Correlation of p16INK4A Overexpression with Human Papillomavirus Infection in Cervical Adenocarcinomas

Adenocarcinoma of the Uterine Cervix: Immunohistochemical Biomarker Expression and Diagnostic Performance

Immunohistochemistry (IHC) improves the diagnosis of cervical adenocarcinoma but is not adequately studied. The performance of 16 antibodies previously reported as potentially discriminating between some histotypes was investigated in 184 tumors comprised of 12 histotype groups collapsed into 3 categories [47 adenocarcinomas in situ (AIS), 121 probable human papillomavirus-dependent adenocarcinomas (HPVD), and 16 of probable independence (HPVI)]. IHC sections from 5 tissue microarrays were scanned, and 3 pathologists independently reviewed images to assess staining percentages and intensities. Biomarker expression was based on published positive and negative cutoffs and agreement between any 2 pathologists. Differences between the 3 categories in the hierarchical ranking of biomarker positivity were analyzed by Random Forest classification, and between select groups by Unsupervised Hierarchical Clustering. Important category discriminants were combined in logistic regression models and the area under the curve (AUC) computed. Potential group discriminants were terminal cluster biomarkers with a 50% or more difference in positivity. Strong associations occurred between the lower expression of carcinoembryonic antigen and stromal actin in AIS compared with HPVD [AUC=0.70, 95% confidence interval (CI), 0.59-0.80] and in the higher expression of p16 and estrogen receptor in comparison to HPVI (AUC=0.86, 95% CI, 0.73-0.98), and between the higher expression of p16, carcinoembryonic antigen and estrogen receptor in HPVD compared with HPVI (AUC=0.88, 95% CI, 0.77-0.99). Between select groups, 9 biomarkers emerged as potential discriminants. Select IHC biomarkers can discriminate AIS from invasive adenocarcinomas, and invasive adenocarcinomas stratified by human papillomavirus dependency from each other. Independent replication in larger studies is needed, and to confirm discriminants of histotype groups.

A Comprehensive Review of Biomarker Use in the Gynecologic Tract Including Differential Diagnoses and Diagnostic Pitfalls

Morphologic (ie, hematoxylin and eosin) evaluation of the Mullerian tract remains the gold standard for diagnostic evaluation; nevertheless, ancillary/biomarker studies are increasingly utilized in daily practice to assist in the subclassification of gynecologic lesions and tumors. The most frequently utilized "biomarker" technique is immunohistochemistry; however, in situ hybridization (chromogenic and fluorescence), chromosomal evaluation, and molecular analysis can also be utilized to aid in diagnosis. This review focuses on the use of immunohistochemistry in the Mullerian tract, and discusses common antibody panels, sensitivity and specificity of specific antibodies, and points out potential diagnostic pitfalls when using such antibodies.

The role of the PI3K/Akt/mTOR signalling pathway in human cancers induced by infection with human papillomaviruses

Infection with Human papillomaviruses (HPVs) leads to the development of a wide-range of cancers, accounting for 5% of all human cancers. A prominent example is cervical cancer, one of the leading causes of cancer death in women worldwide. It has been well established that tumor development and progression induced by HPV infection is driven by the sustained expression of two oncogenes E6 and E7. The expression of E6 and E7 not only inhibits the tumor suppressors p53 and Rb, but also alters additional signalling pathways that may be equally important for transformation. Among these pathways, the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signalling cascade plays a very important role in HPV-induced carcinogenesis by acting through multiple cellular and molecular events. In this review, we summarize the frequent amplification of PI3K/Akt/mTOR signals in HPV-induced cancers and discuss how HPV oncogenes E6/E7/E5 activate the PI3K/Akt/mTOR signalling pathway to modulate tumor initiation and progression and affect patient outcome. Improvement of our understanding of the mechanism by which the PI3K/Akt/mTOR signalling pathway contributes to the immortalization and carcinogenesis of HPV-transduced cells will assist in devising novel strategies for preventing and treating HPV-induced cancers.

Male genital lichen sclerosus

Male genital lichen sclerosus (MGLSc) is a chronic inflammatory skin disease responsible for male sexual dyspareunia and urological morbidity. An afeared complication is squamous cell carcinoma (SCC) of the penis. The precise etiopathogenesis of MGLSc remains controversial although genetic, autoimmune and infective (such as human papillomavirus (HPV) hepatitis C (HCV), Epstein-Barr virus (EBV) and Borrelia) factors have been implicated: Consideration of all the evidence suggests that chronic exposure of susceptible epithelium to urinary occlusion by the foreskin seems the most likely pathomechanism. The mainstay of treatment is topical ultrapotent corticosteroid therapy. Surgery is indicated for cases unresponsive to topical corticosteroid therapy, phimosis, meatal stenosis, urethral stricture, carcinoma in situ (CIS) and squamous cell carcinoma.

The Utility of Immunohistochemistry in the Differential Diagnosis of Gynecologic Disorders

Context

Immunohistochemistry has assumed an increasing role in the identification and characterization of gynecologic disorders including lesions with deceptively bland morphology, uncommon and underdiagnosed neoplasms, and neoplasms with specific genetic alterations associated with overexpression or loss of expression of specific proteins. The diagnostic accuracy has been significantly improved owing to the discovery and increasing experience with the tumor-associated biomarkers, and the increasing demand for precise tumor classification to assess suitability for the expanding therapeutic modalities including clinical trials.

Objective

To differentiate lesions of the gynecologic tract through the use of effective immunohistochemical panels.

Data Sources

Literature review and authors' personal practice experience.

Conclusions

The application of diagnostic and prognostic immunohistochemical panels has enabled pathologists to better guide therapeutic decisions and to better predict the clinical outcome. It is now well established that the use of ancillary testing, including immunohistochemistry, has a significant power in the identification, differentiation, and classification of reactive, premalignant, and malignant gynecologic disorders. This article discusses the utilities and pitfalls of the commonly used immunohistochemical markers in the context of overlapping morphologic features encountered in the uterus, ovaries, and fallopian tubes.

