Immunostaining of p16(INK4a)/Ki-67 and L1 capsid protein on liquid-based cytology specimens obtained from ASC-H and LSIL-H cases

Relationship of P16 and Ki67 in recurrence of HPV infection and cervical intraepithelial neoplasia

This study aimed to investigate the association of P16 and Ki67 expression in cervical conization with postoperative HPV reinfection and cervical intraepithelial neoplasia. This study retrospectively enrolled patients from January 2012 to December 2013. Patients with negative margins were followed up for 2 years to evaluate the correlation between Ki67 and p16 expression levels in the conization of patients with HPV persistence encountering infection or re-infection and CIN recurrence. The positive expression of p16 and Ki67 was significantly correlated with disease progression (P<0.05). p16 and Ki67 expression was chosen, and results showed that positive expression of p16 and ki67 proteins was a risk factor of disease progression (OR=5.3, 95% CI 1.177~24.365, P=0.042; OR=5.1, 95% CI 1.162~22.387, P=0.031, respectively). Results indicated that routine staining for p16 and Ki67 has clinically significant meaning in guiding disease progress and prognosis at follow-up.

Role of Cervical Cancer Biomarkers p16 and Ki67 in Abnormal Cervical Cytological Smear

Introduction

Cervical cancer is the most common cancer in India. Screening for cervical cancer helps in marked reduction of invasive cervical cancers. The low sensitivity of Papanicolaou cytology (Pap smear) and high-risk human papillomavirus (HR-HPV) in excluding high-grade intraepithelial lesion (ASC-H) leads to unnecessary referrals to colposcopy-guided biopsy. The combined cervical cytology screening and HR-HPV have its own limitations and still need further standardization. Using additional biomarkers like staining with p16 and Ki-67 might help in triaging abnormal pap smear.

Materials and Methods

A prospective, cross-sectional study was performed over a period of 16 months in the Department of Obstetrics and Gynaecology, in collaboration with Department of Pathology. Study was conducted to know the efficacy of immunostaining with p16/Ki-67 in predicting the presence of significant lesion in cases of mild cytological atypia. PAP smears (conventional and LBC) along with P16, Ki-67 and available biopsies were correlated.

Results

Liquid-based cytology (LBC) was done in 2134 cases, out of which 46 cases showed abnormal cytological findings such as [22 atypical squamous cells of undetermined significance (ASCUS), 3 low-grade squamous intraepithelial lesion (LSIL), 8 atypical squamous cells cannot exclude high-grade lesion (ASC-H), 6 high-grade squamous intraepithelial lesion (HSIL), 5 squamous cell carcinoma (SCC), 2 adenocarcinoma, 1 atypical glandular cells of undetermined significance (AGUS)]. Immunostaining with p16 and Ki-67 was performed on 38 cases of abnormal cytological smears. Out of 38 abnormal cytology cases, 28 cases had shown co-staining for both p16 and Ki-67, suggestive of true HPV infection of the cells. Of the 38 cases, 07/14 ASCUS, 06/06 HSIL, 07/08 ASC-H, 05/05 squamous cell carcinoma and 02/02 adenocarcinoma also showed dual positivity for p16 and Ki-67. One case of AGUS was diagnosed, but the smear was unsatisfactory for immunocytochemical evaluation and excluded from the study. Three cases of LSIL were also diagnosed on cytological evaluation, and 1 of them however showed positivity for p16 and Ki-67 on immunocytochemistry (ICC). In the ASC-US group, the sensitivity and specificity of the immunostaining in diagnosing CIN2 + lesions were 87.51%, and in LSIL group, the sensitivity and specificity of the immunostaining in diagnosing CIN2 + lesions were 100%. p16/Ki-67 positivity also increased with cytological severity which in turn corresponded with histological findings: it reached from 50% in ASC-US to 100% in both HSIL and SCC categories.

Conclusion

This immunostaining with p16 and Ki67 can be a useful method in the triaging of the ASC-US and the LSIL group as considering the high sensitivity and specificity values.

