p16/ki-67 dual-stain cytology in the triage of ASCUS and LSIL papanicolaou cytology: results from the European equivocal or mildly abnormal Papanicolaou cytology study

BACKGROUND:

The objective of this study was to analyze the diagnostic performance of a newly established immunocytochemical dual‐stain protocol, which simultaneously detects p16^INK4a and Ki‐67 expression in cervical cytology samples, for identifying high‐grade cervical intraepithelial neoplasia (CIN2+) in women with Papanicolaou (Pap) cytology results categorized as atypical squamous cells of undetermined significance (ASCUS) or low‐grade squamous intraepithelial lesions (LSIL).

METHODS:

Residual liquid‐based cytology material from 776 retrospectively collected ASCUS/LSIL cases that were available from a recent study evaluating p16 cytology and HPV testing were subjected to p16/Ki‐67 dual staining. The presence of 1 or more double‐immunoreactive cell(s) was regarded as a positive test outcome, irrespective of morphology. Test results were correlated to histology follow‐up.

RESULTS:

Sensitivity of p16/Ki‐67 dual‐stain cytology for biopsy‐confirmed CIN2+ was 92.2% (ASCUS) and 94.2% (LSIL), while specificity rates were 80.6% (ASCUS) and 68.0% (LSIL), respectively. Similar sensitivity/specificity profiles were found for both age groups of women aged <30 years versus women aged ≥30 years. Dual‐stain cytology showed comparable sensitivity, but significantly higher specificity, when compared with human papillomavirus (HPV) testing.

CONCLUSIONS:

The results of this study show that p16/Ki‐67 dual‐stain cytology provided a high sensitivity for the detection of underlying CIN2+ in women with ASCUS or LSIL Pap cytology results, comparable to the rates previously reported for HPV testing and p16 single‐stain cytology. However, the specificity of this morphology‐independent interpretation of p16/Ki‐67 dual‐stain cytology testing was further improved compared with the earlier p16 single‐stain cytology approach, which required morphology interpretation, and it is significantly higher when compared with HPV testing. Cancer (Cancer Cytopathol) 2011;. © 2011 American Cancer Society.     

Good performance of p16/ki‐67 dual‐stained cytology for surveillance of women treated for high‐grade CIN

Women treated for high‐grade cervical intraepithelial neoplasia (CIN) are at risk of recurrent CIN Grade 2 or worse (rCIN2+). Currently, posttreatment monitoring is performed using cytology or cytology/high‐risk (hr)HPV cotesting. This study aimed to evaluate the performance of p16/Ki‐67 dual‐stained cytology (p16/Ki‐67) for posttreatment monitoring. Three hundred and twenty‐three women treated for high‐grade CIN in the SIMONATH study underwent close surveillance by cytology, hrHPV and DNA methylation marker testing up to 12 months posttreatment. Histological endpoints were ascertained by colposcopy with biopsy at 6 and/or 12 months. p16/Ki‐67 dual‐staining was performed on residual liquid‐based cytology samples obtained at, or shortly before biopsy collection. Clinical performance estimates of cytology, hrHPV, p16/Ki‐67 testing and combinations thereof for the detection of rCIN2+ were determined and compared to each other. Sensitivity of p16/Ki‐67 for rCIN2+ (69.2%) was nonsignificantly lower than that of cytology (82.1%; ratio 0.84, 95% CI: 0.71–1.01), but significantly lower than that of hrHPV testing (84.6%; ratio 0.82, 95% CI: 0.68–0.99). Specificity of p16/Ki‐67 for rCIN2+ (90.4%) was significantly higher compared to both cytology (70.8%; ratio 1.28, 95% CI: 1.19–1.37) and hrHPV testing (76.2%; ratio 1.19, 95% CI: 1.12–1.26). Overall, hrHPV testing showed very high sensitivity, along with a good specificity. When considering cotesting, combined p16/Ki‐67/hrHPV testing showed rCIN2+ sensitivity comparable to cytology/hrHPV cotesting (87.2% vs. 89.7%; ratio 0.97, 95% CI: 0.92–1.03), but with significantly increased specificity (74.2% vs. 58.1%; ratio 1.28, 95% CI: 1.19–1.38). Thus, when considered in combination with hrHPV, p16/Ki‐67 might be an attractive approach for surveillance of women treated for high‐grade CIN.     