β-Adducin siRNA disruption of the spectrin-based cytoskeleton in differentiating keratinocytes prevented by calcium acting through calmodulin/epidermal growth factor receptor/cadherin pathway

Here, we report that siRNA transfection of β-adducin significantly disrupted the spectrin-based cytoskeleton and cytoskeletal arrangements of both β-adducin and PKCδ by substantially inhibiting the expression of β-adducin, spectrin and PKCδ proteins in differentiating keratinocytes. However, extracellular Ca2+ treatment blocked the inhibitory effects of the β-adducin siRNA. Ca2+ also prevented the significant down-regulation of two differentiation markers involucrin and K1/10 and the distinct up-regulation of proliferation marker K14 in β-adducin siRNA transfected keratinocytes. In addition, β-adducin knockdown resulted in a substantial reduction of epidermal growth factor receptor (EGFR), cadherin and β-catenin and enhanced phosphorylation of EGFR on tyrosine 1173 and Ca2+ prevented these changes. Furthermore, Ca2+ blocked the inhibitory effects of β-adducin siRNA on the expression of calmodulin, phosphorylated-calmodulin (P-CaM((Tyr138))) and myristoylated alanine-rich C-kinase substrate (MARCKS) in keratinocytes. Co-immunoprecipitation studies further revealed that calmodulin, not MARCKS, strongly interacted with EGFR, cadherin and β-catenin. Our data suggest that Ca2+ plays an important role in regulating the expression and function of β-adducin to sustain normal organization of the spectrin-based cytoskeleton and the differentiation properties in keratinocytes through the calmodulin/EGFR/cadherin signaling pathway.

The spectrum of cervical glandular neoplasia and issues in differential diagnosis

CONTEXT

Premalignant and malignant glandular lesions of the cervix are known to often cause diagnostic problems with a variety of benign (more common) as well as other malignant mimics, the latter setting often being represented by secondary involvement by endometrioid endometrial carcinoma especially in small samplings.

OBJECTIVE

To highlight key histologic features and immunohistochemical markers that may be helpful in the distinction of in situ endocervical carcinoma from benign glandular proliferations, and those that separate different subtypes of invasive endocervical carcinoma, as well as invasive carcinoma from other carcinomas secondarily involving the cervix and nonneoplastic proliferations of the cervix.

CONCLUSIONS

Clinical and morphologic features as well as immunohistochemistry results should be used in conjunction in the differential diagnosis of glandular proliferations of the cervix, as correct interpretation has major clinical consequences for the patient in most instances (especially benign versus malignant). Immunohistochemical markers should be used as part of a panel of antibodies, as exceptions may occur to the usual pattern of staining, and if used singly, they may mislead the pathologist to establish a wrong diagnosis.

Multiple biomarkers in molecular oncology. I. Molecular diagnostics applications in cervical cancer detection

The screening for cervical carcinoma and its malignant precursors (cervical neoplasia) currently employs morphology-based detection methods (Papanicolaou [Pap] smear) in addition to the detection of high-risk human papillomavirus. The combination of the Pap smear with human papillomavirus testing has achieved significant improvements in sensitivity for the detection of cervical disease. Diagnosis of cervical neoplasia is dependent upon histology assessment of cervical biopsy specimens. Attempts to improve the specificity of cervical disease screening have focused on the investigation of molecular biomarkers for adjunctive use in combination with the Pap smear. Active research into the genomic and proteomic alterations that occur during human papillomavirus-induced neoplastic transformation have begun to characterize some of the basic mechanisms inherent to the disease process of cervical cancer development. This research continues to demonstrate the complexity of multiple genomic and proteomic alterations that accumulate during the tumorigenesis process. Despite this diversity, basic patterns of uncontrolled signal transduction, cell cycle deregulation, activation of DNA replication and altered extracellular matrix interactions are beginning to emerge as common features inherent to cervical cancer development. Some of these gene or protein expression alterations have been investigated as potential biomarkers for screening and diagnostics applications. The contribution of multiple gene alterations in the development of cervical cancer suggests that the application of multiple biomarker panels has the potential to develop clinically useful molecular diagnostics. In this review, the application of biomarkers for the improvement of sensitivity and specificity of the detection of cervical neoplasia within cytology specimens will be discussed.

Differentiating rectal carcinoma by an immunohistological analysis of carcinomas of pelvic organs based on the NCBI Literature Survey and the Human Protein Atlas database

The treatments and prognoses of pelvic organ carcinomas differ, depending on whether the primary tumor originated in the rectum, urinary bladder, prostate, ovary, or uterus; therefore, it is essential to diagnose pathologically the primary origin and stages of these tumors. To establish the panels of immunohistochemical markers for differential diagnosis, we reviewed 91 of the NCBI articles on these topics and found that the results correlated closely with those of the public protein database, the Human Protein Atlas. The results revealed the panels of immunohistochemical markers for the differential diagnosis of rectal adenocarcinoma, in which [+] designates positivity in rectal adenocarcinoma and [-] designates negativity in rectal adenocarcinoma: from bladder adenocarcinoma, CDX2[+], VIL1[+], KRT7[-], THBD[-] and UPK3A[-]; from prostate adenocarcinoma, CDX2[+], VIL1[+], CEACAM5[+], KLK3(PSA)[-], ACPP(PAP)[-] and SLC45A3(prostein)[-]; and from ovarian mucinous adenocarcinoma, CEACAM5[+], VIL1[+], CDX2[+], KRT7[-] and MUC5AC[-]. The panels of markers distinguishing ovarian serous adenocarcinoma, cervical carcinoma, and endometrial adenocarcinoma were also represented. Such a comprehensive review on the differential diagnosis of carcinomas of pelvic organs has not been reported before. Thus, much information has been accumulated in public databases to provide an invaluable resource for clinicians and researchers.

Deregulation of p27 and cyclin D1/D3 control over mitosis is associated with unfavorable prognosis in non-small cell lung cancer, as determined in 405 operated patients

INTRODUCTION

A large group of interacting molecular factors, involved in epithelial-mesenchymal transition, epidermal growth factor receptor (EGFR) signaling, and G1 mitotic phase, are shown to play an important role in cancerogenesis and progression of non-small cell lung cancer (NSCLC). Since success concerning potential correlations, structural and numeric gene aberrations, and biological risk assessment of these molecular factors are still lacking, combined analysis of a multitude of intertwined factors is currently a promising approach.

