Comparison of ProEx C with p16INK4a and Ki‐67 immunohistochemical staining of cell blocks prepared from residual liquid‐based cervicovaginal material

BACKGROUND.

Although liquid‐based cervicovaginal cytology has high sensitivity for detecting dysplastic/malignant lesions, many pitfalls exist. Cell blocks can be prepared from residual liquid‐based cervicovaginal material and used for immunohistochemistry. The aim of this study was to evaluate a new marker, ProEx C, on cell blocks and its ability to distinguish dysplastic/malignant lesions from morphologically abnormal but benign cells. The results of this study were compared with previously reported results for p16 and Ki‐67 on the same material.

METHODS.

ProEx C is a cocktail of monoclonal antibodies against proteins associated with aberrant S phase cell cycle induction (topoisomerase IIA, minichromosome maintenance protein 2). ThinPrep (CytycCorp., Boxborough, Mass) cervicovaginal specimens from 79 patients were selected. Four cases had no residual abnormal cells in the cell block. On the basis of the cell block diagnosis, 29 cases were negative for intraepithelial lesion or malignancy (NILM), 27 had low‐grade squamous intraepithelial lesions (LSIL), 16 had high‐grade squamous intraepithelial lesions (HSIL), and 3 had squamous cell carcinomas (SCC). Cell block sections were immunostained with ProEx C.

RESULTS.

Thirteen of 16 (81%) cases of HSIL stained positively with ProEx C. Two of 27 (7%) LSIL stained positively, and 2 (7%) cases of NILM stained positively. All 3 cases of SCC were strongly positive (100%). Staining for ProEx C showed a higher positive predictive value compared with p16.

CONCLUSIONS.

ProEx C can be used on cell blocks prepared from residual liquid‐based cervicovaginal cytologic specimens. Being a nuclear only stain, it is cleaner and easier to interpret even in scant specimens. Cancer (Cancer Cytopathol) 2008. © 2008 American Cancer Society.     

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.     

p16INK4a is superior to high‐risk human papillomavirus testing in cervical cytology for the prediction of underlying high‐grade dysplasia

BACKGROUND

The primary goal of this study was to compare the clinical performance of an optimized and rigorously controlled immunocytochemical (ICC) assay for p16^INK4a to high‐risk (HR) human papillomavirus (HPV) detection by polymerase chain reaction (PCR) as diagnostic adjuncts for cytology specimens from colposcopy patients.

METHODS:

The study included 403 cervical cytology specimens collected within 3 months of colposcopy. The colposcopic impression and cervical biopsy diagnosis served as the standards for correlation with cytological, p16^INK4a, and HPV data. p16^INK4a was evaluated using an immunoperoxidase‐based assay that was linear over 4 logs for the detection of HeLa‐spiked positive control cytology specimens, using a threshold for positive test results that was based on receiver operating characteristic curve analysis. HR‐HPV was detected by multiplex PCR using genotype‐specific primers.

RESULTS:

In all combined diagnostic categories (negative for intraepithelial lesion and malignancy, atypical glandular cells, atypical squamous cells of undetermined significance, atypical squamous cells cannot exclude high‐grade squamous intraepithelial lesion, low‐grade squamous intraepithelial lesion, and high‐grade squamous intraepithelial lesion), the p16^INK4a ICC and HR‐HPV assays, respectively, had sensitivity of 81.7% and 83.3% (P = .81) and specificity of 78.1% and 50.9% (P < .001) for the detection of underlying ≥grade 2 cervical intraepithelial neoplasia (CIN) lesions on biopsy. Furthermore, the positive predictive value of p16^INK4a ICC was greater than that of HR‐HPV for patients with biopsies ≥CIN‐2 (41.2% and 24.2%, respectively, P = .001).

CONCLUSIONS:

This p16^INK4a immunocytochemical assay has superior specificity but similar sensitivity to HR‐HPV testing to predict underlying high‐grade dysplastic lesions in patients who are referred for colposcopy. The determination of the overall performance characteristics of p16^INK4a immunocytochemistry, as an independent test or in combination with HPV testing in low‐risk screening populations, however, will require subsequent large‐scale prospective clinical trials. Cancer (Cancer Cytopathol) 2010. © 2010 American Cancer Society.     