The influence of type‐specific human papillomavirus infections on the detection of cervical precancer and cancer: A population‐based study of opportunistic cervical screening in the United States

There are limited data on the prospective risks of detecting cervical precancer and cancer in United States (US) populations specifically where the delivery of opportunistic cervical screening takes place outside managed care and in the absence of organized national programs. Such data will inform the management of women with positive screening results before and after widespread human papillomavirus (HPV) vaccination and establishes a baseline preceding recent changes in US cervical cancer screening guidelines. Using data reported to the statewide passive surveillance systems of the New Mexico HPV Pap Registry, we measured the 3‐year HPV type‐specific cumulative incidence of cervical intraepithelial neoplasia grade 2 or more severe (CIN2+) and grade 3 or more severe (CIN3+) detected during real‐world health care delivery across a diversity of organizations, payers, clinical settings, providers and patients. A stratified sample of 47,541 cervical cytology specimens from a screening population of 379,000 women underwent HPV genotyping. Three‐year risks for different combinations of cytologic interpretation and HPV risk group ranged from <1% (for several combinations) to approximately 70% for CIN2+ and 55% for CIN3+ in women with high‐grade (HSIL) cytology and HPV16 infection. A substantial proportion of CIN2+ (35.7%) and CIN3+ (30.9%) were diagnosed following negative cytology, of which 62.3 and 78.2%, respectively, were high‐risk HPV positive. HPV16 had the greatest 3‐year risks (10.9% for CIN2+,8.0% for CIN3+) followed by HPV33, HPV31, and HPV18. Positive results for high‐risk HPV, especially HPV16, the severity of cytologic interpretation, and age contribute independently to the risks of CIN2+ and CIN3+.     

Human papillomavirus testing versus cytology in primary cervical cancer screening: End‐of‐study and extended follow‐up results from the Canadian cervical cancer screening trial

The Canadian Cervical Cancer Screening Trial was a randomized controlled trial comparing the performance of human papillomavirus (HPV) testing and Papanicolaou cytology to detect cervical intraepithelial neoplasia of grades 2 or worse (CIN2+) among women aged 30–69 years attending routine cervical cancer screening in Montreal and St. John's, Canada (n = 10,154). We examined screening and prognostic values of enrollment cytologic and HPV testing results. Extended follow‐up data were available for St. John's participants (n = 5,754; 501,682.6 person‐months). HPV testing detected more CIN2+ than cytology during protocol‐defined (82.9 vs. 44.4%) and extended (54.2 vs. 19.3%) follow‐up periods, respectively. Three‐year risks ranged from 0.87% (95% CI: 0.37–2.05) for HPV‐/Pap‐ women to 35.77% (95% CI: 25.88–48.04) for HPV+/Pap+ women. Genotype‐specific risks ranged from 0.90% (95% CI: 0.40–2.01) to 43.84% (95% CI: 32.42–57.24) among HPV? and HPV16+ women, respectively, exceeding those associated with Pap+ or HPV+ results taken individually or jointly. Ten‐year risks ranged from 1.15% (95% CI: 0.60–2.19) for HPV?/Pap? women to 26.05% (95% CI: 15.34–42.13) for HPV+/Pap+ women and genotype‐specific risks ranged from 1.13% (95% CI: 0.59–2.14) to 32.78% (95% CI: 21.15–48.51) among women testing HPV? and HPV16+, respectively. Abnormal cytology stratified risks most meaningfully for HPV+ women. Primary HPV testing every 3 years provided a similar or greater level of reassurance against disease risks as currently recommended screening strategies. HPV‐based cervical screening may allow for greater disease detection than cytology‐based screening and permit safe extensions of screening intervals; genotype‐specific testing could provide further improvement in the positive predictive value of such screening.     

Combined use of cytology,p16 immunostaining and genotyping for triage of women positive for high-risk human papillomavirus at primary screening

Human papillomavirus (HPV) testing is very sensitive for primary cervical screening but has low specificity. Triage tests that improve specificity but maintain high sensitivity are needed. Women enrolled in the experimental arm of Phase 2 of the New Technologies for Cervical Cancer randomized controlled cervical screening trial were tested for high-risk HPV (hrHPV) and referred to colposcopy if positive. hrHPV-positive women also had HPV genotyping (by polymerase chain reaction with GP5+/GP6+ primers and reverse line blotting), immunostaining for p16 overexpression and cytology. We computed sensitivity, specificity and positive predictive value (PPV) for different combinations of tests and determined potential hierarchical ordering of triage tests. A number of 1,091 HPV-positive women had valid tests for cytology, p16 and genotyping. Ninety-two of them had cervical intraepithelial neoplasia grade 2+ (CIN2+) histology and 40 of them had CIN grade 3+ (CIN3+) histology. The PPV for CIN2+ was >10% in hrHPV-positive women with positive high-grade squamous intraepithelial lesion (61.3%), positive low-grade squamous intraepithelial lesion (LSIL+) (18.3%) and positive atypical squamous cells of undetermined significance (14.8%) cytology, p16 positive (16.7%) and, hierarchically, for infections by HPV33, 16, 35, 59, 31 and 52 (in decreasing order). Referral of women positive for either p16 or LSIL+ cytology had 97.8% sensitivity for CIN2+ and women negative for both of these had a 3-year CIN3+ risk of 0.2%. Similar results were seen for women being either p16 or HPV16/33 positive. hrHPV-positive women who were negative for p16 and cytology (LSIL threshold) had a very low CIN3+ rate in the following 3 years. Recalling them after that interval and referring those positive for either test to immediate colposcopy seem to be an efficient triage strategy. The same applies to p16 and HPV16.     

