p16INK4a immunohistochemistry improves interobserver agreement in the diagnosis of cervical intraepithelial neoplasia

Validation of immunohistochemical overexpression of p16 in the histologic diagnosis of cervical intraepithelial neoplasia grade 2

An accurate cytohistologic diagnosis is important to avoid overtreatment of cervical intraepithelial lesions. The three-tiered Cervical Intraepithelial Neoplasia (CIN) classification, grades 1, 2 and 3, despite poor agreement among pathologists in diagnosing CIN2, is still being used. The College of American Pathologists recommended an alternative two-tiered classification that has not yet been universally accepted. We review the diagnostic results of 286 biopsies performed by three pathologists using haematoxylin and eosin (H&E) and p16 to establish the level of agreement among the readers. Agreement between pathologists in diagnosing CIN2 with H&E was around 45% and improved to 86.7% when interpreting p16 stained biopsies without H&E; agreement with pathologist 3 was lower, around 60%. Discrepant results from one pathologist when assessing p16 highlights the decisive influence of individual criteria. P16 has shown to improve agreement between pathologists with previous good agreement, but did not correct it for the third pathologist. In equivocal cases, protein p16 is a useful conjunctive tool for a histologic diagnosis.

CNN stability training improves robustness to scanner and IHC-based image variability for epithelium segmentation in cervical histology

Background

In digital pathology, image properties such as color, brightness, contrast and blurriness may vary based on the scanner and sample preparation. Convolutional Neural Networks (CNNs) are sensitive to these variations and may underperform on images from a different domain than the one used for training. Robustness to these image property variations is required to enable the use of deep learning in clinical practice and large scale clinical research.

Aims

CNN Stability Training (CST) is proposed and evaluated as a method to increase CNN robustness to scanner and Immunohistochemistry (IHC)-based image variability.

Methods

CST was applied to segment epithelium in immunohistological cervical Whole Slide Images (WSIs). CST randomly distorts input tiles and factors the difference between the CNN prediction for the original and distorted inputs within the loss function. CNNs were trained using 114 p16-stained WSIs from the same scanner, and evaluated on 6 WSI test sets, each with 23 to 24 WSIs of the same tissue but different scanner/IHC combinations. Relative robustness (rAUC) was measured as the difference between the AUC on the training domain test set (i.e., baseline test set) and the remaining test sets.

Results

Across all test sets, The AUC of CST models outperformed "No CST" models (AUC: 0.940-0.989 vs. 0.905-0.986, p < 1e - 8), and obtained an improved robustness (rAUC: [-0.038, -0.003] vs. [-0.081, -0.002]). At a WSI level, CST models showed an increase in performance in 124 of the 142 WSIs. CST models also outperformed models trained with random on-the-fly data augmentation (DA) in all test sets ([0.002, 0.021], p < 1e-6).

Conclusion

CST offers a path to improve CNN performance without the need for more data and allows customizing distortions to specific use cases. A python implementation of CST is publicly available at https://github.com/TIGACenter/CST_v1.

Sequential gene expression analysis of cervical malignant transformation identifies RFC4 as a novel diagnostic and prognostic biomarker

BACKGROUND

Cervical squamous cell carcinoma (SCC) is known to arise through increasingly higher-grade squamous intraepithelial lesions (SILs) or cervical intraepithelial neoplasias (CINs). This study aimed to describe sequential molecular changes and identify biomarkers in cervical malignant transformation.

METHODS

Multidimensional data from five publicly available microarray and TCGA-CESC datasets were analyzed. Immunohistochemistry was carried out on 354 cervical tissues (42 normal, 62 CIN1, 26 CIN2, 47 CIN3, and 177 SCC) to determine the potential diagnostic and prognostic value of identified biomarkers.

RESULTS

We demonstrated that normal epithelium and SILs presented higher molecular homogeneity than SCC. Genes in the region (e.g., 3q, 12q13) with copy number alteration or HPV integration were more likely to lose or gain expression. The IL-17 signaling pathway was enriched throughout disease progression with downregulation of IL17C and decreased Th17 cells at late stage. Furthermore, we identified AURKA, TOP2A, RFC4, and CEP55 as potential causative genes gradually upregulated during the normal-SILs-SCC transition. For detecting high-grade SIL (HSIL), TOP2A and RFC4 showed balanced sensitivity (both 88.2%) and specificity (87.1 and 90.1%), with high AUC (0.88 and 0.89). They had equivalent diagnostic performance alone to the combination of p16^INK4a and Ki-67. Meanwhile, increased expression of RFC4 significantly and independently predicted favorable outcomes in multi-institutional cohorts of SCC patients.

CONCLUSIONS

Our comprehensive study of gene expression profiling has identified dysregulated genes and biological processes during cervical carcinogenesis. RFC4 is proposed as a novel surrogate biomarker for determining HSIL and HSIL+, and an independent prognostic biomarker for SCC.

Cervical Pre-cancers: Biopsy and Immunohistochemistry

The existence of precursor lesions for invasive cervical cancer has been recognized for more than 50 years. Our understanding of the pathobiology and behavior of cervical cancer precursors has evolved considerably over the past five decades. Furthermore, the terminology used to classify pre-invasive lesions of the cervix has frequently changed. The realization that human papillomavirus (HPV) infections constitute a morphologic continuum has prompted efforts to include them within a single classification system, specifically the squamous intraepithelial lesions (SILs) which have now been embraced by the surgical pathologists. The reduced number of specific pathological categories has made clinical decision-making more straightforward. The generic criteria for SIL have two important histological parameters: Alterations in the density of superficial epithelial cells and superficial squamous atypia. The flat condyloma or cervical intraepithelial neoplasia (CIN) I is generally associated with intermediate and high-risk HPV types as against the low-risk viruses that cause exophytic/papillary growth patterns of condylomas. The diagnosis of low-grade SIL (LSIL) (flat and exophytic condylomas) requires first excluding benign mimics of LSIL and second to confirm the characteristic cytologic atypia. For high-grade SILs (HSILs), the extent and degree of atypia generally exceed the limits of that described in flat or exophytic condylomas (LSILs). Less maturation, abnormal cell differentiation, loss of cell polarity, and increased mitotic index with abnormal mitotic figures occupying increasing thickness of the epithelium define a lesion as CIN II or CIN III. Atypical immature metaplasia associated with inflammation and atrophy is a challenge in cervical biopsy interpretation. Careful attention to the growth pattern of the epithelium, the distribution of the atypia, nuclear spacing, and the degree of anisokaryosis and the presence of enlarged hyperchromatic nuclei help in differentiating a non-neoplastic from a neoplastic process. This chapter describes in depth the diagnostic difficulties in the interpretation of cervical biopsies. It also provides useful criteria in distinguishing benign mimics from true precancerous lesions and the role of biomarkers such as the p16ink4 and Ki-67 in the differential diagnosis of precursor lesions and the reactive and metaplastic epithelium.

The role of telepathology in diagnosis of pre-malignant and malignant cervical lesions: Implementation at a tertiary hospital in Northern Tanzania

Introduction

Adequate and timely access to pathology services is a key to scale up cancer control, however, there is an extremely shortage of pathologists in Tanzania. Telepathology (scanned images microscopy) has the potential to increase access to pathology services and it is increasingly being employed for primary diagnosis and consultation services. However, the experience with the use of telepathology in Tanzania is limited. We aimed to investigate the feasibility of using scanned images for primary diagnosis of pre-malignant and malignant cervical lesions by assessing its equivalency to conventional (glass slide) microscopy in Tanzania.

Methods

In this laboratory-based study, assessment of hematoxylin and eosin stained glass slides of 175 cervical biopsies were initially performed conventionally by three pathologists independently. The slides were scanned at x 40 and one to three months later, the scanned images were reviewed by the pathologists in blinded fashion. The agreement between initial and review diagnoses across participating pathologists was described and measured using Cohen’s kappa coefficient (κ).

Results

The overall concordance of diagnoses established on conventional microscopy compared to scanned images across three pathologists was 87.7%; κ = 0.54; CI (0.49–0.57).The overall agreement of diagnoses established by local pathologist on conventional microscopy compared to scanned images was 87.4%; κ = 0.73; CI (0.65–0.79). The concordance of diagnoses established by senior pathologist compared to local pathologist on conventional microscopy and scanned images was 96% and 97.7% respectively. The inter-observer agreement (κ) value were 0.93, CI (0.87–1.00) and 0.94, CI (0.88–1.00) for conventional microscopy and scanned images respectively.

Conclusions

All κ coefficients expressed good intra- and inter-observer agreement, suggesting that telepathology is sufficiently accurate for primary diagnosis in surgical pathology. The discrepancies in interpretation of pre-malignant lesions highlights the importance of p16 immunohistochemistry in definitive diagnosis in these lesions. Sustainability factors including hardware and internet connectivity are essential components to be considered before telepathology may be deemed suitable for widely use in Tanzania.

