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

Cell Block Preparation versus Liquid-Based Thin-Layer Cervical Cytology: A Comparative Study Evaluating Human Papillomavirus Testing by Hybrid Capture-2/Cervista, in situ Hybridization and p16 Immunohistochemistry

OBJECTIVE

Cell block (CB) preparations from residual liquid-based Pap samples have been shown to be of diagnostic value. In this study we evaluated human papillomavirus (HPV) in situ hybridization (ISH) and p16 immunohistochemistry (IHC) on CB preparations and compared the results with the primary diagnosis and standard HPV tests.

DESIGN

In total, 197 HE-stained CB slides prepared from CBs from residual Pap samples (152 ASCUS, 2 ASC-H, 32 LGSIL, 4 HGSIL, 1 AGUS and 6 normal) were analyzed. Hybrid Capture-2 (HC-2)/Cervista testing and HPV ISH and p16 IHC were performed on the CB samples. The test performance characteristics were compared with HPV and p16 assay performances.

RESULTS

The cellular architecture was well maintained in CBs with excellent consistency. HPV ISH testing had an excellent concordance with the HC-2/Cervista methods (85%) with high sensitivity (82.6%; 95% CI 75.9, 89.4) and specificity (89.3%). Of all the p16 tests, 38% were positive (60 out of 159 samples). The overall concordance between p16 and HC-2/Cervista (64%), or between p16 and ISH (68%), was lower than the concordance between ISH and HC-2/Cervista (85%).

CONCLUSIONS

HPV ISH and p16 IHC testing is feasible, cost effective and practical. A combination of the two tests would ultimately improve diagnostic accuracy, leading to better therapeutic decisions.

Overdiagnosis of HSIL on cervical biopsy: errors in p16 immunohistochemistry implementation

In 2012, the lower anogenital squamous terminology (LAST) project introduced new nomenclature for human papillomavirus-related squamous lesions of the lower genital tract: low-grade and high-grade squamous intraepithelial lesion (LSIL and HSIL). Biomarker p16(INK4a) immunohistochemistry (IHC) was also recommended to assist classification: block-like positive staining supports the diagnosis of HSIL. We aim to assess the impact of LAST recommendations on our practice as well as to identify challenges and errors in p16 IHC implementation. We studied 262 cervical biopsies meeting 3 criteria: (1) HSIL diagnosis; (2) p16 IHC performed at time of diagnosis; and (3) patient's follow-up more than 12 months, including cervical cytology, biopsy, and excision. Among these patients, subsequent loop electrosurgical excision procedure and surveillance revealed 163 HSILs (62%), 28 LSILs (11%), and 71 "nondysplastic changes" (27%). We reviewed the latter 2 groups' original hematoxylin and eosin and p16 IHC slides. The diagnosis of HSIL was confirmed in 49 cases (49%), whereas 50 (51%) were reclassified as LSIL (n=46) or negative for dysplasia (n=4). These cases were initially overdiagnosed as HSIL because pathologists (1) overused p16 IHC on unequivocal LSIL (n=27) or (2) upgraded questionable lesions to HSIL based on nonblock p16 staining patterns (patchy or focal, n=23). To implement LAST recommendations successfully, we advocate judicious use of p16 in the designated circumstances and careful interpretation of staining patterns in the context of morphology. A standardized threshold for p16 positivity and supplementary guidance will help clarify the biomarker's utility and will facilitate LAST implementation in routine practice.

Effect of Lower Anogenital Squamous Terminology Recommendations on the Use of p16 Immunohistochemistry and the Proportion of High-Grade Diagnoses in Cervical Biopsy Specimens

OBJECTIVES

The Lower Anogenital Squamous Terminology (LAST) group has recommended that cervical intraepithelial neoplasia (CIN) terminology be replaced by squamous intraepithelial lesion (SIL) terminology, with p16 immunohistochemistry used to separate lesions formerly diagnosed as CIN grade 2 into high-grade SILs (HSILs) and low-grade SILs. This study investigated the impact of these changes on the frequency of p16 testing and the diagnosis of high-grade lesions.

METHODS

Pathology reports for all cervical biopsy specimens in the 1 year before and after the introduction of LAST recommendations (July 2011 to June 2013) were examined.

RESULTS

Before and after the implementation of LAST, 365 (15.4%) of 2,376 cases were diagnosed as high grade (CIN 2/3) vs 486 (17.6%) of 2,761 cases diagnosed as HSILs (P = .0343), and p16 was performed 79 (3.3%) times vs 383 (13.9%) times (P < .0001).

CONCLUSIONS

Immunohistochemistry for p16 increased dramatically as a result of LAST recommendations, and high-grade diagnoses increased.

The Asian-American variant of human papillomavirus type 16 exhibits higher activation of MAPK and PI3K/AKT signaling pathways, transformation, migration and invasion of primary human keratinocytes

Asian-American (AA) HPV-16 variants are associated with higher risk of cancer. Abnormal activation of intracellular signaling play a critical role in cancer development and progression. Our aim was to elucidate mechanisms underlying the higher oncogenic potential attributed to AA variant. We evaluated activation of MAPK and PI3K/AKT pathways in primary human keratinocytes (PHKs) transduced with E6/E7 of three HPV-16 variants: E-P, AA, E-350G. Phenotypes examined included migration, anchorage independent growth and invasion. AA PHKs presented the highest levels of active proteins involved in all cascades analyzed: MAPK-ERK, MAPK-p38 and PI3K-AKT. AA PHKs were more efficient in promoting anchorage independent growth, and in stimulating cell migration and invasion. MEK1 inhibition decreased migration. The mesenchymal phenotype marker vimentin was increased in AA PHKs. Our results suggest that MEK1, ERK2, AKT2 hyperactivation influence cellular behavior by means of GSK-3b inactivation and EMT induction prompting AA immortalized PHKs to more efficiently surpass carcinogenesis steps.

Role of the Biomarker p16 in Downgrading -IN 2 Diagnoses and Predicting Higher-grade Lesions

