Immunocytochemical colocalization of p16INK4a and Ki-67 predicts CIN2/3 and AIS/adenocarcinoma

P16/Ki67 Dual Staining in Glandular Cell Abnormalities of the Uterine Cervix

Very limited information exists about the role of p16/Ki67 dual staining on glandular cells in detecting glandular precancerous lesions and cervical adenocarcinoma. In this study, we investigated the diagnostic accuracy of p16/Ki67 dual staining for the detection of glandular and squamous lesions on the uterine cervix and for cancer of the upper reproductive tract. We performed a retrospective analysis of prospectively collected data on 96 patients with glandular cell abnormalities. We analyzed the diagnostic accuracy of p16/Ki67 dual staining for atypical glandular cells, not otherwise specified (AGC-NOS); atypical glandular cells, favor neoplastic (AGC-FN); adenocarcinoma in situ (AIS); and A-CA (cervical adenocarcinoma). A separate analysis for the detection of squamous precancerous lesions and squamous-cell carcinoma (CIN3+) and for cancer of the upper reproductive tract (EC/OC) was performed. Among patients who had normal histology or a low-grade lesion on final analysis, only 8.5% had positive dual staining. On the other hand, 85.7% of patients with AIS+ on final histology had positive dual staining. The respective specificities of p16/Ki67 dual staining on AGC-NOS for the detection of AIS+ (adenocarcinoma in situ or cervical adenocarcinoma), CIN3+ and EC/OC were 91.5%, 88.7% and 86.4%. High specificity values of p16/Ki67 dual staining on cervical smears labelled as AGC-NOS for the detection of CIN3+ and AIS+ suggest that this method might be a useful addition in cervical cancer screening.

Enhancing Cervical Cancer Screening: Review of p16/Ki-67 Dual Staining as a Promising Triage Strategy

Cervical cancer, primarily caused by high-risk human papillomavirus (HR-HPV) types 16 and 18, is a major global health concern. Persistent HR-HPV infection can progress from reversible precancerous lesions to invasive cervical cancer, which is driven by the oncogenic activity of human papillomavirus (HPV) genes, particularly E6 and E7. Traditional screening methods, including cytology and HPV testing, have limited sensitivity and specificity. This review explores the application of p16/Ki-67 dual-staining cytology for cervical cancer screening. This advanced immunocytochemical method allows for simultaneously detecting p16 and Ki-67 proteins within cervical epithelial cells, offering a more specific approach for triaging HPV-positive women. Dual staining and traditional methods are compared, demonstrating their high sensitivity and negative predictive value but low specificity. The increased sensitivity of dual staining results in higher detection rates of CIN2+ lesions, which is crucial for preventing cervical cancer progression. However, its low specificity may lead to increased false-positive results and unnecessary biopsies. The implications of integrating dual staining into contemporary screening strategies, particularly considering the evolving landscape of HPV vaccination and changes in HPV genotype prevalence, are also discussed. New guidelines and further research are necessary to elucidate the long-term effects of integrating dual staining into screening protocols.

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

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSION

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

Utility of p16/Ki67 double immunocytochemistry for detection of cervical adenocarcinoma

BACKGROUND

Although the incidence of cervical adenocarcinoma has consistently increased, especially among young women, there is no established best means for screening. This study evaluated the screening efficacy of CINtec PLUS (CINtec; p16/Ki67 double immunocytochemistry) expression in cervical glandular cells.

METHODS

Cervical cytology was examined using abnormal glandular cells. The CINtec status of 100 samples with corresponding surgically resected specimens and 11 samples that exhibited negative results for intraepithelial lesion or malignancy at follow-up was analyzed. Additionally, 31 negative samples containing benign glandular cells were included.

RESULTS

Of the 142 samples, CINtec status was diffusely positive in 74, focally positive in 24, and negative in 44. The 74 diffusely positive samples included 70 adenocarcinomas (62 cervical, seven uterine, and one ovarian) and four cases of high-grade cervical intraepithelial neoplasia. The 24 focally positive samples included 15 adenocarcinomas (seven cervical, seven uterine, and one fallopian tube) and nine without malignancy. The 44 negative samples included nine adenocarcinomas (five uterine and four cervical) and 35 without malignancy. The sensitivity, specificity, positive predictive value, and negative predictive value of the CINtec diffusely or focally positive cases for cervical adenocarcinomas were 94.5%, 58.0%, 70.4%, and 90.9%, respectively. In CINtec diffusely positive cases, the respective values were 84.9%, 82.6%, 83.8%, and 83.8%, and in women aged ≤39 years the values were 90.6%, 89.5%, 93.5%, and 85.0%, respectively.