Immunohistochemistry in gynecologic carcinomas: Practical update with diagnostic and clinical considerations based on the 2020 WHO classification of tumors

This review provides an update on immunohistochemistry applications-diagnostic, prognostic, and predictive-in the pathology evaluation of gynecologic carcinomas. The 5th edition of the WHO Classification of Female Genital Tumors introduced important changes in the diagnostic classification of lower genital tract, endometrial, and ovarian carcinomas, with major influence on the routine pathology practice. Lower genital tract carcinomas and their precursor lesions are now classified based on their human papillomavirus (HPV)-associated and HPV-independent pathogenesis, reflecting the clinically significant prognostic differences and impacting the therapeutic decision-making. Immunohistochemical markers have an increasing role in the pathology evaluation of endometrial carcinomas: in addition to their traditional use in the differential diagnosis and histologic subtyping, they have also been recently advocated for prognostic classification as surrogates for the TCGA (The Cancer Genome Atlas) molecular groups. New entities - mesonephric-like adenocarcinoma and gastric (gastrointestinal)-type mucinous adenocarcinoma of the endometrium - have also been added and often require immunostains for diagnostic confirmation. Ovarian carcinomas frequently show overlapping morphologic patterns and heterogeneous appearance within the same tumor, necessitating immunohistochemical work-up. Beyond diagnostic applications, there is increasing clinical demand for screening of inherited cancer syndromes, prediction of prognosis and guiding targeted therapy. Practical issues and pitfalls related to mismatch repair protein immunohistochemistry, HER2, and PD-L1 testing are also discussed.

Cervical Cancer Diagnosis: Insights into Biochemical Biomarkers and Imaging Techniques

Cervical malignancy is known as one of the important cancers which is originated from cervix. This malignancy has been observed in women infected with papillomavirus who had regular oral contraceptives, multiple pregnancies, and sexual relations. Early and fast cervical cancer diagnosis is known as two important aspects of cervical cancer therapy. Several investigations indicated that early and fast detection of cervical cancer could be associated with better treatment process and increasing survival rate of patients with this malignancy. Imaging techniques are very important diagnosis tools that could be employed for diagnosis and following responses to therapy in various cervical cancer stages. Multiple lines of evidence indicated that utilization of imaging techniques is related to some limitations (i.e. high cost, and invasive effects). Hence, it seems that along with using imaging techniques, finding and developing new biomarkers could be useful in the diagnosis and treatment of subjects with cervical cancer. Taken together, many studies showed that a variety of biomarkers including, several proteins, mRNAs, microRNAs, exosomes and polymorphisms might be introduced as prognostic, diagnostic and therapeutic biomarkers in cervical cancer therapy. In this review article, we highlighted imaging techniques as well as novel biomarkers for the diagnosis of cervical cancer.

An Emerging Anti-p16 Antibody-BC42 Clone as an Alternative to the Current E6H4 for Use in the Female Genital Tract Pathological Diagnosis: Our Experience and a Review on p16ink4a Functional Significance, Role in Daily-Practice Diagnosis, Prognostic Potential, and Technical Pitfalls

Background: To date, useful diagnostic applications of p16 IHC have been documented in gynecological pathology both for HPV-related and non-HPV-related lesions. In the present article, we reported our experience with the novel anti-p16 INK4a antibody (clone BC42), whose expression was tested across all different gynecologic neoplasms; we also compared it to the traditional E6H4 clone. Moreover, we discussed and explored all the diagnostic applications of p16 IHC in gynecologic pathology. Methods: Consultation cases covering a 5-year period (2016–2020) regarding gynecological neoplastic and non-neoplastic lesions in which immunohistochemistry for p16, clone E6H4 was originally performed, were retrospectively retrieved from the files of our institution. Immunohistochemical staining for p16ink4a (BC42) [Biocare Medical group-Paceco USA; Bioptica Milan] and p16ink4a (E6H4) [Ventana Medical Systems-Arizona USA; Roche] was performed by using the Ventana automated immunostainer (Ventana Medical Systems, Tucson, AZ, USA). The immunostaining pattern was defined as negative, focal/patchy, or diffuse. Results: A total of 196 cases, represented by 36 high-grade SIL/CIN3 of the uterine cervix, 30 cervical adenocarcinomas, 22 cervical squamous cell carcinoma, 70 endometrial carcinomas, 25 high grade serous ovarian carcinomas, 6 uterine adenomatoid tumors, and 10 uterine leiomyosarcomas were included in this study. Results showed concordant staining quality of both clones on all tested neoplastic tissues. Conclusions: The novel anti-p16 antibody (BC42 clone) appeared as an alternative to the current E6H4 for use in gynecological neoplasms, offering similar levels of positivity and equally reliable staining results.

Clinical evaluation of p16INK4a immunocytology in cervical cancer screening: A population-based cross-sectional study from rural China

BACKGROUND

Cervical cancer screening with cytology suffers from low sensitivity, whereas the efficiency of human papillomavirus (HPV)-based screening is limited by low specificity. The authors evaluated a novel p16^INK4a immunocytology approach in cervical cancer screening compared with HPV-based and cytology-based screening.

METHODS

In total, 2112 women aged 49 to 69 years from Shanxi, China were screened from March to July 2019. HPV testing, liquid-based cytology (LBC), and p16^INK4a immunocytology were performed on samples from all women. Any positive result triggered a referral to colposcopy with biopsy, if indicated. Screening performance for detecting cervical intraepithelial neoplasia grade 2 and 3 or worse (CIN2+/CIN3+) was evaluated using multiple algorithms.

RESULTS

p16^INK4a had a lower positive rate (10.0%) than LBC abnormality (vs 12.1%; P = .004) and a high-risk HPV positivity (21.4%; P < .001). For the detection of CIN3+, the relative sensitivity of p16^INK4a compared with HPV and LBC was 0.93 (95% CI, 0.82-1.07) and 1.12 (95% CI, 0.95-1.32), respectively. The specificity of p16^INK4a was significantly higher than that for HPV and LBC, with a relative specificity of 1.13 (95% CI, 1.11-1.16) and 1.02 (95% CI, 1.01-1.04), respectively. In addition, p16^INK4a alone yielded a clinical performance very similar to that of the current mainstream strategy of using HPV16/18 with reflex cytology (ASC-US+, atypical squamous cells of undetermined significance or worse). The immediate risk of CIN3+ was 14.6% if p16^INK4a results were positive and 0.2% if p16^INK4a results were negative.

CONCLUSIONS

With minimal colposcopy referrals, p16^INK4a screening demonstrated promising utility for risk stratification and yielded a better balance between sensitivity and specificity compared with HPV and LBC primary screening. Moreover, with accuracy and efficiency similar to what is achieved using mainstream cotest algorithms, p16 may simplify the screening practice. More evidence will be required before clinical recommendation.

A Pooled Analysis to Compare the Clinical Characteristics of Human Papillomavirus-positive and -Negative Cervical Precancers

Given that high-risk human papillomavirus (HPV) is the necessary cause of virtually all cervical cancer, the clinical meaning of HPV-negative cervical precancer is unknown. We, therefore, conducted a literature search in Ovid MEDLINE, PubMed Central, and Google Scholar to identify English-language studies in which (i) HPV-negative and -positive, histologically confirmed cervical intraepithelial neoplasia grade 2 or more severe diagnoses (CIN2+) were detected and (ii) summarized statistics or deidentified individual data were available to summarize proportions of biomarkers indicating risk of cancer. Nineteen studies including 3,089 (91.0%) HPV-positive and 307 (9.0%) HPV-negative CIN2+ were analyzed. HPV-positive CIN2+ (vs. HPV-negative CIN2+) was more likely to test positive for biomarkers linked to cancer risk: a study diagnosis of CIN3+ (vs. CIN2; 18 studies; 0.56 vs. 0.24; P < 0.001) preceding high-grade squamous intraepithelial lesion cytology (15 studies; 0.54 vs. 0.10; P < 0.001); and high-grade colposcopic impression (13 studies; 0.30 vs. 0.18; P = 0.03). HPV-negative CIN2+ was more likely to test positive for low-risk HPV genotypes than HPV-positive CIN2+ (P < 0.001). HPV-negative CIN2+ appears to have lower cancer risk than HPV-positive CIN2+. Clinical studies of human high-risk HPV testing for screening to prevent cervical cancer may refer samples of HPV test-negative women for disease ascertainment to correct verification bias in the estimates of clinical performance. However, verification bias adjustment of the clinical performance of HPV testing may overcorrect/underestimate its clinical performance to detect truly precancerous abnormalities.

