Decreased expression of Ki-67 in atrophic cervical epithelium of post-menopausal women

Evaluation of the clinical performance of p16/Ki-67 dual-staining cytology for cervical lesion detection in premenopausal and postmenopausal Chinese women

BACKGROUND

Studies on the clinical performance of p16/Ki-67 dual-staining in detecting cervical lesions by menopausal status were limited.

METHODS

4364 eligible women were enrolled with valid p16/Ki-67, HR-HPV, and LBC test results, including 542 cancer and 217 CIN2/3 cases. The positivity rates of p16 and Ki-67 single staining and p16/ Ki-67 dual-staining were analyzed by different pathological grades and age groups. The sensitivity (SEN), specificity (SPE), positive predictive value (PPV), and negative predictive value (NPV) of each test in different subgroups were calculated and compared.

RESULTS

P16/Ki-67 dual-staining positivity increased with histopathological severity in premenopausal and postmenopausal women (P < 0.05), while no increasing trends of individual expression of p16 single staining and Ki-67 single staining were observed in postmenopausal women. P16/Ki-67 showed higher SPE (88.09% vs. 81.91%, P < 0.001) and PPV (33.8% vs. 13.18%, P < 0.001) in detecting CIN2/3, and higher SEN (89.97% vs. 82.61%, P = 0.012) and SPE (83.22% vs. 79.89%, P = 0.011) in detecting cancer in premenopausal women than postmenopausal women. For triaging the HR-HPV+ population to identify CIN2/3, p16/Ki-67 performed comparably to LBC in the premenopausal women, and showed higher PPV (51.14% vs. 23.08%, P < 0.001) in premenopausal than postmenopausal women. For triaging ASC-US/LSIL population, p16/Ki-67 demonstrated higher SPE and lower colposcopy referral rate than HR-HPV in both premenopausal and postmenopausal women.

CONCLUSIONS

Expressions of p16/Ki-67 dual-staining between premenopausal and postmenopausal women are varied. P16/Ki-67 performs better in detecting cervical lesions in premenopausal women. For triaging, p16/Ki-67 is suitable for HR-HPV+ women, especially premenopausal women, to identify CIN2/3 and women with ASC-US/LSIL.

Pattern of cervical biopsy results in cases with cervical cytology interpreted as higher than low grade in the background with atrophic cellular changes

Objective:

The cytomorphological changes associated with atrophic cellular pattern (ACP) in cervical cytology smears may mimic high-grade squamous intraepithelial lesion (HSIL). Due to this, there may be higher chances of cytomorphological overinterpretation in cases with ACP. Estrogen therapy (ET) (topical or systemic) would reverse the changes related to atrophy and repeat Pap smear after ET should correct the false positives. This approach would minimize the unindicated invasive interventions. However, performing immediate biopsies following “higher than low-grade squamous intraepithelial lesion (LSIL) (atypical squamous cells-cannot exclude HSIL, low-grade squamous intraepithelial lesions-cannot exclude HSIL, and HSIL) interpretations” in such cases, is a general trend. Pap smears with “higher than LSIL interpretations” in association with ACP over a period of 10 years were selected.

Materials and Methods:

A total of 657,871 cases over 10 years were reviewed, of which 188 Pap smears interpreted as higher than LSIL interpretations with ACP were selected randomly for this study.

Result:

Of these 188 cases, 67 underwent biopsies which were reviewed and compared with 67 biopsies performed for “higher than LSIL interpretation” cases without ACP. The follow-up biopsy material was reviewed including elective p16 immunohistochemistry with other clinical details including high-risk HPV test results as indicated.

Conclusion:

The findings demonstrated that Pap smears with ACP have higher false positives due to tendency for cytomorphologic overinterpretation as compared to non-ACP group.

Enhanced Expression of Sodium Hydrogen Exchanger (NHE)-1, 2 and 4 in the Cervix of Ovariectomised Rats by Phytoestrogen Genistein

Restoring the pH of cervicovaginal fluid is important for the cervicovaginal health after menopause. Genistein, which is a widely consumed dietary health supplement to overcome the post-menopausal complications could help to restore the cervicovaginal fluid pH. We hypothesized that genistien effect involves changes in expression of NHE-1, 2 and 4 proteins and mRNAs in the cervix. This study investigated effect of genistein on NHE-1, 2 and 4 protein and mRNA expression in the cervix in order to elucidate the mechanisms underlying possible effect of this compound on cervicovaginal fluid pH after menopause.