Progress in immunocytochemical staining for cervical cancer screening

Cervical cancer is one of the most common gynecological malignancies. In recent years, the implementation of cervical cancer screening has resulted in the effective control of cervical cancer incidence. However, many deficiencies still exist in the current screening techniques and strategies. With advancements in cervical cancer screening research, immunochemical staining to determine cervical cytology has shown a broader application prospect in the early screening for cervical cancer, especially for triage in cervical cancer screening.

Risk stratification of cervical disease using detection of human papillomavirus (HPV) E4 protein and cellular MCM protein in clinical liquid based cytology samples

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Cytospinning is a viable method for preparing LBC cells for antibody staining.

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We assessed the performance of a dual biomarker (one viral: HPVE4, one cellular: MCM2) in risk stratification of cervical disease.

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MCM2 was significantly associated with CIN2+ (p = 0.03). HPVE4 was associated with CIN1/normal (p = 0.06).

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The dual biomarker approach may be useful to risk stratify cervical disease especially in resource-poor settings.

Background

While human papillomavirus (HPV) DNA testing offers high sensitivity for the detection of significant cervical disease, its specificity is suboptimal given the high prevalence of transient HPV infections (CIN1 or less). Biomarkers to identify those suffering from low grade disease from those with high grade disease could save healthcare costs and reduce patient anxiety.

Objective

The objective of the present work was to develop and test an immunohistochemistry (IHC)-based dual viral and cellular biomarker strategy which was applicable to liquid based cytology (LBC) samples.

Study design

We developed a novel IHC assay for detection of HPV E4 and cellular minichromosome maintenance (MCM) proteins in routinely taken cervical LBC samples using cytospin-prepared slides. The assay was applied to a prospective cohort of Scottish women referred to a colposcopy clinic due to preceding cytological abnormalities. The performance of the biomarkers for detection of clinically insignificant (CIN1 or less) versus significant disease was determined.

Results

A total of 81 women were recruited representing 64 cases of <=CIN1 and 28 of CIN2 + . Biomarker performance relative to histopathology outcomes showed high levels of MCM detection was significantly associated with CIN2+ (p = 0.03) while E4 was detected more frequently in <=CIN1 (p = 0.06).

Conclusions

Combined detection of a host proliferation marker and a marker of viral gene expression could allow triage of cases of clinically insignificant disease prior to colposcopy. However, there was overlap between distributions of MCM levels in CIN2+ and <=CIN1 suggesting that additional biomarkers would be required for improved specificity. Combined with cytospin-prepared slides this approach could provide a means of risk stratification of disease in low resource settings.

Performance of P16/Ki67 dual staining in triaging hr-HPV-positive population during cervical Cancer screening in the younger women

BACKGROUND

Cervical cancer is the most common malignancy from the female reproductive tract, and usually develops from low-grade or high-grade squamous intraepithelial lesions (LSIL or HSIL). Detecting the precancerous lesion during the LSIL-HSIL-invasive cancer sequelae can effectively interrupt the oncogenesis and decrease the incidence of invasive carcinoma. The aim of this study is to evaluate the performance of P16/Ki67 dual staining in triaging hr-HPV-positive population.

METHODS

Conventional gynecological examination, cervical cytology and hr-HPV testing were given to all patients. Specimens were collected for cytology examination and HPV genotyping. According to cytology results, patients were divided into cervical cancer group, HSIL group, LSIL group and benign lesion group. Sensitivity and specificity of the dual staining method in each histopathologic group was obtained and compared.

RESULTS

Among the108 patients participated in the study, 65 were diagnosed as normal, 15 as LSIL, 20 as HSIL and 8 as CC, by histopathologic examination. Dual staining of p16/Ki67 on cytology specimen provided a positive predictive value of 86% and the negative predictive value of 96%. The sensitivity approached 96.43% when combining ThinPrep cytological test (TCT) with the dual staining, with a specificity of 60% in detecting HSIL. Joint detection of TCT and p16/Ki67 dual staining displayed the highest specificity among all the attempted combinations of detection methods.

CONCLUSIONS

This study demonstrated that p16/Ki-67 dual staining represents an effective method for cervical cancer screening. Application of this method could lead to a reduction of unnecessary colposcopy referrals and misdiagnosis.