In 2012, the College of American Pathologists and American Society for Colposcopy and Cervical Pathology published the "LAST" recommendations for histopathology reporting of human papilloma virus-related squamous lesions of the lower anogenital tract, including the use of a 2-tier nomenclature (low-grade squamous intraepithelial lesion/high-grade squamous intraepithelial lesion [LSIL/HSIL]) and expanded use of the biomarker p16 to classify equivocal lesions as either precancer (HSIL) or low-grade lesions (LSIL)/non-human papilloma virus changes. We aimed to determine (1) the frequency with which the poorly reproducible diagnosis of intermediate-grade (-IN 2) lesion in the lower anogenital tract would be downgraded on the basis of p16 results, and (2) whether p16 status was predictive of subsequent higher-grade lesions. A total of 200 specimens diagnosed as an intermediate-grade (-IN 2) lesion of the cervix (168), vagina (2), vulva (2), and anus (28) were reviewed and immunostained for p16. Slides were independently reviewed by 2 pathologists, with discrepant p16 interpretations adjudicated by a third pathologist. Of the 200 cases, 32% were negative for p16. Among the 166 patients with subsequent pathology (including 131 excisions), 26.2% of p16-positive cases versus 4.4% of p16-negative cases were associated with a subsequent diagnosis of HSIL (-IN 3) or worse (P=0.002). Reproducibility of the biopsy diagnosis was fair, with no significant difference with the addition of p16 or using 2 versus 3 tiers. In 11.5% of cases, there was discordance in p16 interpretation (κ 0.735, good agreement). The results indicate that using the Lower Anogenital Squamous Terminology recommendations would result in approximately one third of equivocal (-IN 2) diagnoses being downgraded to LSIL over 1 year in a busy academic practice. The significant association of p16 expression with a higher risk for HSIL on a subsequent specimen suggests that use of p16 to adjudicate equivocal (-IN 2) diagnoses in lower anogenital tract specimens as either LSIL or HSIL would likely predict lesion grade more accurately and avoid unnecessary excisional procedures.

Efficacy of p16 and Ki-67 immunostaining in the detection of squamous intraepithelial lesions in a high-risk HPV group

p16 and Ki-67 immunohistochemistry can be used as an ancillary method for the diagnosis of squamous intraepithelial lesion (SIL) versus atrophic change and atypical squamous metaplasia. The aim of the present study was to evaluate the efficacy of these two immunohistochemical markers in the accurate interpretation of cervical biopsies and correlate this data with human papilloma virus (HPV) infection status. The study included 103 formalin-fixed cervical punch and cone biopsy samples, with corresponding HPV DNA test data. Histopathological staining with hematoxylin and eosin, and immunohistochemical staining for p16 and Ki-67 were reviewed by two pathologists. The positivity of p16 and Ki-67 increased significantly with the severity of the cervical lesion in patients with a high-risk-HPV (HR-HPV) infection status (P<0.001). However, there was discordance in the HPV-negative group. Furthermore, concomitant diffuse, strong and block positive staining of p16, and a high Ki-67 index were implicated in high-grade SIL in the HR-HPV group. Thus, the two markers were efficient in advancing the diagnostic accuracy of cervical biopsies in the HR-HPV group; however, application of immunohistochemical results should be carefully considered in the HPV-negative group.

The role of P16ink4a and P53 immunostaining in predicting recurrence of HG-CIN after conization treatment

Objective: Io evaluate the expression of p16INK4a and p53 biomarkers in conization specimens from patients with high grade cervical intraepithelial neoplasia (HG-CIN), correlating them with the ability to predict the recurrence. Methods : we conducted a retrospective study of patients with HG-CIN in cervical biopsy treated with conization between January 1999 and January 2006 who had a minimum follow-up of 18 months. The expression of the p16 and p53 was assessed by tissue microarrays and correlated with disease recurrence. For analysis, we used the test of proportions (chi-square), considering value p<0.05, 95% CI and calculations of sensitivity, specificity and accuracy of these immunomarkers in predicting recurrence. Results : the series comprised 83 patients aged between 16 and 86 years (35±11.7), divided into two groups: 30 with HG-CIN recurrence (study group) and 53 without recurrence (control group). Mean age, parity, smoking and conization technique were similar in both groups. The p53 expression was present in 43% of the study group and 57% of the control group, and the p16 was present in 43% of the study group and in 57% of the control group (p>0.05). p53 had a positive predictive value (PPV) of 42% and negative predictive value (NPV) of 73%, sensitivity 70%, specificity of 47% and accuracy of 59%. The p16, PPV 42%, NPV 72%, sensitivity 66%, specificity of 49% and accuracy of 56%. Conclusion : immunohistochemistry expression of p53 and p16 showed low sensitivity and low specificity as predictors of HG-CIN recurrence after conization treatment.

Efficacy of p16 and Ki-67 immunostaining in the detection of squamous intraepithelial lesions in a high-risk HPV group

p16 and Ki-67 immunohistochemistry can be used as an ancillary method for the diagnosis of squamous intraepithelial lesion (SIL) versus atrophic change and atypical squamous metaplasia. The aim of the present study was to evaluate the efficacy of these two immunohistochemical markers in the accurate interpretation of cervical biopsies and correlate this data with human papilloma virus (HPV) infection status. The study included 103 formalin-fixed cervical punch and cone biopsy samples, with corresponding HPV DNA test data. Histopathological staining with hematoxylin and eosin, and immunohistochemical staining for p16 and Ki-67 were reviewed by two pathologists. The positivity of p16 and Ki-67 increased significantly with the severity of the cervical lesion in patients with a high-risk-HPV (HR-HPV) infection status (P<0.001). However, there was discordance in the HPV-negative group. Furthermore, concomitant diffuse, strong and block positive staining of p16, and a high Ki-67 index were implicated in high-grade SIL in the HR-HPV group. Thus, the two markers were efficient in advancing the diagnostic accuracy of cervical biopsies in the HR-HPV group; however, application of immunohistochemical results should be carefully considered in the HPV-negative group.

A decision support system based on an ensemble of random forests for improving the management of women with abnormal findings at cervical cancer screening

In most cases, cervical cancer (CxCa) develops due to underestimated abnormalities in the Pap test. Today, there are ancillary molecular biology techniques available that provide important information related to CxCa and the Human Papillomavirus (HPV) natural history, including HPV DNA tests, HPV mRNA tests and immunocytochemistry techniques such as overexpression of p16. These techniques are either highly sensitive or highly specific, however not both at the same time, thus no perfect method is available today. In this paper we present a decision support system (DSS) based on an ensemble of Random Forests (RFs) for the intelligent combination of the results of classic and ancillary techniques that are available for CxCa detection, in order to exploit the benefits of each technique and produce more accurate results. The proposed system achieved both, high sensitivity (86.1%) and high specificity (93.3%), as well as high overall accuracy (91.8%), in detecting cervical intraepithelial neoplasia grade 2 or worse (CIN2+). The system's performance was better than any other single test involved in this study. Moreover, the proposed architecture of employing an ensemble of RFs proved to be better than the single classifier approach. The presented system can handle cases with missing tests and more importantly cases with inadequate cytological outcome, thus it can also produce accurate results in the case of stand-alone HPV-based screening, where Pap test is not applied. The proposed system may identify women at true risk of developing CxCa and guide personalised management and therapeutic interventions.

A prospective randomized study on limits of colposcopy and histology: the skill of colposcopist and colposcopy-guided biopsy in diagnosis of cervical intraepithelial lesions

BACKGROUND

The main objective of our study was to evaluate the colposcopist ability to correctly identify the worst area of a cervical lesion where biopsy should be performed; the secondary objective was to investigate the influence of the colposcopist skill in grading cervical preneoplastic lesions.