METHODS

Ovariectomised adult female rats received 25, 50 and 100 mg/kg/day genistein for seven consecutive days. At the end of the treatment, animals were sacrificed and cervix was harvested. Expression of Nhe-1, 2 and 4 mRNA were analyzed by Real-time PCR while distribution of NHE-1, 2 and 4 protein were observed by immunohistochemistry.

RESULTS

Treatment with 50 and 100 mg/kg/day genistein caused marked increase in the levels of expression and distribution of NHE-1, 2 and 4 proteins in the endocervical epithelia. Levels of Nhe-1, 2 and 4 mRNA in the cervix were also increased. Coadministration of ICI 182 780 and genistein reduced the expression levels of NHE-1, 2 and 4 proteins and mRNAs in the cervix.

CONCLUSIONS

Enhanced expression of NHE-1, 2 and 4 proteins and mRNAs expression in cervix under genistein influence could help to restore the cervicovaginal fluid pH that might help to prevent cervicovaginal complications related to menopause.

Diagnostic value of protein Ki67 (MIB-1) in atypical pap smears of postmenopausal women

BACKGROUND

Atrophic epithelium of cervix sampled from postmenopausal women may mimic high-grade cervical intraepithelial neoplasia in Papanicolaou-stained (Pap) smears. Ki-67 (MIB-1) protein presents on proliferating cells, and percentage of cells with positive nuclei provides a reliable tool for rapid evaluation of the growth fraction. The aim of this study was to determine the diagnostic value of protein Ki67 staining in atypical pap smears of postmenopausal women.

METHODS

In a case-control setting, pap smears of 75 women with an atypical pap smear (case group) and 75 with normal pap smears (controls) were obtained before and after estrogen treatment. Afterward, samples were exposed to the monoclonal antibody Ki-67 (MIB-1) and the immunohistochemically demonstrated Ki-67+ cells were compared.

RESULTS

Mean ages of cases and controls were 60.4±4.5 and 59.9±4.3 years respectively (P=0.50). There was one (2.7%) positive Ki-67 specimen in the case group, without any positive Ki-67 specimen in the control group (P=0.50).

CONCLUSIONS

Measurement of proliferative activity index in Pap smears restrained with MIB1 is a simple, reliable, and cost-effective method for excluding negatives. This would imply that it might allow a substantial reduction of diagnostic estrogen courses and subsequent Pap smears in postmenopausal women with atypical findings.

Utility of p16, Ki-67, and HPV Test in Diagnosis of Cervical Intraepithelial Neoplasia and Atrophy in Women Older Than 50 Years With 3- to 7-Year Follow-up

Background. Differentiating cervical intraepithelial neoplasia (CIN) from atrophy in postmenopausal women based on morphology alone is challenging. p16 and Ki-67 help distinguish CIN2/3 from atrophy. The goal of this study is to further characterize the utility of p16, Ki-67, and human papillomavirus (HPV) tests in women older than 50 years, particularly in CIN1. Design. The authors retrospectively identified cervical specimens from three, 1-year time periods. Included were cases from women older than 50 years with benign diagnoses, atrophy, and CIN. Slides were stained with p16 and Ki-67 and graded as positive or negative. Medical records were reviewed for cytology, HPV test, and histopathologic diagnoses from the time of biopsy to 2010. Results. A total of 97 cervical samples were included. In all, 34 (74%) CIN1 cases were negative for p16 and Ki-67. Of CIN1 cases with positive HPV tests, only 1/10 (10%) had positive p16 staining versus 2/2 (100%) of CIN2/3 cases. Of 39 women with CIN1 who had follow-up data available, 4 (10%) had subsequent histologic progression to CIN2/3 and none developed invasive disease. Conclusions. In our study, the majority of cases (74%) diagnosed as CIN1 in women ≥ 50 years are negative for p16 and Ki-67 and do not progress to high-grade dysplasia during 3- to 7-year follow-up. A combination of morphology, p16, and Ki-67 on cervical specimens in women older than 50 years, and furthermore, use of these stains on Pap tests in combination with HPV testing may help distinguish CIN from atrophy and reduce unnecessary invasive follow-up testing.

