Human papillomavirus testing by hybrid capture appears to be useful in triaging women with a cytologic diagnosis of atypical squamous cells of undetermined significance

Contribution of human papillomavirus testing by hybrid capture in the triage of women with repeated abnormal pap smears before colposcopy referral

OBJECTIVE

The purpose of this work was to evaluate the ability of testing for high-risk human papillomavirus (HPV) types using the hybrid capture technique to predict the presence of cervical intraepithelial neoplasia (CIN) II,III in patients with repeated atypical squamous cells of undetermined significance (ASCUS) and low-grade squamous intraepithelial lesion (LGSIL) on Pap smears.

METHODS

Hybrid capture testing and tissue biopsy were performed on 503 consecutive women with ASCUS or LGSIL on repeated Pap smears who were referred for colposcopy.

RESULTS

A highly significant association (P < 0.0001) was found between a positive test for high-risk HPV types and CIN II,III, with an 87.0% positive predictive value and a 95.7% negative predictive value. In 226 women with ASCUS on repeated Pap smears, a positive test for high-risk HPV types had a 85.7% sensitivity and a 97% specificity for CIN II,III. In 277 patients with LGSIL on repeated Pap smears, a positive test for high-risk HPV types had an 88.2% sensitivity and a 94.7% specificity for CIN I,II. Reserving colposcopy examination for women who were positive for high-risk HPV types would have reduced the number of referrals for colposcopy to 24.6% and maintained a sensitivity of 87.0% for CIN II,III.

CONCLUSIONS

A positive hybrid capture test for high-risk HPV types was highly sensitive and specific for the presence of CIN II,III in patients with ASCUS and LGSIL on repeated Pap smears. We believe that improved methodology will eventually enable more selective colposcopy referrals without affecting patient safety among these women.

Significance of atypical squamous cells of undetermined significance on ThinPrep papanicolaou smears

OBJECTIVE

The aim of this study was to assess the prevalence and risk factors predictive of dysplasia among women seen in a gynecologic oncology service with the cytologic diagnosis of atypical squamous cells of undetermined significance (ASCUS) on Papanicolaou smears obtained by the ThinPrep method.

METHODS

Patients with ASCUS ThinPrep Papanicolaou smears seen at the Division of Gynecologic Oncology, University of Vermont, between 1997 and 1999 were identified. The cytologic smears were reviewed and subtyped into reactive or suggestive of squamous intraepithelial lesion (SIL). The charts of these patients were reviewed and the following information was abstracted: age, gravidity, parity, menopausal status, use of hormonal replacement therapy, smoking, history of pelvic cancer, history of radiation therapy, history of abnormal Papanicolaou smear and its treatment, history of human papillomavirus (HPV) infection, and follow-up information including results of repeat Papanicolaou smears, colposcopy, and biopsies. The prevalence of dysplasia was calculated. The demographic features of women with ASCUS, reactive, were compared with those with ASCUS, SIL, using a two-sample t test, chi(2), and Fisher's exact test. Risk factors predictive of dysplasia were calculated using the odds ratio and the 95% confidence interval. P < 0.05 was considered significant.

RESULTS

One hundred twenty-six patients with ASCUS on ThinPrep Papanicolaou smear were identified; 63 patients had ASCUS, reactive, and 63 patients had ASCUS, SIL. The demographic features of both groups were similar. The overall prevalence of dysplasia was 15.9% and was significantly higher among women with ASCUS, SIL, than among women with ASCUS, reactive (25.4% versus 6.4%, P = 0.003). The type of ASCUS cytology (reactive versus SIL), smoking, and history of HPV were significant risk factors for dysplasia (P = 0.003, 0.037, and 0. 042, respectively).

CONCLUSIONS

The prevalence of dysplasia among women seen in a gynecologic oncology service with ASCUS cytology on ThinPrep Papanicolaou smears is 15.9%. Women with ASCUS favor SIL, those who smoke, and those with a history of HPV are at higher risk for dysplasia and should be offered colposcopy.

[Human papillomavirus typing in routine cervical smears. Results from a series of 3778 patients]

AIM

As human papillomavirus (HPV) infection is a significant risk factor for cervical cancer, the aim of this study was to assess the efficacy of HPV detection techniques in predicting the presence or the development of a high-grade squamous intra epithelial lesion. Additional reasons for carrying out this investigation were as follows. It was considered that the clinical value of HPV typing may have been underestimated in certain previous reports, which based their findings on first-generation assays. Moreover, until the present investigation most studies only investigated the cases with abnormal smear findings and did not include long-term follow-up, nor detailed follow-up of women with a normal smear but positive HPV typing, although this patient subgroup is of particular interest. The patient population included 3778 women who underwent routine cytological cervical screening and who gave their informed consent to participate in this study, consisting of a cervical smear, HPV testing via a second-generation Hybrid Capture II assay (which is more sensitive than first-generation tests, and can detect 18 different HPV types, i.e., 13 oncogenic and five non-oncogenic types); and in the case of abnormal smear findings, colposcopic examination and directed biopsies of the sites of suspected lesions. The women with cytomorphologically normal cervical smears but which who HPV-positive were reexamined six months later.

RESULTS

HPV findings were positive in 66 cases where the initial smear indicated the presence of a high-grade lesion with the diagnosis confirmed by biopsy in 65 cases; in 155 cases (76.1%) where the initial smear indicated the presence of a low-grade lesion; in 44 (57.1%) out of 77 smears indicating the presence of ASCUS-type (atypical squamous cells of undetermined significance) lesions; and in 366 cases (10.5%) of apparently normal initial smears. After colposcopy and follow-up, a final diagnosis of high-grade lesion was made for 85 patients. All these patients were found to have high-risk (oncogene-positive) HPV at the first examination, but in only 65 cases (76.5%) was the initial smear indicative of a high-grade lesion. Finally, in the patient groups with low-grade or ASCUS-type smear findings or with an apparently normal smear, a high-grade lesion was only found in those patients with persistent high-risk HPV infection. In all, the sensitivity of the Hybrid Capture II assay in detecting high-grade lesions was 100% versus 85.9% for standard cytology. However, its specificity (86.3%) and positive predictive value were not as high as the latter.