METHODS

Cyclins (D1, D2, D3, and E), p21, p27, EGFR, Snail, E-cadherin, beta-catenin, phosphatidylinositol-3' kinase, phosphatase and tensin homologue, phosphorylated Akt, and phosphorylated signal transducer, and activator of transcription-3 were analyzed by immunohistochemistry in 405 surgically resected NSCLC, using a standardized tissue microarray platform. In addition, the gene status of EGFR and cyclin D1 was examined by fluorescence in situ hybridization. Extensive clinical data were acquired, enabling detailed clinicopathologic correlation during a postoperative follow-up period of up to 14 years.

RESULTS

The protein overexpressions of nuclear p27, cyclin D1, cyclin D3, E-cadherin, and EGFR as assessed by immunohistochemistry were all associated with a significant reduction in overall survival time. In addition, cyclin D1 proved especially important, being the only independent molecular tumor-related factor with prognostic significance by multivariable analysis. In analogy to EGFR, recurrent numeric gene aberrations, particularly high-level amplifications, of cyclin D1 were obvious.

CONCLUSIONS

The results emphasize that deregulation of controlling factors of the early G1 phase is of significant oncogenic relevance and may represent a potential treatment target in NSCLC.

Expression of p16 protein and epidermal growth factor receptor in patients with adenocarcinoma of the uterine cervix: an immunohistochemical analysis

OBJECTIVE

The present study assessed the expression of p16 and epidermal growth factor receptor (EGFR) in patients with adenocarcinoma of the uterine cervix to determine their influence on prognosis and to evaluate a possible association between their expression and various clinicopathologic parameters.

METHODS

p16 and EGFR expression was investigated by immunohistochemistry from paraffin-embedded tissue in 39 patients with adenocarcinoma of the uterine cervix. The immunohistochemical findings were correlated with different clinicopathologic parameters of the patients.

RESULTS

p16 was expressed in 56% of the patients. A trend towards increased lymph vascular space invasion was observed in p16 positive tumors (p = 0.06). There was no statistically significant association between p16 expression and clinical stage, age, histology, tumor size, tumor grade, lymph node status and recurrence disease (p > 0.05). p16 expression did influence neither disease-free nor overall survival (p > 0.05). EGFR was expressed in 44% of the patients. There was no statistically significant correlation between EGFR expression and clinical stage, age, histology, tumor size, tumor grade, lymph vascular space invasion, lymph node status and recurrence disease (p > 0.05). EGFR expression did influence neither disease-free nor overall survival (p > 0.05).

CONCLUSION

p16 and EGFR are frequently expressed in adenocarcinoma of the uterine cervix. Our study observed a trend towards increased lymph vascular space invasion in p16 positive tumors. Otherwise, the expression of the investigated parameters did not correlate with any clinicopathologic parameters and had no influence on overall and disease-free survival. So far, the investigation of p16 and EGFR is of limited use to assess patients' prognosis and guide clinical management.

Current concepts in cervical pathology

CONTEXT

The correct diagnosis and reporting of cervical in situ and invasive carcinoma are essential for the appropriate clinical management of patients with human papillomavirus-associated disease.

OBJECTIVES

To review common mistakes made in the diagnosis of cervical dysplasia and invasive carcinoma, describe variants and benign mimics of high-grade squamous intraepithelial lesion and adenocarcinoma in situ, and discuss available ancillary studies that can be useful in making the distinctions as well as to review important factors related to prognosis that should be included in the pathology report.

DATA SOURCES

Review of current literature.

CONCLUSIONS

There are many mimics and variants of cervical squamous and glandular lesions that can be resolved with ancillary studies and careful histologic examination. Prognostically important features, such as tumor size, presence of vascular invasion, and margin status, should always be included in the pathology report.

p16(INK4a) immunostaining in cytological and histological specimens from the uterine cervix: a systematic review and meta-analysis

BACKGROUND

P16(INK4a) is a biomarker for transforming HPV infections that could act as an adjunct to current cytological and histological assessment of cervical smears and biopsies, allowing the identification of those women with ambiguous results that require referral to colposcopy and potentially treatment.

MATERIAL AND METHODS

We conducted a systematic review of all studies that evaluated the use of p16(INK4a) in cytological or histological specimens from the uterine cervix. We also estimated the mean proportion of samples that were positive for p16(INK4a) in cytology and histology, stratified by the grade of the lesion.

RESULTS

Sixty-one studies were included. The proportion of cervical smears overexpressing p16(INK4a) increased with the severity of cytological abnormality. Among normal smears, only 12% (95% CI: 7-17%) were positive for the biomarker compared to 45% of ASCUS and LSIL (95% CI: 35-54% and 37-57%, respectively) and 89% of HSIL smears (95% CI: 84-95%). Similarly, in histology only 2% of normal biopsies (95% CI: 0.4-30%) and 38% of CIN1 (95% CI: 23-53%) showed diffuse staining for p16(INK4a) compared to 68% of CIN2 (95% CI: 44-92%) and 82% of CIN3 (95% CI: 72-92%).

CONCLUSION

Although there is good evidence that p16(INK4a) immunostaining correlates with the severity of cytological/histological abnormalities, the reproducibility is limited due to insufficiently standardized interpretation of the immunostaining. Therefore, a consensus needs to be reached regarding the evaluation of p16(INK4a) staining and the biomarker needs to be assessed in various clinical settings addressing specific clinical questions.