Evaluation of p16INK4a/Ki‐67 dual stain in comparison with an mRNA human papillomavirus test on liquid‐based cytology samples with low‐grade squamous intraepithelial lesion

BACKGROUND:

The objective of the current study was to investigate the clinical performance of detecting high‐grade lesions with the CINtec PLUS p16^INK4a/Ki‐67 dual stain and the APTIMA human papillomavirus (HPV) Assay in a cohort of women with low‐grade squamous intraepithelial lesion (LSIL) cytology. The authors also assessed the reproducibility of the evaluation of immunocytochemical staining.

METHODS:

The 2 tests were performed on liquid‐based residual material from 469 women with LSILs. The samples had at least 5 years of follow‐up and the gold standard used was high‐grade cervical intraepithelial neoplasia (CIN2+/CIN3+) proven on histology.

RESULTS:

Approximately 69% of all the women included in the study had a positive test for HPV mRNA and 56% was positive for the dual stain. The 2 tests demonstrated high sensitivities. When examining the specificities, the APTIMA HPV Assay performed with significantly lower values than the CINtec PLUS test. For patients with CIN2+, the APTIMA HPV Assay had a specificity of 36.1% versus 51.3% for the CINtec PLUS test, and for women with CIN3+, the specificity was 33.8% versus 48.2%, respectively. The difference was even more pronounced when analyzing women aged < 30 years separately. The kappa values between the 3 observers in scoring the dual stain ranged from 0.43 to 0.49 and improved in a second evaluation round to values ranging from 0.50 to 0.66.

CONCLUSIONS:

The CINtec PLUS p16^INK4a/Ki‐67 dual‐staining test in LSIL cytology samples demonstrated high sensitivity that was similar to that of the APTIMA HPV Assay in the detection of underlying high‐grade disease but with enhanced specificity, especially among women aged < 30 years. The kappa value for the evaluation of the CINtec PLUS dual‐staining test was moderate but could be improved through training. Cancer (Cancer Cytopathol) 2013. © 2012 American Cancer Society.     

The clinical value of HPV genotyping in triage of women with high‐risk‐HPV‐positive self‐samples

Cytology alone, or combined with HPV16/18 genotyping, might be an acceptable method for triage in hrHPV‐cervical cancer screening. Previously studied HPV‐genotype based triage algorithms are based on cytology performed without knowledge of hrHPV status. The aim of this study was to explore the value of hrHPV genotyping combined with cytology as triage tool for hrHPV‐positive women. 520 hrHPV‐positive women were included from a randomised controlled self‐sampling trial on screening non‐attendees (PROHTECT‐3B). Eighteen baseline triage strategies were evaluated for cytology and hrHPV genotyping (Roche Cobas 4800) on physician‐sampled triage material. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), referral rate, and number of referrals needed to diagnose (NRND) were calculated for CIN2+ and CIN3+. A triage strategy was considered acceptable if the NPV for CIN3+ was ≥98%, combined with maintenance or improvement of sensitivity and an increase in specificity in reference to the comparator, being cytology with a threshold of atypical cells of undetermined significance (ASC‐US). Three triage strategies met the criteria: HPV16+ and/or ≥LSIL; HPV16+ and/or ≥HSIL; (HPV16+ and/or HPV18+) and/or ≥HSIL. Combining HPV16+ and/or ≥HSIL yielded the highest specificity (74.9%, 95% CI 70.5–78.9), with a sensitivity (94.4%, 95% CI 89.0–97.7) similar to the comparator (93.5%, 95% CI 87.7–97.1), and a decrease in referral rate from 52.2% to 39.5%. In case of prior knowledge of hrHPV presence, triage by cytology testing can be improved by adjusting its threshold, and combining it with HPV16/18 genotyping. These strategies improve the referral rate and specificity for detecting CIN3+ lesions, while maintaining adequate sensitivity.     