CONCLUSIONS

CINtec may support efficient detection of cervical adenocarcinomas.

Role of immunocytochemistry in cervical cancer screening

The cervical cancer screening has been based conventionally on cytologic analysis. With advances in understanding the role of human papillomavirus, cotesting has been applied. But most of the patients subjected to colposcopy did not benefit, except in cases with HSIL [high-grade squamous intraepithelial lesion] cytology. Because of this, a step to increase the sensitivity to detect cancers and pre-cancers but with higher specificity with minimal overdiagnosis leading to prevention of unindicated cervical biopsies is highly desired. Such triaging step in cases with abnormal screening results is expected to minimize invasive interventions because of low false positivity. With availability of methodologies leading to quantitatively and qualitatively enhanced cell-blocks from residual liquid based cytology specimens, immunostaining can be performed for multiple immunomarkers with potential objectivity to triage initial screening test results. This is enhanced further with inclusion of AV marker in the cell-blocks and application of SCIP (subtractive coordinate immunoreactivity pattern) approach. The cell-blocks are also resource for performing other ancillary studies including molecular pathology and proteomics/metabolomics as potential tests in future. This review explores application of residual liquid based cytology specimen for cell-blocking with application of ancillary studies in algorithmic manner as adjunct to ASCCP management guidelines for improved patient care.

Differential sensitivity of assays for determining vein endothelial cell senescence

In vivo endothelialization of polymer-based cardiovascular implant materials is a promising strategy to reduce the risk of platelet adherence and the subsequent thrombus formation and implant failure. However, endothelial cells from elderly patients are likely to exhibit a senescent phenotype that may counteract endothelialization. The senescence status of cells should therefore be investigated prior to implantation of devices designed to be integrated in the blood vessel wall. Here, human umbilical vein endothelial cells (HUVEC) were cultivated up to passage (P) 4, 10 and 26/27 to determine the population doubling time and the senescence status by four different methods. Determination of the senescence-associated β-galactosidase activity (SA-β-Gal) was carried out by colorimetric staining and microscopy (i), as well as by photometric quantification (ii), and the expression of senescence-associated nuclear proteins p16 and p21 as well as the proliferation marker Ki67 was assessed by immunostaining (iii), and by flow cytometry (iv). The population doubling time of P27-cells was remarkably greater (103±65 h) compared to P4-cells (24±3 h) and P10-cell (37±15 h). Among the four different methods tested, the photometric SA-β-Gal activity assay and the flow cytometric determination of p16 and Ki67 were most effective in discriminating P27-cells from P4- and P10-cells. These methods combined with functional endothelial cell analyses might aid predictions on the performance of implant endothelialization in vivo.

Combining HPV DNA load with p16/Ki-67 staining to detect cervical precancerous lesions and predict the progression of CIN1-2 lesions

Background

Human Papilloma Virus (HPV) DNA tests are highly sensitive and can triage women with mild lesions, improving the prognosis and diagnosis of cervical lesions. However, additional efficient strategies should be developed to improve the specificity of these tests.

Methods

This study aimed to evaluate the clinical value of HPV DNA load in improving the diagnosis and prognosis of cervical lesions by p16/Ki-67 testing. Histological samples were collected from 350 women with HR-HPV genotyping and analyzed by qRT-PCR. Immunohistochemical staining was used to assess p16 and Ki-67 expression and clinical performance characteristics were calculated.

Results

Of the cases, 271 had detectable HR-HPV infection, in which HPV-16 was most prevalent (52.0%), followed by HPV-58 (22.5%). P16/Ki-67-positivity increased with histological severity but not for HR-HPV infection. Amongst the 13 HR-HPV genotypes, only HPV-16 (P = 0.016) and HPV-58 (P = 0.004) viral loads significantly correlated with lesion severity. The P16/Ki-67/HPV DNA load co-test indicated an increased sensitivity for the detection of cervical intraepithelial neoplasia (CIN) lesions compared to p16/Ki-67 staining in HPV-16 and/or 58 positive cases. Viral load did not improve the sensitivity of p16/Ki-67 co-test in non-HPV-16 or 58 positive cases. The clinical performance of the p16/Ki-67/HPV DNA load co-test was limited for the prediction of the outcome of CIN1 lesions. However, amongst the 12 HPV-16 and/or 58 positive CIN2 cases in which return visit results were obtained, the behavior of the lesions could be predicted, with a sensitivity, specificity, positive prediction rate (PPV), and negative prediction rate (NPV) of 0.667, 1, 1 and 0.5, respectively.