METHODS

296 patients referred for colposcopy were enrolled in a prospective study. All patients were randomized in two groups: in the first group, "senior group", the colposcopy was performed by an experienced colposcopist; in the second group, "junior group", the colposcopy was performed by a less experienced colposcopist. A detailed colposcopic description, including a grading of the lesion, was completed for each case. During the colposcopic exam patients underwent two direct biopsies; each biopsy was labeled with letter A (suspicious area with most severe grade) or B (suspicious area with less severe grade) according to the judgment of the colposcopist. An experienced pathologist reanalyzed the histological slides, after routine diagnosis.

RESULTS

The senior group identify the worst area of the cervical lesion in statistical significant higher rates than junior group. Specimen A resulted representative of the higher-grade lesion (A > B) in 73.7 % (N = 28) in senior group and in 48.4 % (N = 15) in junior group; while in 26.3 % (N = 10) the higher-grade lesion corresponded to specimen B (A < B) in senior group and in 51.6 % (N = 16) in junior group (p < .05).

CONCLUSION

The ability of a colposcopist in grading cervical lesion depends on his experience.

The Application of Classification and Regression Trees for the Triage of Women for Referral to Colposcopy and the Estimation of Risk for Cervical Intraepithelial Neoplasia: A Study Based on 1625 Cases with Incomplete Data from Molecular Tests

OBJECTIVE

Nowadays numerous ancillary techniques detecting HPV DNA and mRNA compete with cytology; however no perfect test exists; in this study we evaluated classification and regression trees (CARTs) for the production of triage rules and estimate the risk for cervical intraepithelial neoplasia (CIN) in cases with ASCUS+ in cytology.

STUDY DESIGN

We used 1625 cases. In contrast to other approaches we used missing data to increase the data volume, obtain more accurate results, and simulate real conditions in the everyday practice of gynecologic clinics and laboratories. The proposed CART was based on the cytological result, HPV DNA typing, HPV mRNA detection based on NASBA and flow cytometry, p16 immunocytochemical expression, and finally age and parous status.

RESULTS

Algorithms useful for the triage of women were produced; gynecologists could apply these in conjunction with available examination results and conclude to an estimation of the risk for a woman to harbor CIN expressed as a probability.

CONCLUSIONS

The most important test was the cytological examination; however the CART handled cases with inadequate cytological outcome and increased the diagnostic accuracy by exploiting the results of ancillary techniques even if there were inadequate missing data. The CART performance was better than any other single test involved in this study.

Novel p16 binding peptide development for p16-overexpressing cancer cell detection using phage display

Protein p(16INK4a) (p16) is a well-known biomarker for diagnosis of human papillomavirus (HPV) related cancers. In this work, we identify novel p16 binding peptides by using phage display selection method. A random heptamer phage display library was screened on purified recombinant p16 protein-coated plates to elute only the bound phages from p16 surfaces. Binding affinity of the bound phages was compared with each other by enzyme-linked immunosorbent assay (ELISA), fluorescence imaging technique, and bioinformatic computations. Binding specificity and binding selectivity of the best candidate phage-displayed p16 binding peptide were evaluated by peptide blocking experiment in competition with p16 monoclonal antibody and fluorescence imaging technique, respectively. Five candidate phage-displayed peptides were isolated from the phage display selection method. All candidate p16 binding phages show better binding affinity than wild-type phage in ELISA test, but only three of them can discriminate p16-overexpressing cancer cell, CaSki, from normal uterine fibroblast cell, HUF, with relative fluorescence intensities from 2.6 to 4.2-fold greater than those of wild-type phage. Bioinformatic results indicate that peptide 'Ser-His-Ser-Leu-Leu-Ser-Ser' binds to p16 molecule with the best binding score and does not interfere with the common protein functions of p16. Peptide blocking experiment shows that the phage-displayed peptide 'Ser-His-Ser-Leu-Leu-Ser-Ser' can conceal p16 from monoclonal antibody interaction. This phage clone also selectively interacts with the p16 positive cell lines, and thus, it can be applied for p16-overexpressing cell detection.

P16(INK⁴a) overexpression is associated with CDKN2A mutation and worse prognosis in HPV-negative laryngeal squamous cell carcinomas

We studied the expression of p16(INK4a) in a series of HPV-negative laryngeal squamous cell carcinomas and assessed its association with prognosis. Forty-five patients with laryngeal carcinoma were included in the study. Clinicopathological features and prognosis were reviewed. p16(INK4a) protein expression was analysed through immunohistochemistry. We analysed messenger RNA (mRNA) in 25 cases through quantitative reverse transcription polymerase chain reaction. HPV status was assessed by PCR using three different protocols based on MY09/11 and GP5/6 primers. Four out of 45 (9 %) cases overexpressed p16(INK4a) protein and showed a tendency to worse survival that was significant for stages I-III (log-rank p value = 0.001). Expression of p16(INK4a) mRNA was high in 12 out of 25 (48 %) cases using an arbitrary cut-off level. All tumours were HPV negative with all three detection methods. A CDKN2A mutation was found in eight cases. One case with a missense and one with a frameshift mutation showed p16(INK4a) protein expression by immunohistochemistry. Six out of seven (86 %) mutated but only 6 out of 18 (33 %) non-mutated cases presented p16(INK4a) mRNA overexpression (p = 0.03). Our findings suggest that p16(INK4a) overexpression, both at protein and mRNA levels, may reflect CDKN2A genetic alterations in HPV-negative laryngeal squamous cell carcinomas.

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.

HPV-type distribution and reproducibility of histological diagnosis in cervical neoplasia in Poland

This study was performed to assess attribution of high grade cervical intraepithelial neoplasia (HG-CIN) and invasive cervical cancer (ICC) to human papillomavirus (HPV) genotypes and secondarily to assess reproducibility of HG-CIN/ICC diagnosis obtained in Poland. Formaldehyde fixed, paraffin embedded blocks of HG-CIN/ICC from two distant institutions were sent to a central laboratory together with original histological diagnoses. Central/expert review of histopathological specimens was performed and agreement between local and central/expert diagnoses was calculated. HPV detection and genotyping in the samples was carried out with the use of SPF10-LiPA25 technology. Results were analyzed for 205 HG-CIN and 193 ICC cases with centrally confirmed diagnoses. Kappa coefficients and 95 % confidence intervals for HG-CIN and ICC diagnoses were: 0.13 (0.09;0.17) and 0.19 (0.11;0.26) respectively. Cohen’s kappa coefficients for lesions with representative number of samples ranged from 0.01 for cervical intraepithelial neoplasia grade 2 to 0.75 for adenocarcinoma. HPV DNA was detected in 96.1 and 91.2 % of the confirmed HG-CIN and ICC specimens respectively. HPV positive HG-CIN was most commonly attributed to HPV types: 16 (62.8), 33 (7.8), 31 (6.6), 52 (3.7), 45 (2.6) and 58 (2.6 %). HPV positive ICC was most commonly attributed to HPV types: 16 (72.1), 18 (10.8), 33 (5.7), 45 (3.4) and 31 (1.7 %). Reproducibility of histological diagnosis of HG-CIN/ICC obtained in Poland generally increases with the severity of lesion and is lowest for cervical intraepithelial neoplasia grade 2 and highest for adenocarcinoma. Over 80 % of ICC cases are vaccine-preventable in Poland.

p16INK4a immunohistochemistry in cervical biopsy specimens: A systematic review and meta-analysis of the interobserver agreement

OBJECTIVES

The interpretation of cervical biopsy specimens guides management of women with suspected cervical cancer precursors. However, morphologic evaluation is subjective and has low interobserver agreement. Addition of p16(INK4a) immunohistochemistry may improve interpretation.