European guidelines for quality assurance in cervical histopathology

The current paper presents Chapter 5 of the second edition of the European Guidelines for Quality Assurance in Cervical Cancer Screening, which deals with the histopathological diagnosis of lesions of the uterine cervix. It completes a series of publications in journals containing the contents of other parts of the European Guidelines. Histopathology provides the final diagnosis on the basis of which treatment is planned, and serves as the gold standard for quality control of cytology and colposcopy. It is also the source of the diagnostic data stored at the cancer registry and used for evaluation of screening programmes. It is therefore important that histopathology standards are monitored and based on agreed diagnostic criteria. Histology is required to diagnose the degree of abnormality in women with persistent low-grade abnormalities including HPV-lesions, as well as high-grade lesions. Cytology may also suggest either glandular abnormalities or be suggestive of high-grade CIN, AIS or invasive cancer. Histopathologists should be aware of, and familiar with, the nature of cytological changes which may be relevant to their reports. The accuracy of the histopathological diagnosis of tissue specimens depends on adequate samples, obtained by colposcopically directed punch biopsies (with endocervical curettage if necessary) or excision of the transformation zone or conisation. An accurate histological diagnosis further depends on appropriate macroscopic description, technical processing, microscopic interpretation and quality management correlating cytological and histological diagnosis. This paper proposes guidelines for sampling and processing of cervical tissue specimens obtained by biopsy, excision and/or curettage.

Stromal myofibroblasts and malignant transformation in a 4NQO rat tongue carcinogenesis model

This study assesses the correlation of changes in the density of stromal myofibroblasts to propagation of histopathologic alterations and proliferative activity of the epithelium in a rat 4NQO-induced tongue rat carcinogenesis model.Forty-three male Wistar rats were administered 0.001% 4NQO in drinking water for: 0 (n=7, control), 7 (n=4), 8 (n=8), 14 (n=6), 22 (n=9), and 28 (n=9) weeks, after which they were euthanized. Tongue sections were divided equally into anterior, middle and posterior thirds. Each third was given a histopathologic score (hematoxylin and eosin), ranging from normal, hyperplasia/hyperkeratosis, and escalating degrees of dysplasia to carcinoma, and analyzed by the point-counting method for density of epithelium-associated stromal myofibroblasts (alphaSMA) and of proliferating epithelial cells (PCNA). Histopathologic changes significantly increased in severity (carcinoma) with duration of 4NQO administration (p<0.001) in the posterior third of the tongue. The density of stromal myofibroblasts and proliferating epithelial cells was significantly higher in the posterior third of the tongue at 28 weeks compared to the other time points and locations (p<0.001, p=0.01, respectively). Significant correlations were found between occurrence of carcinoma and the increase in density of stromal myofibroblasts (p<0.001) and of proliferating epithelial cells (p=0.001) in the posterior third of the tongue. Increased density of stromal myofibroblasts was distinctively associated with the development of carcinoma but not with pre-malignant changes. Defining the mechanism of evolvement of carcinoma-associated stromal myofibroblasts is expected to further broaden our knowledge on the micro-environmental events occurring during the malignant transformation.

p14ARF and p16INK4A, two products of the same gene, are differently expressed in cervical intraepithelial neoplasia

OBJECTIVE

To study the expression patterns of two different tumor suppressor proteins p16INK4A and p14ARF in cervical lesions. Both proteins are encoded by the same INK4A/ARF gene on chromosome 9p21. The expression patterns of these two proteins, both playing a central role in the cell cycle, were analyzed in detail in CIN, carcinomas, and normal epithelium to test the hypothesis that p16INK4A positive cells also demonstrate p14ARF expression.

METHODS

Serial tissue sections of 9 CIN1 lesions, 10 CIN2 lesions, 12 CIN3 lesions, and 7 carcinomas were stained with monoclonal antibodies against p16INK4A and p14ARF. The short fragment polymerase chain reaction hybridization line probe assay was used to detect HPV.

RESULTS

Normal epithelium was negative for both proteins. Marked immunoreactivity (++) for p16INK4A and p14ARF was observed in 5/7 carcinomas, 10/12 CIN3, and 1/10 CIN2 lesions and 0/9 CIN1 lesions. Simultaneous expression (+ or ++) was found in 19/22 CIN2/3 and not in CIN1 lesions. The fraction of p16INK4A-stained cells increased with CIN-grade. Overexpression of p14ARF was observed in a subpopulation of p16INK4A positive cells, and exclusively found in lesions infected with high-risk HPV. In two CIN3 lesions with early stromal invasion, p14ARF positivity was mainly found in the invasive cells. In carcinomas, all cells showed p16INK4A expression, whereas p14ARF was limited to the peripheral cells of the invasive tumor nests and individual migrating tumor cells.

CONCLUSIONS

Overexpression of p14ARF is limited to a fraction of the p16INK4A-expressing cells and therefore it is likely that p14ARF- and p16INK4A expression are not induced by the same mechanisms. Before expression of p14ARF can be linked to invasion or invasive phenotype, larger series of (micro-) invasive squamous lesions need to be studied.