Candidate biomarkers in the cervical vaginal fluid for the (self-)diagnosis of cervical precancer

Purpose

Despite improvement in vaccines against human papilloma virus (HPV), the causative agent of cervical cancer, screening women for cervical precancer will remain indispensable in the coming 30–40 years. A simple test that could be performed at home or at a doctor’s practice and that informs the woman whether she is at risk would significantly help make a broader group of patients who aware that they need medical treatment. Cervical vaginal fluid (CVF) is a body fluid that is very well suited for such a test.

Methods

Narrative review of cervical (pre)cancer candidate biomarkers from cervicovaginal fluid, is based on a detailed review of the literature. We will also discuss the possibilities that these biomarkers create for the development of a self-test or point-of-care test for cervical (pre)cancer.

Results

Several DNA, DNA methylation, miRNA, and protein biomarkers were identified in the cervical vaginal fluid; however, not all of these biomarkers are suited for development of a simple diagnostic assay.

Conclusions

Proteins, especially alpha-actinin-4, are most suited for development of a simple assay for cervical (pre)cancer. Accuracy of the test could further be improved by combination of several proteins or by combination with a new type of biomarker, e.g., originating from the cervicovaginal microbiome or metabolome.

Influence of Human Papillomavirus Infection on the Natural History of Cervical Intraepithelial Neoplasia 1: A Meta-Analysis

Objective

To provide a scientific basis for the prevention and treatment of cervical intraepithelial neoplasia grade 1 (CIN1). This study evaluated the impact of human papillomavirus (HPV) infection on the natural history of CIN1.

Methods

Electronic databases of Cochrane Library, EMBASE, PubMed, CNKI, CBM, and Wanfang were searched in April 2016. The eligibility criteria were documented by Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). We used the Newcastle-Ottawa scale (NOS) to assess study quality.

Results

Thirty-eight studies out of 3,246 identified papers were eligible for inclusion. The risk of CIN1 progression (relative risk [RR]: 3.04; 95% confidence interval [CI]: 2.41–3.83; P < 0.00001) and persistence (RR: 1.48; 95% CI: 1.17–1.87; P = 0.001) was higher in the HPV-positive group than HPV-negative group. Specifically, the risk of CIN1 progression (RR: 13.91; 95% CI: 3.46–55.90; P = 0.000) was higher among persistent high-risk HPV-positive patients and the ratio of CIN1 regression (RR: 0.65; 95% CI: 0.59–0.71; P < 0.00001) was lower in the HPV-positive group than HPV-negative group.

Conclusion

HPV infection resulted in an increased risk of CIN1 progression and decreased disease reversibility. Persistent high-risk HPV infection resulted in a further increased risk of CIN1 progression.

Diagnostic performance of dual-staining cytology for cervical cancer screening: A systematic literature review

Cervical cancer screening saves lives. Secondary prevention in cervical cancer screening relies on the results of primary cytology and/or HPV testing. However, primary screening with cytology has a low sensitivity, and HPV screening has a low specificity. This means that either cancers are missed, or women are over-treated. To improve performance outcomes, the concept of dual-stain cytology (CINtec^® PLUS Cytology test) has been introduced. In this approach, additional staining with p16/Ki-67 is performed in cases where cytology results are abnormal (LSIL or ASCUS) and/or HPV-positive. Another way to describe this approach might be "diagnostic" cytology. In order to assess the value of this "diagnostic cytology", a systematic literature review was conducted of dual-stain cytology performance across multiple studies until May 2016. In a Belgian screening population (women age 25-65 years), dual-stain cytology was significantly more sensitive (66%) and slightly less specific (-1.0%) than cytology. In the population referred to colposcopy or with abnormal cytology (ASCUS, LSIL), dual-staining showed a significantly higher increase in specificity, and a slightly lower sensitivity than HPV testing. Specificity gains resulted in fewer false positives and an increase in the number of correct referrals to colposcopy. Dual-staining with p16/Ki-67 cytology is an attractive biomarker approach for triage in cervical cancer screening.