METHODS

We performed a systematic review and meta-analysis of published data on interobserver agreement of p16(INK4a) positivity using p16(INK4a) immunohistochemistry and of cervical intraepithelial neoplasia grade 2 (CIN2+) and CIN grade 3 (CIN3+) classification using H&E morphology in conjunction with p16(INK4a) in comparison with H&E morphology alone.

RESULTS

The literature search revealed five eligible articles. The results show strong agreement of pathologists' interpretation of cervical biopsy specimens as p16(INK4a) positive or negative (pooled κ = 0.90; 95% confidence interval [CI], 0.88-0.92) and significantly higher agreement for a CIN2+ diagnosis with H&E morphology in conjunction with p16(INK4a) (κ = 0.73; 95% CI, 0.67-0.79) compared with H&E morphology alone (κ = 0.41; 95% CI, 0.17-0.65). Also, a slightly higher agreement for CIN3+ can be observed (κ = 0.66; 95% CI, 0.39-0.94 for H&E morphology in conjunction with p16(INK4a) and κ = 0.61; 95% CI, 0.44-0.78 for H&E morphology alone), but this difference was not statistically significant.

CONCLUSIONS

The published literature indicates improved interobserver agreement of the diagnosis of CIN2+ with the conjunctive use of H&E morphology with p16(INK4a) immunohistochemistry compared with H&E morphology alone.

Expression of P16 in high-risk human papillomavirus related lesions of the uterine cervix in a government hospital, Malaysia

Background

Cervical cancer is one of the most common cancers affecting women worldwide. It is well established that human papilloma virus (HPV) infection is the prime risk factor in the development of cervical cancer. The current screening and diagnostic tests have limitations in identifying the range of lesions caused by HPV. The current study aims to evaluate the diagnostic value of p16 immunohistochemical (IHC) investigation in high-risk human papillomavirus (HR-HPV) related lesions of the uterine cervix in Hospital Tuanku Jaafar, Seremban, Malaysia.

Methods

A total of 75 cases were selected from the records of Pathology services, Hospital Tuanku Ja’afar, Seremban. The samples were collected in three separate groups (n = 25 per group) as Carcinoma cervix, Carcinoma in situ and Chronic cervicitis. The demographic data of the patients and the representative paraffin blocks were retrieved from Hospital Tuanku Ja’afar, Seremban. The immunohistochemical staining with p16 and HPV 16 L1 were done on all cases. The staining intensity and density were observed and compared among the three groups of cases.

Results

Immunohistochemistry of p16INK4A staining shows nil (0/25) expression in the cervicitis patients, 72% (18/25) in CIN patients and 100% (25/25) in cervical carcinoma. HPV 16 L1 was positive in 100% (25/25) of cervicitis patients, 96% (24/25) of CIN patients and 40% (10/25) of cervical cancers patients. A chi square test was used to analyze the result and the obtained p value was <0.05.

Conclusion

p16 expression was strongly observed in cervical cancer and minimally observed in cervicitis. Thus indicating p16 immunohistochemistry investigations can aid in diagnosing the different categories of cervical lesions into benign, insitu and malignant.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_202

Histopathogenesis of non-HPV-related differentiated oral squamous intraepithelial neoplasia

INTRODUCTION

A study of immunohistopathologic and cytohistopathologic changes of the parabasal/basal layers in the differentiated squamous intraepithelial neoplasia (DSIN) may elucidate the histopathogenesis and reveal changes aiding early diagnosis and grading of the lesion.

MATERIALS AND METHODS

A total of 55 consecutive resection specimens of nonbasaloid squamous cell carcinoma of the anterior oral cavity and 8 biopsies before resections displaying DSIN in the overlying squamous epithelium were examined.

RESULTS

Squamous epithelium that is continuous/immediately adjacent to invasive squamous cell carcinoma (type 1) and the more peripheral (type 2) epithelium of resection specimens displayed consistent changes in the parabasal/basal layers: (A) cytologic atypia with proliferation of parabasal cells with downward expansion causing reactive proliferation of the basal cell layer in the early stage, invading the basal layer in the late stage; (B) disordered nuclear/cytoplasmic arrangement; (C) "Cobblestone" appearance. Immunoreactivity for TP53 and Ki67 was helpful in the diagnosis. The epithelial spectrum of changes decreased as one moved from type 1 to type 2 lesions. Five out of 8 biopsies showed type 1 lesions (followed by resection in a period of 11±6 mo) and 3 showed type 2 lesions (followed by resection in a period of 55±20 mo). In addition, resections were margin positive for type 2 lesions in 5 cases associated with recurrence at the site of resection during a period of 69±9 months.

CONCLUSIONS

DSIN is characterized by a proliferation of neoplastic parabasal cells with dyskeratosis, downward expansion/pushing of the basal layer with elongation of rete ridges. We proposed grading of DSIN based on the changes of the parabasal/basal layers.

HPV-related squamous neoplasia of the lower anogenital tract: an update and review of recent guidelines

Squamous cell carcinomas of the lower anogenital tract that are related to human papillomavirus (HPV) infection represent a significant disease burden worldwide. The diagnosis and management of their noninvasive precursors has been the subject of extensive study and debate over several decades, accompanied by an evolving understanding of HPV biology. Recent new consensus recommendations for the pathologic diagnosis of these precursor lesions were published in 2012, the result of the Lower Anogenital Squamous Terminology project cosponsored by the College of American Pathologists and the American Society for Colposcopy and Cervical Pathology. Most salient among the new guidelines are the recommendation to switch to a 2-tiered nomenclature (high-grade squamous intraepithelial lesion and low-grade squamous intraepithelial lesion) rather than the traditional 3-tiered "intraepithelial neoplasia" terminology, and the recommendation to expand use of the immunohistochemical marker p16 to distinguish between low-grade squamous intraepithelial lesion and high-grade squamous intraepithelial lesion/intraepithelial neoplasia 2. The goals of the project were to align diagnostic terminology with our knowledge of HPV biology, increase reproducibility, consolidate diverse systems of nomenclature, and ultimately better determine a patient's true cancer risk. The clinical guidelines for screening and management of cervical intraepithelial neoplasia have also been recently updated, most notably with a lengthening of screening intervals. In this review, we focus on the new guidelines put forth for pathologic diagnosis of HPV-related anogenital neoplasia, with discussion of the evidence behind them and their potential implications. We also provide an update on relevant biomarkers, clinical recommendations, and the newest developments relating to cervical neoplasia.