Long‐term risk of cervical intraepithelial neoplasia grade 3 or worse according to high‐risk human papillomavirus genotype and semi‐quantitative viral load among 33,288 women with normal cervical cytology

In this prospective cohort study, we estimated the long‐term risk of cervical intraepithelial neoplasia grade 3 or cancer (CIN3+) by high‐risk human papillomavirus (hrHPV) genotype and semi‐quantitative viral load at baseline among 33,288 women aged 14–90 years with normal baseline cytology. During 2002–2005, residual liquid‐based cervical cytology samples were collected from women screened for cervical cancer in Copenhagen, Denmark. Samples were HPV‐tested with Hybrid Capture 2 (HC2) and genotyped with INNO‐LiPA. Semi‐quantitative viral load was measured by HC2 relative light units in women with single hrHPV infections. The cohort was followed in a nationwide pathology register for up to 11.5 years. In women aged ≥30 years at baseline, the 8‐year absolute risk for CIN3+ following baseline detection of HPV16 was 21.8% (95% confidence interval [CI]: 18.0–25.6%). The corresponding risks for HPV18, HPV31, HPV33, and other hrHPV types, respectively, were 12.8% (95% CI: 7.6–18.0%), 11.3% (95% CI: 7.7–14.9%), 12.9% (95% CI: 7.0–18.8%) and 3.9% (95% CI: 2.7–5.2%). Similar absolute risk estimates were observed in women aged <30 years. Higher HPV16‐viral load was associated with increased risk of CIN3+ (hazard ratio = 1.34, 95% CI: 1.10–1.64, per 10‐fold increase in viral load). A similar trend, although statistically nonsignificant, was found for viral load of HPV18. The 8‐year absolute risk of CIN3+ in women with HPV16‐viral load ≥100.0 pg/ml was 30.2% (95% CI: 21.9–38.6%). Our results support that hrHPV genotyping during cervical cancer screening may help identify women at highest risk of CIN3+.     

Triaging borderline/mild dyskaryotic Pap cytology with p16/Ki-67 dual-stained cytology testing: cross-sectional and longitudinal outcome study

Background:

Women with borderline/mildly dyskaryotic (BMD) cytology smears are currently followed up with repeat testing at 6 and 18 months. The objective of this study is to analyse the cross-sectional and longitudinal performance of p16/Ki-67 dual-stained cytology for the detection of cervical intraepithelial neoplasia (CIN) grade 3 or worse (CIN3+) and CIN2+ in women with BMD, and to compare the results with baseline human papillomavirus (HPV) testing.

Methods:

Conventional Pap cytology specimens of 256 women with BMD were dual stained for p16/Ki-67 retrospectively, and compared with baseline HPV results and long-term follow-up results.

Results:

p16/Ki-67 dual-stained cytology showed a sensitivity of 100%, a specificity of 64.4% and a negative predictive value (NPV) of 100.% for CIN3+. Human papillomavirus testing demonstrated similar sensitivity (96.3%), and NPV (99.1%), but a significantly lower specificity (57.6% P=0.024) for CIN3+. Sensitivity, specificity and NPV for CIN2+ of dual-stained cytology were 89.7%, 73.1% and 95.1%, respectively, which was similar when compared with HPV testing. Dual-stained cytology showed a significant lower referral rate than HPV testing (43.6% vs 49.1% P=0.043). During long-term follow-up, no CIN3+ lesions developed in HPV-positive, dual-stained negative women.

Conclusions:

Comparable sensitivity and NPV of dual-stained cytology for CIN3+, combined with a significantly higher specificity, makes p16/Ki-67 dual-stained cytology a viable alternative to HPV testing for triaging BMD.     

Cumulative 5-year diagnoses of CIN2, CIN3 or cervical cancer after concurrent high-risk HPV and cytology testing in a primary screening setting

The aim of our study was to assess the cumulative 5-year diagnoses of CIN2, CIN3 or invasive cervical cancer (CIN2+) after concurrent screening by high-risk HPV test and Pap smear in a primary screening setting. Four thousand thirty-four women from Eastern Thuringia/Germany were recruited from 1996 to 1998 for baseline screening that included routine cytology, high-risk HPV testing by consensus primer PCR GP5+/6+ and routine colposcopy. After a median of 59 months 3,153 women participated in final screening using identical methods. Women with abnormal cytology or colposcopy or a positive high-risk HPV test at any time during the study period were recalled for expert colposcopy and histologic verification. CIN2+ was detected in 160 women resulting in a cumulative 5-year proportion of 4.4% (95% CI: 3.7-5.0%). Of 3,702 women who were high-risk HPV negative at baseline, 34 (1.1-95% CI: 0.7-1.4%) had either prevalent CIN2+ or developed CIN2+ within the observation period. HPV/cytology double negatives at baseline were at lowest risk for CIN2+ (1.0-95% CI: 0.7-1.4%) compared to screening positives (16.8-100% depending on combined test results). The 5-year negative predictive value in HPV-/Cyto- women was 99.0% (95% CI: 98.6-99.3%). This suggests that a prolongation of the screening intervals in this group is feasible. However, it should be noted that 1 woman developed a microinvasive carcinoma within the observation period. Moreover, 2 women with prevalent cancer were missed by both tests. The prognostic relevance of concurrent high-risk HPV/cytology screening needs to be verified further by randomized trials.     