CONCLUSION

The results of this study indicate that HPV typing via this second-generation assay displays good sensitivity for the detection of at-risk cases, i.e., those involving the presence or development of high-grade cervical lesions. However, a number of issues have to be addressed before HPV typing is adopted in clinical practice, such as the fairly high HPV prevalence in women aged over 60 years, and whether the implications of this are the same as for younger age groups. Also, the present cost of complete typing remains too high for it to be used on a widespread scale. Nevertheless, HPV typing may have a useful role to play in the detection of cervical cancer.

A systematic review of the role of human papilloma virus (HPV) testing within a cervical screening programme: summary and conclusions

A systematic review of the available evidence on the role of HPV testing in cervical screening has been published by the Health Technology Assessment Committee of the UK Department of Health. The review summarized relevant data on testing methods, natural history, and prevalence of the virus in different disease groups. Cost-effectiveness modelling was undertaken. Ten major conclusions were reached and are reported here. The key conclusions were that HPV testing was more sensitive than cytology, but that there were concerns about specificity, especially in young women. The increased sensitivity led to a recommendation that HPV testing be introduced on a pilot basis for women with borderline and mild smears. HPV testing has great potential as a primary screening test, but large trials are needed to properly evaluate this application and to determine if its introduction can reduce invasive cancer rates. There is an urgent need to undertake a large trial of HPV testing in conjunction with other new technologies (liquid-based cytology and computer-assisted cytology reading) to determine the best way to integrate them into ongoing screening programmes. A range of issues including the age to start and stop screening, the appropriate screening interval, the role of self-sampling for HPV testing and the choice of primary test (HPV and/or cytology) require further evaluation.

Human papillomavirus detection by the hybrid capture II assay: a reliable test to select women with normal cervical smears at risk for developing cervical lesions

The reliability of the Hybrid Capture II (HC-II; Digene, Silver Spring, MD, U.S.A.) assay was tested in detecting 18 human Papillomavirus (HPV) types for the screening of cervical lesions. Cytology, HPV testing, colposcopy, and biopsy were used to monitor 204 women with normal smears at the first entry. The median follow-up was 15 months (range, 4-27 months). The primary endpoint was clinical progression defined as the presence of a cervical intraepithelial lesion at the biopsy. In the patient population of 204 HPV-infected women, 81 (39.7%) had a persistent HPV infection at two or three examinations with a final histologic diagnosis of 14 high-grade and 13 low-grade squamous intraepithelial lesions (SIL) within 4 to 22 months. Women with regressive HPV infection did not develop any lesion during the same period. The evaluation of the viral load of high-risk HPV by the HC-II did not represent a sensitive approach to predict the persistence or the apparition of high-grade lesions. Thus, persistent high-risk HPV infection detected with HC-II represents a reliable tool to select populations at risk for the development of high-grade cervical lesions.

Viral load of human papilloma virus 16 as a determinant for development of cervical carcinoma in situ: a nested case-control study

BACKGROUND

Infection with certain types of human papillomavirus (HPV), which is common among young women, increases the risk of cervical cancer. However, less than 1% of young women positive for oncogenic types of HPV develop cervical cancer. We investigated whether the amount of HPV DNA is a useful predictor of progression to cervical carcinoma in situ.

METHODS

We estimated the amount of HPV 16 DNA by a PCR that uses the 5'-exonuclease (Taqman) method, in 478 women with cervical carcinoma in situ and 608 individually matched controls. To adjust for differences in the amount of genomic DNA between samples, we estimated the amount of a nuclear gene (beta-actin). We studied multiple smears (total 3835 archived samples) from each woman, taken over periods of up to 26 years, that covered normal cytology to development of cervical cancer.

FINDINGS

The risk of cervical carcinoma in situ increased with the amount of HPV 16 DNA. Analysis of the first smear from each woman, collected a mean of 7.8 years before cancer diagnosis, showed that women with the 20% highest amount of HPV 16 DNA were at a 60-fold higher risk of developing cervical carcinoma in situ than women negative for HPV 16. The first smear samples were classified as normal by squamous-cell cytology.

INTERPRETATION

Analysis of the amount of HPV DNA can predict cancer risk at a stage when current screening methods are uninformative. Testing for the amount of HPV 16 DNA during gynaecological health checks might strikingly improve our ability to distinguish between infections that have a high or low risk of progressing into cervical cancer.

Human papillomavirus DNA testing for cervical cancer screening in low-resource settings

BACKGROUND

In many low-resource settings, there are barriers to cytologic screening for cervical cancer. This study evaluates human papillomavirus (HPV) DNA testing as an alternative screening method.

METHODS

Cervical samples from 2944 previously unscreened South African women aged 35-65 years were tested for high-risk types of HPV with the use of the Hybrid Capture I (HCI) assay. Women also had a Pap smear, direct visual inspection of the cervix, and Cervicography(TM). Women positive on any screening test were referred for colposcopy. Samples from women with biopsy-confirmed, low-grade squamous intraepithelial lesions (SILs) (n = 95), high-grade SILs (n = 74), or invasive cervical cancer (n = 12) and a random sample of women with no cervical disease (n = 243) were retested for HPV DNA with the use of the more sensitive Hybrid Capture II (HCII) assay. All P values are two-sided.