Improved abnormal Pap smear triage using cervical cancer biomarkers

OBJECTIVE

The current system of Pap smear screening and management of abnormal cytology has resulted in a marked reduction in invasive cervical cancer. Many women, however, are not found to have significant precursor lesions. This is due to the poor specificity of high-risk human papillomavirus (HPV) triage. More specific cervical cancer biomarkers may be more effective triage tools than hr-HPV. We evaluated whether a dual stain for p16 and Ki-67 might improve the triage of abnormal Pap smears.

MATERIALS AND METHODS

p16/Ki-67 immunostaining was performed on additional slides prepared from 515 women with abnormal Pap smears (301 atypical squamous cells of undetermined significance [ASCUS], 169 low-grade squamous intraepithelial lesion [LSIL], 29 atypical squamous cells-cannot exclude high-grade lesion [ASC-H], 16 high-grade squamous intraepithelial lesion [HSIL]). High-risk HPV typing was performed on all cases. Immunostaining and hr-HPV were compared in relation to their diagnostic accuracy for the detection of biopsy-proven cervical intraepithelial neoplasia (CIN) 2/3. A cost analysis comparing hr-HPV versus immunostaining as the initial triage tool used for abnormal Pap smears was also performed.

RESULTS

High-risk HPV was positive in 127 (42.2%) ASCUS, 129 (76.3%) LSIL, 20 (69.0%) ASC-H, and 15 (93.8%) HSIL. p16/Ki-67 was positive in 54 (17.9%) ASCUS, 73 (43.2%) LSIL, 19 (65.5%) ASC-H, and 15 (93.8%) HSIL. For detection of CIN 2/3, sensitivity/specificity of hr-HPV and p16/Ki-67 was 89.29%/14.94% and 96.43%/60.92%, respectively. Overall, diagnostic accuracy was statistically significantly higher for p16/Ki-67 compared with hr-HPV. Compared to HPV, immunostain triage could have generated approximately $46,000 savings in the study population.

CONCLUSIONS

The triage of abnormal Pap smears by p16/Ki-67 immunostaining shows comparable sensitivity, improved specificity, and significantly improved diagnostic performance when compared to hr-HPV. Immunostaining is of value in triaging LSIL and ASC-H Pap smears in addition to ASCUS. The widespread utilization of biomarker triage could result in significant health care cost savings without compromising the detection of significant cervical cancer precursors.

Methylated ZNF582 gene as a marker for triage of women with Pap smear reporting low-grade squamous intraepithelial lesions - a Taiwanese Gynecologic Oncology Group (TGOG) study

OBJECTIVE

Our previous work revealed that host genes ZNF582, PTPRR, PAX1, and SOX1 are highly methylated in cervical intraepithelial neoplasias grade 3 or worse (CIN3(+)). In this study, we used a standardized testing assay to evaluate the clinical efficacy of these biomarkers in the triage of cytological diagnoses of low-grade squamous intraepithelial lesions (LSILs), and compared the performance with human papillomavirus (HPV) testing.

METHODS

This 2-year multicenter prospective study examined a population of 230 women from 12 medical centers who were diagnosed with LSILs on cervical cytology. Cervical scrapings were obtained prior to a colposcopy-directed biopsy for quantitative methylation analysis of ZNF582, PTPRR, PAX1, and SOX1, and HPV testing. Using logistic regression and receiver operating characteristic curve analyses, the abilities of methylated genes and HPV to predict CIN3(+) were assessed.

RESULTS

Fifteen (6.5%) of the 230 women with a cytological diagnosis of LSIL were confirmed to have CIN3(+) after a colposcopy-directed biopsy. Among the 4 methylated genes, ZNF582 was found to be the best biomarker for detecting CIN3(+). The sensitivities for methylated ZNF582 and HPV testing were 73% and 80%, and the specificities were 71% and 28%, respectively. The odds ratio for predicting CIN3(+) using methylated ZNF582 was 6.8 (95% confidence interval (CI) 2.1-22.1), which was much better than HPV testing (OR=1.6, 95% CI 0.4-5.8).

CONCLUSION

This is the first study to show that ZNF582 methylation analysis of cervical swabs may be a promising choice in the positive triage of cytological diagnoses of LSILs.

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

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

Assessment of correlation between p16INK4a staining, specific subtype of human papillomavirus, and progression of LSIL/CIN1 lesions: first comparative study

OBJECTIVES

To study and compare the effectiveness of p16(INK4a) staining and specific human papillomavirus (HPV) subtypes as a prognostic marker in cervical intraepithelial neoplasia grade 1 (CIN1; low-grade squamous intraepithelial lesions).

METHODS

Sixty-four cervical samples diagnosed as CIN1 and stained with p16(INK4a), with HPV status assessed by polymerase chain reaction-direct sequencing.

RESULTS

Of the 34 p16(INK4a)-negative biopsy specimens, 26 regressed, seven persisted, and one progressed. Of the 20 p16(INK4a) diffusely positive biopsy specimens, seven regressed, eight persisted, and five progressed. Ten biopsy specimens stained positive only in the lower one-third of the sample, of which seven regressed and three persisted. p16(INK4a) diffusely positive CIN1 lesions were associated with only high-risk HPV subtypes, with the exception of one HPV-negative biopsy specimen. Three different high-risk HPV subtypes and one low-risk HPV subtype (HPV66) were identified in the six CIN1 lesions that progressed.

CONCLUSIONS

There is a significant relationship between p16(INK4a) immunostaining and follow-up (P = .002). p16(INK4a)-negative specimens or positivity in the lower one-third of CIN1 lesions seldom progress to a CIN2-3 lesion.

The clinical impact of using p16(INK4a) immunochemistry in cervical histopathology and cytology: an update of recent developments

Cervical cancer screening test performance has been hampered by either lack of sensitivity of Pap cytology or lack of specificity of Human Papillomavirus (HPV) testing. This uncertainty can lead to unnecessary referral and treatment, which is disturbing for patients and increases costs for health care providers. The identification of p16(INK4a) as a marker for neoplastic transformation of cervical squamous epithelial cells by HPVs allows the identification of HPV-transformed cells in histopathology or cytopathology specimens. Diagnostic studies have demonstrated that the use of p16(INK4a) immunohistochemistry substantially improves the reproducibility and diagnostic accuracy of histopathologic diagnoses. p16(INK4a) cytology has substantially higher sensitivity for detection of cervical precancer in comparison to conventional Pap tests. Compared to HPV DNA tests, immunochemical detection of p16(INK4a) -stained cells demonstrates a significantly improved specificity with remarkably good sensitivity. About 15 years after the initial observation that p16(INK4a) is overexpressed in HPV-transformed cells we review the accumulated clinical evidence suggesting that p16(INK4a) can serve as a useful biomarker in the routine diagnostic work up of patients with HPV infections and associated lesions of the female anogenital tract.