Juvenile-Onset Recurrent Respiratory Papillomatosis Aggressiveness: In Situ Study of the Level of Transcription of HPV E6 and E7

Simple Summary

Juvenile-onset recurrent respiratory papillomatosis (JoRRP) is a condition related to HPV 6 and 11 infection which is characterized by the repeated growth of benign exophytic papilloma in the respiratory tract of children. Disease progression is unpredictable leading sometimes to airway compromise and death. The aim of this study was to explore p16^INK4a and expression of the RNA of HPV genes E6 and E7 with a chromogenic in situ hybridization (CISH) as biomarkers of JoRRP aggressiveness on a bicentric cohort of forty-eight children. CISH was scored semi-quantitatively as high (2+ score) and low (1+ score) levels of transcription of E6 and E7. Patients with a 2+ score had a more aggressive disease compared to those with a 1+ score. These data are a first step towards the use of biomarkers predictive of disease severity in JoRRP, this could improve the disease management, for example, by implementing adjuvant treatment at the early stages.

Abstract

Juvenile-onset recurrent respiratory papillomatosis (JoRRP) is a condition related to HPV 6 and 11 infection which is characterized by the repeated growth of benign exophytic papilloma in the respiratory tract. Disease progression is unpredictable: some children experience minor symptoms, while others require multiple interventions due to florid growth. The aim of this study was to explore the biomarkers of JoRRP severity on a bicentric cohort of forty-eight children. We performed a CISH on the most recent sample of papilloma with a probe targeting the mRNA of the E6 and E7 genes of HPV 6 and 11 and an immunostaining with p16^INK4a antibody. For each patient HPV RNA CISH staining was assessed semi-quantitatively to define two scores: 1+, defined as a low staining extent, and 2+, defined as a high staining extent. This series contained 19 patients with a score of 1+ and 29 with a score of 2+. Patients with a score of 2+ had a median of surgical excision (SE) per year that was twice that of patients with a score of 1+ (respectively 6.1 versus 2.8, p = 0.036). We found similar results with the median number of SE the first year. Regarding p16^INK4a, all patients were negative. To conclude, HPV RNA CISH might be a biomarker which is predictive of disease aggressiveness in JoRRP, and might help in patient care management.

Relationships of p16 Immunohistochemistry and Other Biomarkers With Diagnoses of Cervical Abnormalities: Implications for LAST Terminology

CONTEXT.—

Lower Anogenital Squamous Terminology (LAST) standardization recommended p16INK4a immunohistochemistry (p16 IHC) for biopsies diagnosed morphologically as cervical intraepithelial neoplasia (CIN) grade 2 (CIN2) to classify them as low-grade or high-grade squamous intraepithelial lesions (HSILs).

OBJECTIVE.—

To describe the relationships of p16 IHC and other biomarkers associated with cervical cancer risk with biopsy diagnoses.

DESIGN.—

A statewide, stratified sample of cervical biopsies diagnosed by community pathologists (CPs), including 1512 CIN2, underwent a consensus, expert pathologist panel (EP) review (without p16 IHC results), p16 IHC interpretation by a third pathology group, and human papillomavirus (HPV) genotyping, results of which were grouped hierarchically according to cancer risk. Antecedent cytologic interpretations were also available.

RESULTS.—

Biopsies were more likely to test p16 IHC positive with increasing severity of CP diagnoses, overall (Ptrend ≤ .001) and within each HPV risk group (Ptrend ≤ .001 except for low-risk HPV [Ptrend < .010]). All abnormal grades of CP-diagnosed biopsies were more likely to test p16 IHC positive with a higher HPV risk group (Ptrend < .001), and testing p16 IHC positive was associated with higher HPV risk group than testing p16 IHC negative for each grade of CP-diagnosed biopsies (P < .001). p16 IHC-positive, CP-diagnosed CIN2 biopsies were less likely than CP-diagnosed CIN3 biopsies to test HPV16 positive, have an antecedent HSIL+ cytology, or to be diagnosed as CIN3+ by the EP (P < .001 for all). p16 IHC-positive, CP-diagnosed CIN1 biopsies had lower HPV risk groups than p16 IHC-negative, CP-diagnosed CIN2 biopsies (P < .001).

CONCLUSIONS.—

p16 IHC-positive, CP-diagnosed CIN2 appears to be lower cancer risk than CP-diagnosed CIN3. LAST classification of "HSIL" diagnosis, which includes p16 IHC-positive CIN2, should annotate the morphologic diagnosis (CIN2 or CIN3) to inform all management decisions, which is especially important for young (<30 years) women diagnosed with CIN2 for whom surveillance rather than treatment is recommended.

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.

Uterine cervical squamous cell carcinoma without p16 (CDKN2A) expression: Heterogeneous causes of an unusual immunophenotype

Immunohistochemically p16 (CDKN2A)-negative uterine cervical squamous cell carcinoma (SCC) is uncommon, and there are few reports about its pathological features. This study explored the causes of p16 negativity in such cases. We analyzed diagnostic tissue samples of five cases of p16-negative cervical SCC among 107 patients who underwent hysterectomy at Kyoto University Hospital between January 2010 and December 2015. The samples were subjected to immunohistochemical staining, in situ hybridization and a genetic analysis. Two of five cases were positive for human papilloma virus (HPV) by genotyping. One was positive for HPV56 with promoter hypermethylation of CDKN2A and co-existing Epstein-Barr virus infection. Another was positive for HPV6 categorized as low-risk HPV with condylomatous morphology. Among the remaining three cases, one had amplification of the L1 gene of HPV with promoter hypermethylation of CDKN2A and TP53 mutation, and one of the other two HPV-negative cases had a homozygous CDKN2A deletion, while the other was positive for p53 and CK7. p16-negativity of cervical SCC is often associated with an unusual virus infection status and CDKN2A gene abnormality.

Grading immunohistochemical markers p16INK4a and HPV E4 identifies productive and transforming lesions caused by low- and high-risk HPV within high-grade anal squamous intraepithelial lesions

OBJECTIVES

Because current guidelines recognise high-grade anal squamous intraepithelial lesions (HSILs) and low-grade SILs (LSILs), and recommend treatment of all HSILs although not all progress to cancer, this study aims to distinguish transforming and productive HSILs by grading immunohistochemical (IHC) biomarkers p16INK 4a (p16) and E4 in low-risk human papillomavirus (lrHPV) and high-risk (hr)HPV-associated SILs as a potential basis for more selective treatment.

METHODS

Immunostaining for p16 and HPV E4 was performed and graded in 183 biopsies from 108 HIV-positive men who have sex with men. The causative HPV genotype of the worst lesion was identified using the HPV SPF10-PCR-DEIA-LiPA25 version 1 system, with laser capture microdissection for multiple infections. The worst lesions were scored for p16 (0-4) to identify activity of the hrHPV E7 gene, and panHPV E4 (0-2) to mark HPV production and life cycle completion.

RESULTS

There were 37 normal biopsies, 60 LSILs and 86 HSILs, with 85% of LSILs caused by lrHPV and 93% of HSILs by hrHPV. No normal biopsy showed E4, but 43% of LSILs and 37% of HSILs were E4 positive. No differences in E4 positivity rates were found between lrHPV and hrHPV lesions. Most of the lesions caused by lrHPV (90%) showed very extensive patchy p16 staining; p16 grade in HSILs was variable, with frequency of productive HPV infection dropping with increasing p16 grade.

CONCLUSIONS

Combined p16/E4 IHC identifies productive and nonproductive HSILs associated with hrHPV within the group of HSILs defined by the Lower Anogenital Squamous Terminology recommendations. This opens the possibility of investigating selective treatment of advanced transforming HSILs caused by hrHPV, and a 'wait and see' policy for productive HSILs. What's already known about this topic? For preventing anal cancer in high-risk populations, all patients with high-grade squamous intraepithelial lesions (HSILs) are treated, even though this group of lesions is heterogeneous, the histology is variable and regression is frequent. What does this study add? By adding human papillomavirus (HPV) E4 immunohistochemistry to p16 INK4a (p16), and grading expression of both markers, different biomarker expression patterns that reflect the heterogeneity of HSILs can be identified. Moreover, p16/E4 staining can separate high-risk HPV-associated HSILs into productive and more advanced transforming lesions, providing a potential basis for selective treatment.

Laryngeal Squamous Cell Carcinomas are Commonly Associated With Differentiated Squamous Intraepithelial Neoplasia With or Without an Admixture With Usual Type of Squamous Intraepithelial Neoplasia: Clinical and Pathologic Significance

BACKGROUND

Differentiated squamous intraepithelial neoplasia (dSIN) is a pathway in the development of invasive squamous cell carcinoma (SCC) distinct from the usual-type squamous intraepithelial neoplasia (uSIN) and has not been described in the larynx.