Triaging HPV‐positive women with normal cytology by p16/Ki‐67 dual‐stained cytology testing: Baseline and longitudinal data

Primary human papillomavirus (HPV)‐based screening results in a 2–5% lower specificity for cervical intraepithelial neoplasia Grade 2 or worse (CIN2+) compared to Pap cytology. To identify HPV‐positive women with CIN2+, we retrospectively evaluated the cross‐sectional and longitudinal performance of p16/Ki‐67 dual‐stained cytology in HPV‐positive women with normal cytology participating in population‐based cervical screening. Conventional Pap cytology specimens of 847 of these women derived from the VUSA‐Screen study were dual‐stained for p16/Ki‐67. Cross‐sectional clinical performance in detecting CIN3 or worse (CIN3+), and CIN2+ was compared to that of baseline HPV genotyping. Moreover, 5‐year cumulative incidence risks (CIR) for CIN3+ (CIN2+) were determined. The sensitivity of p16/Ki‐67 dual‐stained cytology for CIN3+ (CIN2+) was 73.3% (68.8%) with a specificity of 70.0% (72.8%). HPV16/18 genotyping showed a sensitivity for CIN3+ (CIN2+) of 46.7% (43.8%), with a specificity of 78.3% (79.4%). The 5‐year CIR for CIN3+ in HPV‐positive women with normal cytology was 6.9%. Testing these women with p16/Ki‐67 dual‐stained cytology resulted in a significantly lower CIN3+ 5‐year CIR of 3.3% (p = 0.017) in case of a negative test result. A negative HPV16/18 genotyping test result also led to a lower 5‐year CIN3+ CIR of 3.6%. p16/Ki‐67 dual‐stained cytology detects more than 70% of underlying CIN3+ lesions in HPV‐positive women with normal cytology at baseline and is therefore suitable for triaging these women to colposcopy. Furthermore, the CIN3+ 5‐year CIR of 3.3% after a negative dual‐stain result is significantly lower compared to the 5‐year CIR of 6.9% in women without p16/Ki‐67 dual‐stained cytology triage.     

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.     

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.     

Immunochemical analysis of HPV L1 capsid protein and p16 protein in liquid‐based cytology samples from uterine cervical lesions

BACKGROUND

HPV L1 capsid protein is expressed together with the production of infectious viral particles, but its expression and relation to p16 expression, which has been a surrogate marker for human papilloma virus (HPV) infection in cervix, are little studied in cytology samples. The authors aimed to elucidate the relation between L1 capsid protein and p16 protein expressions in liquid‐based samples from uterine cervical lesions.

METHODS

Immunochemical analyses using antibodies against L1 capsid protein and p16 protein were carried out on cytological materials obtained from uterine cervical lesions of low‐grade squamous intraepithelial lesions (LSILs), high‐grade squamous intraepithelial lesions (HSILs), and squamous cell carcinomas (SCCs).

RESULTS

L1 capsid protein was positive in 30% of LSILs and 12% of HSILs, but in 0% of SCCs. In contrast, p16 protein was positive in 55% of LSILs, 100% of HSILs, and 100% of SCCs. L1‐positive cells were only observed in the superficial layer, whereas p16‐positive cells were seen throughout the full thickness of the epithelium. The relation between L1 capsid protein and p16 protein, p16(?)/L1(+) cases represented 44% of LSILs, but 0% of HSILs, and 0% of SCCs, whereas p16(+)/L1(?) cases represented 82% of LSILs, 88% of HSILs, and 100% of SCCs.

CONCLUSIONS

Expression of L1 capsid protein decreased with lesion progression from LSILs to HSILs and SCCs, whereas p16 protein was positive in all HSILs and SCCs. The correlation between L1 and p16 expressions suggests that L1(?)/p16(+) cases have the potential for progression, whereas L1(+)/p16(?) and L1(?)/p16(?) cases may be nonprogressive lesions or potentially in remission. Cancer (Cancer Cytopathol) 2008. ? 2008 American Cancer Society.     

Immunohistochemical detection of p16INK4a in liquid‐based cytology specimens on cell block sections

BACKGROUND

Colposcopy biopsy procedure is a standard recommendation for atypical squamous cell cannot exclude high‐grade lesion (ASC‐H) in abnormal Papanicolaou smears. p16 (p16INK4a), a cell cycle regulator, has been shown to be overexpressed in squamous dysplasia. To further improve the diagnostic accuracy of the ASC‐H Papanicolaou smear and to reduce unnecessary procedures, the authors evaluated the utility of immunodetection of p16 in liquid‐based cytology specimens on cell blocks.