Endocervical adenocarcinomas with ovarian metastases: analysis of 29 cases with emphasis on minimally invasive cervical tumors and the ability of the metastases to simulate primary ovarian neoplasms

Most endocervical adenocarcinomas ( approximately 90%) are high-risk human papillomavirus (HPV)-related neoplasms, with the remainder being unrelated to HPV; both types infrequently metastasize to the ovaries. Clinicopathologic features of 29 cases of synchronous and metachronous endocervical and ovarian tumors (26 HPV-related, 3 unrelated to HPV) were analyzed. In 18 cases, the cervical tumors were clearly invasive; these included 5 clinically evident tumors diagnosed before the ovarian metastases (immediately preoperatively to 7 y), 11 clinically unsuspected tumors diagnosed concurrently in specimens obtained for evaluation of ovarian/pelvic masses, 1 case with concurrent clinically evident cervical and ovarian masses, and 1 clinically occult tumor diagnosed subsequent to the ovarian metastasis. In 11 cases, the cervical tumors were more limited; these included 5 tumors comprised predominantly of adenocarcinoma in situ with small foci of superficial invasion ("microinvasive carcinomas") diagnosed before the ovarian metastases (3 mo to 7 y) and 6 tumors comprised of extensive adenocarcinoma in situ lacking unequivocally recognizable stromal invasion diagnosed before (9 mo to 7 y, n=4), concurrently with (n=1), or subsequent to (n=1) the ovarian metastases. Fifteen cervical tumors involved lower uterine segment corpus endometrium or endomyometrium, including 4 tumors that were minimally invasive or not recognizably invasive in the cervix. The ovarian tumors ranged in size from 2.1 to 30.0 cm (mean/median=12.7/13.5); they were unilateral in 19 cases (65.5%) and 12 of these were unilateral and 10 cm or greater. In 26 cases, including the 19 unilateral tumors, the ovarian tumors exhibited "borderlinelike," confluent glandular, cribriform, and/or villoglandular patterns simulating primary ovarian atypical proliferative (borderline) tumors or well-differentiated carcinomas; these patterns were pure in 24 and admixed with minor infiltrative foci in 2. The ovarian tumors had features typical of metastases (bilateral and infiltrative) in only 3 cases. In all HPV-related cases the paired endocervical and ovarian tumors contained identical HPV types, establishing the ovarian tumors as metastases. Endocervical adenocarcinomas, including microinvasive forms and some not recognizably invasive, have the potential to metastasize to the ovaries; extension into the lower uterine segment/corpus endometrium may be a risk factor, with retrograde uterine/transtubal spread as a possible mechanism.

Ancillary testing of liquid-based cytology specimens for identification of patients at high risk of cervical cancer

Integration of human papillomavirus DNAs into the host genome is crucial to the development of cervical cancer. Overexpression of the P16 protein has been reported in cervical intraepithelial neoplasia (CIN) as well as cervical cancer. Such molecular biomarkers have been utilized for ancillary testing of liquid-based cytology specimens; however, their clinical application remains controversial. To detect CIN 2 or more advanced lesions, 153 liquid-based cytology (LBC) specimens were investigated to determine the physical status of the human papillomavirus (HPV) DNA by in situ hybridization (ISH) and to detect overexpression of the P16 protein by immunocytochemistry combined with HPV genotyping by polymerase chain reaction. The combination of ISH, P16 immunocytochemistry, and LBC showed high sensitivity (89.3%) as well as high specificity (92.6%). We confirmed the usefulness of P16 immunocytochemistry combined with ISH and HPV genotyping as ancillary molecular-biological tests of LBC specimens for identifying patients at high risk of cervical cancer.

Application of immunohistochemistry to gynecologic pathology

CONTEXT

A large variety of tumors and lesions arise in the female genital tract. Although the majority of these can be correctly recognized on routine hematoxylin-eosin-stained slides, occasional cases present a diagnostic challenge. Immunohistochemical stains are extremely useful in resolving many of these problematic cases. As the knowledge in this area is constantly expanding, it is useful to have this updated information in a review form for easy access.

OBJECTIVE

To present our current knowledge of immunohistochemistry of the lesions of the female genital tract in a readily accessible form.

DATA SOURCES

The review is based on previously published articles on this topic.

CONCLUSIONS

Immunohistochemical stains help in reaching a conclusive diagnosis in a variety of problematic lesions seen in gynecologic pathology. As in any other system, immunohistochemical findings need to be interpreted in light of the clinical history and morphologic findings.

Gastric morphology and immunophenotype predict poor outcome in mucinous adenocarcinoma of the uterine cervix

Endocervical-type mucinous adenocarcinoma (ECA) of the uterine cervix is defined as a tumor composed of cells resembling those of the endocervical glands, but recent studies have demonstrated that a minority of ECAs displays a gastric immunophenotype. The aim of this study was to assess the significance of the gastric phenotype. Fifty-three cases of mucinous adenocarcinoma of the uterine cervix (37 FIGO stage IB, 4 stage IIA, and 12 stage IIB) were reviewed and reevaluated using a newly established morphologic criteria for distinguishing gastric type adenocarcinoma, which was defined as a tumor showing clear and/or pale eosinophilic and voluminous cytoplasm, with distinct cell borders. The results were correlated with gastric immunophenotype, determined by HIK1083 and MUC6 immunostaining, and patient outcome. Following the current World Health Organization scheme (2003), 47 tumors (89%) were classified as ECA, 1 (2%) as intestinal type, 1 (2%) as mixed endocervical and intestinal type, and 4 (8%) as minimal deviation adenocarcinoma. Twelve of 47 (26%) ECAs and all 4 minimal deviation adenocarcinomas, reclassified as gastric type using the novel criteria, were frequently positive for HIK1083 with a rate of 75% (12/16), whereas only 11% (4/37) of nongastric tumors were positive. There was no significant difference in MUC6 reactivity between gastric and nongastric type tumors (31%, 5/16 vs. 16%, 6/37; P=0.4). Patients with gastric-type adenocarcinomas had a significantly decreased 5-year disease-specific survival rate (30 vs. 77%; P<0.0001), and the gastric type morphology was related to a significant risk for disease recurrence compared with the nongastric type (P=0.001; HR, 4.5; 95% confidence interval, 1.42-14.2). HIK1083-positivity was also related to decreased 5-year disease-specific survival rate (38% vs. 74%; P<0.005). Mucinous adenocarcinoma of the uterine cervix with gastric immunophenotype can be a distinct morphologic variant showing an aggressive clinical course.

p16 expression in primary ovarian mucinous and endometrioid tumors and metastatic adenocarcinomas in the ovary: utility for identification of metastatic HPV-related endocervical adenocarcinomas