MATERIALS AND METHODS

Sixty-nine consecutive cases of SCC were identified which included 25 dSIN, 13 uSIN, and 31 mixed dSIN+usual-like SIN (u-like SIN) cases.

RESULTS

dSIN was characterized by atypical squamous cells limited to the basal/parabasal layers and u-like SIN was characterized by cytologic atypia limited to less than full thickness. Despite the lack of neoplastic involvement of the full thickness of the epithelium, these types of SIN were commonly connected with invasive carcinoma. Prior biopsies demonstrating only dSIN, without the underlying invasive SCC, were underdiagnosed in 2 cases. Because of the frequent keratinization, u-like SIN likely represents the "keratinized dysplasia" and shows changes suggestive of dSIN with upward spread of neoplastic cells into the upper layer of the epithelium.

CONCLUSIONS

Laryngeal dSIN represents an important but under recognized pathway of invasive SCC development. As moderate dysplasia of uSIN type are not associated with invasive SCC, labeling u-like SIN as dysplasia of grade 2 or 3 likely leads to the controversies in the current grading systems in the upper aerodigestive system and causes confusion for clinicians.

HPV-ISH-Negative Invasive Cervical Squamous Cell Carcinoma: Histologic and Pap Test Results

INTRODUCTION

A causal link between infection with a high-risk strain of human papilloma virus (hrHPV) and the development of cervical squamous cell carcinoma (SCC) is well established. However, a small number of SCCs are hrHPV-negative by either HPV co-DNA testing and/or HPV-in situ hybridization (HPV-ISH) at the time of diagnosis. These apparently hrHPV-negative lesions are poorly understood, specifically whether hrHPV-positive precursor lesions exist, which would be detected through hrHPV-based screening.

METHODS

A search of the pathology archives at the Johns Hopkins Hospital identified women with a diagnosis of hrHPV-negative cervical SCC on surgical specimen. All prior pathologies, including cervical cytology and surgical pathology specimens, and associated hrHPV DNA test results, p16 immunohistochemistry, and HPV-ISH were reviewed.

RESULTS

A total of 25 women were identified having a surgical specimen diagnosed as SCC with either negative or equivocal HPV-ISH. Fifteen had a Pap test in the 6 months preceding a diagnosis of SCC, with cytology diagnoses as follows: high-grade squamous intraepithelial lesion n = 14/15; atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion n = 1/15. hrHPV co-testing was performed for 5 of these 15 women and was negative in 2/5 cases. Cervical biopsy was performed for 24 women. HPV-ISH testing, performed on 14 of the biopsy specimens, was negative for 11/14 patients. Of 15 specimens stained for p16, 14 were positive.

CONCLUSION

A subset of patients exist in whom hrHPV is not detectable at or near the time of progression to SCC. Additional research is necessary to further describe this population and determine whether maintaining cytological screening would provide benefit.

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.

Role of Ancillary Techniques in Cervical Biopsy and Endocervical Curettage Specimens as Follow-Up to Papanicolaou Test Results Indicating a Diagnosis of Atypical Squamous Cells, Cannot Exclude High-Grade Squamous Intraepithelial Lesion, or High-Grade Squamous Intraepithelial Lesion

The Papanicolaou (PAP) test is widely used to screen for cervical cancer. All high-grade lesions such as atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion (ASC-H), and high-grade squamous intraepithelial lesion, identified on a PAP test should be followed-up by a confirmatory cervical biopsy. In this review, we discuss the challenges in interpreting cervical tissue specimens and the various ancillary techniques used in the evaluation of cervical dysplasia. Ancillary studies include deeper levels, p16 immunohistochemistry (IHC), human papillomavirus (HPV) testing, and, importantly, cyto-histologic correlation. Of these, p16 IHC is consistently sensitive and specific for detecting HSIL. HPV RNA in situ hybridization (ISH) is a newer technique with excellent sensitivity and specificity for detecting virally infected cells and it may be more broadly applicable to both low- and high-grade squamous intraepithelial lesions.

Cervical, Ovarian and Endometrial Tumor Markers: Potential Clinical Value

Tumors markers can be described as molecular products expressed by neoplasia tissues (immunohistochemistry), or metabolized and secreted by tumor and characterized biochemically in body fluids such as blood and urine. They may have utility as indicators of tumor stage and grade as well useful for monitoring responses to treatment and predicting recurrence, progression, development of metastases, or even patient survival. Unfortunately, in some cases they may have no identified clinical potential. Several investigations have been carried out, especially in the last decade, using biotechnological methods, in order to identify new potential tumor markers. By translating these findings into clinical use one may facilitate accurate diagnosis and prognostic prediction, and contribute to individualized treatment. The objective of this review is to describe some biomarkers with potential use in clinical settings of uterine cervix, ovary, and endometrium carcinomas.

Human papillomavirus DNA, HPV L1 capsid protein and p16INK4a protein as markers to predict cervical lesion progression

OBJECTIVES

Cervical cancer is the most common malignant tumors in women leading to serious morbidity and mortality worldwide, especially among developing countries. A main cause of the disease is the high-risk human papillomavirus (HR-HPV) infection. HSIL usually progress to cervical cancer, and low-grade lesions, including LSIL and ASCUS, mostly turn to normal or benign lesions, but there are still a small number of patients who will progress to HSIL. Up to now there is no efficient biomarker clinically available to predict people with high risk to progress into HSIL. This study was conducted to evaluate the value of human papillomavirus (HPV) DNA, p16^INK4a protein, and HPV L1 capsid protein in predicting HSIL and minimizing unnecessary colposcopy treatments.

METHODS

1222 patients with HR-HPV infection or with abnormal Thinprep cytologic test (TCT) were chosen to conduct colposcopy in the cervical out-patient clinic of Shanghai First Maternity and Infant Hospital affiliated to Shanghai Tongji University from June 2014 to January 2017. TCT, cervical biopsy, HPV DNA and HPVL1 were performed on all patients. 110 patients were selected to detect p16^INK4a protein. Hybrid capture 2 (HC-2) was used to detect HPV DNA, and their subgroups using gene typing system. Immunohistochemical technology was used to detect HPV L1 and p16.

RESULTS

HPV DNA was positive in 1097 cases, with the positive rate of 89.7% (1097/1222). In particular, the positive expression rates of HPV DNA were 82.3, 95.7, 96.6 and 100% in Normal/CC, LSIL, HSIL and cervical cancer groups, respectively (p < 0.001). HPV L1 was negative in 781 cases with HR-HPV infection, and the overall negative rate is 71.1%. In patients with Normal/CC, LSIL and HSIL, the negative expression rates of HPV L1 were 91.3, 40 and 81.2%, respectively (p value < 0.001). In the 110 patients, HPV L1 was negative in 98.1% (53/54) of Normal/CC, 42.9% (12/28) of LSIL and 85.1% (23/27) of HSIL (p value = 0.0043). P16-positive rates in patients with Normal/CC, LSIL and HSIL were 33.3% (18/54), 75% (21/28) and 96.2% (26/27), respectively (p value < 0.001). 18 out of 28 cases express low positive (+) in LSIL, 25 out of 27 cases express strong positive (3+) in HSIL. Patients with L1(-) p16(+) including 18.5% (10/54) of normal/cervicitis, 60.7% (17/28) of LSIL and 85.1% (23/27) of HSIL (p value < 0.005). Furthermore, patients with L1(-) p16(1+) included 37% (10/27) of normal/cervicitis 59.3% (16/27) of LSIL and 3.7% (1/27) of HSIL; patients with L1(-) p16(2+) consisted of 0% of normal/cervicitis/LSIL and 100% (1/1) of HSIL; patients with L1(-) p16(3+) were composed of 0% of normal/cervicitis, 4.5% (1/22) of LSIL and 95.5% (21/22) of HSIL (p value < 0.005) (Table 6).

CONCLUSION

With the increase in the degree of the cervical lesions, the expression of HPV DNA and p16 is up-regulated while HPV L1 protein is down-regulated. HPV DNA, HPV L1 and p16 are useful markers for the prediction of HSIL. Combined detection of these three markers has important potential to predicting HSIL and minimizing unnecessary colposcope examination.

p16 Immunohistochemistry Is Not Always Required For Accurate Diagnosis of Grade 2 Squamous Intraepithelial Lesions

OBJECTIVES

Preinvasive squamous neoplasms of the lower genital tract are currently classified using a two-tier system (high- or low-grade squamous intraepithelial lesion) as directed by the Lower Anogenital Squamous Terminology (LAST) guidelines but may also be subclassified as intraepithelial neoplasia grade 1 (-IN1), -IN2, or -IN3. The LAST recommended that all diagnoses of -IN2 be supported by immunohistochemistry (IHC) for p16. We examined whether p16 and Ki-67 IHC are necessary to diagnose -IN2 when the lesion has obvious high-grade histology.