RESULTS

High-risk HPV DNA was detected in 73.3% and 88.4% of 86 women with high-grade SIL or invasive cancer and in 12.2% of 2680 and 18.1% of 243 women without evidence of cervical disease, with the use of the HCI and HCII assays, respectively. HPV DNA testing with the HCII assay was more sensitive than cytology for detecting high-grade SIL and invasive cancer (McNemar's test, P =.04), and testing with the HCI assay was of equivalent sensitivity (P =.61). Cytology had a statistically significantly better specificity (96.8%) than either the HCI assay (87.8%) or the HCII assay (81.9%) (P<.01). Receiver operating characteristic curves identified test cutoff values that allow HPV DNA testing to identify 57% of women with high-grade SIL or cancer, while classifying less than 5% of women with no cervical disease as HPV DNA positive.

CONCLUSIONS

HPV DNA testing has a sensitivity equivalent to, or better than, that of cytology. Since HPV DNA testing programs may be easier to implement than cytologic screening, HPV testing should be considered for primary cervical cancer screening in low-resource settings.

Accuracy of the Papanicolaou test in screening for and follow-up of cervical cytologic abnormalities: a systematic review

PURPOSE

To evaluate the accuracy of conventional and new methods of Papanicolaou (Pap) testing when used to detect cervical cancer and its precursors.

DATA SOURCES

Systematic search of English-language literature through October 1999 using MEDLINE, EMBASE, other computerized databases, and hand searching.

STUDY SELECTION

All studies that compared Pap testing (conventional methods, computer screening or rescreening, or monolayer cytology) with a concurrent reference standard (histologic examination, colposcopy, or cytology).

DATA EXTRACTION

Two reviewers independently reviewed selection criteria and completed 2 x 2 tables for each study.

DATA SYNTHESIS

94 studies of the conventional Pap test and three studies of monolayer cytology met inclusion criteria. No studies of computerized screening were included. Data were organized by cytologic and histologic thresholds used to define disease. For conventional Pap tests, estimates of sensitivity and specificity varied greatly in individual studies. Methodologic quality and frequency of histologic abnormalities also varied greatly between studies. In the 12 studies with the least biased estimates, sensitivity ranged from 30% to 87% and specificity ranged from 86% to 100%.

CONCLUSIONS

Insufficient high-quality data exist to estimate test operating characteristics of new cytologic methods for cervical screening. Future studies of these technologies should apply adequate reference standards. Most studies of the conventional Pap test are severely biased: The best estimates suggest that it is only moderately accurate and does not achieve concurrently high sensitivity and specificity. Cost-effectiveness models of cervical cancer screening should use more conservative estimates of Pap test sensitivity.

Prevention of cervix cancer

Cervix carcinoma is an important health problem world-wide, being the second most common cancer among women, ranking first in many developing countries. A number of important epidemiological risk factors have been identified as contributing to the development of CIN and invasive cervix carcinoma. Of key importance is infection with human papillomavirus (HPV), which is the primary risk factor. There are evolving primary and secondary preventive strategies that could further reduce the burden from cervical carcinoma. The possible primary preventive strategies include risk reduction, diet or dietary supplements, HPV vaccines, and other chemopreventive agents. The possible advances in secondary preventive strategies include new technologies for Pap smears, HPV typing triage, and other adjuvant screening procedures. The impact of these strategies will depend upon evidence to support their use along with the characteristics of the population and environment in which they are used.

Additional human papillomavirus types detected by the hybrid capture tube test among samples from women with cytological and colposcopical atypia

The type specificity of the human papillomavirus (HPV) Hybrid Capture Tube (HCT) test was evaluated by using typing with PCR (MY09-MY11)-restriction fragment length polymorphism (RFLP) and sequencing. All samples HCT test positive for only low-risk HPV (n = 15) or only high-risk HPV (n = 102) were confirmed, whereas 9 of 12 HCT test double-positive samples contained only high-risk HPV types as determined by PCR-RFLP. Several high-risk HPV types (HPV-53, -58, -62, -66, -CP8304, and -MM4) not included in the HCT test were indeed detected, indicating a broader detection range with retained distinction between low-risk and high-risk HPV types.

Evaluation of a human papillomavirus assay in cervical screening in Zimbabwe

OBJECTIVE

To determine the utility of an assay for high risk genital human papillomavirus (HPV) in cervical screening in Zimbabwe, Africa.

DESIGN

Cross-sectional study.

SETTING

Harare, Zimbabwe.

POPULATION

Zimbabwe women (n = 2,140), 25 to 55 years old, recruited in clinics in Chitungwiza and Greater Harare.

METHODS

Genital specimens were assessed for HPV, using the HPV DNA test Hybrid Capture II (probe B). Further assessment of the women was conducted using colposcopy and biopsy as indicated. High grade squamous intraepithelial lesions were diagnosed in 215 women. Colposcopy and/or biopsy showed low grade lesions in 346 women.

RESULTS

The overall prevalences were: 42 x 7% for HPV, 10% for high grade squamous intraepithelial lesions and 16% for low grade lesions. Prevalence for HPV decreased significantly with increase in age (P for trend < 0 x 0001) and increased significantly with increasing disease severity, from 35% in normal women, to 53% in women with low grade lesions and 81% in women with high grade lesions (P for trend < 0 x 001). In specimens positive for HPV, the amount was 14-fold higher in women with high grade lesions compared with normal women. In screening for high grade lesions the assay for HPV had a sensitivity of 81% (CI 75%-86%); sensitivity for low grade lesions was 64% (CI 60%-68%). Specificity was 62% (CI 59%-64%) for high grade lesions and 65% (CI 62%-67%) for low grade lesions. The positive predictive value was 19% (CI 17%-22%) for high grade lesions and 39% (CI 36%-42%) for low grade lesions.