Conclusion

Combination of the assessment of HPV DNA load with the intensity of p16 and Ki-67 staining could increase the sensitivity of CIN lesion diagnosis and predict the outcome of CIN2 in patients with a HPV-16 and/or 58 infection.

Application of p16/Ki-67 dual-staining cytology in cervical cancers

Cytology-based Papanicolaou test on and primary HPV screening have been widely used in the identification of cervical cancer and precancerous lesions, which is of great significance for the prevention and treatment of cervical cancer. Patients diagnosed as ASCUS/LSIL usually need follow-up because some of them may develop into CIN2+. The consequences of women positive for HPV vary from person to person; some of them may progress into cervical dysplasia, reversible forms of precancerous lesions, and eventually invasive cervical cancer. Therefore, it is necessary to establish an effective biomarker to triage different patients according to the preliminary screening results. p16 acts as a cell cycle regulatory protein that induces cell cycle arrest, and Ki-67 is a cell proliferation marker. Under physiological conditions, they could not co-express in the same cervical epithelial cells. The co-expression of these two molecules suggests a deregulation of the cell cycle mediated by HR-HPV infection and predicts the presence of high-grade cervical epithelial lesions. There is increasing evidence that p16/Ki-67 dual-staining cytology can be used as an alternative biomarker, showing overall high sensitivity and specificity for identifying high-grade CIN and cervical cancer. In this review, we discuss the significance of p16/Ki-67 dual-staining and summarize its application in the screening and triaging of cervical cancer and precancerous lesions.

A cocktail of p16INK4a and Ki-67, p16INK4a and minichromosome maintenance protein 2 as triage tests for human papillomavirus primary cervical cancer screening

Most human papillomavirus (HPV) infections are transient and additional triage approaches should be built after HPV-based primary cervical cancer screening. We evaluated the accuracy of p16/Ki-67 and p16/mcm2 dual staining as biomarkers for triaging HPV positive women in China. 4070 participants aged 35 to 64 years attending ongoing cervical cancer screening were enrolled in 2015-2016. Cervical exfoliated cells were collected for HPV DNA analysis and the residual positive specimens were tested for liquid-based cytology and biomarkers. Women infected with HPV 16/18 type or other 12 high-risk HPV types with abnormal cytology results received colposcopy. We found the positive rates of both biomarkers increased significantly with histology severity. p16/Ki-67 positivity in HPV16/18 group, other 12 high-risk HPV group and HPV negative group was 50.0%, 33.7% and 8.9%, respectively. The corresponding p16/mcm2 positivity was 70.0%, 56.3% and 6.7%, respectively. The sensitivity and specificity of p16/Ki-67 for CIN2+ in all HPV-positive women were 91.7% and 63.5%, with a referral rate of 36.2%, while p16/mcm2 were 87.5% and 42.1%, with a referral rate of 58.4%, respectively. The sensitivity of p16/Ki-67 increased to 95.8% for CIN2+ and 100% for CIN3+ when combined with high-grade cytology, without decrease in specificity. Our studies suggest that p16/Ki-67 is an efficient triaging biomarker for HPV-positive women and could reduce colposcopy workload. p16/mcm2 is more sensitive compared with cytology for identifying cervical lesions.

Keratin 17 Is a Prognostic Biomarker in Endocervical Glandular Neoplasia

OBJECTIVES

Previous work in our laboratory identified keratin 17 (K17) as a specific and sensitive biomarker for high-grade squamous intraepithelial lesions and cervical squamous cell carcinoma (SCC). K17, however, has not been previously evaluated in endocervical glandular neoplasia. Based on the similar pathogenesis of squamous and glandular lesions of the cervix, we hypothesized that K17 overexpression could also be a diagnostic and/or prognostic biomarker for endocervical neoplasia.

METHODS

Cases of endocervical adenocarcinoma (n = 90), adenocarcinoma in situ (AIS) (n = 32), benign glandular lesions (n = 36), and normal endocervical mucosa (n = 5) were selected from Stony Brook Medicine and the University of Massachusetts from 2002 to 2013. Immunohistochemical staining for K17 was performed by an indirect immunoperoxidase method and was scored based on the proportion of cells that showed strong (2+) staining.

RESULTS

K17 was highly expressed in 21 (65.6%) of 32 AIS and in 75 (83.0%) of 90 adenocarcinoma cases. In adenocarcinomas, K17 staining was detected in a mean of 33.9% of malignant cells. Staining tended to be strongest at the periphery of pseudoglandular groups and at the invasive front of tumors. K17 was not detected in the epithelial cells of benign glandular lesions, but groups of cuboidal cells, residing beneath the epithelial layer of benign glands, were frequently positive for K17, especially in cases of microglandular hyperplasia. High levels of K17 expression were significantly associated with decreased patient survival.