The expression patterns of p53 and p16 and an analysis of a possible role of HPV in primary adenocarcinoma of the urinary bladder

BACKGROUND

Primary adenocarcinoma of the urinary bladder is rare. The molecular and cellular events leading to its pathogenesis are not well delineated. The goal of this study was to investigate p53 and p16 expression, as well as HPV status, in a relatively large series of primary bladder adenocarcinomas.

MATERIALS AND METHODS

Thirty six cases of urinary bladder adenocarcinoma were chosen from participating institutions. The diagnosis and available clinical history were reviewed in each case. Immunostains for p53, p16 and HPV and high-risk and low-risk HPV-ISH were performed on all tumors.

RESULTS

Patients had an average age of 61 years with a male predominance (1.5 ∶ 1 male ∶ female ratio). The average tumor size in cystectomy specimens was 4.3 cm. Of the cases managed by transurethral resection, 40% were pT2 at the time of diagnosis. In cystectomy specimens, 77% were either pT3 or pT4. Strong nuclear p16 expression was seen in 67% of all cases and p53 expression was present in 58% of the cases. Expression of both markers was seen in 33% of cases. Expression of p16 or p53 alone was present in 12 (33%) and 9 (25%) cases, respectively. Neither marker was expressed in only 3 (8%) of the tumors. No significant correlation between clinical variables and any of the markers we studied was identified. No HPV infection was detected in any case.

CONCLUSIONS

Expression of p53 and/or p16 is very common in urinary bladder adenocarcinoma. These findings implicate a high likelihood that alterations in these cell cycle proteins contribute to the pathogenesis of these tumors. Despite frequent immunohistochemical labeling for p16, no evidence of HPV infection was found.

An intelligent clinical decision support system for patient-specific predictions to improve cervical intraepithelial neoplasia detection

Nowadays, there are molecular biology techniques providing information related to cervical cancer and its cause: the human Papillomavirus (HPV), including DNA microarrays identifying HPV subtypes, mRNA techniques such as nucleic acid based amplification or flow cytometry identifying E6/E7 oncogenes, and immunocytochemistry techniques such as overexpression of p16. Each one of these techniques has its own performance, limitations and advantages, thus a combinatorial approach via computational intelligence methods could exploit the benefits of each method and produce more accurate results. In this article we propose a clinical decision support system (CDSS), composed by artificial neural networks, intelligently combining the results of classic and ancillary techniques for diagnostic accuracy improvement. We evaluated this method on 740 cases with complete series of cytological assessment, molecular tests, and colposcopy examination. The CDSS demonstrated high sensitivity (89.4%), high specificity (97.1%), high positive predictive value (89.4%), and high negative predictive value (97.1%), for detecting cervical intraepithelial neoplasia grade 2 or worse (CIN2+). In comparison to the tests involved in this study and their combinations, the CDSS produced the most balanced results in terms of sensitivity, specificity, PPV, and NPV. The proposed system may reduce the referral rate for colposcopy and guide personalised management and therapeutic interventions.

Keratin 17 in premalignant and malignant squamous lesions of the cervix: proteomic discovery and immunohistochemical validation as a diagnostic and prognostic biomarker

Most previously described immunohistochemical markers of cervical high-grade squamous intraepithelial lesion (HSIL) and squamous cell carcinoma may help to improve diagnostic accuracy but have a minimal prognostic value. The goals of the current study were to identify and validate novel candidate biomarkers that could potentially improve diagnostic and prognostic accuracy for cervical HSIL and squamous cell carcinoma. Microdissected tissue sections from formalin-fixed paraffin-embedded normal ectocervical squamous mucosa, low-grade squamous intraepithelial lesion (LSIL), HSIL and squamous cell carcinoma sections were analyzed by mass spectrometry-based shotgun proteomics for biomarker discovery. The diagnostic specificity of candidate biomarkers was subsequently evaluated by immunohistochemical analysis of tissue microarrays. Among 1750 proteins identified by proteomic analyses, keratin 4 (KRT4) and keratin 17 (KRT17) showed reciprocal patterns of expression in the spectrum of cases ranging from normal ectocervical squamous mucosa to squamous cell carcinoma. Immunohistochemical studies confirmed that KRT4 expression was significantly decreased in squamous cell carcinoma compared with the other diagnostic categories. By contrast, KRT17 expression was significantly increased in HSIL and squamous cell carcinoma compared with normal ectocervical squamous mucosa and LSIL. KRT17 was also highly expressed in immature squamous metaplasia and in endocervical reserve cells but was generally not detected in mature squamous metaplasia. Furthermore, high levels of KRT17 expression were significantly associated with poor survival of squamous cell carcinoma patients (Hazard ratio=14.76, P=0.01). In summary, both KRT4 and KRT17 expressions are related to the histopathology of the cervical squamous mucosa; KRT17 is highly overexpressed in immature squamous metaplasia, in HSIL, and in squamous cell carcinoma and the level of KRT17 in squamous cell carcinoma may help to identify patients who are at greatest risk for cervical cancer mortality.

High-risk human papillomavirus is transcriptionally active in a subset of sinonasal squamous cell carcinomas

It has been reported that high-risk human papillomavirus (HPV) is a causative agent of a subgroup of oropharyngeal carcinomas. In these tumors, the presence of the transcriptionally active HPV has been proved through the identification of HPV E6 or E7 messenger RNA (mRNA) transcripts. The aim of the study was to assess the HPV-active transcription in a series of sinonasal carcinomas, in correlation with the HPV DNA identification and the p16 immunohistochemistry. Seventy patients with squamous cell carcinomas of the sinonasal tract were included in the survey. The main clinicopathological characteristics were recorded. All tumors were investigated for HPV through the HPV DNA detection by PCR, using the SPF10 primers and by in situ hybridization, using the high-risk GenPoint probe (Dako, Glostrup, Denmark). HPV16 E7 mRNA transcripts detection was performed by RT-PCR in 27 cases. The immunostaining for p16 was performed in all cases. Fourteen carcinomas (20%) were positive for high-risk HPV by PCR: 13 HPV16 and one HPV35. In situ hybridization showed a dotted nuclear positivity in all these cases. HPV16 E7 mRNA was detected in seven tumors harboring HPV16; in the remaining HPV-positive cases, RNA did not reach the quality for analysis. Strong, diffuse positivity for p16 was observed only in the HPV-positive cases. The 14 HPV-positive squamous cell carcinomas were non-keratinizing or scarcely keratinizing tumors. No significant differences were found in terms of gender, age, or staging at diagnosis between HPV-positive and HPV-negative tumors. However, differences in disease-free survival and overall survival between both groups of patients were significant (P=0.004 and P=0.028, respectively). In conclusion, we have shown that HPV is the etiological agent of a subset of sinonasal carcinomas demonstrating the transcriptionally active HPV in these tumors. Immunostaining for p16 can be used as a surrogate marker to identify these tumors.