Distinction of primary ovarian epithelial tumors from metastatic adenocarcinomas is challenging for tumors exhibiting mucinous, endometrioid, or mixed endometrioid/mucinous differentiation. Metastatic carcinomas with these types of differentiation can be derived from several sites, including the gastrointestinal tract and the uterus. Most endocervical adenocarcinomas exhibit mucinous and/or endometrioid differentiation; they infrequently metastasize to the ovaries but may simulate primary ovarian tumors [both atypical proliferative (borderline) and carcinoma]. Most are high-risk human papillomavirus (HPV)-related and demonstrate diffuse p16 over-expression due to complex molecular mechanisms by which high-risk HPV transforming proteins interact with cell cycle regulatory proteins. The performance of this expression pattern for identifying metastatic endocervical adenocarcinomas in the ovaries among primary ovarian tumors and other metastatic adenocarcinomas having mucinous and/or endometrioid/endometrioidlike differentiation has not been evaluated. Immunohistochemical expression of p16 was assessed in 195 tumors, including 98 primary ovarian tumors (51 mucinous, 47 endometrioid, and 4 mixed mucinous-endometrioid tumors), 93 metastatic adenocarcinomas of known primary sites (colorectum: 34, endocervix: 19, pancreaticobiliary tract: 17, appendix: 7, stomach: 5), 11 metastatic adenocarcinomas of unknown origin (7 established as noncervical), and 4 adenocarcinomas of uncertain (primary ovarian vs. metastatic) origin. The HPV status of the endocervical adenocarcinomas was determined by in situ hybridization and polymerase chain reaction (when in situ hybridization was negative). Expression was assessed based on the percentage of moderately to strongly positive cells, estimated to the nearest 10%. Mean and median expression values for HPV-positive endocervical adenocarcinomas (99%, 100%; range 90% to 100%) were substantially higher than those for primary ovarian mucinous (5%, 0%; range 0% to 70%) and endometrioid (20%, 10%; range 0% to 100%) tumors, HPV-unrelated endocervical adenocarcinomas (0%, 0%; range 0% to 60%), metastatic adenocarcinomas of unknown origin (11%, 0%; range 0% to 30%), and adenocarcinomas of uncertain (primary ovarian vs. metastatic) origin (40%, 35%; range 0% to 90%); only the 15 HPV-positive endocervical adenocarcinomas and 6 other tumors had values of 80% or greater. Diffuse (>75% positive tumor cells) moderate to strong p16 expression is a sensitive (100%) and specific (97%) marker for identifying HPV-related endocervical adenocarcinomas metastatic to the ovary among the primary ovarian tumors and metastatic adenocarcinomas from other sites that are in the differential diagnosis of ovarian tumors having mucinous and/or endometrioid/endometrioidlike differentiation. p16 is useful as part of a panel of immunohistochemical markers for distinguishing primary ovarian tumors from metastases and, when diffusely positive, can suggest the cervix as a potential primary site for metastatic adenocarcinomas of unknown origin.

Immunohistochemical expression of p16(INK4A) in normal uterine cervix, nonneoplastic epithelial lesions, and low-grade squamous intraepithelial lesions

OBJECTIVES

In this study, the authors analyzed the immunoexpression of p16 in high-risk human papillomavirus DNA-negative normal and nonneoplastic cervical epithelia, in low-grade cervical intraepithelial neoplasia (CIN), high-grade CIN, and squamous cell carcinoma.

MATERIALS AND METHODS

A retrospective study, in which 58 normal cervical hysterectomy samples, 56 nonneoplastic cervical biopsies, 88 CIN 1, 33 CIN 2, 32 CIN 3, and 47 invasive squamous cell carcinoma biopsies, were evaluated for p16 immunoexpression. Human papillomavirus tests were also performed.

RESULTS

p16 immunohistochemistry seems to reveal possible different biological subgroups of lesions among morphologically similar mildly dysplastic cervical epithelia.

CONCLUSION

Distribution patterns of p16 protein might be useful to predict different outcomes in CIN 1.

Immunohistochemistry as a diagnostic aid in cervical pathology

As with biopsies from other sites in the female genital tract, immunohistochemistry is now being increasingly used in cervical pathology as an aid to diagnosis. In this review, I discuss applications of immunohistochemistry in diagnostic cervical pathology with a particular focus on recent developments. It is emphasised that immunohistochemistry is to be used as an adjunct to routine morphological examination and that no marker is totally specific or sensitive for a given lesion. Although much of this review focuses on glandular lesions, the value of markers, such as MIB1 and p16, in the assessment of pre-invasive cervical squamous lesions is discussed. In the broad field of cervical glandular lesions, topics covered include: the value of markers such as MIB1, p16 and bcl-2 in distinguishing adenocarcinoma in situ and glandular dysplasia from benign mimics; markers of mesonephric lesions, including CD10; markers of value in the diagnosis of minimal deviation adenocarcinoma, such as HIK1083; markers of value in distinguishing metastatic cervical adenocarcinoma in the ovary from primary ovarian endometrioid or mucinous adenocarcinoma. Rarely ectopic prostatic tissue occurs in the cervix, which can be confirmed by positive staining with prostatic markers. A panel of markers, comprising oestrogen receptor, vimentin, monoclonal carcinoembryonic antigen and p16, is of value in distinguishing between a cervical adenocarcinoma and an endometrial adenocarcinoma of endometrioid type. Markers of use in the diagnosis of cervical neuroendocrine neoplasms, including small cell and large cell neuroendocrine carcinoma, are discussed. It is stressed that small cell neuroendocrine carcinomas may be negative with most of the commonly used neuroendocrine markers and this does not preclude the diagnosis. p63, a useful marker of squamous neoplasms within the cervix, is of value in distinguishing small cell neuroendocrine carcinoma (p63 negative) from small cell squamous carcinoma (p63 positive) and in confirming that a poorly differentiated carcinoma is squamous in type.

A comparison of the clinical utility of p16(INK4a) immunolocalization with the presence of human papillomavirus by hybrid capture 2 for the detection of cervical dysplasia/neoplasia

BACKGROUND

Evidence suggests that overexpression of p16(INK4a) protein indicates infection and genomic integration of high-risk human papillomavirus (HR HPV) and predicts progression to cervical high-grade squamous intraepithelial lesions (HSILs) and carcinoma. The authors compared the ability of p16(INK4a) and HR HPV detection by Hybrid Capture 2 (HC2) to detect the presence of significant cervical disease. METHODS.: Four hundred ThinPrep specimens (100 each in 4 categories: 100 specimens that were negative for intraepithelial lesions, 100 specimens of atypical squamous cells of undetermined significance [ASC-US], 100 specimens of low-grade squamous intraepithelial lesions [LSILs], and 100 specimens of HSILs) were analyzed. p16(INK4a) protein was immunolocalized using a specific monoclonal antibody, and the detection of HR HPV in all 400 specimens was determined using HC2.