METHODS

Seventy‐five liquid‐based (SurePath; TriPath Imaging, Inc. Burlington, NC) cytology specimens were prepared for cell blocks. Three groups (G1, G2, and G3) of cases were included: G1 comprised 44 cases of ASC‐H; G2, 14 cases of high‐grade dysplasia; and G3, 17 negative/reactive cases. All cases in G1 were confirmed by cervical biopsy or Digene Hybrid Capture 2 (Digene, Gaithersburg, Md) human papilloma virus (HPV) testing. Immunodetection for p16 was performed on cell blocks.

RESULTS

In G1, 26 of 44 (59%) cases showed squamous dysplasia, with 14 high‐grade squamous intraepithelial lesion (HSIL) cases. Twenty‐two of 28 (79%) p16‐positive cases were confirmed by surgical biopsy or HPV testing, with a diagnostic sensitivity of 85%, specificity of 67%, positive predictive value (PPV) of 79%, and negative predictive value (NPV) of 75%. Four cases with false‐negative staining for p16 were identified. All 28 cases of HSIL (14 from G1 and 14 from G2) were positive for p16.

CONCLUSIONS

1) p16 is a sensitive marker to confirm the diagnosis of ASC‐H on a cell block; 2) Multiple unstained slides with adequate cellularity can be obtained from each cell block; and 3) Additional markers can be used to further increase diagnostic sensitivity and specificity. Cancer (Cancer Cytopathol) 2007. © 2007 American Cancer Society.     

不同宫颈组织中PIK3CA、PTEN和p16蛋白表达及其与HPV16/18感染的关系

 目的 探讨PIK3CA、PTEN和p16蛋白在人正常宫颈上皮、宫颈上皮内瘤变（cervical intraepithelial neoplasia,CIN） 和宫颈鳞癌组织中的表达,以及PIK3CA、PTEN和p16蛋白表达与人乳头瘤病毒（human papillomavirus,HPV）感染 之间的关系。方法采用免疫组织化学二步法在22例健康者宫颈组织、72例宫颈上皮内瘤变（cervical intraepithelial neoplasia,CIN）和30例宫颈鳞癌组织中检测PIK3CA、PTEN和p16蛋白的表达,显色原位杂交方 法检测高危型HPV16/18的感染。结果PIK3CA和p16蛋白表达阳性率和HPV16/18的感染率均随着宫颈上皮逐渐恶变而 上升,PTEN蛋白表达却 呈现相反的结果。PIK3CA、PTEN、p16蛋白和 HPV16/18的感染率在宫颈鳞癌和CIN Ⅱ～Ⅲ组中的表达分别与对照组和CIN Ⅰ组相比,差异均有统计学意义（P＜ 0.05）。在宫颈上皮内瘤变组织中,39例（76.47%）CIN Ⅱ～Ⅲ 中显示PIK3CA阳性,仅有9例 （42.86%）CIN Ⅰ中显示 PIK3CA阳性,两组间差异有统计学意义（P=0.006）,而PTEN和p16蛋白在宫颈上皮内瘤 变不同组别中相比差异均无统计学意义。在81例CIN Ⅱ～Ⅲ和鳞癌组织中,PIK3CA和p16蛋白呈显著正相关关系 （P=0.000,r=0.544）。PIK3CA、p16蛋白与PTEN蛋白表达之间,两者均呈显著负相关（P＜0.05）。 HPV16/18阳性的47例标本中,PIK3CA和p16蛋白几乎均呈阳性表达,呈显著正相关（P<0.01）,但PTEN蛋白却有37例呈阴性表达,无显著相关（P=0.116）。结论PIK3CA、PTEN、p16蛋白表达以及高危型HPV感染与宫颈癌的发生发展均密切相关。PIK3CA、PTEN、p16蛋白和高危型HPV感染联合检测,可作为宫颈癌早期癌变的分子标志物。高危型HPV感染可能有助于PIK3CA和p16蛋白的高表达。     

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.     