CONCLUSION

For high grade squamous intraepithelial lesions the sensitivity of the Hybrid Capture II HPV DNA test was high, but the specificity was relatively low. The test may therefore be most useful in conjunction with other screening tests.

Human papillomavirus testing in primary screening for cervical cancer of human immunodeficiency virus-infected women, 1990-1998

OBJECTIVE

Women infected with the human immunodeficiency virus (HIV) have an increased risk of cervical neoplasia while the value of cytologic screening is limited due to a high prevalence of inflammatory disease. The study was conducted to determine whether testing for human papillomavirus (HPV) DNA could improve primary screening for cervical cancer of these patients.

METHODS

One hundred thirty-eight HIV-infected women were examined between 1990 and 1998. Ninety-four patients with a total of 279 women-years were eligible for incidence evaluation. Colposcopy, cytology, and HPV DNA testing with the hybrid capture I assay were performed at each visit.

RESULTS

Seventeen cases of high-grade cervical neoplasia were diagnosed at study entry and 13 developed CIN II or CIN III during follow-up. The hybrid capture I assay detected 94.1% of prevalent and 100% of incident high-grade neoplasia, while the corresponding sensitivity of Pap smears using CIN I or worse as the referral criteria was 82.3% for prevalent and 69.2% for incident high-grade neoplasia. Eleven of 13 patients who progressed to histologically confirmed CIN II/III tested positive for HPV DNA at study entry compared with 5/13 women presenting with any degree of cytologic atypia at recruitment. The Pap smears of 36/94 women remained normal throughout the study while 54/94 patients remained negative for high-risk HPV types.

CONCLUSION

Hybrid capture I identified high-grade cervical neoplasia more accurately than the Pap smear and appeared to be beneficial for primary cervical cancer screening in HIV-infected women.

Molecular diagnosis and prognosis in gynecologic oncology

Currently, molecular pathology plays a limited role in improving patient outcome in gynecologic oncology. However, molecular investigation is providing important insights into the epidemiology, pathogenesis, and progression of female genital cancers. Future roles should include prediction of poor outcome in low-risk cases, more accurate staging of multifocal tumors, identification of new precursor lesions, and prediction of response to specific therapeutic regimens. Gene therapy of some malignant tumors may become important in the near future. In the immediate future, however, the most significant role of molecular pathology may be in the screening and triage of putative cervical cancer precursors and in the possible prophylaxis of these lesions by means of a vaccine or vaccines against human papillomaviruses.

Short fragment polymerase chain reaction reverse hybridization line probe assay to detect and genotype a broad spectrum of human papillomavirus types. Clinical evaluation and follow-up

The purpose of this study was to detect and genotype 16 different human papilloma virus (HPV) types simultaneously using a short fragment polymerase chain reaction (SPF) hybridization line probe assay (LiPA). 152 women who were referred to the gynecologist because of abnormal cervical smear underwent colposcopic examination and repeat cervical smear. In addition, the cervical scrapes were analyzed for the presence of HPV by a novel general HPV polymerase chain reaction assay followed by a single reaction genotyping assay allowing for a simultaneous detection and identification of 16 different HPV types. HPV DNA was detected in 38% of normal follow-up cervical scrapes, 51% of scrapes with atypical squamous cells of undetermined significance, 78% of scrapes with mild dysplasia (low grade squamous intraepithelial lesions), 86% of scrapes with moderate dysplasia (high grade squamous intraepithelial lesions), and in 88% of scrapes with severe dysplasia and carcinoma in situ. One case of invasive squamous cell carcinoma was positive for HPV 16. Overall, a single HPV type was detected in 56% of HPV positive scrapes, with HPV 16 being the most common and accounting for 45% of all single infections. Forty-four percent of the positive scrapes contained multiple HPV types, of which double infections prevailed. Follow-up results proved the reproducibility and reliability of SPF HPV LiPA. In conclusion, we have used and evaluated the SPF-HPV-LiPA system for the detection and genotyping of HPV infections. The combined detection-typing method proved to be sensitive, specific, simple, and fast, making mass screening of cervical scrapes accessible for routine practice and facilitating individual patient management.

HPV testing in primary screening of older women

Certain types of the human papilloma virus (HPV) are well established as the primary cause of cervical cancer. Several studies have shown that HPV testing can improve the detection rate of high-grade cervical intraepithelial neoplasia (CIN), but these have been carried out primarily in younger women. In this study we evaluated the role of HPV testing as an adjunct to cytology in women aged 35 or over. An additional aim was to evaluate commercially available kits for HPV testing. A total of 2988 eligible women aged 34 or more attending for a routine smear in 40 general practitioner practices received HPV testing in addition to routine cytology, after having given written informed consent. Samples were assayed by polymerase chain reaction (PCR) and two versions of the Hybrid Capture test for HPV, and women were invited for colposcopy if there was any cytological abnormality (including borderline smears) or the PCR test was positive. Any apparent abnormality was biopsied and loop-excision was performed as necessary. CIN was judged by histology; 42 women had high-grade CIN, of which six were cytology negative (86% sensitivity for borderline or worse) and three had a borderline smear (79% sensitivity for mild dyskaryosis or worse). The positive predictive value of a borderline smear was only 3.1%. Eleven high-grade lesions were negative by the PCR HPV test (sensitivity 74%). The first generation Hybrid Capture II test had a similar sensitivity but an unacceptably high false positive rate (18.3%), while the newer Hybrid Capture II microtitre kit had a 95% sensitivity and a 2.3% positivity rate in normal women when used at a 2 pg ml(-1) cut-off (positive predictive value 27%). Cytology performed very well in this older cohort of women. The newer Hybrid Capture II microtitre test may be a useful adjunct, especially if the results reported here are reproducible in other studies. A combined screening test offers the possibility of greater protection and/or longer screening intervals, which could reduce the overall cost of the screening programme.