RESULTS

p16(INK4a) was found to be positive in 78% of HSIL specimens, 42% of LSIL specimens, and 36% of ASC-US specimens; whereas HC2 was positive in 92% of HSIL specimens, 81% of LSIL specimens, and 45% of ASC-US specimens. In the HSIL category, the sensitivity, which was calculated using Grade 2 or greater cervical intraepithelial neoplasia as the endpoint, was 78% (50 of 66 specimens) for p16(INK4a) and 91% (60 of 66 specimens) for HC2. For LSIL, the sensitivity was 75% (3 of 4 specimens) for p16(INK4a) and 100% (4 of 4 specimens) for HC2. In the ASC-US category, the sensitivity was 89% (8 of 9 specimens) for p16(INK4a) and 100% (9 of 9 specimens) for HC2. Overall, the sensitivity for HSIL was 92% for HC2 and 78% for p16(INK4a). The specificity for HC2 was 8.3% for HSIL, 16.9% for LSIL, and 48.7% for ASC-US; whereas the specificity for p16(INK4a) was 25% in HSIL, 59.1% in LSIL, and 68.4% in ASC-US. The overall specificity was 25% for HC2 and 56% for p16(INK4a).

CONCLUSIONS

Although both p16(INK4a) and HC2 may aid in the clinical management of patients with clinically significant lesions, HC2 was found to have greater sensitivity, and p16(INK4a) greater specificity. The labeling of normal cells and bacteria may preclude the use of p16(INK4a) in automated screening or nonmorphologic assays.

Human papillomavirus localization in cervical adenocarcinoma and adenosquamous carcinoma using in situ polymerase chain reaction: review of the literature of human papillomavirus detection in these carcinomas

Many studies have suggested that human papillomavirus (HPV) infection plays an important role in the carcinogenesis of the cervical adenocarcinoma. However, the prevalence of HPV infection in cervical adenocarcinoma and adenosquamous carcinoma varies among the studies. Cervical adenocarcinoma (24 cases) and adenosquamous carcinoma (16 cases), including the underlying non-neoplastic epithelium were examined for HPV-DNA using in situ polymerase chain reaction (PCR), which enabled visualization of the localization on a glass slide. In adenocarcinoma, HPV-DNA was found in 13 cases (54%) and in eight cases in underlying non-neoplastic epithelium, resulting in a total of 21 positive cases (88%). In adenosquamous carcinoma, HPV-DNA was detected in 12 cases (75%) and and the HPV-DNA localization of each component was pure adenocarcinoma, 28.6%; mixed, 54.5%; and pure squamous cell carcinoma, 83.3%. In the underlying non-neoplastic epithelium, HPV-DNA was found more frequently in the squamous epithelium (73.3%) than the cervical glands (6.3%). In conclusion, HPV-DNA was detected in 54% of adenocarcinoma, and the rate was elevated by HPV localization in the underlying non-neoplastic epithelium. HPV infection in the underlying squamous epithelium might be related to the carcinogenesis, even in cervical adenocarcinoma. HPV-DNA localization was different in each component of adenosquamous carcinoma.

Overexpression of p16 INK4a as an indicator for human papillomavirus oncogenic activity in cervical squamous neoplasia

Overexpression of p16(INK4a) has been observed when retinoblastoma protein is inactivated by high-risk human papillomavirus (HPV) oncoprotein E7. We investigated overexpression of p16(INK4a) and HPV infection in cervical squamous neoplasia to evaluate the oncogenic potential among various HPV subtypes. The high-risk HPV was detected by PCR in 69.8% (37/53), 97.5% (39/40), 91.7% (44/48), and 100% (16/16) of cervical intraepithelial neoplasia (CIN)1, CIN2, CIN3, and squamous cell carcinoma (SCC), respectively. The p16(INK4a) overexpression was investigated immunohistochemically using a p16(INK4a)-specific monoclonal antibody (clone E6H4). In high-risk HPV positive cases, 32.4% (12/37) of CIN1, 82.1% (32/39) of CIN2, 93.2% (41/44) of CIN3, and all (16/16) SCC showed p16(INK4a) overexpression. The incidence of p16(INK4a) overexpression was significantly different between CIN1 and CIN2, suggesting that the disorder of cell cycle regulation by HPV frequently occurred from CIN2. As for CIN1 cases, p16(INK4a) overexpression was observed more frequently in HPV16 and HPV52 than in HPV51 and HPV35. Using p16(INK4a) as a bio marker of HPV oncogenic activity, we demonstrate that the level of pRb dysfunction by high-risk HPV varied from subtypes and was getting more frequent from CIN2.

p16INK4a Overexpression Independent of Human Papillomavirus Infection in Lobular Endocervical Glandular Hyperplasia

A high rate of human papillomavirus (HPV) infection has been reported in cervical cancer and precancerous lesions. Many studies also have shown that p16INK4a overexpression is of diagnostic value for high-risk HPV-related cervical cancer and precursors. Lobular endocervical glandular hyperplasia (LEGH) is a rare lesion of the uterine cervix. There is one report about HPV infection and few studies on p16INK4a expression in LEGH. Therefore, we 1) detected HPV infection and examined p16INK4a expression and 2) observed the relationship between HPV and p16INK4a overexpression in LEGH. The immunohistochemical expression of p16INK4a was studied in 24 cases of LEGH. HPV DNA was also evaluated in these cases using a polymerase chain reaction technique. Strong (++) p16INK4a immunoreactivity was observed in 10 (41.7%) of the 24 LEGH cases; a moderate (+) pattern was observed in 9 (37.5%) cases; a weak (+) pattern was observed in 2 (8.3%) cases; and the remaining 3 (12.5%) cases showed negative expression. Overall, p16INK4a overexpression was seen in 87.5% of the cases (21/24). HPV DNA was not detected in any of the 24 LEGH cases. These results suggest that p16INK4a overexpression is independent of HPV infection in LEGH.