Predictive value of p16/Ki-67 immunocytochemistry for triage of women with abnormal Papanicolaou test in cervical cancer screening: a systematic review and meta-analysis

BACKGROUND

The Papanicolaou (Pap) test is one screening strategy used to prevent cervical cancer in developed countries. The p16/Ki-67 immunocytochemistry is a triage test performed on Pap smears in women with atypical squamous cells of undetermined significance (ASCUS) or low grade squamous intraepithelial lesion.

OBJECTIVE

Our objective was to review studies investigating the diagnostic performance of p16/Ki-67 dual stain for triage of women with abnormal Pap tests.

DESIGN

We conducted a systematic review and meta-analysis of diagnostic test accuracy studies.

SETTINGS

We followed the protocol of systematic review of diagnostic accuracy studies.

PATIENTS AND METHODS

We searched PubMed, The Cochrane Library, BioMed Central, and ClinicalTrials.gov for relevant studies. We included research that assessed the accuracy of p16/Ki-67 dual stain and high risk human papillomavirus testing for triage of abnormal Pap smears. Review articles and studies that provided insufficient data to construct 2.2 tables were excluded. Data synthesis was conducted using a random-effects model.

MAIN OUTCOME MEASURES

Sensitivity and specificity.

RESULTS

In seven studies encompassing 2628 patients, the pooled sensitivity and specificity of p16/Ki-67 for triage of abnormal Pap smear results were 0.91 (95% CI, 0.89 to 0.93) and 0.64 (95% CI, 0.62 to 0.66), respectively. No study used a case-control design. A subgroup analysis involving liquid-based cytology showed a sensitivity of 0.91 (95%CI, 0.89 to 0.93) and specificity of 0.64 (95%CI, 0.61 to 0.66).

CONCLUSIONS

Our meta-analysis of p16/Ki-67 dual stain studies showed that the test achieved high sensitivity and moderate specificity for p16/Ki-67 immunocytochemistry for high-grade squamous intraepi.thelial lesion and cervical cancer. We suggest that p16/Ki-67 dual stain might be a reliable ancillary method identifying high-grade squamous intraepithelial lesions in women with abnormal Pap tests.

LIMITATIONS

No study in the meta-analysis examined the accuracy of the p16/Ki-67 dual stain for inter.pretation of glandular neoplasms.

Overall accuracy of cervical cytology and clinicopathological significance of LSIL cells in ASC-H cytology

OBJECTIVE

The aims of this study were (i) to investigate the diagnostic accuracy of Papanicolaou (Pap) smears and (ii) to evaluate the clinicopathological significance of the presence of low-grade squamous intraepithelial lesion (LSIL) cells in atypical squamous cells cannot exclude high-grade squamous intraepithelial lesion (HSIL) (ASC-H) cytology.

METHODS

We retrospectively reviewed paired cytological and histological findings from 3141 patients. ASC-H cytology was classified as either ASC-H or LSIL with some features suggestive of the presence of a concurrent HSIL (LSIL-H). Clinicopathological characteristics were evaluated through a retrospective study and meta-analysis.

RESULTS

The accuracy of the cytological diagnosis was 93.7% (2942 of 3141 cases). The positive predictive value (PPV) of ASC-H for cervical intraepithelial neoplasia grade 2 or worse (CIN 2+ ) was 51.4%. In cases of LSIL-H, CIN 2+ histology was more prevalent in the pre-menopausal period (19-44 years) than in peri- and postmenopausal periods (older than 45 years) (P = 0.024). There was no difference in the ability of LSIL-H and ASC-H to predict CIN 2+.

CONCLUSION

The Pap smear is a good cervical cancer screening method. Although there was no difference in the predictive value for CIN 2+ between LSIL-H and ASC-H, the presence of definite LSIL cells was more predictive of CIN 2+ in younger patients than in older patients.

