partially abrogated this minor difference. In 241 specimens diagnosed as low-grade and 31 as high-grade squamous intraepithelial lesions, there were no significant differences in HPVpositivity (>85% and 90%, respectively) between STP and NPM. NPM reduces specimen handling and decreases total testing time by approximately 33% without significant losses in HCII test performance.

Adjunctive human papillomavirus testing in the 2-year follow-up of women with low-grade cervical cytologic abnormalities: a randomized trial and economic evaluation

CONTEXT

Although human papillomavirus (HPV) testing may aid in managing low-grade abnormality on screening cervical cytology, patient compliance with repeat testing programs requires consideration.

OBJECTIVES

To determine effectiveness and costs of repeated Papanicolaou (Pap) test and oncogenic HPV testing for detecting cervical intraepithelial neoplasia 2 or 3.

DESIGN

We conducted a randomized controlled trial of combined Pap test and cervical HPV testing by Hybrid Capture 1 test compared with Pap test alone; tests were performed every 6 months for up to 2 years. The study end point was colposcopic examination performed on all women at 2 years, or earlier if an HPV test was positive or if a Pap test showed high-grade squamous intraepithelial lesion.

SETTING

Sixty-six community family practices.

PARTICIPANTS

Two hundred fifty-seven women with atypical squamous cells of undetermined significance or low-grade squamous intraepithelial lesion on screening cervical cytology.

MAIN OUTCOME MEASURES

Detection of histologically confirmed cervical intraepithelial neoplasia 2 or 3, fully allocated costs, and loss to follow-up.

RESULTS

Combined Pap test and HPV testing detected 11 (100%) of 11 cases of cervical intraepithelial neoplasia 2/3, whereas Pap test alone detected 7 (63.6%) of these 11 cases (P =.14); corresponding specificities were 39 (46.4%) of 84 and 45 (71.4%) of 63 (P =.005). The cost-effectiveness ratio was Can $4456 per additional case of high-grade cervical intraepithelial neoplasia. Sixty-nine (26.8%) of the 257 women (24.6% combined group vs 29.1% Pap test only group, P =.41) defaulted from testing or from colposcopy when referred with an abnormal result.

CONCLUSIONS

Combined testing was more costly but may detect more cases of cervical intraepithelial neoplasia 2/3 than Pap test alone. However, poor adherence limits usefulness of a management strategy that requires repeated follow-up.

Comparison between prototype hybrid capture 3 and hybrid capture 2 human papillomavirus DNA assays for detection of high-grade cervical intraepithelial neoplasia and cancer

We compared the performance of a prototype version of the Hybrid Capture 3 (HC3) human papillomavirus (HPV) DNA assay to the current generation Hybrid Capture 2 (HC2) assay, both of which target 13 oncogenic HPV types, for the detection of cervical intraepithelial neoplasia grade 3 and cancer (CIN3+) with cervicovaginal lavage specimens collected at enrollment into a 10-year cohort study at Kaiser Permanente (Portland, Oreg.). HC3 results for a risk-stratified sample (n = 4,364) were compared to HC2 results for the entire cohort (n = 20,810) with receiver operating characteristics curves, and the optimal cut points for both tests (relative light units [RLU]/positive control [PC]) for the detection of CIN3+ were determined. Specimens were also tested for HPV16 and HPV18 with separate HC3 type-specific probes. The optimal cut point for detecting CIN3+ was 1.0 RLU/PC for HC2, as previously shown, and was 0.6 RLU/PC for HC3. At the optimal cut points, HC3 and HC2 had similar screening performance characteristics for CIN3+ diagnosed at the enrollment visit. In analyses that included cases CIN3+ at enrollment and those diagnosed during early follow-up, HC3 had nonsignificantly higher sensitivity and equal specificity for the detection of CIN3+ compared to HC2; this increase in sensitivity was primarily the result of increased detection of CIN3+ in women who were 30 years of age or older and were cytologically negative (P = 0.006). We also compared the performance of the hybrid capture tests to MY09/11 L1 consensus primer PCR results (n = 1,247). HC3 was less likely than HC2 to test positive for specimens that tested positive by PCR for any untargeted types (P < 0.001). HC3 was less likely than HC2 to test positive for untargeted PCR-detected single infections with HPV53 (P = 0.001) and HPV66 (P = 0.01). There was good agreement between test positivity by PCR and by single type-specific HC3 probes for HPV16 (kappa = 0.76; 95% confidence interval [CI] = 0.71 to 0.82) and for HPV18 (kappa = 0.73; 95% CI = 0.68 to 0.79). In conclusion, we suggest that HC3 (>/=0.6 RLU/PC) may be slightly more sensitive than and equally specific test as HC2 (>/=1.0 RLU/PC) for the detection of CIN3+ over the duration of typical screening intervals.