Chromosome in situ hybridisation, Ki-67, and telomerase immunocytochemistry in liquid based cervical cytology

AIMS

To assess the potential value of chromosome in situ hybridisation (CISH), Ki-67, and telomerase immunocytochemistry in liquid based cervical cytology to help detect carcinoma cells and precursors.

METHOD

Sixty ThinPrep processed cervical cytology samples were studied: 23 cases within the normal limit, 13 low grade squamous intraepithelial lesions (LSILs), 10 high grade squamous intraepithelial lesions (HSILs), six squamous cell carcinomas, three endocervical adenocarcinomas, two cervical adenosquamous cell carcinomas, and three endometrial adenocarcinomas. CISH was performed with DNA probes specific for the pericentromeric regions of chromosome 11 and 16. Hybridisation signals were visualised with the streptavidin-biotin peroxidase technique. The monoclonal MIB1 and polyclonal TRT-H231 antibodies were used to detect Ki-67 and telomerase immunoreactivity, respectively.

RESULTS

Non-specific background staining was almost absent in CISH slides. Normal squamous and glandular cells showed a diploid chromosomal pattern. A relative gain in chromosomes 11 and 16 (aneusomy) was seen in HSIL and the carcinomas (p<0.0001). In MIB1 stained smears, normal cells and koilocytes showed inconspicuous immunoreactivity, whereas strongly immunoreactive nuclei were found in cancer cells and HSIL (p<0.0001). Not only carcinoma and HSIL cells, but also some normal cells, showed cytoplasmic staining for telomerase.

CONCLUSIONS

These preliminary results indicate that ThinPrep processed cervical smears are suitable for CISH and immunocytochemical studies. The neoplastic squamous and glandular cells were easily identified based on nuclear aneusomy and strong Ki-67 immuoreactivity in the context of abnormal nuclear morphology. This is the first study to apply CISH in cervical cytology using an immunoenzymatic approach.

Ki-67 immunocytochemistry in liquid based cervical cytology: useful as an adjunctive tool?

AIMS

To test the ability of Ki-67 to detect cytological lesions in a screening setting and its use as a surrogate marker of human papillomavirus (HPV) infection.

METHODS

A study of liquid based cytology, HPV DNA testing by MY09/MY11 consensus polymerase chain reaction (PCR), type specific PCRs, and Ki-67 immunocytochemistry on a randomly selected series of 147 patients.

RESULTS

Comparison of the number of Ki-67 immunoreactive cells/1000 cells in the different cytological groups showed that the HSIL group yielded a significantly higher mean count than did the other groups. The number of Ki-67 immunoreactive cells/1000 cells was significantly higher in HPV-16 positive samples than in samples containing infections with other high risk types. Receiver operating characteristic curves indicated a test accuracy (area under curve) of 0.68, 0.72, and 0.86 for atypical squamous cells of undetermined significance (ASCUS), low grade squamous intraepithelial lesions (LSIL), and high grade squamous intraepithelial lesions (HSIL), respectively. Thresholds for 95% sensitivity were 0.07, 0.08, and 0.15 Ki-67 immunopositive cells/1000 cells for ASCUS, LSIL and HSIL, respectively. The threshold for 95% specificity was 1.9 Ki-67 immunopositive cells/1000 cells.

CONCLUSIONS

Ki-67 immunocytochemistry can be applied to liquid based cytology. The accuracy and diagnostic indices of the test are good when compared with those of other techniques. As part of a panel of screening procedures, it could be used as an adjunct to liquid based cytology to identify HSIL, and as a surrogate marker of HPV-16 infection.

Translational approaches to improving cervical screening

Screening programmes for cervical cancer using the current test--the Pap smear--have markedly reduced the incidence of the disease. However, an individual Pap test is of limited sensitivity and is difficult and expensive to perform. Increased understanding of the molecular pathogenesis of cervical cancer indicates that new approaches to screening might offer increased accuracy, affordability and the potential for automation. Such approaches exemplify how improved understanding of the biology of neoplasia might be translated into clinical benefit.