CONCLUSIONS

K17 is highly expressed in most cases of both invasive adenocarcinoma and in AIS and is a powerful, negative prognostic marker for patient survival.

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.

Management of HPV-related cervical disease: role of p16INK4a immunochemistry. Review of the literature

This systematic review of 43 studies aims to evaluate the absolute and relative sensitivity and specificity of p16INK4a with regard to uterine cervix lesions, describing innovations and techniques for the detection of high-grade cervical dysplasia and allowing correct treatment. Studies were identified in the PubMed database up to March 2015. The keywords hrHPV, p16INK4a gene, and uterine cervical disease (MeSH terms) were used. Only English-language articles were included. We considered retrospective and prospective studies that assessed p16INK4a or p16INK4a/Ki67 staining, with or without HPV-DNA testing (HC2/PCR) as a comparator test, in cytological/histological specimens for which the diagnosis of ASCUS, LSIL or HSIL was verified with a reference standard. The primary outcome for cervical lesions was evaluation of the absolute p16INK4a immunoreactivity; the secondary outcome was evaluation of the relative p16INK4a immunoreactivity versus HPV testing in those studies where comparator tests were available. p16INK4a was more specific than HPV-DNA test (median values of 56.1% vs. 52.25% in CIN grade ≥2 lesions; 82.5% vs. 53% in negative and CIN grade ≥1 lesions). The main limitation of this study is linked to both qualitative and quantitative p16INK4a levels of expression, while the second limitation is the lack of standardized scales. p16INK4a and HPV-DNA used together increased the sensitivity and negative predictive value for CIN detection. p16INK4a can be considered a biomarker of CIN2 or CIN3, indicating a high risk of relapse or evolution to invasive carcinoma. Also p16INK4a-negative CIN should be considered and further research should be performed.

Immunocytochemical study of TOP2A and Ki-67 in cervical smears from women under routine gynecological care

BACKGROUND

Cervical cancer is one of the most common female cancers and is caused by human papillomavirus (HPV). Viral infection leads to cell cycle deregulation by inactivating p53 and retinoblastoma protein by viral oncoproteins E6 and E7, respectively. Then, nuclear proteins such as DNA topoisomerase type IIa (TOP2A) and Ki-67 show increased expression because of increased cell division. These molecules are used as biomarkers for immunohistochemistry analysis of cervical tissue.

METHODS

In this cross-sectional study, we recruited 110 women receiving regular gynecological surveillance at public health centers in Olinda - PE, Brazil. Cervicovaginal cells were collected to determine the presence of cytological abnormalities and HPV infection. Pap smear slides were used to evaluate the expression of TOP2A and Ki-67 using immunocytochemistry techniques.

RESULTS

Of the 110 women, 75.4 % showed HPV-DNA(+) infection (83/110) and 29.1 % showed cellular abnormalities (32/110). Two atypical cells of undetermined significance, one low-grade squamous intraepithelial lesion, and one high-grade squamous intraepithelial lesion samples showed no HPV-DNA. TOP2A was positive in 71.9 % of samples, while Ki-67 was positive in 81.2 %. Immunocytochemistry results were positive in 4 of 5 atypical cells of undetermined significance samples. In HPV-DNA(+) samples with cytological abnormalities, immunocytochemistry results were positive 96.4 % of samples (p < 0.0001; odds ratio = 28.0). Among the samples infected with HR-HPV, TOP2A(+) was effective in 71 % samples, while and Ki-67(+) was 77.4 %. Ki-67 and TOP2A were positive for all samples infected with HPV6, HPV11, and HPV18. Ki-67 was also positive for all HPV16 samples, except for one negative sample in cytopathology analysis.

CONCLUSIONS

TOP2A and Ki-67 antibodies may be used in combination for cervical cancer screening in immunocytochemistry assays.

HPV immunohistochemical testing and cervical dysplasia

Background and aim

HPV (Human Papilloma Virus) infection represents a necessary condition for cervical carcinogenesis. The purpose of this study was to evaluate the efficiency of HPV testing using an immunohistochemical staining kit with implications upon both diagnosis and treatment of cervical intraepithelial neoplasia (CIN).

Methods

Seventy-nine patients and eighty-six controls were enrolled in the study. Each patient had completed a physical examination, gynecological examination with cervical sampling using a liquid-based cytology system and also colposcopy. The cervical samples were analyzed according to Bethesda terminology and HPV-HR immunohistochemical staining was performed. In all the patients with high-grade lesion a surgical excision procedure was performed followed by pathological examination of the specimen. The collected data were analyzed using statistical software.