Diagnostic performance of p16 staining in atypical squamous cells 'cannot exclude high-grade squamous epithelial lesion' in predicting high-grade cervical pathology

Atypical squamous cells 'cannot exclude high-grade squamous epithelial lesion' (ASC-H) cytology represents clear risk and has been a controversial issue in clinical practice. The objective of this study is to investigate the diagnostic performance of p16(INK4A) immunohistochemistry (IHC) among ASC-H Pap smears in predicting high-grade cervical intraepithelial lesions. Decolourisation and staining process with p16(INK4A) is applied to 27 ASC-H diagnosed conventional Pap smears, which were all managed with colposcopy-directed cervical biopsy priorly. Staining characteristics of ASC-H Pap smears were compared with histopathological data and sensitivity-specificity values of p16 triage to detect CIN2 + histopathology were determined. The sensitivity and specificity of positive p16(INK4A) immune staining to detect CIN2 + histopathology were as 87.5% and 68%, respectively. The positive predictive value of p16 triage is found as 53.8% and negative predictive value was as 92.8%. p16(INK4A) IHC seems applicable for conventional Pap smears and may provide an alternative triage option in ASC-H category.

p16 INK4a and Ki67 expression in normal, dysplastic and neoplastic uterine cervical epithelium and human papillomavirus (HPV) infection

Cellular cycle proteins like the p16(INK4a) and the Ki67 proliferation nuclear antigen have been used as oncogenicity cellular markers. The E6 and E7 oncoproteins interact with tumor suppressor genes p53 and pRb, culminating with the p16(INK4a) overexpression. The objective of this study was to evaluate the presence of HPV-DNA in 174 cervical biopsies and correlate the different histological grades with the p16(INK4a) and Ki67 immunohistochemical expression (IHC). A cross-sectional study that enrolled a total of 174 women who underwent uterine cervical biopsies between February 2003 and December 2006, in southern Brazil, was performed. Cervical smear samples were analyzed for the presence of HPV-DNA through polymerase chain reaction (PCR), and biopsy samples were examined for p16(INK4A) and Ki67 expression through IHC techniques. The presence of HPV-DNA was observed in 89% of the tested patients, among which 52% were positive for high-risk (HR) viral types [16, 18 and 31]. Regarding p16(INK4a), an expression of 69% was observed, being expressed in 100% of the high-grade squamous lesions (HSIL) and HR-HPV-DNA positives. Ki67 expression was associated with the lesion grade, being more expressive in the most severe lesions (p<0.001). p16(INK4A) and Ki67 markers coexpression was present in 86% of the samples (p<0.001), being 100% among those positive to HR-HPV-DNA with HSIL (p<0.001). The results suggest an association between the presence of HR-HPV infection and the p16(INK4a) and Ki67 expression and which is even stronger among women with HSIL.

Malignant mixed Müllerian tumor with an extensive squamous-cell carcinomatous component: a potential pitfall in liquid-based cervical cytology

BACKGROUND

Malignant mixed Müllerian tumors (MMMTs) are aggressive tumors arising in the female lower genital tract and characterized by the presence of both a malignant epithelial and a mesenchymal component. Here, we report a case of an MMMT of the uterine corpus with an extensive squamous-cell carcinomatous component processed by liquid-based cytology (LBC).

CASE REPORT

An 84-year-old woman with a prior history of anal squamous-cell carcinoma, who complained of vaginal bleeding, was discovered to have a mass protruding from the uterine cervix. A Papanicolaou (Pap) test was performed and the LBC (ThinPrep) preparation showed a background of neutrophils and cellular debris. Atypical cells were identified that presented with hyperchromatic nuclei, nuclear membrane irregularities, multinucleation and abundant cytoplasm with focal keratinization. Scattered nucleolated malignant elements were also identified. The cytological diagnosis resulted in 'suspicious for squamous-cell carcinoma', favoring primary cervical carcinoma rather than extracervical (anal) carcinoma. The histological examination showed that it was an MMMT with an extensive squamous-cell carcinomatous component.

CONCLUSION

This case illustrates the potential diagnostic pitfall of MMMTs with extensive squamous-cell carcinomatous components in LBC Pap smears. Cytopathologists should keep in mind this diagnostic possibility in postmenopausal women who experience vaginal bleeding or spotting.