Diagnostic value of p16INK4A,Ki‐67, and human papillomavirus L1 capsid protein immunochemical staining on cell blocks from residual liquid‐based gynecologic cytology specimens

BACKGROUND:

This study was conducted to evaluate the reliability and role of cell block preparations in the diagnosis of neoplastic and preneoplastic lesions of the cervix and to improve the value of cell block preparations in diagnosing and predicting the prognosis of cervical lesions through immunostaining of p16INK4A (p16), Ki‐67, and human papillomavirus (HPV) L1 capsid protein (HPV L1).

METHODS:

In total, 138 specimens were diagnosed on liquid‐based cytology (LBC) and cell block preparations, and 63 specimens were subjected subsequently to tissue follow‐up and immunostaining for p16, Ki‐67, and HPV L1 on cell block sections.

RESULTS:

In 42 specimens that were diagnosed as low‐grade squamous intraepithelial lesion, high‐grade squamous intraepithelial lesion (HSIL), and squamous cell carcinoma (SCC) on cell blocks, 38 specimens (90.5%) were confirmed by histopathologic reports, and there was slightly better than 81.6% agreement between LBC and tissue follow‐up. Immunointensity and cells that were positive for p16 were enhanced according to increased pathologic grade and differed statistically between cervical intraepithelial neoplasia 1 (CIN‐1) and CIN‐2/CIN‐3 as well as SCC. The positive rates of HPV L1 decreased gradually according to the severity of cervical neoplasia, and HPV L1/p16 expression patterns were related to the severity of cervical lesions.

CONCLUSIONS:

The cell block preparation technique was complementary to LBC, and the authors concluded that the application of LBC combined with cell block preparations may improve the diagnostic accuracy of cytology. Immunostaining for p16 and Ki‐67 on cell block preparations can help to improve the diagnostic accuracy of HSIL and SCC. A combined expression pattern of p16 and HPV L1 may serve as a valuable index for predicting prognosis and follow‐up of cervical dysplastic lesions. Cancer (Cancer Cytopathol) 2010. © 2010 American Cancer Society.     

The role of human papillomavirus type 16/18 genotyping in predicting high‐grade cervical/vaginal intraepithelial neoplasm in women with mildly abnormal Papanicolaou results

BACKGROUND:

The authors compared the predictive value of type 16 and/or 18 human papillomavirus (HPV) versus non‐16/18 HPV types for high‐grade (grade ≥2) cervical neoplasm/vaginal intraepithelial neoplasm and carcinoma (CIN/VAIN2+) in women with mildly abnormal Papanicolaou (Pap) results (ie, atypical squamous cells of undetermined significance [ASCUS] or low‐grade squamous epithelial lesion [LSIL]).

METHODS:

The authors retrospectively selected Pap specimens with HPV testing results obtained from 243 women (155 with ASCUS and 88 with LSIL Pap results) in their Department of Pathology. HPV genotyping was performed using the EasyChip HPV blot assay. The Pap specimens with HPV16/18 and non‐16/18 HPV types were compared with follow‐up biopsy results. Follow‐up duration ranged from 1 month to 58 months (mean, 26 months).

RESULTS:

In total, 58 of 155 specimens (37%) that had ASCUS and 29 of 88 specimens (33%) that had LSIL were positive for HPV16/18. CIN/VAIN2+ biopsies were identified in 43 of 155 women (28%) with ASCUS and in 28 of 88 women (32%) with LSIL. Women with ASCUS and HPV16/18 had a significantly higher rate (43%) of CIN/VAIN2+ than women with ASCUS and non‐16/18 HPV types (19%; P = .003; odds ratio, 3.10; 95% confidence interval, 1.48‐6.53). There was no statistically significant difference in the rate of CIN/VAIN2+ between women who had LSIL and HPV16/18 (45%) and those who had LSIL and non‐16/18 HPV types (29%; P = .16; odds ratio, 1.96; 95% confidence interval, 0.77‐4.97).

CONCLUSIONS:

HPV genotyping for HPV16/18 improved risk assessment for women with ASCUS Pap results and may be used to predict the risk of CIN/VAIN2+ to better guide follow‐up management. Cancer (Cancer Cytopathol) 2013. © 2012 American Cancer Society.     