Results

The colposcopic examination has detected acetowhite modifications of the cervical epithelium in 47% of patients with ASC-US (Atypical squamous cells of undetermined significance) in 71% of patients with LSIL (Low grade squamous intraepithelial lesion) and in 100% of patients with HSIL ( High grade squamous intraepithelial lesion). The biopsy confirmed the diagnosis of LSIL in 27% of biopsy specimens in patients with ASC-US and in 79.99% of patients with LSIL respectively. In all patients with HSIL the diagnosis was CIN II or higher. The percentage of HPV-HR (Human Papilloma Virus – High Risk) positivity porportionaly increased with the severity of cytological diagnosis: 30% in ASC-US, 42.86% in LSIL and 75% in HSIL patients. The sensitivity of detection of HPV-HR was 50% with CI 95% [17.45;82.55] for ASC-US, 77.77% with CI 95% [51.91;92.62] for LSIL and 81.81% with CI 95% [58.99;94.00] for HSIL.

Conclusion

HPV testing can be an important screening tool for cervical dysplasia. The HPV testing targeting high risk types is indicated for ASC-US and LSIL triage. The present work sustains the idea of introducing HPV testing as a primary screening tool for cervical cancer.

[Primary cervical cancer screening]

Cervico-uterine cancer screening with cytology decrease incidence by more than 50%. The cause of this cancer is the human papilloma virus high risk, and requires a sensitive test to provide sufficient sensitivity and specificity for early detection and greater interval period when the results are negative. The test of the human papilloma virus high risk, is effective and safe because of its excellent sensitivity, negative predictive value and optimal reproducibility, especially when combined with liquid-based cytology or biomarkers with viral load, with higher sensitivity and specificity, by reducing false positives for the detection of cervical intraepithelial neoplasia grade 2 or greater injury, with excellent clinical benefits to cervical cancer screening and related infection of human papilloma virus diseases, is currently the best test for early detection infection of human papillomavirus and the risk of carcinogenesis.

Cytological variations and typical diagnostic features of endocervical adenocarcinoma in situ: A retrospective study of 74 cases

Background:

The sensitivity of Papanicolaou smears for detecting endocervical adenocarcinoma in situ (AIS) is very low. A comprehensive cytological analysis of endocervical AIS is necessary to increase diagnostic accuracy.

Methods:

The subjects were 74 patients with pathologically-diagnosed AIS. A total of 140 Papanicolaou smears were reviewed to calculate the sensitivity of the Papanicolaou smears for detecting AIS and the incidence of sampling/screening/diagnostic errors. The cytological review was performed by 6 cytotechnologists, and the final cytological diagnosis was obtained at the consensus meeting. We classified the cases into three differentiation types; typical type (well-differentiated AIS), polymorphic type (poorly differentiated AIS), and mixed typical and polymorphic type. Three cytological subtypes (endocervical, endometrioid and intestinal subtypes) of AIS were also analyzed.

Results:

The sensitivity of the original Papanicolaou smears for the detection of AIS was 44.6%, while that for the detection of AIS and adenocarcinoma was 63.5%. The diagnostic accuracy of AIS increased to 78.5% in the final diagnosis. The common characteristic features were microbiopsies/hyperchromatic crowded groups (HCG) (82.0%) and mitotic figures (72.2%). The appearance of single cells (2.8%) was rare, and all the cervical cytology smears showed no evidence of necrotic tumor diathesis. The most common AIS was the typical type (41 cases, 67.2%) among all cytologically-diagnosed AIS or adenocarcinoma cases (61 cases). Although mixed typical and polymorphic AIS existed in 17 cases (27.9%), pure polymorphic AIS was very rare (3 cases, 4.9%). The endocervical subtype was the most predominant subtype (67.2%), followed by a few mixed subtypes. The important diagnostic keys for AIS cytology are as follows: (1) The appearance of microbiopsies/HCG (single-cell pattern is rare), (2) mitotic figures in the microbiopsies/HCG, (3) a lack of necrotic tumor diathesis in cases with polymorphic AIS, and (4) recognition of typical cytological subtypes.

Conclusions:

The relatively low diagnostic accuracy AIS was caused by the underestimation of microbiopsies/HCG and the overestimation of polymorphic components. The typical cytological features of AIS are the presence of microbiopsies/HCG with mitotic figures in the absence of necrotic tumor diathesis in specimens containing endocervical samples. The recognition of infrequent AIS subtypes (endometrioid and intestinal subtypes) is also important.