p16INK4A overexpression and HPV infection in uterine cervix adenocarcinoma

Human papillomaviruses (HPVs) are causally involved in the genesis of cervical carcinomas and their precursors, and there is a strong relationship between the cyclin-dependant kinase inhibitor p16INK4A and HPV infection. This study was carried out to assess the correlations between p16INK4A expression as an early biomarker of the endocervical adenocarcinoma and HPV infection. p16INK4A expression and HPV typing were performed on 46 samples including 5 normal endocervix, 9 benign lesions of the endocervix, 25 endocervical adenocarcinomas, and 7 endometrioid adenocarcinomas of the uterine corpus. A semiquantification of the p16INK4A immunostaining was realized (using both the staining intensity and the percentage of positive cells) and was graded from 0 to 15. All of the 25 endocervical adenocarcinomas overexpressed p16INK4A; the adjacent epithelium and the connective tissue were strictly negative. No p16INK4A was detected in nine benign endocervical lesions and in five normal endocervix. Few endometrioid adenocarcinomas of the uterine corpus that infiltrate the endocervix exhibited a low immunoreactivity (score 0/15 or 1/15). This pattern of expression is significantly associated with HPV infection (p<10(-3)), mainly high-risk HPV types (p=0.02). Our results suggest that p16INK4A is a putative molecular biomarker that consistently discriminates uterine cervix adenocarcinomas from benign lesions and from endometrioid adenocarcinomas of the uterine corpus.

p16INK4A, CDC6, and MCM5: predictive biomarkers in cervical preinvasive neoplasia and cervical cancer

AIM

To analyse and compare expression patterns of three potential biomarkers-p16(INK4A), CDC6, and MCM5-and evaluate their use as predictive biomarkers in squamous and glandular cervical preinvasive neoplasia.

METHODS

Immunocytochemical analysis of p16(INK4A), MCM5, and CDC6 expression was performed on 20 normal, 38 cervical intraepithelial neoplasia 1 (CIN1), 33 CIN2, 46 CIN3, 10 squamous cell carcinoma, 19 cervical glandular intraepithelial neoplasia (cGIN), and 10 adenocarcinoma samples. Staining intensity was assessed using a 0-3 scoring system. p16(INK4A), MCM5, and CDC6 expression was also examined in ThinPrep slides exhibiting mild, moderate, and severe dyskaryosis. Human papillomavirus (HPV) was detected using a modified SYBR green assay. Fluorogenic polymerase chain reaction (PCR) and solution phase PCR were used for specific HPV typing.

RESULTS

All three markers showed a linear correlation between expression and grade of dysplasia. p16(INK4A) and MCM5 protein expression was upregulated in all grades of squamous and glandular dysplasia. CDC6 protein was preferentially expressed in high grade lesions and in invasive squamous cell carcinoma.

CONCLUSION

p16(INK4A) expression was closely associated with high risk HPV infection-all grades of squamous and glandular cervical lesions were immunohistochemically positive. MCM5 staining intensity was independent of high risk HPV infection, highlighting its potential as a biomarker in both HPV dependent and independent cervical dysplasia. CDC6 may be a biomarker of high grade and invasive lesions of the cervix, with limited use in low grade dysplasia. p16(INK4A) was the most reliable marker of cervical dysplasia. Combinations of dysplastic biomarkers may be useful in difficult diagnostic cases.

Synchronous and metachronous endocervical and ovarian neoplasms: evidence supporting interpretation of the ovarian neoplasms as metastatic endocervical adenocarcinomas simulating primary ovarian surface epithelial neoplasms

The vast majority of endocervical adenocarcinomas are high-risk human papillomavirus (HPV)-related neoplasms, characterized by p16 expression and frequent loss of hormone receptor expression, which infrequently metastasize to the ovaries. We report 10 cases of endocervical adenocarcinomas with ovarian metastases in which the ovarian tumors simulated primary ovarian surface epithelial neoplasms. The presence of HPV DNA was assessed to determine whether the ovarian neoplasms were metastases or independent neoplasms. Immunohistochemistry for hormone receptors and p16 was also performed. The ovarian metastases presented concurrently with the primary endocervical tumors in 5 cases, subsequent to the endocervical tumors in 3 cases, and prior to diagnosis of the endocervical tumors in 2 cases. The ovarian tumors ranged in size from 2 to 30 cm, with tumors in 7 cases measuring 10 cm or greater. The ovarian tumors were unilateral in 8 cases and bilateral in 2. In all cases, the ovarian tumors were initially diagnosed as or thought to represent independent primary ovarian surface epithelial tumors (atypical proliferative [borderline] tumors or well-differentiated carcinomas of endometrioid or mucinous type). The endocervical tumors ranged in size from microscopic foci to 3 cm, with depth of invasion ranging from 0.2 to 1.5 cm; in 2 cases, the invasive foci qualified as microinvasive according to Federation Internationale de Gynecologie et d'Obstetrique staging criteria for cervical carcinoma. Adenocarcinoma in situ was identified in all tumors. In all cases, the paired endocervical and ovarian tumors contained identical HPV types. All evaluable tumors were diffusely positive for p16; and in 8 cases, there was absent or only limited expression of hormone receptors. Two of the minimally invasive endocervical tumors were initially interpreted as adenocarcinoma in situ and not recognized as unequivocally invasive even when evaluated in conjunction with the histologically identical ovarian tumors. HPV DNA detection in the ovarian tumors of 2 patients without known cervical disease led to discovery of occult cervical adenocarcinomas in those patients. Endocervical adenocarcinomas, including some qualifying as microinvasive, can metastasize to the ovaries and simulate primary ovarian surface epithelial neoplasms. The presence of HPV DNA in these ovarian tumors confirms that they are metastatic endocervical adenocarcinomas.