MATERIALS AND METHODS

p16 and Ki-67 IHC were performed prospectively and retrospectively on vulvar, vaginal, and cervical specimens with an initial diagnosis of -IN2 based on hematoxylin and eosin morphology, and a final diagnosis was made after consensus review.

RESULTS

Five of 46 prospective and four of 38 retrospective cases were p16 negative. The diagnosis of -IN2 was maintained in eight of these nine cases because of compelling high-grade squamous intraepithelial lesion histology. Overall, p16 and Ki-67 IHC altered the -IN2 diagnosis to a lower grade in only one of 84 cases (1.2%, <0.01%-7.1%). Moreover, p16 was positive in all cases where the preanalytic impression was of -IN2/3 (13/13).

CONCLUSIONS

p16 IHC lacks utility in cases of morphologically obvious -IN2, because the stain is positive in most cases. The LAST recommendation to use p16 IHC to support all diagnoses of -IN2 will result in performing the immunostain in many circumstances where it is not medically necessary. Among cases that are p16 negative, many have compelling high-grade morphology. The LAST perspective that the stain trumps histology may allow false-negative IHC results to prevail.

P16INK4a expression in patients with penile cancer

BACKGROUND

Infection with human papillomavirus (HPV) is reported to be present in 30-50% of penile cancer cases. The immunohistochemical test for p16INK4a is used as an indicator of the presence of HPV and as a prognostic marker for squamous cell carcinomas in various sites. However, the role of this marker in penile carcinoma has not yet been completely elucidated. The aim of this study was to analyze whether the expression of p16INK4a is associated with the presence of HPV, histological parameters, and survival in penile cancer.

METHODS

A study was conducted from 2014 to 2016 that included 55 patients with penile carcinoma. HPV DNA was detected through PCR using fresh tumor tissue, and immunohistochemistry was performed for analysis of p16INK4a protein using paraffin-embedded tissue. Evaluation of histological parameters was performed following complete embedding of the tumor tissue in paraffin.

RESULTS

HPV DNA (low-risk and high-risk genotypes) was found in 49 (89.1%) cases, and 46/49 (93.9%) showed high-oncogenic risk HPV (HR-HPV). Of the 22 cases positive for p16INK4a, HR-HPV DNA was present in 21 (95.5%) (p = 0.032). Regarding histological parameters, p16INK4a and HR-HPV were significantly associated only with tumor subtype (p = 0.036 and p = 0.032, respectively); all carcinomas with basaloid characteristics were positive for p16INK4a. Although HPV+ patients had a higher disease-free survival (p <0.001), p16INK4a expression was not associated with patient survival.

CONCLUSIONS

Our study, using fresh tissue samples, showed the highest incidence of HPV compared to that observed in the literature. Expression of the p16INK4a protein was significantly associated with the presence of HR-HPV and this expression may serve as a marker for the presence of the virus. The p16INK4a protein was not associated with the histological prognostic parameters, with the exception of tumor subtype, nor with patient survival. In the results, we showed that the objective of the present study was reached.

Potential influence of p16 immunohistochemical staining on the diagnosis of squamous cell lesions in cervical biopsy specimens: observation from cytologic-histologic correlation

BACKGROUND

The p16 immunohistochemical (IHC) marker has been used increasingly as an adjunct to morphologic assessment of cervical biopsies in which the differential diagnoses include high-grade squamous intraepithelial lesion (HSIL) and its mimics. The objective of this study was to assess the potential influence of p16 IHC staining on the evaluation of cervical biopsy as observed through cytologic-histologic correlation (CHC).

METHODS

Cervical biopsy samples that had cytologic diagnoses of either low-grade squamous intraepithelial lesion (LSIL) or HSIL and also had histologic follow-up were retrieved from the department database. CHC and the use of p16 IHC from 2 periods (group 1, 2008; group 2, 2014-2016) were compared and analyzed.

RESULTS

Histology on 452 samples from patients who had prior LSIL cytology in group 1 yielded 126 benign (27.9%), 272 LSIL (60.2%), and 54 HSIL (11.9%) diagnoses. By comparison, 491 samples from the patients in group 2 yielded 106 benign (21.6%), 277 LSIL (56.4%), and 108 HSIL (22.0%) diagnoses. The difference in CHC discrepancies between the 2 groups was significant (P = .0001), mainly because of the increased diagnosis of HSIL in group 2. Although p16 IHC was not applied to any sample from group 1, it was performed on 141 of 491 samples (28.7%) from group 2. Further follow-up of patients who had histologic HSIL revealed that residual HSIL was identified significantly more often in those who did not have p16 IHC applied in the preceding cervical biopsy than in those did (P = .0004). A similar comparison was performed between 113 patients from group 1 and 152 patients from group 2 who had a prior diagnosis of HSIL cytology, and the difference was statistically insignificant.

CONCLUSIONS

The use of p16 IHC on cervical biopsies in patients who had a prior cytologic diagnosis of LSIL may lead to greater detection and upgrading of HSIL, thereby compounding the discrepancy in CHC.

p16 Expression and Biological Behavior of Flat Vulvar Low-grade Squamous Intraepithelial Lesions (LSIL)

Flat low-grade squamous intraepithelial lesion (LSIL) of the vulva [vulvar intraepithelial neoplasia (VIN) 1, flat condyloma] is an uncommon entity with poorly understood biological behavior. We aimed to determine the risk of subsequent vulvar high-grade squamous intraepithelial lesion (HSIL) or carcinoma following a diagnosis of vulvar LSIL/VIN 1, as well as the frequency and predictive value of p16 immunohistochemical expression in this setting. Of the 51 included cases, p16 positivity (diffuse block staining) was identified in 2 (4%). Follow-up data were available in 34 cases, of which 2 (5.9%) developed subsequent vulvar HSIL, including 1/2 p16-positive cases and 1/32 p16-negative cases. The difference in HSIL frequency between p16-positive and p16-negative cases was not statistically significant (P=0.116 for VIN 2+, P=0.061 for VIN 3). For the 18 patients with treatment information available, 10 (56%) received medical or surgical treatment after biopsy. Our results indicate that flat vulvar LSIL is infrequently p16 positive, and that few patients with vulvar LSIL develop subsequent vulvar HSIL. Despite the use of destructive treatment in some cases, the data provide support for the nonpreneoplastic nature of the entity. Immunohistochemical expression of p16 may not be a predictor of HSIL risk in vulvar LSIL, although this result may also be related to the very low rates of both p16 positivity and subsequent vulvar HSIL in our sample. It is clear that vulvar LSIL is distinct from LSIL in other lower anogenital sites in terms of its behavior and p16 expression frequency.

Effects of HPV Pseudotype Virus in Cutting E6 Gene Selectively in SiHa Cells

The objectives of this study were to investigate the effects of the CRISPR/Cas9 system mediated by the HPV pseudotype virus on SiHa cytobiology behavior by cutting the HPV16 E6 gene selectively and to explore the role of this system in the treatment of cervical cancer. After designing specific gRNA sequences targeting HPV16 E6, generating hCas9-EGFP and E6-gRNA-RFP plasmids, and preparing the pseudovirus of HPV16 carrying E6-gRNA and Cas9 plasmids, we determined the titer of the pseudotype virus using the TCID50 method. We obtained the pseudotype virus of HPV16 carrying E6-gRNA and Cas9 plasmids to transfect cervical cancer SiHa cells. Experimental subjects were divided into control group, empty virus group, E6-gRNA transfected group, Cas9 transfected group and Cas9+E6-gRNA transfected group. The molecular size of the cutting sequence was detected using the T7E1 enzyme digestion method and agarose gel electrophoresis, and the cleavage function of CRISPR/Cas9 on the E6 gene was determined at the same time. RT-PCR and Western blotting were performed to detect the mRNA and protein expression levels of E6 in all the groups; the Transwell cell migration assay was performed to detect the cell migration ability and metastasis in all groups. Heterotopic transplantation tumors were incorporated into mice and were used to investigate the effects of the CRISPR/Cas9 system mediated by the HPV pseudovirus on the tumorigenic ability of SiHa cells by selectively cutting HPV16 E6. The HPV16 pseudotype virus carrying E6-gRNA and Cas9 plasmids could successfully infect SiHa cells, and there were two cutting zones in the Cas9+E6-gRNA transfected group. However, the empty virus group, E6-gRNA transfected group and Cas9 transfected group had no corresponding zone. Compared with those in the control group, the empty virus group, E6-gRNA transfected group and Cas9 transfected group, the mRNA and protein expression levels of E6 in SiHa cells were downregulated in the Cas9+E6-gRNA transfected group (P<0.01). In addition, the proliferation and migration abilities of SiHa cells were significantly inhibited (P<0.01). There were no significant differences among the other groups. In contrast to the control group, the HPV pseudotype virus carrying E6-gRNA and Cas9 plasmids could significantly delay the growth of tumor cells of the ectopic tumor transplantation model (P<0.01). The CRISPR/Cas9 system mediated by the HPV pseudotype virus to knockout E6 gene expression exhibited a clear inhibitory effect on the biological function of SiHa cells, which indicated that knocking out the E6 gene using the CRISPR/Cas9 system mediated by the HPV pseudotype virus had a potential effect of eliminating HPV infection and inhibiting the growth of HPV-related tumors. Taken together, these findings provide insight into a new treatment strategy for the prevention and treatment of hr-HPV infected disease, particularly in HPV-related tumors.

