Human papillomavirus triage for young women with atypical squamous cells of undetermined significance

Performance of p16/Ki67 Immunostaining for Triage of Elderly Women with Atypical Squamous Cells of Undetermined Significance

BACKGROUND

The p16/Ki67 technique has been poorly studied in postmenopausal women with ASC-US cytology. The objective of this study was to compare the accuracy of p16/Ki67 staining, HPV testing and HPV 16 genotyping for the identification of CIN2 + lesions in postmenopausal women with ASC-US cytology.

METHOD

A total of 324 postmenopausal women with positive ASC-US were included. The women underwent HPV test, colposcopy, and biopsy. The slides were discolored and then stained with the CINtec Plus Kit for p16/Ki67. The HPV test results were classified as HPV16 +, hrHPV+ (other hrHPV genotypes), or HPV negative.

RESULTS

The p16/Ki67 sensitivity for CIN2+ was 94.5%, the specificity 86.6%, PPV of 59% and NPV of 95.9%. The HPV test showed a sensitivity of 96.4% for CIN2+, a specificity of 62.8%, a PPV of 35% and a NPV of 98.8%. In postmenopausal women, the prevalence of genotype 16 decreases in favor of the other high-risk genotypes.

CONCLUSION

Given the low sensitivity of cytology and the low percentage of HPV16-positive cancers among elderly women, triage via cytology and genotyping is not the best strategy; double staining cytology shows high profiles of sensibility and specificity for CIN2+ in ASCUS postmenopausal women.

High lifetime probability of screen-detected cervical abnormalities

Objective

Regular screening and follow-up is an important key to cervical cancer prevention; however, screening inevitably detects mild or borderline abnormalities that would never progress to a more severe stage. We analysed the cumulative probability and recurrence of cervical abnormalities in the Finnish organized screening programme during a 22-year follow-up.

Methods

Screening histories were collected for 364,487 women born between 1950 and 1965. Data consisted of 1 207,017 routine screens and 88,143 follow-up screens between 1991 and 2012. Probabilities of cervical abnormalities by age were estimated using logistic regression and generalized estimating equations methodology.

Results

The probability of experiencing any abnormality at least once at ages 30–64 was 34.0% (95% confidence interval [CI]: 33.3–34.6%). Probability was 5.4% (95% CI: 5.0–5.8%) for results warranting referral and 2.2% (95% CI: 2.0–2.4%) for results with histologically confirmed findings. Previous occurrences were associated with an increased risk of detecting new ones, specifically in older women.

Conclusion

A considerable proportion of women experience at least one abnormal screening result during their lifetime, and yet very few eventually develop an actual precancerous lesion. Re-evaluation of diagnostic criteria concerning mild abnormalities might improve the balance of harms and benefits of screening. Special monitoring of women with recurrent abnormalities especially at older ages may also be needed.

Prospective evaluation of p16/Ki-67 dual-stained cytology for managing women with abnormal Papanicolaou cytology: PALMS study results

BACKGROUND

Testing for the presence of the human papillomavirus (HPV) is widely accepted for triaging Papanicolaou cytology results categorized as atypical squamous cells of undetermined significance (ASC-US). In contrast, HPV testing has limited use in triaging cytological low-grade squamous intraepithelial lesions (LSILs) due to prevalence rates of typically >80%. In the current study, the authors assessed the diagnostic performance of p16/Ki-67 dual-stained cytology in triaging ASC-US and LSIL cases within the prospective, multicentric Primary ASC-US LSIL Marker Study (PALMS).

METHODS

A total of 575 ASC-US cases and 529 LSIL cases from a cohort of 27,349 women who were prospectively enrolled into the PALMS study in 5 European countries were tested with p16/Ki-67 dual-stained cytology and Hybrid Capture 2 (HC2) HPV testing. Colposcopy-guided biopsy results of cervical intraepithelial neoplasia of grade 2 or worse (CIN2+) were used as clinical endpoints.