Genital human papillomavirus infection among women recruited for routine cervical cancer screening or for colposcopy determined by Hybrid Capture II and polymerase chain reaction

The purpose of this study was to evaluate the clinical use of the Hybrid Capture (HC)-II system for the detection of human papillomavirus (HPV) DNA to identify women at risk of progression to high grade squamous intraepithelial lesions (HGSIL) and carcinomas by differentiating low risk (LR) HPV types (6, 11, 42, 43, 44) and high/intermediate risk (HR) HPV types (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68). Five hundred and ninety-six women were enrolled in the study. Among them, 466 attended the hospital for routine cytologic screening and 130 were referred for colposcopy because of an abnormal Pap smear. The presence of HPV DNA was tested in cervical samples collected with the Digene Cervical Sampler in Digene Specimen Transport Medium (Digene Corporation, Silver Spring, MD, U.S.A.) using the HC-II assay. Results were compared with those obtained by polymerase chain reaction (PCR) using the MY09-MY11 primers followed by several hybridizations with specific probes. The overall HPV positivity was 32.9% by HC-II and 37.8% by PCR. Among cytologically normal smears, 19.5% were positive by HC-II (14.3% HR) and 25.1% by PCR. Of the atypical squamous cells of undetermined significance samples, 52.9% were positive by HC-II (41.1% HR) and 55.9% by PCR. Of the low grade SIL, 64.5% were positive by HC-II (59.4% HR) and 68.7% by PCR. The HPV positivity rate was found identical by both techniques in high grade smears (81.6%) and squamous cervical carcinomas (100%). By using PCR as the reference method, the sensitivity of HC-II was higher among women with abnormal cytology than with normal cytology (87.3% vs. 70%). Specificity was 80.8% and 97.5%, respectively. In summary, these results indicate that the HC-II method and MY-PCR identified nearly equivalent prevalences of HPV in cervical smear specimens.

Human papillomavirus type 16 and 18 detection in the management of mild dyskaryosis

OBJECTIVE

To determine if semi-quantitative human papillomavirus (HPV) types 16 and 18 detection by polymerase chain reaction can increase the sensitivity and specificity of repeat cytology alone for underlying high grade cervical intraepithelial neoplasia (CIN).

DESIGN

Prospective randomised study of immediate treatment and surveillance.

SETTING

A dedicated colposcopy clinic serving a regional population.

SAMPLE

Three hundred and four women with smears reported as mild dyskaryosis.

METHODS

Repeat cytology, HPV 16 and 18 tests, and colposcopy were performed at study entry. Women were randomised to either immediate treatment or surveillance with repeated tests at 6 and 12 months. Unless all study smears were negative, women were treated at study exit by large loop excision of the transformation zone.

MAIN OUTCOME MEASURES

Sensitivity and specificity of HPV testing for types 16 and 18 in conjunction with cytology for high grade CIN.

RESULTS

Combining repeat cytology with HPV 16 and 18 testing had a sensitivity of 94% and a specificity of 26%, a positive predictive value of 71%, and a negative predictive value of 71%, for underlying high grade CIN. If used to secondary screen in conjunction with repeat cytology for mild dyskaryosis, 88% of women would have been referred for colposcopy on the basis of either test being positive.

CONCLUSION

Combining repeat cytology and HPV 16 and 18 detection would result in the majority of women being referred for immediate colposcopy. Taken with an overall default rate of 17%, immediate referral of all women with mild dyskaryosis for colposcopic assessment still appears to be a more effective clinical strategy.

Development and clinical evaluation of a highly sensitive PCR-reverse hybridization line probe assay for detection and identification of anogenital human papillomavirus

Human papillomavirus (HPV) can be detected by amplification of viral DNA. A novel PCR primer set generating a short PCR fragment (SPF PCR) was used for amplification of a fragment of only 65 bp from the L1 region and permitted ultrasensitive detection of a broad spectrum of HPV genotypes. The intra- and intertypic sequence variations of the 22-bp interprimer region of this amplimer were studied. Among 238 HPV sequences from GenBank and clinical specimens, HPV genotypes were correctly identified based on the 22-bp sequence in 232 cases (97.2%). Genotype-specific probes for HPV genotypes 6, 11, 16, 18, 31, 33 to 35, 39, 40, 42 to 45, 51 to 54, 56, 58, 59, 66, 68, 70, and 74 were selected, and a reverse hybridization line probe assay (LiPA) (the INNO-LiPA HPV prototype research assay) was developed. This LiPA permits the use of amplimers generated by the SPF as well as the MY 09/11 primers. The assay was evaluated with a total of 1, 354 clinical specimens, comprising cervical scrapes (classifications ranging from normal cytology to severe dyskaryosis) and formalin-fixed, paraffin-embedded cervical carcinoma samples. LiPA results were highly concordant with sequence analysis of the SPF amplimer, genotype-specific PCR, and sequence analysis of amplimers generated by MY 09/11 primers. The sensitivity of the SPF primers was higher than that of the GP5(+)/6(+) primers over a broad range of HPV types, especially when multiple HPV genotypes were present. In conclusion, the SPF LiPA method allows extremely sensitive detection of HPV DNA as well as reliable identification of HPV genotypes in both cervical smears and paraffin-embedded materials.

Assessing gains in diagnostic utility when human papillomavirus testing is used as an adjunct to papanicolaou smear in the triage of women with cervical cytologic abnormalities

OBJECTIVE

We aimed to provide simple methods for calculating expected sensitivity and specificity when an adjunctive test is added to a conventional test.