Detection of Merkel Cell Polyomavirus in Seborrheic Keratosis

Seborrheic keratosis (SK) is the most common benign cutaneous neoplasm. A subset shows increased p16 expression. Since SK shares several features with verruca vulgaris, e.g., increased p16 expression, human papillomaviruses (HPV) have been suggested as possible causal agents. However, a relevant association could not be established between HPV and SK. In the present study we aimed to investigate the presence of Merkel cell polyomavirus (MCPyV) in relation to p16 expression in SK. P16 expression was investigated using immunohistochemistry (IHC). Presence of MCPyV was assessed in 23 formalin-fixed paraffin-embedded tissue samples of SK by molecular techniques (i.e., PCR and FISH) and IHC. 16/23 SK showed strong to moderate p16 expression. 6/23 of SK were MCPyV positive by PCR which was confirmed by FISH. Of interest, two samples with strong FISH signals also showed MCPyV expression as tested by IHC. Samples with weaker signal intensity were negative in IHC. P16 expression was not associated with the presence of MCPyV. Concluding, the detection of MCPyV DNA by PCR and FISH in SK reflects the widespread prevalence of MCPyV in the skin. However, low detection rates exclude MCPyV as a major pathogenic factor in SK, most likely representing a coincidental infection. P16 IHC does not appear as useful adjunctive surrogate marker for the presence of MCPyV in SK.

HPV-related vulvar diseases and perspectives of p16INK4a immunochemistry: a review of the literature

INTRODUCTION

Two different types of vulvar intraepithelial neoplasia (VIN), HPV-related and HPV-unrelated, should be considered as two separate entities with different management options. The incidence of HPV-related VIN is increasing worldwide and is implicated in carcinogenesis. Our objective is to investigate the use of p16INK4a immunostaining or p16INK4a/p53 double staining for the detection of HPV-related disease to overcome the problem that histological criteria often have significant overlap.

METHODS

A systematic literature search was carried out in the online databases PubMed, EMBASE, Cochrane Library, Clincaltrials.gov and Scopus. The key search terms were HPV, VIN, p16INK4a immunochemistry and p53.

RESULTS

We found that nuclear and cytoplasmic immunostaining for p16INK4a was intense and diffuse in HPV-associated lesions and weak and focal in normal vulvar epithelium, nondysplastic lesions, lichen sclerosus and keratinizing vulvar squamous cell carcinoma. p53 nuclear immunostaining was always negative in HPV-related disease.

CONCLUSIONS

Our findings indicated that p16INK4a or p16INK4a/p53 immunoreactivity, along with histological diagnosis, could be a convenient means to adequately classify VIN and its connection to HPV infection. Therefore, the clear recognition of HPV-associated VIN would lead to an appropriate strategy of treatment and follow-up.

Immunohistochemistry in Gynecologic Pathology: An Example-Based Practical Update

CONTEXT

- Immunohistochemical stains are routinely applied in the pathology diagnostic workup of gynecologic lesions. The rapidly expanding repertoire of available markers helps in refining the diagnostic criteria for each disease entity; however, limitations and pitfalls exist.

OBJECTIVE

- To provide a practical, relevant update on the use of immunohistochemistry for commonly encountered differential diagnoses in gynecologic pathology.

DATA SOURCES

- Literature review and authors' diagnostic experience.

CONCLUSIONS

- Immunohistochemistry is a helpful adjunct tool in gynecologic pathology. Although the primary application is in the diagnostic workup, novel prognostic and predictive markers, and immunostains to screen for genetic cancer syndromes, have also been recently introduced in the field.

Human papillomavirus infection in oral potentially malignant disorders and cancer

Human papillomavirus (HPV) infects keratinocytes in the mucosa or skin, and persistent infection with HPV may lead to premalignant lesions and invasive cancer, especially cervical cancer. It has also been hypothesized that HPV infection is an etiological factor of oral squamous cell carcinoma and oral precancerous disorders such as lichen planus, leukoplakia, and erythroplakia. A high percentage of HPV in oral lesions supports the possible viral contribution, but an association of HPV infection with these lesions remains to be established. The current paper will update the latest progress of HPV infection in several oral potentially malignant disorders and oral squamous cell carcinoma and discuss the impact of HPV infection on the progression of oral potentially malignant disorders.

[Modern biomarkers for precancerous lesions of the uterine cervix : Histological-cytological correlation and use]

The correlation between the cytological findings from the PAP smear and the histological outcome in cases where the cytological findings must be histologically verified, is an integral component of the German screening program for cervical cancer. These data are collected nationwide as part of a benchmarking process by the individual Associations of Statutory Health Insurance Physicians (KV) in the federal states and reported to the National Association of Statutory Health Insurance Physicians (KBV) in Berlin. In most cases there is a good correlation between cytology and histology but in some cases either a different grade of severity of cervical intraepithelial neoplasia (CIN) is found or the histological findings are negative. The reasons for a lack of correlation can be insufficient sampling in the cytology or the biopsy or a misinterpretation of the individual findings. Although the findings from H&E sections are considered to be the gold standard in the histological evaluation, it has long been known that the interobserver agreement in these preparations is only moderate. A significant improvement becomes apparent, firstly by the classification of cervical cancer precursors into low-grade and high-grade groups and secondly by the targeted application of biomarkers, in particular p16 and Ki-67, according to the recommendations of the lower anogenital squamous terminology standardization (LAST) project. The biomarkers p16 and Ki-67 should be used in the differential diagnostics between reactive and reparative alterations and for further differentiation of a CIN grade 2 but not to confirm a CIN grade 3. It is still unclear whether p16 is suitable as a prognostic marker for low-grade lesions.

Role of quantitative p16INK4A mRNA assay and digital reading of p16INK4A immunostained sections in diagnosis of cervical intraepithelial neoplasia

Visual interpretation of cervical biopsies is subjective and variable, generally showing fair to moderate inter-reader agreement in distinguishing high from low grade cervical intraepithelial neoplasia (CIN). We investigated the performance of two objective p16 quantitative tests in comparison with visual assessment: (i) p16-mRNA assay and (ii) digital analysis of sections stained for p16 protein. The primary analysis considered 232 high-risk human papilloma virus positive (HPV+) samples from diagnostic cervical specimens. A p16 RT-qPCR (p16-mRNA assay) was run on mRNA extracted from formalin-fixed paraffin-embedded sections. Two p16 immunohistochemistry (IHC) readings, a visual read by a histopathologist (Visual IHC) and a digital read of a high-resolution scan (Digital IHC), were done on adjacent sections. The worst reviewed CIN grade (agreed by at least two histopathologists) from up to two biopsies and a loop excision was taken, with CIN2/3 as the primary endpoint. Visual IHC attained a specificity of 70% (95%CI 61-77) for 85% (95%CI 77-91%) sensitivity. The four-point Visual IHC staining area under the curve (AUC) was 0.77 (95%CI 0.71-0.82), compared with 0.71 (95%CI 0.64-0.77) for p16-mRNA and 0.67 (95%CI 0.60-0.74) for Digital IHC. Spearman rank-order correlations were: visual to p16-mRNA 0.41, visual to digital 0.49 and p16-mRNA to digital: 0.22. The addition of p16-mRNA assay to visual reading of p16 IHC improved the AUC from 0.77 to 0.84 (p = 0.0049). p16-mRNA testing may be complementary to visual IHC p16 staining for a more accurate diagnosis of CIN, or perhaps a substitute in locations with a lack of skilled pathologists.