Relationship between the presence of oncogenic HPV DNA assessed by polymerase chain reaction and Ki-67 immunoquantitative features in cervical intraepithelial neoplasia

The aims of this study were firstly to determine which Ki-67 immunoquantitative parameters correlate with the presence of oncogenic human papillomavirus (HPV) in cervical intraepithelial neoplasia (CIN) lesions; and secondly to compare prospectively the routinely assessed CIN grades with the Ki-67 quantitative pathological CIN grade, the expert revised grade, and the presence of oncogenic HPV DNA. HPV polymerase chain reaction (PCR) and Ki-67 immunoquantitation were performed on 90 consecutive biopsies (16 CIN 1, 35 CIN 2, and 39 CIN 3). CIN grade was assessed routinely by six different pathologists. The presence of the lesion was confirmed in a histological section following the material used for PCR and Ki-67 analysis. In a second prospective routine test set analysis, 66 more CIN lesions (14 CIN 1, 15 CIN 2, and 37 CIN 3) were routinely graded (also by six different pathologists, routine CIN grade=CIN(ROUT)), studied for oncogenic HPV DNA, and graded by quantitative Ki-67 features (quantitative pathological CIN grade=CIN(QP)). These latter cases were blindly revised by one of the authors (reference CIN grade=CIN(REF)). Eight of the nine Ki-67 immunoquantitative features showed a significant difference between the oncogenic HPV-positive and -negative cases. The best single discriminator was the 90th percentile of the stratification index (SI90). All 61 cases with Ki-67 SI90>0.60 were HPV-positive (68% of the total group studied). Of the 29 cases with SI90< or =0.60, 16 were negative and 13 positive for oncogenic HPV and none of the Ki-67 features (either single or combined) could distinguish them. Using stepwise multivariate analysis, the best discriminating combination of features was SI90 and the percentage of Ki-67-positive nuclei in the deep third layer of the epithelium (PERC DL). The combination of SI90 and the percentage of Ki-67-positive nuclei per 100 microm basal membrane was nearly as strong as that of SI90 and PERC DL. With these two features, 86% of the cases were correctly classified. The subjective estimate of SI90 (>0.60 or < or =0.60) by two independent observers was not accurate and not reproducible. In the prospective routine test set analysis of 66 cases, the 37 CIN(ROUT)=3 all had CIN(QP) and CIN(REF)=3 and all these cases were oncogenic HPV-positive. Eight of the 14 original CIN(ROUT)=1 grades were oncogenic HPV (=HPV)-positive and five of these eight were upgraded by CIN(QP) to CIN 2 and CIN 3. These upgrades were in agreement with the blind reference revisions. The six HPV-negative CIN(ROUT)=1 cases were CIN 1 both by CIN(QP) and by CIN(REF). Thirteen of the 15 original CIN(ROUT)=2 grades were HPV-positive and seven of these were CIN(QP)=3. All six HPV-positive CIN(ROUT)=2 cases that were CIN(QP)=2 were also CIN(REF)=2 at blind revision. In conclusion, this study has shown firstly, that in CIN lesions, Ki-67 immunoquantitative features and the presence of oncogenic HPV are highly correlated, and also within one subjective CIN grade; secondly, that subjective impressions of SI90 are not as accurate or reproducible as quantitative image analysis results; and thirdly, that the routine application of QP CIN-grading gives results that are in very good agreement with CIN grades assessed by an expert. Thus, routine QP-grading may be used to correct the subjective grade assessed by non-expert pathologists.

Proliferation in "atypical" atrophic pap smears

OBJECTIVE

Atrophic cervical epithelium of postmenopausal women may mimic high-grade cervical intraepithelial neoplasia (CIN2-3) in Papanicolaou-stained cervical smears (Pap smears). Women with such an "atypical" Pap smear need a repeated Pap smear after a course of estrogens before a definite diagnosis can be made. The aim of this study was to determine whether measurement of proliferative activity in Pap smears of postmenopausal patients that were difficult to interpret is a reliable test for differentiating between cervical atrophy and high-grade CIN.

METHODS

Pap smears obtained before and after estrogen treatment of 30 postmenopausal women with an atypical Pap smear were restained with the monoclonal antibody MIB1 to visualize proliferating cells. The proliferative activity index (PAI) was subsequently measured in order to explore the feasibility of a recently proposed PAI-based diagnostic decision tree to reduce the number of estrogen courses and follow-up Pap smears in postmenopausal women.

RESULTS

The PAI-based test to discriminate between cervical atrophy and high-grade CIN resulted in 100 and 96% correct diagnoses in women with high-grade CIN and cervical atrophy, respectively. Only 2 of the 30 women would have needed a repeated Pap smear after estrogen treatment for definite diagnosis if the PAI-based diagnostic decision had been used.

CONCLUSIONS

Measurement of PAI in MIB1 restained Pap smears is a simple, reliable, safe, and probably also cost-effective method to obtain a substantial reduction of diagnostic estrogen courses and subsequent Pap smears in postmenopausal women with an atypical Pap smear.