RESULTS

p16/Ki-67 dual-stained cytology demonstrated comparable (ASC-US: 94.4% for dual-stained cytology vs 100% for HC2 testing; P = .317) or lower (LSIL: 85.7% for dual-stained cytology vs 98.4% for HC2 testing; P = .005) sensitivity for CIN2+, but higher levels of specificity compared with HC2 HPV testing in both ASC-US (78.7% vs 60.4%; P<.001) and LSIL (53.3% vs 15.6%; P<.001) cases. Positive predictive values for CIN2+ were substantially higher for dual-stained cytology versus HC2 HPV testing, especially in LSIL, and in ASC-US cases for women aged <30 years.

CONCLUSIONS

The clinical usefulness and efficiency of triaging women with ASC-US or LSIL Papanicolaou cytology results by p16/Ki-67 dual-stained cytology testing has been confirmed in this prospective, pan-European study. The high positive predictive value of dual-stained cytology for the presence of high-grade CIN may help to reduce the number of unnecessary colposcopy referrals.

Human papillomavirus testing versus repeat cytology for triage of minor cytological cervical lesions

BACKGROUND

Atypical squamous cells of undetermined significance (ASCUS) and low-grade squamous intra-epithelial lesions (LSIL) are minor lesions of the cervical epithelium, detectable by cytological examination of cells collected from the surface of the cervix of a woman.Usually, women with ASCUS and LSIL do not have cervical (pre-) cancer, however a substantial proportion of them do have underlying high-grade cervical intra-epithelial neoplasia (CIN, grade 2 or 3) and so are at increased risk for developing cervical cancer. Therefore, accurate triage of women with ASCUS or LSIL is required to identify those who need further management.This review evaluates two ways to triage women with ASCUS or LSIL: repeating the cytological test, and DNA testing for high-risk types of the human papillomavirus (hrHPV) - the main causal factor of cervical cancer.

OBJECTIVES

Main objective To compare the accuracy of hrHPV testing with the Hybrid Capture 2 (HC2) assay against that of repeat cytology for detection of underlying cervical intraepithelial neoplasia of grade 2 or worse (CIN2+) or grade 3 or worse (CIN3+) in women with ASCUS or LSIL. For the HC2 assay, a positive result was defined as proposed by the manufacturer. For repeat cytology, different cut-offs were used to define positivity: Atypical squamous cells of undetermined significance or worse (ASCUS+), low-grade squamous intra-epithelial lesions or worse (LSIL+) or high-grade squamous intra-epithelial lesions or worse (HSIL+).Secondary objective To assess the accuracy of the HC2 assay to detect CIN2+ or CIN3+ in women with ASCUS or LSIL in a larger group of reports of studies that applied hrHPV testing and the reference standard (coloscopy and biopsy), irrespective whether or not repeat cytology was done.

SEARCH METHODS

We made a comprehensive literature search that included the Cochrane Register of Diagnostic Test Accuracy Studies; the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE (through PubMed), and EMBASE (last search 6 January 2011). Selected journals likely to contain relevant papers were handsearched from 1992 to 2010 (December). We also searched CERVIX, the bibliographic database of the Unit of Cancer Epidemiology at the Scientific Institute of Public Health (Brussels, Belgium) which contains more than 20,000 references on cervical cancer.More recent searches, up to December 2012, targeted reports on the accuracy of triage of ASCUS or LSIL with other HPV DNA assays, or HPV RNA assays and other molecular markers. These searches will be used for new Cochrane reviews as well as for updates of the current review.

SELECTION CRITERIA

Studies eligible for inclusion in the review had to include: women presenting with a cervical cytology result of ASCUS or LSIL, who had undergone both HC2 testing and repeat cytology, or HC2 testing alone, and were subsequently subjected to reference standard verification with colposcopy and colposcopy-directed biopsies for histologic verification.

DATA COLLECTION AND ANALYSIS

The review authors independently extracted data from the selected studies, and obtained additional data from report authors.Two groups of meta-analyses were performed: group I concerned triage of women with ASCUS, group II concerned women with LSIL. The bivariate model (METADAS-macro in SAS) was used to assess the absolute accuracy of the triage tests in both groups as well as the differences in accuracy between the triage tests.