p16INK4a免疫细胞化学检测在筛查宫颈癌中的作用

目的 探讨p16^INK4a免疫细胞化学检测在筛查宫颈癌及其癌前病变中的作用。方法 选择220例宫颈液基细胞学剩余标本,制作液基薄片进行p16^INK4a 免疫细胞化学检测,随访组织活检结果,并与高危人乳头瘤病毒（HR—HPV）DNA检测结果进行对照。结果 p16^INK4a在宫颈细胞学诊断的鳞状细胞癌（SCC）、鳞状上皮内高度病变（HSIL）、鳞状上皮内低度病变（LSIL）、非典型鳞状细胞-小除外上皮内高度病变（ASC—H）和非典型鳞状细胞-不能明确意义（ASC—US）病例的阳性表达率分别为100．0％（7／7）、92．2％（107／116）、24．3％（17／70）、100．0％（14／14）和36．4％（4／11）。150例p16^INK4a阳性者中,111例有组织活检诊断,其中宫颈上皮内瘤变（CIN）2级及以上病变者97例（87．4％）;70例p16^INK4a阴性者中,18例有组织活检诊断,无一例CIN2及以上病变。p16^INK4a在CIN2及以上病变与在CIN1之间的阳性表达率差异有统计学意义（P〈0.01）,而HR-HPV DNA的阳性率在两者之间差异无统计学意义。结论 p16^INK4a在宫颈HSIL及以上病变中高表达,有利于高危病例的筛选。     

Reflex Human Papillomavirus Test Results as an Option for the Management of Korean Women With Atypical Squamous Cells Cannot Exclude High‐Grade Squamous Intraepithelial Lesion

Background.

Current guidelines recommend initial colposcopy with biopsy regardless of human papillomavirus (HPV) test results in women with atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion (ASC-H). The purpose of this study was to evaluate the value of HPV testing in women with ASC-H based on colposcopic pathology results.

Materials and Methods.

A multicenter cross-sectional study was carried out at three academic hospitals and involved 40,847 Korean women who underwent cervical cancer screening with cytology and HPV tests with or without subsequent colposcopic biopsies between January 2007 and December 2013.

Results.

ASC-H was diagnosed in 276 women (0.7%). Only 6 of 68 (8.8%) women with ASC-H who were HPV negative had cervical intraepithelial neoplasia grade ≥2 (CIN ≥2) lesions, whereas 47.4% of the women with ASC-H who were HPV positive had CIN ≥2 lesions. No cases of invasive cervical cancer were diagnosed among women with ASC-H who were HPV negative. Logistic regression analysis was performed using the group with normal Papanicolaou test results and HPV-negative status as the reference group. Women with ASC-H who were HPV positive had a significantly increased risk of CIN ≥2 lesions, whereas no significant increase was observed in patients with ASC-H and HPV-negative status.

Conclusion.

If the result of the HPV test was negative, the risk of CIN ≥2 lesions in Korean women with ASC-H cytology was low. Reflex HPV testing should be an option for the management of women with cytology showing ASC-H to decrease unnecessary colposcopic biopsies, which are expensive and invasive.

Implications for Practice:

Current American Society for Colposcopy and Cervical Pathology guidelines recommend universal colposcopy for the management of women with atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion (ASC-H) on cytology, regardless of human papillomavirus (HPV) test results. The present study suggested that HPV cotesting in patients with ASC-H cytology can provide more detailed and useful information regarding the risk of high-grade cervical intraepithelial neoplasia (CIN) lesions and the need for further treatment. When the result of the HPV test was negative, the risk of CIN lesions of grade ≥2 in women with ASC-H cytology was low. Consequently, reflex HPV testing, rather than immediately performance of invasive and expensive colposcopy with biopsy, should be an option for the management of women with ASC-H.     

Significance and possible causes of false‐negative results of reflex human papillomavirus infection testing

BACKGROUND.

The objective of this study was to assess the rate and possible reasons for false‐negative (FN) reflex human papillomavirus (HPV)‐DNA tests.

METHODS.

The authors reviewed all ThinPrep cervical specimens that were submitted for reflex HPV‐DNA testing using the Digene Hybrid Capture II (HC2) method from January 2002 to January 2004. Follow‐up biopsies were reviewed. The results were considered HPV‐FN if the HPV‐DNA test was negative and the biopsy was positive for grade ≥2 cervical intraepithelial neoplasia (CIN2+), and the results were considered true positive (HPV‐TP) if the HPV‐DNA test was positive and the biopsy showed CIN2+. HPV‐FN cases were compared with HPV‐TP cases regarding the grade and extent of CIN, the number of abnormal cells on the original ThinPrep slide, and the presence of amplifiable, viral DNA on biopsy.