Combination of p16(INK4a) /Ki67 immunocytology and HPV polymerase chain reaction for the noninvasive analysis of HPV involvement in head and neck cancer

BACKGROUND

High-risk human papillomavirus (HPV) infection has been identified as a relevant risk for the development of head and neck squamous cell carcinomas (HNSCCs). As HPV status has also gained a role as a prognostic and predictive biomarker for this entity, there is a growing demand for valid HPV testing in HNSCC patients

METHODS

Liquid-based cytological smears from 45 HNSCC and 20 control patients were collected and used for simultaneous immunocytochemical p16(INK4a) /Ki67 staining using a CINtec PLUS kit after the presence of tumor cells was verified in a Papanicolaou-stained slide. The same cytological suspension was used for the detection of HPV DNA by specific polymerase chain reaction (PCR).

RESULTS

Tumor cells were detected in the swab material of 44 HNSCC patients corresponding to a sensitivity of 98% (44 of 45). PCR analysis revealed the presence of HPV DNA in the cytological suspension of 13 patients (13 of 65, 20%) with simultaneous p16(INK4a) /Ki67 expression by the tumor cells in 11 of these HPV DNA-positive samples (11 of 13, 85%) - a staining pattern that is strongly associated with a carcinogenic HPV infection.

CONCLUSIONS

A simultaneous immunocytochemical detection of p16(INK4a) and Ki67 can reliably be performed on liquid-based cytological smears from HNSCC patients using a CINtec PLUS kit. In addition, the same cytological material can be used for the detection of HPV DNA by specific PCR. The combined results of both techniques enable better discrimination between latent and carcinogenic HPV infections as well as HPV-negative cases and thus can provide information on the prognosis of HNSCC patients and facilitate therapeutic decisions.

Immunocytochemical analysis of the cervical Pap smear

Although immunostained cervical Pap smears are not yet FDA approved for clinical use, it is very likely that they will become widely employed in the near future to identify neoplastic squamous and iendocervical glandular cells when screening liquid-based cytological preparations (i.e., SurePath™ or ThinPrep™). The current problem with cytology complemented by high-risk human papillomavirus (HPV) testing is poor specificity. HPV testing provides superior sensitivity, but many women are infected with the virus, while very few have had persistent infections leading to carcinoma. Pathologists routinely use antibodies directed against the cyclin-dependent kinase inhibitor p16 (p16(INK4a)) or a combination of antibodies directed against topoisomerase-2-alpha and minichromosome maintenance protein-2 (as in ProEx™ C) to improve diagnostic precision and accuracy in cervical tissue biopsies. This chapter will describe the immunocytochemical methods used by our group to immunostain cervical Pap smears and provide significantly improved positive predictive value when screening for cervical cancer.

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.

p16/Ki-67 dual-stained cytology testing may predict postpartum outcome in patients with abnormal papanicolaou cytology during pregnancy

OBJECTIVE

To evaluate the use of a new immunocytochemical dual-staining protocol, which allows for the detection of coexpression of the p16(INK4a) (p16) and Ki-67 biomarkers in prenatal care. It was hypothesized that dual-staining cytology may predict postpartum outcome in patients with abnormal cervical Papanicolaou (Pap) smears during pregnancy.

STUDY DESIGN

In this retrospective pilot study, 27 abnormal Pap smears collected from women during early pregnancy were destained and subsequently stained for p16/Ki-67. RESULTS were correlated with histologic outcome collected during postpartum follow-up.

RESULTS

Fourteen of 20 abnormal Pap smears during pregnancy showed a positive p16/Ki-67 dual-stained cytology result, whereas 6 specimens tested negative. Seven cases were excluded due to technical reasons. All 14 patients who were positive for p16/Ki-67 dual stain had cervical intraepithelial neoplasia (CIN) on postpartum histology. In contrast, 5 out of 6 patients negative for p16/Ki-67 dual-staining had a negative histology postpartum and during follow-up, and the remaining patient showed a CIN1 (p < 0.001).

CONCLUSION

p16/Ki-67 dual-stained cytology may provide a valuable novel approach to identify pregnant women with persistent or progressing CIN disease and may help improve the management of abnormal Pap cytology results during pregnancy.