Using p16 immunohistochemistry to classify morphologic cervical intraepithelial neoplasia 2: correlation of ambiguous staining patterns with HPV subtypes and clinical outcome

p16^INK4a immunohistochemistry (IHC) is widely used to facilitate the diagnosis of human papillomavirus (HPV)-associated cervical precancerous lesions. Although most p16 results are distinctly positive or negative, certain ones are ambiguous: they meet some but not all requirements for the "block-positive" pattern. It is unclear whether ambiguous p16 immunoreactivity indicates oncogenic HPV infection or risk of progression. Herein, we compared HPV genotypes and subsequent high-grade squamous intraepithelial lesion (HSIL) outcomes among 220 cervical biopsies with a differential diagnosis of cervical intraepithelial neoplasia 2 based on hematoxylin and eosin morphology and varying degrees of p16 immunoreactivity. p16 results were classified as block positive (n=40, 18%), negative (n=130, 59%), or ambiguous (n=50, 23%), a category we further grouped into 3 patterns: strong/basal (n=18), strong/focal (n=15), and weak/diffuse (n=17). Seventy percent of ambiguous p16 lesions were negative for the most common low- and high-risk HPV types; the remaining 30% were positive for HPV 16, 18, 45, 58, 59, or 66. Three patterns revealed comparably low HPV detection rates (28%, 27%, and 35%). During 12-month surveillance, HSILs were detected in 35% of the p16 block-positive group, 1.5% of negative group, and 16% of the ambiguous group. The accuracy of ambiguous p16 immunoreactivity in predicting oncogenic HPV and HSIL outcome is significantly lower than that of the block-positive pattern but greater than negative staining. Specific guidelines for this intermediate category should prevent diagnostic errors and help implement p16 IHC in general practice.

Proposed Terminology for Anal Squamous Lesions: Its Application and Interobserver Agreement Among Pathologists in Academic and Community Hospitals

OBJECTIVES

To analyze interobserver reproducibility and compare practice patterns between academic and community settings of Lower Anogenital Squamous Terminology (LAST).

METHODS

In total, 132 anal biopsy slides were revised as well as p16 immunostains.

RESULTS

LAST was used in 49% of cases (academic center, 68%; satellite hospitals [community practice setting], 32%). After pathology review and consensus interpretation, 23 (17%) case diagnoses were reclassified: eight (34.8%) cases (benign or low-grade squamous intraepithelial lesion [LSIL]) were upgraded to high-grade squamous intraepithelial lesion (HSIL) (p16 confirmed ordered during review); four (17.4%) cases originally classified as HSIL were downgraded to LSIL (p16 originally ordered in one case). There was no significant difference in discrepancies between original and consensus diagnosis in the community vs academic setting or by subspecialty (gynecological vs gastrointestinal). Overall interobserver agreement among reviewers was substantial (κ = 0.63) and improved with the use of p16 immunostain in challenging cases (κ = 0.71; P < .001).

CONCLUSIONS

This new terminology is not yet uniformly used by pathologists in anal/perianal biopsy specimens; this two-tier system has a good interobserver agreement and is further improved with p16 use in appropriate cases.

A systematic investigation of the association between HPV and the clinicopathological parameters and prognosis of oral and oropharyngeal squamous cell carcinomas

Human papillomavirus (HPV), the causal factor of cervical cancers, was closely linked to the etiology and prognosis of oropharyngeal squamous cell carcinoma (OPSCC), but its role in oral squamous cell carcinoma (OSCC) was unclear. In addition, few researches based on Chinese population were documented. Hence, we sought to investigate the relationship of HPV marker P16 protein to the clinicopathological parameters and survival of OPSCC and OSCC patients systematically to assess the influence of ethnic, regional difference on HPV susceptibility. Specimens from 93 OPSCC patients and 95 OSCC patients were recut, and P16 immunohistochemistry (IHC) was performed. Moreover, survival analysis was conducted to confirm the independent factors that influenced the prognosis. The P16 results were positive in 25.8% and 9.5% of patients with OPSCC and OSCC, respectively. The overall survival (OS) of HPV-positive OPSCC patients was significantly longer than that of HPV-negative OPSCC patients (P = 0.004). Conversely, statistical significance was not observed regarding the OS of OSCC patients (P = 0.343). Cox regression analysis indicated that T stage and P16 status were independent factors that affected the prognosis of OPSCC patients, and the smoking index influenced the prognosis of OSCC patients. Among OPSCC patients who received radiochemotherapy (RCT), HPV-positive patients had a better survival rate than their HPV-negative counterparts (P = 0.015). Conversely, no significant difference was observed between HPV-positive and HPV-negative OSCC patients who received RCT (P = 0.237). P16 is a credible surrogate by which to define HPV status. HPV expression had a favorable effect on OPSCC patients as opposed to their OSCC counterparts in this single center population-based study.

p16 Staining of Cervical Biopsies May Decrease the Frequency of Unnecessary Loop Electrosurgical Excision Procedures

OBJECTIVE

Loop electrosurgical excision procedures (LEEPs) are negative for high-grade cervical intraepithelial neoplasia (CIN 2+) after a hematoxylin and eosin-based CIN 2+ colposcopic biopsy diagnosis in 14% to 24% of cases. This may be due to diagnostic errors or biopsy-related regression of the dysplasia. Because p16 immunohistochemical staining of cervical biopsies improves diagnostic accuracy, we hypothesized that p16-based cervical biopsy diagnoses may reduce the frequency of negative LEEPs.

MATERIALS AND METHODS

We performed a retrospective cross-sectional study of all cervical LEEPs completed at our institution from 2002 to 2012. We recorded patient age, sexual history, smoking history, pathologic diagnoses (including whether the diagnosis was p16 based), the number of days from biopsy to follow-up LEEP, and clinical follow-up. This yielded 593 study subjects meeting inclusion criteria of CIN 2+ colposcopic diagnoses with follow-up LEEP and 2 years of clinical follow-up. Colposcopic biopsies and follow-up LEEPs were reviewed and p16 immunostaining was performed on all samples to provide criterion standard results. Data were analyzed by χ and regression modeling.

RESULTS

Our practice employed p16 to aid cervical biopsy diagnoses by 2006. The frequency of negative LEEPs before 2006 was 12 (10%) of 126. The frequency dropped during the p16 era (2006-2012) to 23 (5%) of 467. Overall, we observed an inverse relationship between the frequency of p16 employment and the frequency of negative LEEP outcomes (R = 0.71; p < .001), independent of potential covariates.

CONCLUSIONS

Our data suggest that more accurate p16-based diagnoses may reduce the frequency of unnecessary LEEPs.

Usefulness of p16INK4a staining for managing histological high-grade squamous intraepithelial cervical lesions

p16^INK4a (p16) tumor-suppressor protein is a biomarker of human papillomavirus (HPV) oncogenic activity that has revealed a high rate of positivity in histological high-gade squamous intraepithelial lesion/cervical intraepithelial neoplasia grade 2 (HSIL/CIN2) lesions. However, there is a paucity of data regarding p16 status as a surrogate marker of HSIL/CIN2 evolution. The aim of this study was to evaluate the outcome of HSIL/CIN2 patients followed up without treatment for 12 months according to p16 immunohistochemical staining. Patients diagnosed with HSIL/CIN2 colposcopy-directed biopsy, were recruited prospectively between December 2011 and October 2013. p16 staining was performed in all HSIL/CIN2 diagnostic biopsies. Follow-up was conducted every 4 months by cytology, colposcopy and biopsy if suspicion of progression and once the 12 months of follow-up completed. Complete regression, partial regression, persistence, and progression rates of HSIL/CIN2 were defined as a final outcome. A total of 96 patients were included in the analysis. The rate of spontaneous regression was 64%, while 28% had persistent disease, and 8% progressed at 12 months of follow-up. p16 was positive in 81 (84%) initial HSIL/CIN2 biopsies. Regression was observed in all 15 p16 negative cases and in 46 of 81 (57%) p16 positive cases (P=0.001). In conclusion, patients with p16 negative HSIL/CIN2 biopsy had a high rate of regression during first 12 months of follow-up. Status of p16 staining could be considered for HSIL/CIN2 management.

HPV Detection Methods

Human papilloma viruses (HPVs) have been acknowledged to be the leading risk factor of cervical intra-epithelial lesion creation (CIN) and cervical cancer development (CxCa). Many different techniques have been created and utilized in HPV detection and monitoring with a vast amount of them being commercialized and few of them integrated in official screening strategies. A growing trend for DNA typing of the 14 most commonly accepted high risk HPV types has been introduced, supporting that in many cases molecular testing could replace classic morphologic diagnostic routines, even though DNA detection has lower specificity than other molecular and morphology tests. However, there have been limited attempts in combining data from all different techniques to provide efficient patient triaging schemes, since, apart from the obvious increase of patient cost, the amount of data and its interpretation in patient management has been impossible. Complex computer based clinical support decision systems, many of which are based on artificial intelligence may abolish these limitations.

Prevalence of human papillomavirus16 DNA and p16INK4a protein in oral squamous cell carcinoma: A systematic review and meta-analysis

BACKGROUND AND AIM

Indian patients with oral squamous cell carcinoma (OSCC) are etiologically associated with the use of tobacco and alcohol; yet, a proportion of tumors that may harbor human papillomavirus (HPV) infections cannot be neglected. The following meta-analysis was conducted to address the association of p16INK4a and HPV DNA with OSCC. In addition, the study also provides the updated prevalence of HPV-induced OSCC.