RESULTS.

In total, 1520 (66%) of 2309 patients who had diagnoses of atypical squamous cells of undetermined significance (ASCUS) were negative for HPV DNA and 789 patients of 2309 patients (34%) were positive for HPV DNA. Three hundred sixteen women (40%) who had a positive HPV‐DNA test underwent a biopsy. Of those, 36 biopsies (11%) showed CIN2+ (HPV‐TP), and 154 biopsies (66%) showed CIN1. Cervical tissue was available for review from 82 women who had negative HPV‐DNA tests; of these, 6 tissue samples (7%) showed CIN2+ (HPV‐FN), and 13 tissue samples (16%) showed CIN1. Therefore, in the total ASCUS population that was triaged with reflex HPV testing, there were at least 42 women who were diagnosed with CIN2+, for an estimated CIN2+ FN fraction of 14% (6 of 42 women). HPV‐FN lesions were smaller (but the difference was not statistically significant) and shed significantly fewer abnormal cells than HPV‐TP cases. Polymerase chain reaction testing for viral DNA in the biopsy was detected in 3 of 6 women who had HPV‐FN results; none of those positive results demonstrated a viral type that was not included in the Digene probes.

CONCLUSIONS.

Although the rate of FN high‐grade lesions was significantly higher than that reported in the ASCUS/Low‐grade Squamous Intraepithelial Lesion Triage trial, most missed lesions were small and shed few abnormal cells. It was assumed that those lesions were either in early stages or in regressing stages, which made their clinical significance uncertain. Cancer (Cancer Cytopathol) 2007. © 2007 American Cancer Society.     

Expression of the p16INK4a and Ki-67 in relation to the grade of cervical intraepithelial neoplasia and high-risk human papillomavirus infection

Objective

The purposes of this study were to evaluate the expression of p16^INK4a (referred as to p16) and Ki-67 in cervical intraepithelial neoplasia (CIN), and the correlation between high-risk human papillomavirus (HPV) infection and the above biomarkers.

Methods

We analyzed 31 patients who were diagnosed with CIN at Kwandong University Myongji Hospital from October 2006 to September 2007. CIN specimens (CIN1, 12; CIN2, 6; CIN3, 13) were obtained by colposcopy-directed biopsy (CDB) or loop electrical excision procedure (LEEP). The expressions of p16 and Ki-67 were evaluated by immunohistochemical methods with antibodies to p16 and Ki67. The immunohistochemical staining results were classified into four grades: 0, 1, 2 and 3. HPV genotyping or Hybrid Capture-II test was used to detect high-risk HPV.

Results

The expression of p16 (p<0.001) and Ki-67 (p=0.003) were positively associated with CIN grade. p16 expressions increased significantly with high-risk HPV infection (p=0.014), especially HPV type 16 and 58. Ki-67 expression was not related with high-risk HPV. There was positive correlation between the expression of the p16 and Ki-67 (p=0.007).

Conclusion

CIN grade were positively related to the expression of p16 and Ki-67. p16 expressions of high-risk HPV specimens significantly increased more than Ki-67. Therefore, in the diagnosis of CIN and high-risk HPV infection, p16 can be a useful biomarker.     

Accuracy of liquid‐based cytology

BACKGROUND:

In the New Technologies for Cervical Cancer Screening (NTCC) randomized controlled trial, no significant increase in the sensitivity of liquid‐based cytology (LBC) was observed compared with conventional cytology. Both were interpreted by cytologists who had limited previous LBC experience. The objective of the current study was to assess whether different results could be expected with experienced LBC interpreters.

METHODS:

A stratified, random sample of 818 LBC slides from the NTCC study was obtained. These slides were reviewed blindly and independently by 3 international experts who did not participate in the NTCC. The sensitivity and specificity of external experts were estimated for cervical intraepithelial neoplasia grade 2 or greater (CIN2+) and for CIN3+ histology, and the differences were compared with the sensitivity and specificity of the original cytologic interpretation using cutoffs of atypical squamous cells of undetermined significance (ASCUS) and low‐grade squamous intraepithelial lesion (LSIL).