STUDY DESIGN

Use of adjunctive methods for the triage of women with cervical abnormalities produces an apparent gain in sensitivity over Papanicolaou cytologic testing alone. This increase in sensitivity can be misleading, even if deemed significant by results of a statistical test. Combined testing prevents a loss in specificity but sometimes offers no real gain in sensitivity. A nominal increase in sensitivity always occurs by chance whenever an adjunctive test is used in parallel with a conventional one, even if the new test is totally random with respect to the disease being evaluated.

RESULTS

Gains in sensitivity and losses in specificity have to be gauged against expected levels of these parameters when a random adjunctive test is coupled with Papanicolaou screening and not gauged against the performance of cytologic testing alone.

CONCLUSION

We provide simple formulas for calculating the expected sensitivity and specificity in conditions of combination testing to provide more realistic baselines for assessment of the screening efficacy contributed by the adjunctive test.

Reliable high risk HPV DNA testing by polymerase chain reaction: an intermethod and intramethod comparison

BACKGROUND

The development of a reproducible, sensitive, and standardised human papillomavirus (HPV) polymerase chain reaction (PCR) test is required to implement HPV testing in cervical cancer screening programmes and for triaging women with mild to moderate dysplasia.

AIMS

To determine the intermethod agreement between different GP5+/6+ and MY09/11 PCR based protocols for the detection and typing of high risk (HR) HPV DNA in cervical smears and to assess the intramethod reproducibility of the GP5+/6+ PCR enzyme immunoassay (EIA) for HR-HPV detection.

METHODS

For the intermethod comparison, crude aliquots of 20 well characterised cervical smears comprising five HPV negative samples, and six and nine samples containing single and multiple HPV infections, respectively, were coded and sent from reference laboratory (A) to three other laboratories. One of these (laboratory B) used the GP5+/6+ PCR-EIA and was provided with standard protocols. Another laboratory (C) used GP5+/6+ PCR combined with sequence analysis and type specific PCR, whereas two laboratories (D and E) used MY09/11 PCR followed by restriction fragment length polymorphism (RFLP) analysis for the detection and typing of HR-HPV. The intramethod agreement of GP5+/6+ PCR-EIA was analysed in a subsequent study with four other laboratories (F to I) on crude aliquots of 50 well characterised cervical smears, consisting of 32 HR-HPV positive and 18 HPV negative samples. Standardised protocols, primers, and probes were also provided by the reference laboratory for HR-HPV detection.

RESULTS

In the intermethod comparison, pairwise agreement of the different laboratories with reference laboratory A for the detection of HR-HPV varied between 75% and 100% (kappa values: 0.5 to 1). Typing data revealed a broader range in pairwise agreement rates between 32% and 100%. The highest agreement was found between laboratories A and B using standardised protocols and validated reagents. In the intramethod evaluation, pairwise comparison of the laboratories F to I with reference laboratory A revealed excellent agreement rates from 92% to 100% (kappa values: 0.88 to 1.0) with an overall sensitivity of 97.5% (195/200) and specificity of 99.5% (199/200).

CONCLUSIONS

The detection of HR-HPV as a group is highly reproducible with GP5+/6+ PCR-EIA provided that standardised protocols and validated reagents are used.

Hybrid Capture II-based human papillomavirus detection, a sensitive test to detect in routine high-grade cervical lesions: a preliminary study on 1518 women

Hybrid Capture II (HC-II) is a commercial human papillomavirus (HPV) detection test designed to detect 18 HPV types divided into high-risk and low-risk groups. We have tested 1647 scrapes from 1518 unselected women attending routine cytological screening by this assay for the detection of histologically proven high-grade lesions. The reliability of this test was also evaluated on 117 fresh cone biopsy samples. HPV DNA has been detected in 400 scrapes (24.3%), 296 containing a high-risk HPV (18.0%). All the smears evocative of high-grade lesions were positive for high-risk HPV, and high-risk HPV were detected in all the 34 cases presenting a histologically proven high-grade lesion and in 68 (97.1%) of the 70 cone biopsy samples showing a high-grade lesion or an invasive carcinoma. Thus, the sensitivity was superior to the sensitivity of cytology (85.3%). Nevertheless, the quantitative approach provided by the HC-II assay for the assessment of the viral load could not clearly distinguish among cases with or without high-grade lesions. Thus this assay is recommended for the screening of high-grade lesions on a large scale, in association with classic cytology.

Rapid test for identification of a human papillomavirus 16 E6 L83V variant

A variant of human papillomavirus (HPV) 16 has been shown recently to be more prevalent in invasive cervical carcinoma than in preinvasive lesions. This HPV 16 variant possesses a common mutation (T to G) in nucleotide 350 (codon 83) of the E6 gene, resulting in an amino acid shift, L83V, in the E6 protein. This mutation was believed to signify preinvasive cervical lesions with a high probability of progression to invasive carcinoma. The purpose of the present investigation is to describe a rapid method for the detection of this variant HPV 16, E6 (L83V). Paraffin blocks of 18 gynecologic biopsy specimens were collected, all displaying the morphology of cervical intraepithelial neoplasia (CIN I-III) and a positive HPV 16 test. Sections from these blocks were used for DNA extraction. A DNA sequence of the E6 gene containing 176 bases (including codon 83) was amplified by polymerase chain reaction (PCR) and analyzed by non-radioactive single-strand conformational polymorphism (SSCP) analysis. A divergent SSCP pattern was observed in 7 of the HPV 16 positive biopsy specimens. A DNA sequence analysis of the PCR products revealed the conversion of Leu to Val in codon 83 of the E6 gene, correlating to the divergent band pattern. This PCR-SSCP method can be used to test for HPV 16 in women who are at serious risk of developing invasive cervical carcinoma.