Epidemiologic correlates of antibody response to human papillomavirus among women at low risk of cervical cancer

A population at low risk for developing cervical cancer in Southern Brazil was studied to identify the main determinants of serological response to human papillomavirus (HPV). Enzyme-linked immunosorbent assay tests were performed in 976 women to detect serum IgG antibodies against HPV 16 L1 virus-like particles (VLPs) and HPVs 16, 18, 6 and 11 L1 VLPs as a mixture of antigens. Women with four or more sexual partners were more likely to be seropositive than women with one partner (HPV 16 serology odds ratio [OR]=3.06, 95% confidence interval [CI]: 2.0-4.8; HPV 6/11/16/18 serology OR=4.64, 95% CI: 3.0-7.2). HPV DNA and both serological responses were associated. Those positives to HPV 16 serology were twice as likely to have a cytological diagnosis of squamous intraepithelial lesions (SILs) than seronegatives (OR=2.07; 95% CI: 1.0-4.5, and OR=1.73; 95% CI: 0.8-3.8). Seropositivity to HPV 16 and HPV 6/11/16/18 antigens seem to be better markers of past sexual activity than current HPV infection, and humoral response to HPV 16 or HPV 6/11/16/18 may not be a strong indicator of cervical lesions in populations at low risk for cervical lesions.

Baseline cytology, human papillomavirus testing, and risk for cervical neoplasia: a 10-year cohort analysis

BACKGROUND

Annual Pap smear screening has been favored over less frequent screening in the United States to minimize the risk of cervical cancer. We evaluated whether simultaneous screening with a Pap test and human papillomavirus (HPV) testing is useful for assessing the risk for cervical intraepithelial neoplasia (CIN) 3 or cervical cancer.

METHODS

We enrolled 23 702 subjects in a study of HPV infection at Kaiser Permanente, Northwest Division, Portland, OR. Data were analyzed for 20 810 volunteers who were at least 16 years old (mean = 35.9 years) with satisfactory baseline Pap tests and suitable samples for HPV testing. Women were followed for up to 122 months (from April 1, 1989, to June 30, 1999) to determine the risk for histopathologically confirmed CIN3 or cancer.

RESULTS

Among 171 women with CIN3 or cancer diagnosed over 122 months, 123 (71.9%, 95% confidence interval [CI] = 65.2% to 78.7%) had baseline Pap results of atypical squamous cells or worse and/or a positive HPV test, including 102 (86.4%, 95% CI = 80.3% to 92.6%) of the 118 cases diagnosed within the first 45 months of follow-up. During this 45-month period, the cumulative incidence of CIN3 or cancer was 4.54% (95% CI = 3.61% to 5.46%) among women with a Pap test result of atypical squamous cells or worse, positive HPV tests, or both compared with 0.16% (95% CI = 0.08% to 0.24%) among women with negative Pap and HPV tests. Age, screening behavior, a history of cervical cancer precursors, and a history of treatment for CIN minimally affected results.

CONCLUSIONS

Negative baseline Pap and HPV tests were associated with a low risk for CIN3 or cancer in the subsequent 45 months, largely because a negative HPV test was associated with a decreased risk of cervical neoplasia. Negative combined test results should provide added reassurance for lengthening the screening interval among low-risk women, whereas positive results identify a relatively small subgroup that requires more frequent surveillance.

Absolute risk of a subsequent abnormal pap among oncogenic human papillomavirus DNA-positive, cytologically negative women

BACKGROUND

The addition of human papillomavirus (HPV) DNA testing to cytologic screening for cervical carcinoma is now being considered. The majority of women in screening cohorts who test positive for oncogenic types of HPV DNA have concurrent negative Pap tests. The absolute risk of a subsequent abnormal Pap test for these women is uncertain. Therefore, the proper counseling and clinical management of these women is also uncertain.

METHODS

A subcohort of 2020 women with a negative Pap test who tested positive at enrollment for oncogenic HPV DNA types using the Hybrid Capture 2 Test were followed for 57 months at Kaiser Permanente (Portland, OR). Absolute risks of new abnormal cytologic interpretations were computed using Kaplan-Meier methods. Logistic regression models were used to evaluate determinants of a new abnormal Pap test.

RESULTS

The cumulative incidence for a Pap test interpreted as atypical squamous cells or more severe (>or= ASC) was 16.8% (95% confidence interval [CI] = 15.0-18.6%), 6.4% (95% CI = 5.2-7.6%) for low-grade squamous intraepithelial lesions or more severe, and 2.2% (95% CI = 1.5-2.9%) for high-grade squamous intraepithelial lesions or more severe. By comparison, the cumulative incidence of greater than or equal to ASC among HPV-negative women was 4.2% (95% CI = 3.9-4.6%). The highest viral load (100 relative light units per the positive control or greater) was associated with a greater risk of an abnormal Pap test (odds ratio= 2.7, 95% CI = 1.7-4.1) than lower viral loads.

CONCLUSIONS

These results suggest that about 15% of women in annual screening programs who concurrently have a negative Pap test and a positive oncogenic HPV test will have a subsequent abnormal Pap test within 5 years. This risk estimate will be useful to the many clinicians and patients likely to be diagnosed with an HPV infection and negative cytology if HPV DNA is added to general screening.