RESULTS:

With the endpoint of CIN2+ histology, the difference in sensitivity between external experts and the original interpretation was ?5.3 (95% confidence interval [CI], ?16.0 to 5.4) with ASCUS as the cutoff and 3.8 (95% CI, ?8.2 to 15.8) with LSIL as the cutoff. External experts had slightly lower specificity using ASCUS as the cutoff (?3.4; 95% CI, ?3.9 to ?2.9) and LSIL as the cutoff (?0.7; 95% CI, ?1.0 to ?0.4).

CONCLUSIONS:

The accuracy of the external experts' interpretation was similar to that of the original interpretation. Therefore, the current results indicated that LBC is not expected to increase sensitivity even if it is used by interpreters who have extensive experience with this technique. Cancer (Cancer Cytopathol) 2010. © 2010 American Cancer Society.     

The utility of p16INK4a and Ki-67 staining on cell blocks prepared from residual thin-layer cervicovaginal material

BACKGROUND: Cell blocks can be prepared from residual thin-layer cervicovaginal (ThinPrep) material and can be used in immunohistochemical staining assays for p16INK4a and Ki-67, which are surrogate markers related to human papillomavirus infection and cell proliferation, respectively. The objectives of the current study were 1) to investigate the feasibility and the role of cell block preparations in identifying significant neoplastic and preneoplastic lesions of the uterine cervix and 2) to assess the feasibility of using p16INK4a and Ki-67 immunohistochemical staining patterns on cell blocks to identify significant preneoplastic cervical lesions. METHODS: Cervicovaginal cytology specimens from 85 patients were analyzed. Cytologic diagnoses based on ThinPrep Papanicolaou test results were as follows: squamous cell carcinoma was diagnosed in 3 specimens, high-grade squamous intraepithelial lesions (HSIL) were diagnosed in 27 specimens, low-grade squamous intraepithelial lesions (LSIL) were diagnosed in 20 specimens, and atypical squamous cells of uncertain significance (ASCUS) were diagnosed in 11 specimens. Diagnoses of negativity for intraepithelial lesions or malignancy (NILM) were made in 24 specimens. Cell block sections were stained with hematoxylin and eosin and were immunostained with antibodies against p16INK4a protein and Ki-67 antigen. RESULTS: The cytomorphologic diagnoses made using cell block preparations were as follows: SCC in 2 specimens, HSIL in 20 specimens, LSIL in 30 specimens, NILM in 32 specimens, and no diagnosis in 1 specimen. In 62 cases (73%), the diagnoses made using cell block preparations were in agreement with the ThinPrep diagnoses. Immunostaining of cell blocks for p16INK4a and Ki-67 exhibited a statistically significant association (P < 0.05) with the presence of significant lesions on either cell block or ThinPrep analysis. CONCLUSIONS: To the authors' knowledge, p16INK4a has not been analyzed previously in ThinPrep cell blocks, and the correlation between Ki-67 expression and cell block diagnoses also has not been reported previously. The current results indicate that cell blocks prepared from residual ThinPrep material represent an additional reliable diagnostic tool in the evaluation of cervical samples. Furthermore, immunohistochemical studies may be helpful in differentiating significant preneoplastic changes from other cervical lesions, such as atrophy.     

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.     

Human Papillomavirus Detection and Abnormal Anal Cytology in HIV-infected Patients Using p16/Ki-67 Dual-Staining

Objective: We investigated human papillomavirus (HPV) infection and detected anal squamous intraepithelial lesions by modified liquid-based cytology (LBC) and p16/Ki67 dual-staining. Methods: Anal swabs (n=393) were collected from patients with HIV infection. Anal cells were kept in 95% ethyl alcohol for modified LBC. DNA was extracted from cells for HPV detection and genotyping using real-time PCR and reverse line blot hybridization. Results: Nine samples (2.3%) were unsatisfactory specimens, 74.8% (294/393) were negative for intraepithelial malignancies (NILM) and 22.9% (90/393) exhibited squamous intraepithelial lesions (SIL). In the latter category, 13.7% of samples (54/393) contained atypical squamous cells of undetermined significance (ASCUS), 6.9% (27/393) were classified as low-grade SIL (LSIL) and 2.3% (9/393) as high-grade SIL (HSIL). A total of 331 from 393 swab samples were suitable for detection of HPV infection. Among these, 34.1% (113/331) were positive. HPV 58 (15.9%) was the most common genotype, followed by HPV 18 (14.2%) and HPV 16 (11.5%). The severity of abnormal cells was significantly associated with HPV infection. Dual staining with p16/Ki-67 was performed on 130 samples: in 30.8% (40/130) of samples positive staining was significantly associated with severity of abnormal cells. Agreement between cytology, p16/Ki67 dual-staining and high-risk HPV detection was 100% in HSIL samples. Interestingly, eight apparently NIML cases might have contained abnormal cells, since they were positive by both p16/Ki67 dual-staining and high-risk HPV detection. Conclusion: Anal specimens screened using modified LBC with 95% ethyl alcohol solution as the fixative are suitable for screening anal precancerous lesions by cytology, HPV testing and p16/Ki-67 dual staining.     