Infection and cervical intraepithelial neoplasia

The impact of sexually transmitted diseases (STDs) on the development of cervical intraepithelial neoplasia (CIN) has been increasingly recognized over the last 20 years. Much attention has been focused on human papillomavirus (HPV) and the potential for screening for certain HPV types alongside standard cervical cytology in the hope of identifying those females at particular risk of developing high grade CIN or invasive carcinoma. Some infections, for example herpes simplex virus (HSV), have been heavily investigated in the past as they were thought to be involved in the development of CIN but were subsequently discounted. Also discounted as causes of CIN are Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT). These infections were found to be associated with higher rates of CIN in early studies but transpired to be markers for the presence of other infections and pathology and therefore not themselves directly responsible for cytological changes. The role of bacterial vaginosis (BV) is the focus of several current investigations, not only in the genesis of CIN but also in the development of other gynecological and obstetric conditions and complications. Evidence to implicate Trichomonas vaginalis (TV) in the genesis of CIN is conflicting, but there is some evidence that it may exert its influence in a similar way to that hypothesized for BV, ie via abnormal amines. It is well known that there is a high level of concordance of STDs whereby the presence of one infection greatly increases the likelihood of there being one or more others present. There may be a synergism between some infections with regard to the causation of CIN, although the evidence for this is putative. Presented here is an overview of current and previous research in the field of lower genital tract infection as it relates to the development of CIN.

Is human papillomavirus testing of value in clinical practice?

The objective of this review was to evaluate the current status of human papillomavirus testing in predicting the presence of high-grade or invasive disease in the cervix in women with Papanicolaou smears reported as atypical squamous cells of undetermined significance (ASCUS) or low-grade squamous intraepithelial lesion. This is a review of many of the studies already published evaluating the utility of human papillomavirus testing as part of the triage for patients whose Papanicolaou smears were reported as ASCUS or low-grade squamous intraepithelial lesion. Two triage approaches for follow-up of such patients are presented, and recommendations are made as to which is most cost-effective and safe. Data related to human papillomavirus testing were obtained with both currently available commercial kits for detection of high-risk human papillomavirus and the polymerase chain reaction. There was variation in results reported, possibly related to populations studied. The approach to management by cytologic screening and colposcopy, when indicated, appeared over the long term to be equal to human papillomavirus testing. In our opinion current human papillomavirus testing is of little clinical use to the practitioner. Its use should be limited to appropriately designed and implemented research studies.

A prospective study of biopsy-confirmed cervical intraepithelial neoplasia grade 1: colposcopic, cytological, and virological risk factors for progression

OBJECTIVES

The objective of this prospective study of histologically confirmed cervical intraepithelial neoplasia (CIN) (including equivocal CIN1) was to determine risk factors for progression to histologically confirmed CIN3, particularly human papillomavirus (HPV) types and cofactors. We postulated that HPV DNA positivity would be a strong, prospective risk factor for progression.

MATERIALS AND METHODS

Possible participants were referred with an abnormal cytological diagnosis of CIN1 or lower-grade disease or external genital warts. Women with histologically confirmed CIN1 (including koilocytotic atypia) or equivocal CIN1 were eligible for follow-up. Of these, 163 women were assessed every 3 months (if a lesion were present) or every 6 months (if a lesion regressed colposcopically during the course of the study), for up to 52 months. Progression was defined histologically, whereas persistence and regression were defined by combined cytological, colposcopic, and histological assessments. Subjects who progressed to a biopsy-confirmed CIN3 or who developed a lesion that was clinically unsafe to follow up (i.e., because of movement into the endocervical canal), were removed from the study and were treated.

RESULTS

A total of 237 patients were evaluated as possible participants. The 74 exclusions at enrollment included 33 patients who had an entry diagnosis of CIN2 to CIN3 or who had lesions that were otherwise already unsafe to follow up, 39 who did not have a lesion on colposcopically directed biopsy, and 2 who were immediately noncompliant. Among the remaining 163 participants, the overall progression rate to histologically confirmed CIN3 was 8%, the persistence rate was 49%, and the regression rate was 43%. All progressions occurred among women who were HPV DNA-positive and had colposcopically immature abnormal transformation zones.

Withdrawing low risk women from cervical screening programmes: mathematical modelling study

OBJECTIVE

To evaluate the impact of policies for removing women before the recommended age of 64 from screening programmes for cervical cancer in the United Kingdom.

DESIGN

A mathematical model of the clinical course of precancerous lesions which accounts for the influence of infection with the human papillomavirus, the effects of screening on the progression of disease, and the accuracy of the testing procedures. Two policies are compared: one in which women are withdrawn from the programme if their current smear is negative and they have a recent history of regular, negative results and one in which women are withdrawn if their current smear test is negative and a simultaneous test is negative for exposure to high risk types of human papillomavirus.

SETTING

United Kingdom cervical screening programme.

MAIN OUTCOME MEASURES

The incidence of invasive cervical cancer and the use of resources.

RESULTS

Early withdrawal of selected women from the programme is predicted to give rise to resource savings of up to 25% for smear tests and 18% for colposcopies when withdrawal occurs from age 50, the youngest age considered in the study. An increase in the incidence of invasive cervical cancer, by up to 2 cases/100 000 women each year is predicted. Testing for human papillomavirus infection to determine which women should be withdrawn from the programme makes little difference to outcome.

CONCLUSIONS

This model systematically analyses the consequences of screening options using available data and the clinical course of precancerous lesions. If further audit studies confirm the model's forecasts, a policy of early withdrawal might be considered. This would be likely to release substantial resources which could be channelled into other aspects of health care or may be more effectively used within the cervical screening programme to counteract the possible increase in cancer incidence that early withdrawal might bring.