Adjunct p16(INK4a) immunohistochemistry aids the detection of high-grade squamous intraepithelial lesions in endocervical curettage specimens

OBJECTIVES

We questioned whether the use of p16(INK4a) immunohistochemistry in endocervical curettage (ECC) specimens would improve the detection of high-grade squamous intraepithelial lesions (HSIL) in a high-risk patient population.

METHODS

Papanicolaou test results were retrieved in 58 consecutive ECC specimens that were previously diagnosed as no histopathologic abnormality in patients with antecedent HSIL or atypical squamous cells, cannot exclude HSIL. An H&E recut and immunohistochemistry for p16(INK4a) were performed on all cases.

RESULTS

HSIL were found in 18 (31%) ECC specimens originally interpreted as negative. Of these 18 cases, three had moderate-sized fragments of ectocervical epithelium with HSIL seen on the recut H&E with concurrent positivity for p16(INK4a). Fourteen cases had rare to occasional clusters of atypical cells with strong immunoreactivity for p16(INK4a). A single case showed a medium-sized fragment of HSIL on the p16(INK4a)-stained section.

CONCLUSIONS

The use of recuts and adjunct p16(INK4a) should be considered when evaluating ECC specimens in high-risk patient populations.

Impact of p16(INK4a) immunohistochemistry staining on interobserver agreement on the diagnosis of cervical intraepithelial neoplasia

OBJECTIVES

This study aimed to compare the interobserver Cohen κ on H&E staining and on H&E plus p16(INK4a) staining of all cervical biopsy specimens in a population-based screening program.

METHODS

All the colposcopy-guided biopsies generated by the routine screening of 23,258 women aged 25 to 64 years were stained with H&E and H&E plus p16. Biopsy specimens were reviewed by six external experts.

RESULTS

The four diagnoses were available in 441 cases. The interobserver κ values were 0.52 (95% confidence interval [CI], 0.45-0.58) and 0.48 (95% CI, 0.42-0.56) with H&E and H&E + p16, respectively, when using a five-group classification (normal, CIN 1, CIN 2, CIN 3, and cancer); adopting a two-group classification (≤CIN 1 and ≥CIN 2), the values were 0.75 (95% CI, 0.66-0.82) and 0.70 (95% CI, 0.61-0.79), respectively.

CONCLUSIONS

The use of p16 on all cervical biopsy specimens in a screening program showed virtually no effect on reproducibility of the histologic diagnosis.

Ancillary Diagnostics in Gynecologic Cytology

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

Distribution of Human Papillomavirus 52 and 58 Genotypes, and Their Expression of p16 and p53 in Cervical Neoplasia

Background

This study investigates the prevalence of human papillomavirus (HPV) 52 and 58 genotypes among women residing in Busan, and the expression of p16 and p53 proteins in cervical neoplasia with HPV 52 and 58 infections.

Methods

A total of three hundred fifteen cases were analyzed using the HPV DNA chip test for HPV genotypes, and of these, we retrospectively examined p16 and p53 expression in 62 cases of cervical tissues infected with HPV 52 and 58 using immunohistochemistry.

Results

HPV 52 and 58 genotypes were identified in 62 (54.9%) out of 113 high-risk, HPV-infected cases. Of the cases examined, there were 19 single HPV 52 infections (16.8%), 23 single HPV 58 infections (20.4%), 4 multiple HPV 52 infections (3.5%), and 16 multiple HPV-58 infections (14.2%). Immunoreactivity of p16 and p53 was observed in 41 (66.1%) and 23 (37.1%) of the 62 cases of cervical neoplasia infected with HPV 52 and 58 genotypes, respectively.

Conclusions

This study demonstrates a high prevalence of HPV 52 and 58 genotypes, in addition to HPV 16, among high-risk strains of cervical neoplasia in Korea. These findings suggest that development of more vaccines would be beneficial for the prevention of the various HPV genotypes.

Variability of Pathologists' Utilization of p16 and Ki-67 Immunostaining in the Diagnosis of Cervical Biopsies in Routine Pathology Practice and Its Impact on the Frequencies of Cervical Intraepithelial Neoplasia Diagnoses and Cytohistologic Correlations

Context.—The use of p16 in cervical biopsies improves the accuracy of cervical intraepithelial neoplasia (CIN) diagnosis and grading and decreases its interpathologist variability.

Objective.—To determine the impact of the frequency of use of p16 immunostains in cervical biopsies on pathologists' diagnoses of CIN grade 1 and grade 2 or above (CIN1 and CIN2+) and on cytohistologic correlations.

Design.—We identified all cervical biopsy specimens with cytologic correlations subjected or not to p16 staining from January 1, 2005, to September 30, 2010; calculated each pathologist's percentage of p16 use; and correlated it with their major cytohistologic discrepancy rates, CIN2+ diagnoses, and CIN1/CIN2+ ratios.

Results.—During the study period, each of the 23 pathologists interpreted 59 to 1811 (mean, 518) of 11 850 cervical biopsy specimens, used p16 for 0% to 21.31% (mean, 10.14%) of these, had CIN2+ detection rates of 9.5% to 24.1% (mean, 18.9%), and CIN1/CIN2+ ratios of 0.7 to 4.5 (mean, 1.5). Compared to the 12 “low users” of p16, who used p16 fewer times than the institution's mean for p16 use, the 11 “high users” of p16 diagnosed more biopsies (8391 versus 3459), had a lower rate of major cytohistologic discrepancies (12.62% versus 14.92%, P &lt; .001), a higher rate of CIN2+ diagnoses (19.9% versus 16.4%, P &lt; .001), a lower range of CIN2+ rates (15.0%–23.1% versus 9.5%–24.1%), and lower CIN1/CIN2+ ratios (1.2 versus 2.3).

Conclusions.—We found a high intrainstitutional variability of p16 use in cervical biopsies, CIN2+ rates, and CIN1/CIN2+ ratios. Use of p16 for greater than 10% of cervical biopsies was associated with improved cytohistologic correlation rates and with lower variability in the frequencies of histologic diagnoses.

Human papillomavirus infection a favorable prognostic factor in laryngeal squamous cell carcinoma is associated with the expression of proliferating cell nuclear antigen

Objective: It has been documented that human papilloma virus (HPV) DNA replication requires proliferating cell nuclear antigen (PCNA). However the association between them in tumors is still controversial. Up to now, the role of HPV in laryngeal squamous cell carcinoma (LSCC) has not been clearly established, and the correlation between HPV and PCNA in LSCC remains poorly explored.

Methods: We retrospectively reviewed the clinicopathological features and follow-up data of 71 patients with LSCC. The lesions were examined for PCNA using immunohistochemistry, and for HPV using in situ hybridization.