MAIN RESULTS

The pooled sensitivity of HC2 was significantly higher than that of repeat cytology at cut-off ASCUS+ to detect CIN2+ in both triage of ASCUS and LSIL (relative sensitivity of 1.27 (95% CI 1.16 to 1.39; P value < 0.0001) and 1.23 (95% CI 1.06 to 1.4; P value 0.007), respectively. In ASCUS triage, the pooled specificity of the triage methods did not differ significantly from each other (relative specificity: 0.99 (95% CI 0.97 to 1.03; P value 0.98)). However, the specificity of HC2 was substantially, and significantly, lower than that of repeat cytology in the triage of LSIL (relative specificity: 0.66 (95% CI 0.58 to 0.75) P value < 0.0001).

AUTHORS' CONCLUSIONS

HPV-triage with HC2 can be recommended to triage women with ASCUS because it has higher accuracy (significantly higher sensitivity, and similar specificity) than repeat cytology. When triaging women with LSIL, an HC2 test yields a significantly higher sensitivity, but a significantly lower specificity, compared to a repeat cytology. Therefore, practice recommendations for management of women with LSIL should be balanced, taking local circumstances into account.

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+.

CINtec® PLUS dual immunostain: a triage tool for cervical pap smears with atypical squamous cells of undetermined significance and low grade squamous intraepithelial lesion

ASC and LSIL comprise the majority of abnormal Pap smears. Currently, high-risk human papillomavirus testing is utilized to triage women with ASC for colposcopy; however, no cost effective triage method is available for LSIL. p16 and Ki-67 have each been shown to be good biomarkers for high grade cervical intraepithelial neoplasia (HG CIN).We evaluated the role of the CINtec® PLUS p16/Ki-67 dual immunostain as a marker for underlying (U) or subsequent (S) HG CIN. One hundred and eighty eight cervical SurePath Pap smears with histological and/or cytological follow-up were retrieved from our departmental files. The Pap stained slides were destained and then immunostained utilizing the CINtec® PLUS dual staining reagent kit. Results of the dual stain were correlated with follow-up diagnoses. Sensitivity, specificity, and positive and negative predictive values of CINtec® PLUS for U or S HG CIN were compared with those of HR HPV testing and with p16 and Ki-67 immunostaining alone. The sensitivity of CINtec® PLUS for U or S HG CIN was 91% in the ASC group and 100% in the LSIL group, while the corresponding specificities were 61 and 43%, respectively. The sensitivity and specificity of CINtec® PLUS for U or S HG CIN in both groups combined were 97 and 53%, respectively. CINtec® PLUS was more specific than HR HPV testing and Ki-67 and p16 immunostains alone in detecting an U or S HG CIN. CINtec® PLUS is a helpful adjunct in identifying U or S HG CIN when applied to SurePath Pap smears with ASC or LSIL.

The interplay of age stratification and HPV testing on the predictive value of ASC-US cytology. Results from the ATHENA HPV study

We have previously shown that human papillomavirus (HPV) genotyping, using the cobas HPV Test (Roche Molecular Systems, Pleasanton, CA), can be used to identify women with atypical squamous cells of undetermined significance (ASC-US) at the highest risk for cervical intraepithelial neoplasia (CIN) grade 2 or worse. We investigated the impact of age stratification on the risk of CIN 2 or worse in women with ASC-US and the performance of HPV genotyping in different age strata. The sensitivity of the cobas HPV Test was 93.3% in the 21- to 29-year-old age group and 67.7% in the 40 years or older group, most likely owing to pathologic misclassification of CIN 2 or worse in older women. The prevalence of CIN 2 or worse in younger women was nearly 4-fold that detected in older women and was predominantly HPV-16-related. Age-specific evaluation of ASC-US cytology in conjunction with HPV genotype status enables more effective risk assessment and could be used in clinical management.

Prevalence and patient characteristics associated with CIN 3 in adolescents

OBJECTIVE

We sought to identify patient characteristics associated with cervical intraepithelial neoplasia (CIN) 3 in adolescents.

STUDY DESIGN

A cross-sectional cohort study was done using a colposcopic database. Data collected included demographic and clinical information as well as cytologic and histologic results. Variables associated with CIN 3 in the univariable analysis (P ≤ .10) were included in a multivariable logistic regression model.