Ancillary Diagnostics in Gynecologic Cytology

Cytology has been the mainstay of cervical dysplasia and cancer screening in the United States. The specificity of a woman harboring a high-grade lesion when identified as high-grade squamous intraepithelial lesion on Pap test is high; however, the test suffers from low sensitivity. Epidemiology studies have demonstrated that human papillomavirus (HPV) types 16 and 18 account for most cervical squamous cell carcinomas. Tests have been developed to identify high-risk HPV, some specifically to identify HPV 16 and 18. Simultaneous to the increase in HPV detection methods, interdisciplinary groups are making recommendations on the managerial use of the tests.

Molecular targets of HPV oncoproteins: potential biomarkers for cervical carcinogenesis

Cervical cancer is the second most common cancer among women worldwide and is responsible for 275,000 deaths each year. Persistent infection with high-risk human papillomavirus (HR-HPV) is an essential factor for the development of cervical cancer. Although the process is not fully understood, molecular mechanisms caused by HPV infection are necessary for its development and reveal a large number of potential biomarkers for diagnosis and prognosis. These molecules are host genes and/or proteins, and cellular microRNAs involved in cell cycle regulation that result from disturbed expression of HR-HPV E5, E6 and E7 oncoproteins. One of the current challenges in medicine is to discover potent biomarkers that can correctly diagnose cervical premalignant lesions and standardize clinical management. Currently, studies are showing that some of these molecules are potential biomarkers of cervical carcinogenesis, and it is possible to carry out a more accurate diagnosis and provide more appropriate follow-up treatment for women with cervical dysplasia. In this paper, we review recent research studies on cell cycle molecules deregulated by HPV infections, as well as their potential use for cervical cancer screening.

Predictive value of the combined p16 and Ki-67 immunocytochemistry in low-grade squamous intraepithelial lesions

OBJECTIVE

The reliability of cytological diagnoses, especially for low-grade squamous intraepithelial lesions (LSIL), is limited. This leads to uncertainty in patient management. The application of adjunctive biomarkers is meant to improve this situation. Therefore, we examined the prognostic value of p16/Ki-67 immunostaining of LSIL cytology specimens.

STUDY DESIGN

We analyzed the p16(INK4a) and Ki-67 immunocytochemistry (CINtec® PLUS, dual stain) of 260 patients with LSIL. Cytology and dual-stain results were correlated with histology at the time of treatment or with cytological follow-up.

RESULTS

After an average duration of 24.9 months (1-58) and a histology rate of 36.2% [cervical intraepithelial neoplasia, grade 2 or higher (CIN2+) as positive], the statistical evaluation for cytology and dual stain resulted in a sensitivity of 98.3 and 90.0%, respectively, a specificity of 74.5% for dual stain, a positive predictive value (PPV) of 22.8 and 51.4%, and a negative predictive value (NPV) of 96.1% for dual stain.

CONCLUSION

The combined immunocytochemical investigation of p16(INK4a) and Ki-67 leads to a significantly better PPV and a very good NPV for CIN2+ in LSIL, especially in women 30 years of age and older. An objective individualized prognosis may not be achieved with p16(INK4a)/Ki-67. Statistical data from our study, however, indicate that patient management can be significantly improved by the application of combined p16/Ki-67 immunocytochemistry as an adjunct to cytology.

Screening for cervical cancer precursors with p16/Ki-67 dual-stained cytology: results of the PALMS study

Background

Pap cytology is known to be more specific but less sensitive than testing for human papillomavirus (HPV) for the detection of high-grade cervical intraepithelial neoplasia (CIN2+). We assessed whether p16/Ki-67 dual-stained cytology, a biomarker combination indicative of transforming HPV infections, can provide high sensitivity for CIN2+ in screening while maintaining high specificity. Results were compared with Pap cytology and HPV testing.

Methods

A total of 27349 women 18 years or older attending routine cervical cancer screening were prospectively enrolled in five European countries. Pap cytology, p16/Ki-67 immunostaining, and HPV testing were performed on all women. Positive test results triggered colposcopy referral, except for women younger than 30 years with only positive HPV test results. Presence of CIN2+ on adjudicated histology was used as the reference standard. Two-sided bias-corrected McNemar P values were determined.

Results

The p16/Ki-67 dual-stained cytology positivity rates were comparable with the prevalence of abnormal Pap cytology results and less than 50% of the positivity rates observed for HPV testing. In women of all ages, dual-stained cytology was more sensitive than Pap cytology (86.7% vs 68.5%; P < .001) for detecting CIN2+, with comparable specificity (95.2% vs 95.4%; P = .15). The relative performance of the tests was similar in both groups of women: younger than age 30 and 30 years or older. HPV testing in women 30 years or older was more sensitive than dual-stained cytology (93.3% vs 84.7%; P = .03) but less specific (93.0% vs 96.2%; P < .001).