Results: 31 (43.7%) cases showed infection of HPV and 38 (53.5%) showed overexpression of PCNA. No significant difference of HPV status in clinicopathological features was found. While there was a significant difference of PCNA expression in histology grade but no significant difference of PCNA expression in other clinicopathological features could be detected, and the expression of PCNA is not a significant predictor of survival in LSCC patients. However, HPV infection is a favorable prognostic factor in LSCC patients. Moreover, HPV infection is associated with PCNA overexpression.

Conclusion: Human papilloma virus (HPV) infection is an indicator of better prognosis in LSCC and associated with the expression of PCNA.

Immunohistochemical expression of p16 and HPV L1 capsid proteins as predictive markers in cervical lesions

PURPOSE

Human papilloma virus (HPV) infection is the most important cause of cervical cancer, but only 2 % of cervical HPV infections will develop into cervical cancer. p16 INK4A has been introduced as a marker for HPV infection in cervix. HPV L1 capsid protein is also known to be associated with the productive phase of HPV infection; however, expression pattern in different HPV-associated cervical lesion and its correlation to p16 expression is not still well understood. The authors aimed to elucidate the relationship between L1 and p16 expression in cervical lesions.

METHODS

Immunohistochemical studies using antibodies against L1 capsid and P16 proteins were carried out on 89 paraffin-embedded tissue samples including 11 low-grade cervical intraepithelial neoplasias (CIN), 11 high-grade CINs, 20 cervical squamous cell carcinomas (SCC), eight cervical adenocarcinomas and 39 normal cervical tissues as a control group.

RESULTS

L1 capsid protein was positive in 63.6 % of low-grade CINs and 9.1 % of high-grade CINs; while none of the cervical SCCs, adenocarcinomas or normal cervical tissues showed this marker. In contrast, p16 protein was positive in 81.8 % of low-grade CINs, 90.1 % of high-grade CINs, 90 % of SCCs, 75 % of adenocarcinomas and 10.25 % of normal cervical tissues (p value < 0.001).

CONCLUSION

Despite the presence of interobserver variation in the histopathologic interpretation of cervical lesions, in more instances definite diagnosis is made by routine histopathological examination and these ancillary tests are supportive in follow-up of the patient.

Immunohistochemical staining for p16 is a useful adjunctive test in the diagnosis of Bowen's disease

AIMS

The aim of this study was to document the pattern of immunohistochemical staining seen with p16 (INK4a) in actinic keratosis, Bowen's disease and seborrhoeic keratosis.

METHODS

We gathered 20 examples each of actinic keratosis, Bowen's disease and seborrheic keratosis. The cases were stained for p16 using standard immunohistochemical techniques, and the staining patterns were categorised into one of five different patterns.

RESULTS

All cases of Bowen's disease as defined in our practice showed strong positive staining in all abnormal cells, and 95% of these cases showed a distinctive pattern of sparing in a layer of palisaded basal cells. None of the actinic keratoses or seborrheic keratoses, as defined by our morphological criteria, showed this distinctive pattern.

CONCLUSIONS

Bowen's disease, as we define the term, shows a distinctive, repeatable pattern of staining with p16, characterised by moderate to strong staining of all abnormal cells with sparing of a layer of basal cells. This pattern is not seen in actinic keratoses or in seborrheic keratoses. Thus immunohistochemistry for p16 is a useful adjunctive test in the differential diagnosis of these lesions.

Squamous Cell Carcinomas of the Anterior Oral Cavity Are Commonly Associated With Simplex (or Differentiated) Oral Intraepithelial Neoplasia

Introduction: We investigated the occurrence of differentiated oral intraepithelial neoplasia (DOIN) that met the criteria for differentiated intravulvar neoplasia, associated with invasive squamous cell carcinoma (SCC) of the anterior oral cavity, and its clinicopathologic significance. Materials and Methods: Sixty-nine consecutive cases of SCC of the anterior oral cavity were categorized into 2 groups: group A comprised SCC associated with DOIN; Group B consisted of cases associated with classical SCC in situ. Results: Fifty-five cases (80%) were classified as group A, or DOIN lesions, with only 14 (20%) as group B. All cases were associated with invasive SCC, except 2 cases in group B. Squamous epithelium continuous or adjacent to invasive SCC displayed consistent changes in the parabasal and basal layers with (1) cytologic atypia with proliferation of parabasal cells in downward expansion causing reactive proliferation of the basal cell layer in early stage and invading the basal layer in late stage, (2) disordered nuclear/cytoplasmic arrangement, and (3) a “cobblestone” appearance characterized by prominent intercellular spaces and cytoplasmic density involving the entire cell (dyskeratosis) of the parabasal layer. p53 and Ki67 immunostaining revealed linear reactivity mainly in the parabasal layer. Conclusions: DOIN lesions are frequently associated with invasive SCC of anterior oral cavity. Due to the subtle histopathologic changes, DOIN lesions pose potential diagnostic difficulty with differentiation from mild dysplasia or reactive atypia.

P16(INK4A) immunostaining is a strong indicator for high-risk-HPV-associated oropharyngeal carcinomas and dysplasias, but is unreliable to predict low-risk-HPV-infection in head and neck papillomas and laryngeal dysplasias

Human papillomavirus (HPV) is a risk factor for the development of benign and malignant mucosal head and neck lesions. P16(INK4A) is often used as a surrogate marker for HPV-infection, although there is still controversy with respect its reliability. Our aim was to determine if p16(INK4A) overexpression can accurately predict both high-risk and low-risk-HPV-presence in (pre)malignant and benign head and neck lesions. P16(INK4A) immunohistochemistry was performed on paraffin-embedded tissue sections of 162 oropharyngeal squamous cell carcinomas (OPSCC), 14 tonsillar and 23 laryngeal dysplasias, and 20 tonsillar and 27 laryngeal papillomas. PCR, enzyme-immunoassay and FISH analysis were used to assess HPV-presence and type. Of the 162 OPSCC and 14 tonsillar dysplasias, 51 (31%) and 10 (71%) were HPV16-positive, respectively. All tonsillar papillomas were HPV-negative and four laryngeal dysplasias and 26 laryngeal papillomas were positive for HPV6 or -11. P16(INK4A) immunohistochemistry revealed a strong nuclear and cytoplasmic staining in 50 out of 51 HPV16-positive and 5 out of 111 HPV-negative OPSCC (p < 0.0001) and in all HPV16-positive tonsillar dysplasias, whereas highly variable staining patterns were detected in the papillomas and laryngeal dysplasias, irrespective of the HPV-status. In addition, the latter lesions generally showed a higher nuclear than cytoplasmic p16(INK4A) immunostaining intensity. In conclusion, our data show that strong nuclear and cytoplasmic p16(INK4A) overexpression is a reliable surrogate indicator for HPV16 in OPSCC and (adjacent) dysplasias. For HPV6 or -11-positive and HPV-negative benign and premalignant lesions of the tonsil and larynx, however, p16(INK4A) immunostaining is highly variable and cannot be recommended to predict HPV-presence.

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

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