Evaluation of quantity and staining pattern of human papillomavirus (HPV)‐infected epithelial cells in thin‐layer cervical specimens using optimized HPV‐CARD assay

BACKGROUND.

Testing for human papillomavirus (HPV) is used in the triage of women with a cervical cytology of atypical squamous cells of undetermined significance (ASCUS). A fluorescent in situ hybridization assay was developed for the detection of HPV using the catalyzed receptor deposition technique (HPV‐CARD). In this study, the utility of this assay was tested for the detection of HPV in liquid‐based cervical cytology specimens.

METHODS.

A total of 195 liquid‐based cytology specimens were analyzed using the HPV‐CARD assay. The results from the assay were compared with HPV polymerase chain reaction (PCR) and typing results. The number of HPV‐infected cells and the staining pattern was correlated with the cytology classification.

RESULTS.

A 91% concordance between HPV‐CARD and PCR was observed for the detection of high‐risk HPV viruses. A 78% concordance was observed for specimens that were negative for HPV. In ASCUS, low‐grade squamous intraepithelial lesion (LSIL), and high‐grade squamous intraepithelial lesion (HSIL) categories, the average number of HPV‐positive cells per slide was 19 cells, 127 cells, and 450 cells, respectively. The number of cells with a punctate staining, suggestive of HPV integration, was 21% in ASCUS, 34% in LSIL, and 46% in HSIL specimens.

CONCLUSIONS.

The results of the current study indicate positive correlations between the severity of the disease and the increased overall quantity of HPV‐positive epithelial cells in cervical cytology specimens and accumulation of cells with punctate staining suggestive of integrated HPV. In summary, the developed HPV‐CARD assay was found to provide novel information regarding the proportion and staining pattern of HPV‐infected epithelial cells in different cytologic categories of cervical specimens. Cancer (Cancer Cytopathol) 2007. © 2007 American Cancer Society.     

Expression of the p16 and Ki67 in Cervical Squamous Intraepithelial Lesions and Cancer

Purpose: To evaluate the expression of p16 and Ki67 in cervical intraepithelial neoplasia (CIN) and cancer. Materials and Methods: We performed a immunohistochemical study of p16 and Ki67 in 243 cervical tissues 53 nondysplastic lesions, 106 CIN1, 61 CIN2/3 and 23 squamous cell carcinomas. The expression of p16 and Ki67 was interpreted independently by 2 researchers and the sensitivity and specificity to detect clinically significant lesions ( CIN2) were determined. Results: The overall agreement results of positive or negative immunostaining of intrainter observer variability were 0.659 for p16 and 0.808 for Ki67. p16 expression was demonstrated in 91.3% of invasive carcinomas, 78.7% of CIN2/3, 10.4% of CIN1 and 9.4% of nondysplasic lesions. The corresponding Ki67 expression was: 100% of all invasive carcinomas, 75.4% of CIN2/3, 22.6% of CIN1, and 11.3% with nondysplasia. The expression was significantly different between CIN2/3 vs CIN1 for both p16 and Ki67 (pvalues CIN2 were 84.5% and 90.5% by p16 and 82.1% and 88.6% by Ki67. Conclusions: The rates for 16 and Ki67 expression were directly associated with the severity of cervical lesions. Significant differences in these markers expression may be useful in cases with equivocal histologic features among cervical intraepithelial lesions, but not between CIN1 and nondysplastic lesions. The two markers had high sensitivity and specificity in determining >CIN2.