Conclusions

The p16/Ki-67 dual-stained cytology combines superior sensitivity and noninferior specificity over Pap cytology for detecting CIN2+. It suggests a potential role of dual-stained cytology in screening, especially in younger women where HPV testing has its limitations.

Dual immunostaining of cervical cytology specimens with atypical squamous cells for p16/Ki-67 does not exclude the existence of a high-grade squamous intraepithelial lesion

This study was conducted to evaluate the accuracy of p16/Ki-67 dual immunostaining compared to high-risk human papillomavirus (HR-HPV) DNA testing for cervical intraepithelial neoplasia (CIN) in women with atypical squamous cells, cytology not excluding high-grade squamous intraepithelial lesion (ASC-H). Data were collected from 73 patients diagnosed to have ASC-H on a Pap smear who were HPV genotyped and had histological examination of a cervical biopsy. The CINtecPLUS kit was used on residual liquid-based material, and the immunoreactivity of dual-stained cells was graded according to the number as follows: G1 (1-5 positive cells), G2 (6-10), G3 (11-20), and G4 (> 20). Accuracy was evaluated based on the histological examination of colposcopy-guided biopsy or cervical conization on follow-up. Of the 70 patients with available data, positive p16/Ki-67 was associated with histological severity as follows: 15% in negative histology, 67% in CIN 1, 90% in CIN 2, and 100% in CIN 3. The average grade of positive p16/Ki-67 staining also increased from 0.2 in histologically negative cases to 1.2 in CIN 1, 2.4 in CIN 2, and 2.9 in CIN 3 (p < 0.01). For patients with CIN 2 or higher, p16/Ki-67 had a sensitivity of 94.6% and a specificity of 75.8%, while HR-HPV testing showed a sensitivity of 67.6% and a specificity of 66.7%. p16/Ki-67 immunostaining demonstrated better accuracy than HR-HPV for detecting CIN 2 or higher in patients with ASC-H cytology. Given the higher concordance with histological diagnosis, the grading system of positive p16/Ki-67 can be a useful adjunct for predicting high-grade lesions in clinical practice.

Carbonic anhydrase type IX expression in lobular endocervical glandular hyperplasia and gastric-type adenocarcinoma of the uterine cervix

The significance of carbonic anhydrase (CA-IX) expression in endocervical glandular lesions was determined to assess the utility of CA-IX immunohistochemistry for the identification of gastric-type endocervical adenocarcinoma and its related lesions. In this study, lobular endocervical glandular hyperplasia (LEGH) (n=5), atypical LEGH (ALEGH) (n=6), and endocervical adenocarcinomas, including usual-type (UEA) (n=6) and gastric-type (GAS) (n=7), were examined by immunohistochemistry for CA-IX expression. The proportion of positive staining and intensity was evaluated as between 0 and 3+. All 13 UEAs and GASs were positive for CA-IX, with 9 cases showing 3+ staining, and 8 cases showing positive areas exceeding 50%. All 11 LEGHs were positive for CA-IX, with all cases showing 50% or more positive areas, although only one case was 3+ positive. Five of 6 ALEGHs were positive for CA-IX, with 4 cases showing 3+ positivity in 100% of the lesion. Non-neoplastic glands were negative for CA-IX, although reserve cell populations and tubal metaplasias were positive for CA-IX. Although CA-IX appears to be involved in tumor progression and may be diagnostically useful in cases of endocervical adenocarcinoma and its precursors, LEGH can be a pitfall, and staining results should be combined with morphology.

CINtec PLUS immunocytochemistry as a tool for the cytologic diagnosis of glandular lesions of the cervix uteri

Cytologic findings of glandular lesions of the cervix uteri are often difficult to evaluate. We studied the usefulness of CINtec PLUS p16/Ki-67 double stain (mtm laboratories, Heidelberg, Germany) for the diagnosis of glandular lesions. The study included 47 abnormal results on liquid-based cytologic tests with a subsequent histologic diagnosis of adenocarcinoma in situ or with early invasion, and 16 samples with negative results on follow-up. All samples were stained with CINtec PLUS p16/Ki-67 double stain. Of the neoplastic samples, 7 were excluded because of insufficient residual cellularity or loss of neoplastic cells. Of the samples that were adequate, 92.5% were stained with CINtec PLUS, whereas 7.5% were judged inconclusive. All inconclusive cases were at least 3 years old. Of the 16 negative samples, 15 (93.8%) stained negative and only 1 (6.2%) showed several positive clusters of cells. Our study shows that CINtec PLUS is a robust and useful tool for the diagnosis of glandular lesions of the cervix uteri.

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

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