Molecular diagnostic assays for cervical neoplasia: emerging markers for the detection of high-grade cervical disease

The accurate detection and diagnosis of cervical carcinoma and its malignant precursors (collectively referred to as high-grade cervical disease) represents one of the current challenges in clinical medicine and cytopathology. The advent of molecular diagnostics and the use of whole-genome profiling using DNA microarrays promises to yield improved understanding of the disease process with the subsequent development of more accurate diagnostic procedures based upon these discoveries. Recent reports describing a variety of experimental approaches have identified a series of candidate genes that are overexpressed in cervical carcinoma. In this article, representative examples of these markers and the resulting translational research will be reviewed within the context of improved cervical disease detection. An emerging class of markers, the minichromosome maintenance protein family of DNA licensing factors (MCM-2, MCM-6, MCM-7), shows promise for the specific detection of high-grade cervical disease using simple antibody-based immunochemistry formats. These proteins are overexpressed in cervical disease as a result of infection by oncogenic strains of human papillomavirus (HPV) and subsequent uncontrolled activation of gene transcription and aberrant S-phase induction, mediated through the E2F transcription factor pathway. This behavior appears to be a hallmark of high-grade cervical disease and provides the link between oncogenic HPV infections and the molecular behavior of cervical neoplasia (CN). The use of these molecular descriptors of CN in simple immunochemistry formats compatible with conventional cytology preparations is anticipated to improve the screening and detection of cervical disease within the healthcare system.

Is p16INK4A expression more useful than human papillomavirus test to determine the outcome of atypical squamous cells of undetermined significance-categorized Pap smear? A comparative analysis using abnormal cervical smears with follow-up biopsies

OBJECTIVE

To correlate high-risk human papillomavirus (HR-HPV) viral load to p16(INK4A) expression in atypical squamous cells of undetermined significance (ASCUS)-categorized Pap smears with follow-up biopsies in order to elucidate their relationships in gynecological pathology.

METHODS

We studied 66 ASCUS-categorized Pap smears with subsequent follow-up biopsies. HR-HPV viral load was determined by Hybrid Capture II assay from the cervical swab in each ASCUS-diagnosed Pap smear. Both smears and biopsies were immunostained with a primary anti-p16 antibody, clone E6H4, and we analyzed the correlations between HR-HPV viral load in each ASCUS-diagnosed Pap smear and p16 expression of smears with follow-up biopsies.

RESULTS

Correlation analyses of the corresponding histological diagnoses from 66 ASCUS-diagnosed Pap smears revealed that 21 (32%) cases had only reactive changes and 45 cases showed cervical intraepithelial neoplasia including LSIL (24 cases, 36%) and HSIL or higher (21 cases, 32%). Tests for HR-HPV viral load revealed 17 (26%) negative cases and 49 (74%) positive cases. Immunostaining showed that 26 cases (39%) were negative and 40 (61%) were positive for p16 expression. Comparative analysis of these two tests indicated consistencies as well as discrepancies. They showed significant differences (P < 0.001) between negative p16 expressions of Pap smears with the presence of reactive lesions in follow-up biopsies and HR-HPV viral load. However, no significant difference (P = 0.739 and 0.606) between p16 expression of Pap smears with the presence of LSIL, HSIL or higher in follow-up biopsies and high HR-HPV viral load was found. In addition, there were significant differences (P < 0.001) in specificity and positive predictive value, but no significant differences were found in sensitivity (P = 0.606) and negative predictive value (P = 0.062) between p16 immunostaining and HR-HPV viral load.

CONCLUSION

The results indicate that there is a close association between weak or strong p16 expressions in ASCUS-categorized smears with the presence of SILs in follow-up biopsies and positive HR-HPV viral loads. Conversely, there is also a clear association between the lack of p16 expression and the absence of significant lesions in follow-up biopsies, but this is not consistent with a negative HR-HPV viral load. It is concluded that p16 expression is an indicator of pathogenic activity of HR-HPV, which is an objective biomarker for clarification of ASCUS-categorized Pap smears in gynecological cytopathology. Furthermore, through comparative analysis, directly visualized p16 immunostaining on smears appears to be a more effective method than HR-HPV viral load for the detection of reactive changes and LSILs from ASCUS-categorized Pap smears.

Detection of Human Papillomavirus DNA and Expression of p16, Rb, and p53 Proteins in Small Cell Carcinomas of the Uterine Cervix

Human papillomavirus (HPV) has been implicated as an etiologic agent for the development of primary small cell carcinoma of the uterine cervix, a rare but highly aggressive malignancy. It has been shown that the HPV E6 and E7 oncoproteins are able to inactivate the tumor suppressor functions of p53 and Rb. In squamous cell carcinoma and adenocarcinoma of the cervix, HPV infection is also associated with overexpression of p16, a cyclin-dependent kinase inhibitor. In this study, 22 cases of primary small cell carcinoma of the uterine cervix were subjected to broad-spectrum HPV DNA amplification and typing, and immunohistochemically examined for the expression of p16, Rb, and p53 proteins. The results show that HPV DNA was detected in every case (100%), with 18 cases (82%) harboring type 18. The tumor cells exhibited strong nuclear staining for p16 in 20 cases (91%). This was associated with a complete loss of Rb nuclear staining in tumor cells in 16 cases (73%). The p53 protein was essentially undetectable in all cases. In contrast, HPV DNA was not detected in 9 colorectal and 8 urinary bladder small cell carcinomas included in this study for comparison. While similar p16 and Rb expression patterns were observed in these HPV-negative tumors, a different expression pattern for p53 was noted where strong nuclear staining was seen in 8 cases (47%; P = 0.0004 compared with cervical tumors). These observations indicate that different mechanisms are involved in the pathogenesis of small cell carcinomas of the uterine cervix and support the notion that nuclear p16 overexpression serves as an indication of Rb defunctioning in tumor cells, which may or may not result from high-risk HPV infection.

Immunohistochemistry in gynaecological pathology: a review

This paper reviews some aspects of the application of immunohistochemistry in gynaecological pathology. The use of cytokeratins 7 and 20 are discussed with reference to applications in ovarian pathology, including metastatic disease to the ovaries. Developments in utilising MIB-1 and p16 in cervical squamous and glandular lesions are discussed. Recent assertions regarding the differential diagnosis between endocervical and endometrial carcinomas are also reviewed. Antibodies that may be of use in the diagnosis of uterine mesenchymal and ovarian tumours are highlighted, as are antibodies of use in trophoblastic lesions including the use of p57 in evaluating hydatidiform moles.