RESULTS

Of 614 adolescents evaluated, 48 (8%; 95% confidence interval, 6-10%) had CIN 3. No cancers were detected. In the univariable analysis, parity, ≥ 4 lifetime male sexual partners, and a history of sexually transmitted infections were associated with an increased risk of CIN 3. In the final model, only ≥ 4 sexual partners (compared to <4; adjusted odds ratio, 3.66; 95% confidence interval, 1.26-10.61) was significantly associated with the finding of CIN 3.

CONCLUSION

CIN 3 was infrequently encountered in adolescents, and those with multiple sexual partners were at increased risk for CIN 3.

The sensitivity and specificity of p16(INK4a) cytology vs HPV testing for detecting high-grade cervical disease in the triage of ASC-US and LSIL pap cytology results

We analyzed the performance of p16(INK4a) immunocytochemistry on a series of 810 retrospectively collected atypical squamous cells of undetermined significance (ASC-US) and low-grade squamous intraepithelial lesion (LSIL) cases with available biopsy follow-up data, including 94 cases of cervical intraepithelial neoplasia (CIN) 2 and 128 cases of CIN 3. Human papillomavirus (HPV) testing was performed from the same residual liquid-based cytologic specimen, and results for both tests were correlated with histologic follow-up data. Sensitivity values for high-grade CIN (HGCIN) confirmed on biopsy within 6 months were 92.6% (ASC-US) and 92.2% (LSIL) for cytotechnologists' reviews of p16 cytology and 90.1% (ASC-US) and 95.7% (LSIL) for HPV testing. Sensitivity rates of initial pathologists' reviews were slightly lower, 76.4% to 80.1%, with levels comparable to cytotechnologists' results after adjudication. The specificity of p16 cytology for HGCIN detection was significantly higher than for HPV testing for cytotechnologists and pathologists: 63.2% to 71.1% (p16 cytology) vs 37.8% for HPV in ASC-US (P < .001) and 37.3% to 53.3% (p16 cytology) vs 18.5% for HPV in LSIL (P < .001). This evaluation of the diagnostic performance of p16 cytology confirms the potential of this stain for the efficient triage of ASC-US and LSIL cytologic results.

Triage of women with equivocal or low-grade cervical cytology results: a meta-analysis of the HPV test positivity rate

Consistent evidence underlines the utility of human papillomavirus (HPV) DNA testing in the management of women with equivocal cervical cytological abnormalities, but not in case of low-grade lesions. We performed a meta-analysis including studies where the high-risk probe of the Hybrid Capture-II is used to triage these two cytological categories. The triage test-positivity rate reflects the colposcopy referral workload.Data were pooled on the HPV test positivity rate in women with atypical squamous cells of undetermined significance (ASCUS/ASC-US) or low-grade squamous intraepithelial lesions (LSIL), derived from different cytological classification systems. The meta-analysis was restricted to studies, published between 1991 and 2007. A random-effect model was applied for meta-analytical pooling and the influence of covariates on the HPV positivity rate was analyzed by meta-regression. The variation by age was assessed within individual studies since age strata were not defined uniformly. On an average, 43% (95% CI: 40–46%) of women with ASCUS/ASC-US were high-risk HPV positive (range 23–74%). In women with LSIL, the pooled positivity rate was 76% (95% CI: 71–81%; range 55–89%). In spite of considerable inter-study heterogeneity, the difference in HPV positivity between the two triage groups was large and highly significant: 32% (95% CI: 27–38%). HPV rates dropped tremendously as age and cutoffs of test positivity increased. Other factors (cytological classification system, country, continent, collection method and year of publication) had no statistically significant impact, except in LSIL triage where HPV positivity was significantly lower in European compared to American studies. Women with LSIL, especially younger women, have high HPV positivity rates suggesting limited utility of reflex HPV triaging these cases. Research is needed to identify more specific methods to triage women with low-grade squamous cervical lesions.

Longitudinal clinical evaluation of a novel antibody cocktail for detection of high-grade squamous intraepithelial lesions on cervical cytology specimens

CONTEXT

Although cervical cancer screening by cytology is successful, the test continues to show relatively poor operating characteristics. Cell cycle markers may enhance detection of high-grade squamous intraepithelial lesions.