MATERIALS AND METHODS

Literature survey was performed using databases such as PubMed with the help of the following keywords - "HPV infection," "oral squamous cell carcinoma," "p16INK4a," "HPV DNA," "E6," "E7," "L1," "L2" and "LCR." Proportion method was performed to derive the forest plot using MedCalc statistical software version 16.4.3.

RESULTS

Among 145 research articles, 33 articles were selected for further analysis, in which 13 articles were related to HPV DNA detection in tissues, 11 articles detected the overexpression of p16INK4a and nine articles reported the detection of both HPV DNA and p16INK4a expression. Meta-analysis revealed significant heterogeneity (P < 0.0001) among the articles. Overall, the study consisted of 3339 patients with OSCC, among which 559 patients were diagnosed with the presence of HPV16 DNA with a random proportion of 20.1% at 95% confidence interval (CI) (13.9-27.1, P < 0.0001). Overexpression of p16INK4a protein was observed in 709 patients with a random proportion of 25.4% at 95% CI (14.3-38.3, P < 0.0001).

CONCLUSION

HPV DNA and expression of p16INK4a was suggested as gold standard for the detection of HPV infection in many cases of cancers. Frequency of HPV infection is significantly higher in patients with OSCC as identified through the detection of HPV DNA and p16INK4a expression. Even though the association of HPV infection has been established in head and neck cancer, this review could further the establishment of molecular level interaction of HPV in patients with oral cancer.

p16ink4 and cytokeratin 7 immunostaining in predicting HSIL outcome for low-grade squamous intraepithelial lesions: a case series, literature review and commentary

p16ink4 and cytokeratin 7 (CK7) have been proposed to identify low-grade squamous intraepithelial lesions (LSIL) at greater or lesser risk for an outcome of high-grade squamous intraepithelial lesion (HSIL). We correlated CK7 and p16ink4 staining in LSILs with outcome on follow-up and placed this information in the context of prior reports. Cervical LSIL biopsies with at least 1-year follow-up information were immunostained for CK7 and p16ink4. Follow-up outcomes included no SIL, LSIL (persistence) or HSIL (CIN2+). In all, 109 LSILs were studied and 18.3% stained positive for CK7. Ninety-one percent of CK7-negative LSILs regressed, 4.5% persisted, and 4.5% had an HSIL outcome, versus 60, 20, and 20% of CK7-positive LSILs, respectively (P=0.036). p16ink4 status did not significantly associate with outcome. Review of the literature revealed a highly variable rate of both positive p16ink4 immunoreactivity in LSIL and CIN2+ outcome for p16-positive LSIL but a consistently high negative predictive value (>90%) in the case of no/low p16 expression. Inter-observer reproducibility for the diagnosis of CIN2 in the literature ranged from poor to good, with unanimous agreement on the diagnosis of CIN2 occurring in less than 25% of cases. As with high-risk human papillomavirus testing, the most clinically useful result of p16ink4 staining is a negative test, implying no lesion or CIN1 and conferring a low risk of HSIL outcome. HSIL outcomes ('progression') are highly variable and are subject to wide differences in inter-observer interpretation for CIN2. This argues against the wisdom of relying on p16ink4 to both predict CIN2+ or upgrade CIN1 to CIN2. It also begs the question of whether CIN2 should be replaced by an alternate and less pejorative term (SIL of intermediate grade) for lesions that are not reproducibly classified as LSIL or HSIL, with an appropriate management scheme.

p16 immunostaining as a predictor of anal and cervical dysplasia in women attending a sexually transmitted infection clinic

BACKGROUND

Carcinogenesis caused by human papillomavirus (HPV) leads to over-expression of p16 protein. p16 may act as a marker of HPV integration with host genome and serve as a surrogate marker of HPV oncogenesis.

MATERIALS AND METHODS

A single center study of 75 women (35 HIV-positive and 40 HIV-negative women) was conducted. Anal and cervical specimens were obtained for cytology and p16 immunostaining.

RESULTS

The sensitivity of p16 to diagnose anal and cervical dysplasia was 50% and 58.8%, respectively, whereas specificity was 98.6% and 100%, respectively. Positive predictive value for anal and cervical was 75% and 100%, whereas negative predictive value was 95.8% and 89.2%, respectively. A strong relationship between the grade of dysplasia and intensity of p16 immunoscore was observed (Pearson correlation r = 0.666, P < 0.0001 and r = 0.496, P < 0.0001 for anal and cervical, respectively).

CONCLUSION

p16 immunostaining with greater specificity for high-grade lesions may improve the diagnostic accuracy, especially for high-grade lesions which have a high risk of progression to malignancy and thereby necessitate treatment.

The terminology of pre-invasive cervical lesions in the UK cervical screening programme

The terminology of non-invasive epithelial abnormalities associated with an elevated risk of having or developing invasive cervical carcinoma (pre-invasive lesions) has been modified frequently over time as understanding of the underlying biology, and approaches to disease management, have changed. The arguments are now converging on the conclusion that the most appropriate terminology for cervical squamous intraepithelial abnormalities should be two-tier rather than three-tier. Given the findings of the Lower Anogenital Squamous Terminology (LAST) project in the USA, which have recently been endorsed by the World Health Organisation classification of tumours of female reproductive organs, the recommended terms are low-grade and high-grade squamous intraepithelial lesion (SIL), with the option of including the relevant cervical intraepithelial neoplasia (CIN) grade in parentheses. Although, at first sight, this appears to represent only a small change, there is a fundamental conceptual difference between the systems. The CIN system requires, first, the identification of a CIN lesion and, second, the determination of its grade on a continuum, with subsequent division into three grades. The SIL system is based on the existence of two different forms of human papillomavirus (HPV) infection, with productive infection leading to low-grade SIL and transforming infection leading to high-grade SIL.

p16 overexpression in high-grade neuroendocrine carcinomas of the head and neck: potential diagnostic pitfall with HPV-related carcinomas

High-grade neuroendocrine carcinomas (HGNECs) of the head and neck have the morphological appearance of undifferentiated carcinomas and could be histologically similar to human papillomavirus (HPV)-associated non-keratinizing squamous cell carcinomas of the head and neck. The aim of the study is to characterize histologically, immunohistochemically, and virologically these unusual neoplasms. Nineteen HGNECs of the head and neck (1 oropharyngeal, 5 sinonasal, 7 of the larynx, and 6 of the parotid gland) were reviewed and analyzed with a immunohistochemical panel, with special emphasis on cell cycle proteins. The tumors were tested for HPV by in situ hybridization (GenPoint HPV, Dako) and PCR (SPF10-DEIA-LiPA25). Merkel cell polyomavirus was studied using the antibody CM2B4. Fifteen HGNEC were of small cell and 4 of large cell type. Most of the tumors (14/19, 73.7 %), including all the pure small cell carcinomas, showed a strong and diffuse positive staining for p16. Eleven of them (78.5 %) had Rb loss and a low or absent cyclin D1 expression. All cases were negative for HPV and polyomavirus. Most patients were smokers, diagnosed at advanced stages of the disease, and had a poor outcome, with a 5-year survival of 18 %. In conclusion, HGNECs of the head and neck are infrequently related to HPV infection, but usually show strong, diffuse positive p16 immunostaining due to Rb pathway dysregulation. Awareness of this immunohistochemical pattern of expression may avoid a potential diagnostic pitfall with HPV-associated non-keratinizing squamous cell carcinomas, which have a better prognosis.

Human Papillomavirus Genotyping and p16(INK4a) Expression in Cervical Lesions: A Combined Test to Avoid Cervical Cancer Progression

Cervical cancer is a major public health problem in Morocco. The cervical cancer has a long precancerous period that provides an opportunity for the screening and treatment. Improving screening tests is a priority goal for the early diagnosis of cervical cancer. This study was conducted to evaluate the combination of p16(INK4a) protein expression, human papillomavirus (HPV) typing, and histopathology for the identification of cervical lesions with high risk to progress to cervical cancer among Moroccan women. A total of 96 cervical biopsies were included in this study. Signal amplification in situ hybridization with biotinylated probes was used to detect HPV. Immunohistochemistry was used to evaluate the expression of p16(INK4a) protein. HPV DNA was detected in 74.0% of the biopsies (71/96). Of the seventy-one positive HPV cases, we detected 67.6% (48/71) of high risk (HR)-HPV (HPV 16 and 18), 24% of low risk-HPV (HPV 6 and 11), 1.4% intermediate risk-HPV (HPV 31, 33, and 35), and 7% coinfections (HPV 6/11 and 16/18). Overexpression of p16(INK4a) protein was observed in 72.9% (70/96) of the biopsies. In addition, p16(INK4a) protein detection was closely correlated with recovery of HR HPV. Our result showed that p16(INK4a) expression level is correlated with HR-HPV status.