Distribution of 14 high risk HPV types in cervical intraepithelial neoplasia detected by a non-radioactive general primer PCR mediated enzyme immunoassay

AIM

To evaluate the presence of high risk human papillomaviruses (HPV) in cervical smears showing intraepithelial neoplasia (CIN).

METHODS

The presence of 14 high risk HPV was evaluated in 114 cervical smears with CIN of different degrees, by comparing a non-radioactive polymerase chain reaction (PCR) enzyme immunoassay (EIA) with conventional PCR followed by radioactive Southern blot hybridisation. General primer PCR amplicons detecting low risk and high risk HPV were typed for 14 different high risk HPV types (HPV 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68) by a non-radioactive PCR-EIA. Virus load of HPV 16 positive CIN was assessed using the semiquantitative PCR-EIA.

RESULTS

Histological evaluation confirmed CIN I in 49 cases (mean age 29.0 years, range 17 to 52), CIN II in 31 cases (mean age 30.8 years, 18 to 54), and CIN III in 34 cases (mean age 31.1 years, 16 to 57). The non-radioactive PCR-EIA showed an overall agreement rate of 90% (kappa value 0.75) when compared with conventional general primer PCR followed by radioactive Southern blot hybridisation. High risk HPVs were detected in 47% of CIN I, 77% of CIN II, and 97% of CIN III (p < or = 0.02). HPV types 39, 51, 56, and 58 were found in CIN I exclusively (between 2% and 8%). HPV 16 and HPV 31 were detected in 12% and 2% of CIN I, 35% and 21% of CIN II, and 74% and 13% of CIN III, respectively (p < or = 0.03 and p < or = 0.04). The virus load estimated by the semiquantitative PCR-EIA of HPV 16 was similar in CIN I, CIN II, and CIN III.

CONCLUSIONS

The PCR-EIA has high clinical sensitivity for detecting CIN II/III (90%). There was a significantly higher prevalence rate of HPV 16 and 31 in CIN III than in CIN I and II.

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.

Comparison of PCR- and hybrid capture-based human papillomavirus detection systems using multiple cervical specimen collection strategies

This study compared the performances of three human papillomavirus (HPV) detection tests with specimens collected by three alternative procedures. The HPV tests included the Hybrid Capture Tube test (HCT), the microplate-based Hybrid Capture II test (HC II), and the MY09-MY11 L1 consensus primer PCR-based assay. Initial cervical specimens were collected from study subjects with a broom device, and after Papanicolaou smears were made, residual specimens were placed into PreservCyt (PC), a liquid cytology medium. A second specimen was collected from each subject and placed into Digene Specimen Transport Medium (STM). The device for collection of the second specimen alternated with consecutive subjects between a conical cytology brush and a Dacron swab. At the 1.0-pg/ml cutoff, the results of the HC II agreed well with those of the PCR. Specifically, when PCR data were restricted to the types found by the HC II (HPV types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, and 68), there was greater than 90% agreement between the HC II and PCR results with both STM and PC. At a lower cutoff (0.2 pg/ml), HC II-positive results increased further, especially when the test was applied to the PC specimens. However, false-positive HC II results were more often observed at the 0.2-pg/ml cutoff. HC II yielded the highest HPV positivity with specimens placed into PC, followed by specimens collected with a conical brush and placed into STM and, last, by those collected with a Dacron swab and placed into STM. Our results demonstrate the utility of both the STM and PC specimen collection methods and show good agreement between the HC II and PCR.

Pap smear screening in an urban STD clinic. Yield of screening and predictors of abnormalities

BACKGROUND

Pap smear screening studies in STD clinics have reported high rates of squamous intraepithelial lesions (SIL); however, there are limited data on levels of unsatisfactory smears of characteristics associated with cytologic abnormalities.

GOAL

To assess the yield to Pap smear screening in an STD clinic and to evaluate the rates of and risk factors for atypia, low-grade SIL (LSIL), and high-grade SIL (HSIL).

STUDY DESIGN

A chart review of the clinic records of women undergoing Pap smear screening between 1991 and 1994 was conducted. Results were assessed from two different screening protocols, the first using a Dacron swab to obtain the endocervical sample and the second using a cytobrush.

RESULTS

Of 2034 Pap smears, 1313 (64.6%) were negative, 202 (9.9%) were unsatisfactory, 257 (12.6%) were atypical, 211 (10.4%) had LSIL, and 51 (2.5%) had HSIL. With the change to the cytobrush protocol, the rate of unsatisfactory smears decreased from 14.4% to 3% (p < 0.001), atypia increased from 10% to 16.7% (p < 0.001), and HSIL rose from 1.7% to 3.7% (p < 0.001). By multivariate analysis, atypia was associated with genital warts (odds ratio (OR) 1.53, 95% confidence interval (CI): 1.16-2.02); LSIL with younger age (p < 0.001, for trend), black race (OR 1.51, 95% CI: 1.08-2.10), genital warts (OR 1.81, 95% CI: 1.33-2.47), and an abnormal appearance of the cervix on examination (OR 2.49, 95% CI: 1.85-3.35); and HSIL with a previous abnormal Pap smear (OR 2.48, 95% CI: 1.08-2.10). Overall, abnormality rates were significantly higher in adolescents (35.5%) than older women (21.7%) (p < 0.01).

CONCLUSIONS

Obtaining satisfactory Pap smears among women undergoing screening in an STD clinic is feasible and cytologic abnormalities are common. These results continue to support the need for Pap smear screening in STD clinics, but the high rates in adolescents, a group in whom the natural history of cytologic abnormalities has not been well-defined, raise questions about the need to develop age-appropriate screening and management strategies.