A prospective study of high-grade cervical neoplasia risk among human papillomavirus-infected women

BACKGROUND

In case-control studies, smoking, parity, and oral contraceptive use have been associated with an increased risk of cervical intraepithelial neoplasia grade 3 (CIN3) and cervical cancer among women who are infected with oncogenic human papillomavirus (HPV). However, these potential risk factors have not been adequately studied in prospective studies.

METHODS

We studied 1812 women who were enrolled in a 10-year prospective study of cervical neoplasia at Kaiser Permanente in Portland, Oregon, and who at enrollment had tested positive for oncogenic HPV DNA and had responded to a questionnaire that included questions on smoking, oral contraceptive use, and parity. Absolute risks and crude relative risks (RRs) with 95% confidence intervals (CIs) for CIN3 or cervical cancer were computed for three time intervals (0-8, 9-68, and 69-122 months after enrollment) using the Kaplan-Meier method. Conditional logistic regression models were used to control for factors that may have influenced our risk estimates, specifically the cytologic interpretation of baseline Pap smear, number of Pap smears during follow-up, age at enrollment, age at prediagnosis visit, and age at diagnosis. All statistical tests were two-sided.

RESULTS

Oral contraceptive use and parity were not associated with risk of CIN3 or cervical cancer. Former smokers, women who smoked less than one pack of cigarettes per day, and women who smoked one or more packs per day had crude RRs for CIN3 or cervical cancer for the entire follow-up period of 2.1 (95% CI = 1.1 to 3.9), 2.2 (95% CI = 1.2 to 4.2), and 2.9 (95% CI = 1.5 to 5.6), respectively, compared with never smokers. In the multivariable model, former smokers, women who smoked less than one pack/day, and women who smoked one or more packs/day had RRs of 3.3 (95% CI = 1.6 to 6.7), 2.9 (95% CI = 1.4 to 6.1), and 4.3 (95% CI = 2.0 to 9.3), respectively, for CIN3 or cervical cancer compared with never smokers.

CONCLUSIONS

Smoking is associated with an increased risk of invasive cervical cancer in women who are infected with oncogenic HPV. Subsequent studies should examine the role of smoking in the multistage pathogenesis of cervical cancer.

Viral load of human papillomavirus and risk of CIN3 or cervical cancer

Carcinogenic human papillomaviruses (HPV) are thought to be necessary for development of cervical cancer. We assessed whether higher viral loads of such viruses predicted future risk of CIN3 or cancer (CIN3+) in a cohort of 20810 women followed up for 10 years with cytological screening. We measured the viral load for 13 types of carcinogenic HPV (relative light units normalised to 1 pg/mL HPV 16 positive controls [RLU/PC]) using Hybrid Capture 2 testing of cervicovaginal lavages obtained at enrolment. Results were stratified into four groups (RLU/PC 1 to <10, 10 to <100, 100 to <1000, > or = 1000). Although presence of HPV strongly increased risk of CIN3+, high viral load did not further predict risk of CIN3+.

Comparison of two signal-amplification DNA tests for high-risk HPV as an aid to colposcopy

OBJECTIVE

To compare Hybrid Capture Tube (HCT) and the second-generation Hybrid Capture II (HC II) test for detection of high-risk human papillomavirus (HPV) DNA at the time of colposcopy.

STUDY DESIGN

Colposcopy and HPV testing were performed by HCT and HC II on 1,309 women for evaluation of abnormal Pap smears. Differences in the proportions were tested with chi 2 and 95% CI calculations.

RESULTS

When compared to HCT, HC II was more often positive in women with any abnormal Pap smear (44% [95% CI 41-46%] vs. 34% [31-37%], P < .005) and in the subset of women with atypical squamous cells of undetermined significance Pap smears (32% [29-35%] vs. 24% [22-27%], P < .005). HC II was more sensitive in detecting cervical intraepithelial neoplasia (CIN) 2 or worse (93% [88-97%] vs. 78% [70-84%], P < .005) and had a lower rate of undetected > or = CIN 2 in HPV test-negative subjects (1.5% [0.7-2.7%]) vs. 4.3% [3.0-5.9%], P < .005). HC II was also more often positive in women with negative colposcopic evaluations (29% [25.7-32.4%] vs. 20% [17.6-23.5%], P < .005). The specificity of HC II in detection of > or = CIN 2 was lower than that for HCT (63% [60.5-66.2%] vs. 73% [69.5-74.8%], P < .005).

Results of human papillomavirus DNA testing with the hybrid capture 2 assay are reproducible

Reproducibility of the Hybrid Capture 2 Test (HC 2) for human papillomavirus (HPV) DNA detection was evaluated by assaying frozen cervical specimens in 1997 and again in 2001 from 1,775 women with normal cervical cytology. Using a cutoff point of 1.0 pg of HPV DNA/ml between a negative and a positive test result, the result of the kappa test for agreement was 0.72 (a kappa value of >0.60 is considered good agreement). Using cutoff points of 1.0 and 10.0 pg/ml between negative and low positive and between low positive and high positive, respectively, the kappa was 0.68 and the linear-weighted kappa was 0.76. The results of this study indicate that HC 2 testing is reproducible even among cytologically normal women with low test values.