Approaches to triage optimization in HPV primary screening: Extended genotyping and p16/Ki-67 dual-stained cytology—Retrospective insights from ATHENA

The objective of our study was to assess the performance of different triage strategies for high-risk human papillomavirus (hrHPV)-positive results utilizing either extended genotyping or a p16/Ki-67 dual-stained cytology (DS) approach, with or without partial genotyping. A subset of women with hrHPV infections participating in the Addressing the Need for Advanced HPV Diagnostics (ATHENA) study were analyzed to determine the number of cervical intraepithelial neoplasia grade 3 or worse (≥CIN3) cases detected, and the absolute risk for ≥CIN3 of each genotype. A clinical utility table was constructed to compare the impact of different triage strategies. In all, 2,339 women with single-genotype hrHPV infections were identified. Among these were 171 ≥CIN3 cases. The U.S. Food and Drug Administration (FDA)-approved algorithm (HPV16/18 positive, or 12-other hrHPV positive and Pap positive, i.e., ≥ atypical squamous cells of undetermined significance) for primary HPV screening detected 132/171 (77.2%) ≥CIN3 cases and required 964 colposcopies (colposcopies per ≥CIN3 ratio: 7.3). An approach that uses DS instead of cytology in the FDA-approved algorithm detected 147/171 (86.0%) ≥CIN3 cases, requiring 1,012 colposcopies (ratio: 6.9). Utilizing DS for triage of all hrHPV-positive women identified 126/171 (73.7%) ≥CIN3 cases, requiring 640 colposcopies (ratio: 5.1). A strategy that detected HPV16/18/31/33/35+ captured 130/171 (76.0%) ≥CIN3 cases, requiring 1,025 colposcopies (ratio: 7.9). Inclusion of additional genotypes resulted in greater disease detection at the expense of higher colposcopy ratios. Substituting cytology with a DS triage approach improved disease detection and the colposcopy detection rate. Further reduction of colposcopy rates can be achieved by using DS without partial genotyping. Extended genotyping strategies can identify a comparable number of cases but requires an increased number of colposcopies.     

Human papilloma virus genotyping for the cross‐sectional and longitudinal probability of developing cervical intraepithelial neoplasia grade 2 or more

Human papilloma virus (HPV) testing is more sensitive but less specific than cytology. We evaluated stand‐alone genotyping as a possible triage method. During a multicentre randomised controlled trial comparing HPV testing to conventional cytology, HPV‐positive women were referred to colposcopy and followed up if no high‐grade lesion was detected. HPV‐positive samples were genotyped by GP5+/GP6+ primed polymerase chain reaction followed by reverse line blot. Genotypes were hierarchically ordered by positive predictive value (PPV) for CIN grade 2 or more (CIN2+), and grouped by cluster analysis into three groups (A, B and C in decreasing order). Receiver operating characteristic curves were computed. Among 2,255 HPV‐positive women with genotyping, 239 CIN2+ (including 113 CIN3+) were detected at baseline or during a 3‐year follow‐up. HPV33 had the highest PPV with CIN2+ and CIN3+ as the endpoint and when considering lesions detected at baseline or also during follow‐up. HPV16 and HPV35 were the second and third, respectively. Cross‐sectional sensitivity for CIN2+ at baseline was 67.3% (95% CI 59.7–74.2), 91.8% (95% CI 86.6–95.5) and 94.7% (95% CI 90.2–97.6), respectively, when considering as “positive” any of the HPV types in group A (33, 16 and 35), A or B (31, 52, 18, 59 and 58) and A or B or C (39, 51, 56, 45 and 68). The corresponding cross‐sectional PPVs for CIN2+ were 15.8% 95% (CI 13.2–18.7), 12.0% (95% CI 10.3–13.9) and 9.6% (95% CI 8.2–11.1), respectively. HPV33, 16 and 35 confer a high probability of CIN2+ but this rapidly decreases when adding other genotypes.     

Long‐term follow‐up of the risk for cervical intraepithelial neoplasia grade 2 or worse in HPV‐negative women after conization

Little research has been conducted on the long‐term value of human papillomavirus (HPV) testing after conization. We investigated whether cytology adds to the value of a negative HPV test for long‐term prediction of cervical intraepithelial neoplasia grade 2 or worse (CIN2+). In addition, we compared risk of CIN2+ following a negative HPV test in women after conization with that in women from the general population. During 2002–2005, 667 women treated for CIN2+ were tested for HPV and cytology 46 months after conization. Only HPV‐negative women were included. Women participating in routine screening were age‐matched with post‐conization HPV‐negative women, leaving 13,230 and 477 women, respectively, for analysis. By linkage to the Pathology Data Bank, we identified all cases of CIN2+ by December 2013. The 3‐, 5‐, 8‐ and 10‐year risks for CIN2+ were 0.7, 0.9, 2.8 and 5.7% after a negative HPV test and 0.5, 0.8, 2.9 and 6.1% in HPV and cytology‐negative women. HPV‐negative women in the general population had similar 3‐year and 5‐year risks of 0.4 and 1.0%; thereafter, they had lower risks of 1.9% at 8 years and 2.7% at 10 years. Our results indicate that HPV testing may be used as a test of cure after conization. In the first 5 years after testing, the risk for CIN2+ of women who were HPV‐negative at 34 months after conization was similar to that of HPV‐negative women in the general population. After 67 years, however, women who have undergone conization may be at higher risk for CIN2+.     