OBJECTIVE

To determine the clinical usefulness of ProExC, an immunocytochemical assay for cell cycle components, performed on routine cervical cytology samples.

DESIGN

Cervical cytology samples were collected using the SurePath method. Residual cells remaining after preparation of the Papanicolaou-stained slide were used to make a second slide for ProExC staining using an indirect polymer-based immunoperoxidase method. Only adequately cellular slides were evaluated for the presence of nuclear staining within cytologically abnormal epithelial cells. Results were correlated with clinical follow-up.

RESULTS

Six hundred twenty-four samples were satisfactorily cellular and stained. Correlation with clinical follow-up for subsequent cervical intraepithelial neoplasia 2+ on biopsy/high-grade squamous intraepithelial lesion on cytology (CIN 2+/HSIL) showed that 434 results were true negative, 78 true positive, 18 false-negative, and 94 false-positive, resulting in a sensitivity/specificity of 81%/82%. When ProExC results were combined with any level of cytologic atypia, sensitivity for CIN 2+/HSIL was 92% and specificity was 84%.

CONCLUSIONS

ProExC shows promise as an aid in enhancing the sensitivity and specificity of cervical cytology for subsequent CIN 2+/HSIL and may be useful in identifying those cervical lesions most apt to progress.

An audit of Colposcopy referrals from a GU/STD clinic

BACKGROUND

Cervical cancer is increasing at 1.5% per year in Ireland with 50% mortality giving 2.2% of all cancer deaths. In the Mid-West region a pilot screening programme has begun to screen all women 25-60 years. 66% of Genitourinary/Sexually transmitted disease (GU/STD) clinics' abnormal smears are <25 years. Requests to abandon "opportunistic" screening prompted this GU/STD clinic audit.

METHODS

221(8.4%) patients referred to colposcopy over 4 years were audited. Retrospective analysis was carried out on GU/STD clinic files, hospital files and computer records for biopsy reports. Ethical approval was prospectively granted.

RESULTS

2637 smears were carried out from November 1999 - September 2003.221 patients referred to colposcopy were audited.1%, 3%, 5% had severe, moderate and, mild dyskaryosis, respectively, on cervical screening while 0.8%, 1.2%, 1.5% had CIN3, CIN2, CIN1 abnormalities, respectively, on biopsy with 3.5% having no abnormality (Cervical Intraepithelial Neoplasia = CIN).53% referred to colposcopy were <25 years.

CONCLUSION

2% had high grade lesions. 37% of high grade lesions are <25 years.Of the high grade lesions 13% had Chlamydia trachomatis (27% of CIN3) and 44% had HPV despite Relative Risks (RR) being 0.75 and 1.09 respectively. Older women had higher grade changes. No statistical difference was found for progression, regression and persistence in those over and under 25.

HPV triage for low grade (L-SIL) cytology is appropriate for women over 35 in mass cervical cancer screening using liquid based cytology

In the experimental arm of a randomised trial, women were tested both for liquid-based cytology and human papillomavirus (HPV) DNA and referred for colposcopy if cytology was ASCUS (atypical cells of undetermined significance) or more severe. We considered those with ASCUS (757) or LSIL (low-grade squamous intraepithelial lesions) (485) and a valid HPV test who received colposcopy. We computed sensitivity, specificity and ROC curves with different values of relative light units (RLU, that are related to viral load) as cut off, using cervical intraepithelial neoplasia grade 2 or more severe (CIN2+) at blind histology review as the endpoint. The area under the receiver operating characteristic (ROC) curve was significantly less among women aged 25-34 years than in those older, both considering ASCUS/AGUS (atypical glandular cells of undetermined significance) (p=0.0355) and LSIL (p=0.0009). At age 35-60 the curves for ASCUS and LSIL were similar, while at age 25-34 the area under the curve for LSIL was significantly less than for ASCUS (p=0.0084). With LSIL cytology, specificity of Hybrid Capture 2 with 2 RLU cut-off was 35.0% (95%CI 28.4-42.1) at age 25-34 and 64.5% (95%CI 58.3-70.3) at age 35-60. In conclusion, triaging by HPV testing performed better in women aged over 35 years than those younger. For older women, HPV triaging should also be considered for managing those with LSIL cytology.