Immunocytochemical colocalization of P16(INK4a) and Ki-67 predicts CIN2/3 and AIS/adenocarcinoma

BACKGROUND:

Although previous studies have shown that p16^INK4a and Ki‐67 are sensitive and specific markers for high‐grade lesions (≥CIN2) on cervical biopsies, limited information is available regarding the performance of a dual‐staining approach as a diagnostic adjunct in cervical cytology. We evaluated a dual p16^INK4a/Ki‐67 immunocytochemistry (ICC) assay to determine its sensitivity and specificity versus that of high‐risk HPV (HR‐HPV) in a US‐based pilot cytology study.

METHODS:

ThinPrep specimens from 122 cervical cytology specimens encompassing 23 negative (NILM), 20 ASC‐US, 22 LSIL, 17 ASCH, 22 HSIL, and 18 AGC cases were processed for multiplexed ICC staining using a CINtec Plus Kit. Dual‐positive assay results were defined based on the detection of 1 or more epithelial cells that were stained for both p16^INK4a and Ki‐67 without regard to cellular morphology. HR‐HPV testing was performed by multiplex PCR with capillary electrophoresis genotyping.

RESULTS:

Dual staining for p16^INK4a and Ki‐67 was frequently detected in HSIL and AGC but was rarely detected in NILM cases. The HR‐HPV assay showed a sensitivity of 76.2% and a specificity of 55.8% for the detection of clinically significant cervical squamous or endometrial lesions. In contrast, the colocalization of p16^INK4a plus Ki‐67 maintained a high sensitivity of 81.8% and improved specificity to 81.8% for biopsy‐confirmed CIN2/3, endocervical adenocarcinoma, or endometrial adenocarcinoma.

CONCLUSIONS:

Dual staining for p16^INK4a/Ki‐67 immunocytochemistry dramatically increased specificity and maintained high‐level sensitivity for the diagnosis of CIN2/3 or glandular lesions compared with PCR‐based testing for HR‐HPV. Cancer (Cancer Cytopathol) 2012. © 2011 American Cancer Society.     

A cohort study of cervical screening using partial HPV typing and cytology triage

HPV testing is more sensitive than cytology for cervical screening. However, to incorporate HPV tests into screening, risk‐stratification (“triage”) of HPV‐positive women is needed to avoid excessive colposcopy and overtreatment. We prospectively evaluated combinations of partial HPV typing (Onclarity, BD) and cytology triage, and explored whether management could be simplified, based on grouping combinations yielding similar 3‐year or 18‐month CIN3+ risks. We typed ～9,000 archived specimens, taken at enrollment (2007–2011) into the NCI‐Kaiser Permanente Northern California (KPNC) HPV Persistence and Progression (PaP) cohort. Stratified sampling, with reweighting in the statistical analysis, permitted risk estimation of HPV/cytology combinations for the 700,000+‐woman KPNC screening population. Based on 3‐year CIN3+ risks, Onclarity results could be combined into five groups (HPV16, else HPV18/45, else HPV31/33/58/52, else HPV51/35/39/68/56/66/68, else HPV negative); cytology results fell into three risk groups (“high‐grade,” ASC‐US/LSIL, NILM). For the resultant 15 HPV group‐cytology combinations, 3‐year CIN3+ risks ranged 1,000‐fold from 60.6% to 0.06%. To guide management, we compared the risks to established “benchmark” risk/management thresholds in this same population (e.g., LSIL predicted 3‐year CIN3+ risk of 5.8% in the screening population, providing the benchmark for colposcopic referral). By benchmarking to 3‐year risk thresholds (supplemented by 18‐month estimates), the widely varying risk strata could be condensed into four action bands (very high risk of CIN3+ mandating consideration of cone biopsy if colposcopy did not find precancer; moderate risk justifying colposcopy; low risk managed by intensified follow‐up to permit HPV “clearance”; and very low risk permitting routine screening.) Overall, the results support primary HPV testing, with management of HPV‐positive women using partial HPV typing and cytology.     

Stratifying HPV‐positive women for CIN3+ risk after one and two rounds of HPV‐based screening

A main challenge of human papilloma (HPV)‐based screening for cervical cancer is to adequately identify HPV‐positive women at highest risk of cervical intraepithelial neoplasia grade 3 or worse, CIN3+. The prognostic value of currently used adjunct markers (HPV16/18 genotyping and reflex cytology) may change after multiple rounds of HPV‐based screening because of a change in the proportion of HPV‐positive women with incident infections. To this end, we re‐analyzed results from the POBASCAM trial (Population Based Screening Study Amsterdam). Women were randomized to HPV/cytology cotesting (intervention group) or to cytology‐only (HPV blinded; control group) at enrolment. Our analytical population consisted of women with an HPV‐positive result at the second round, 5 years after enrolment (n = 381 intervention, n = 392 control). Nine‐year CIN3+ risks were estimated by Kaplan–Meier. HPV‐positive women were stratified by risk markers: HPV16/18 genotyping, reflex cytology and preceding HPV results. When comparing one to two rounds of HPV‐based screening, the prognostic value of an abnormal cytology result did not change (40.0% vs. 42.3%, p = 0.5617), but diminished for an HPV16/18 positive result (25.4% vs. 38.0%, p = 0.0132). HPV16/18 genotyping was nondiscriminative in women with incident HPV infections (HPV16/18 positive 10.0% vs. negative 12.1%, p = 0.3193). Women from the intervention group were more likely to have incident infections compared to women from the control group (incident screen‐positive results 75.6% vs. 64.6%, p = 0.001) Our results indicate that at a second round of HPV‐based screening, risk differentiation by cytology remained strong, but was diminished for HPV 16/18 genotyping because of a larger proportion of incident infections.     

Image‐guided ThinPrep Papanicolaou tests and cotesting with high‐risk human papillomavirus in women aged 30 years and older in a low‐risk private practice population

BACKGROUND:

Screening for cervical cancer precursors has evolved considerably with the introduction of new technologies to improve the early detection of disease. The objective of this study was to analyze the accuracy and effectiveness of combined screening with cytology and high‐risk human papillomavirus (HR‐HPV) testing in a low‐risk population of women aged ≥30 years.

METHODS:

Consecutive unselected samples from a group of 1871 women aged ≥30 years were screened with image‐guided ThinPrep tests and HR‐HPV tests during a 6‐month period. Histologic follow‐up was reviewed among women with positive HR‐HPV tests.

RESULTS:

A total of 85 (4.5%) women had positive HR‐HPV tests. In 48 HR‐HPV–positive women with follow‐up biopsies, 41 (85%) were found to have histologic abnormalities. Thirty‐three (1.9%) women with cytologically normal Papanicolaou (Pap) tests harbored HR‐HPV, and a cervical intraepithelial neoplasia (CIN) 2+ lesion was detected in 1 (16%) of 6 women with histologic follow‐up. Conversely, 2 (28%) of 7 women with high‐grade intraepithelial lesion on cytology tested negative for HR‐HPV during the same period. A case of serous carcinoma with atypical glandular cells on cytology was also negative for HR‐HPV, as expected.

CONCLUSIONS:

In this low‐risk population of women aged ≥30 years, histology‐confirmed CIN2+ lesions were identified in women with negative cytology and positive HR‐HPV tests, as well as in those with positive cytology and negative HR‐HPV tests. Because both cytology and HPV testing alone missed significant lesions, cotesting with Pap and HR‐HPV in women aged ≥30 years appears to be a reasonable option in a low‐risk population. (Cancer Cytopathol) 2009. © 2009 American Cancer Society.     

Age‐stratified 5‐year risks of cervical precancer among women with enrollment and newly detected HPV infection

It is unclear whether a woman's age influences her risk of cervical intraepithelial neoplasia grade 3 or worse (CIN3+) upon detection of HPV. A large change in risk as women age would influence vaccination and screening policies. Among 972,029 women age 30–64 undergoing screening with Pap and HPV testing (Hybrid Capture 2, Qiagen, Germantown, MD) at Kaiser Permanente Northern California (KPNC), we calculated age‐specific 5‐year CIN3+ risks among women with HPV infections detected at enrollment, and among women with “newly detected” HPV infections at their second screening visit. Women (57,899, 6.0%) had an enrollment HPV infection. Among the women testing HPV negative at enrollment with a second screening visit, 16,724 (3.3%) had a newly detected HPV infection at their second visit. Both enrollment and newly detected HPV rates declined with age (p < 0.001). Women with enrollment versus newly detected HPV infection had higher 5‐year CIN3+ risks: 8.5% versus 3.9%, (p < 0.0001). Risks did not increase with age but declined slightly from 30–34 years to 60–64 years: 9.4% versus 7.4% (p = 0.017) for enrollment HPV and 5.1% versus 3.5% (p = 0.014) for newly detected HPV. Among women age 30–64 in an established screening program, women with newly detected HPV infections were at lower risk than women with enrollment infections, suggesting reduced benefit vaccinating women at older ages. Although the rates of HPV infection declined dramatically with age, the subsequent CIN3+ risks associated with HPV infection declined only slightly. The CIN3+ risks among older women are sufficiently elevated to warrant continued screening through age 65.