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Introduction: Triple-negative breast cancer (TNBC) is associated with alterations in the retinoblastoma pathway. As a consequence of retinoblastoma protein (pRB) loss, compensatory upregulation of p16 occurs due to the loss of phosphorylated pRB-mediated negative feedback on p16 expression. The aim of this study is to investigate the clinicopathological and genomic characteristics associated with the diffuse pattern of p16 immunohistochemistry (IHC) in TNBC., Methods: The study analyzed surgically resected TNBC for whole-exome sequencing in 113 cases and for cDNA microarray in 144 cases. The p16 IHC results were classified into two patterns: diffuse and negative/mosaic., Results: In the entire cohort (n = 257), the diffuse pattern of p16 IHC was observed in 123 (47.9%) patients and the negative/mosaic pattern in 134 (52.1%). Biallelic RB1 inactivation was observed in 14.3% of patients with the diffuse pattern. The diffuse pattern of p16 IHC showed more frequent RB1 alterations and cell cycle progression signatures, a higher Ki-67 labeling index, more frequent chromosome segment copy number changes, a higher frequency of homologous recombination deficiency high, and immune-related signatures. PIK3CA mutations were more frequent in the negative/mosaic pattern. CCND1 amplification was identified in 5 cases, all with the negative/mosaic pattern., Conclusion: In TNBC, the diffuse p16 pattern shows clinical and genomic similarities to pRB-deficient tumors, suggesting shared characteristics. This suggests that p16 IHC testing may provide new therapeutic approaches, underscoring its potential clinical importance., (© 2024 The Author(s). Published by S. Karger AG, Basel.)

Background & Objective: p16 has different roles in the nuclear and cytoplasmic locations. The nuclear localization of the p16 protein explains its role in cell cycle regulation. Cytoplasmic expression was considered an artifact in the initial years, but there is evidence to prove that cytoplasmic localization is real and that p16 has different roles in the nuclear and cytoplasmic locations. We aimed to study the immunoexpression of p16 protein in the nuclear and cytoplasmic locations of the epithelial and stromal compartments of fibroadenoma, invasive breast carcinoma, and a select number of phyllodes tumors., Methods: The study included a total of 107 patients, comprising 51 cases of invasive breast carcinoma, 51 cases of fibroadenoma, 4 cases of benign phyllodes tumors, and 1 case of lobular carcinoma in situ (LCIS). The p16 immunohistochemistry was evaluated for nuclear and cytoplasmic localization in the epithelial and stromal compartments of the tumors., Results: Of the 51 fibroadenoma cases, 23 showed strong nuclear p16 epithelial expression, but no case showed cytoplasmic expression. In 19/51 cases, stromal cells also showed strong p16 nuclear expression. Moderate stromal p16 expression was observed in 3 out of 4 cases of benign phyllodes. Out of the 51 cases of invasive carcinoma, 31 showed moderate to strong nuclear p16 immunopositivity, while 27 cases exhibited cytoplasmic p16 expression. We found a statistically significant correlation between moderate to strong nuclear p16 immunoexpression and the molecular subtype of breast carcinoma., Conclusion: The cytoplasmic localization of p16 immunohistochemistry is not seen in epithelial components of fibroadenoma, while it is seen frequently in breast carcinoma. Nuclear p16 expression has a statistically significant correlation with molecular subtypes of breast carcinoma., Competing Interests: The authors declared no conflicts of interest., (© 2024.)

The sinonasal tract is considered a second hotspot for human papillomavirus (HPV)-related tumors in the head and neck, with HPV being identified in up to 62% of squamous cell carcinomas (SCCs) and 38% of papillomas. There is limited data from geographical regions with low prevalence of high-risk (HR)-HPV on the association of HR-HPV in sinonasal neoplasms and on utility of p16 as a surrogate marker. p16 immunohistochemistry, HR-HPV mRNA ISH and quantitative real-time PCR (qPCR) were performed on a retrospective cohort of sinonasal papillomas and SCCs. KRAS mutation analysis was done in oncocytic papillomas. p16 positivity was present in 22/142 cases (15.5%) including eight inverted papillomas, one oncocytic papilloma (OP), and 13 SCC. Among these, mRNA ISH showed HR-HPV in the OP and two SCC, while another SCC was found to harbour HPV18 by qPCR. Two HPV-associated SCCs had foci of OP. mRNA ISH was negative in all p16 negative cases. p16 immunohistochemistry showed 68% concordance with mRNA ISH, and had sensitivity and negative predictive value of 100%; specificity was 67%, and positive predictive value was 14.3%. Association with HR-HPV in sinonasal papillomas and SCC is rare, and may be seen in cases demonstrating oncocytic morphology. p16 immunohistochemistry has low specificity and positive predictive value in low-prevalence populations; thus, reflex direct HR-HPV testing should be performed in p16 immunopositive cases. This two-step approach is viable in resource-limited settings, as the proportion of p16 positive cases is small., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

There are few pathologic or molecular studies of penile precancerous lesions, and the majority refers to lesions associated with invasive carcinomas. Penile Intraepithelial Neoplasia (PeIN) is classified in two morphologically and distinctive molecular groups, non-HPV and HPV-related with special subtypes. The primary purpose of this international series was to classify PeIN morphologically, detect HPV genotypes and determine their distribution according to PeIN subtypes. A secondary aim was to evaluate the p16 INK4a immunostaining as a possible HPV surrogate for high-risk HPV infection in penile precancerous lesions. Samples consisted of 84 PeIN cases, part of a retrospective cross-sectional analysis of 1095 penile carcinomas designed to estimate the HPV DNA prevalence in penile cancers using PCR and p16 INK4a immunostaining. Penile Intraepithelial Neoplasia (PeIN) was classified in HPV-related (basaloid, warty-basaloid, warty, hybrid, and mixed subtypes) and non-HPV-related (differentiated), the former being the most frequent. PeIN subtypes were differentiated (non-HPV-related) and basaloid, warty-basaloid, warty, hybrid and mixed (HPV-related). Basaloid PeIN was the most commonly diagnosed subtype, and HPV16 was the most frequent HPV genotype detected. Warty-basaloid and warty PeIN showed a more heterogeneous genotypic composition. Most HPV genotypes were high-risk but low-risk HPV genotypes were also present in a few cases (4%). A single HPV genotype was detected in 82% of HPV positive cases. In contrast, multiple genotypes were detected in the remaining 18% of cases. The findings in this study support the paradigm that penile in situ neoplasia, like its invasive counterparts, is HPV dependent or independent and has distinctive morphological subtypes readily identified in routine practice. Considering that HPV16 is clearly the predominant type, and that the three available vaccines have HPV16, all of them will be suitable for vaccination programs; the price of the vaccines will be probably the main determinant to choose the vaccine., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: HPV-associated oral cavity squamous cell carcinoma (SCC) is not well-characterized in the literature, and also has a clinical significance that is poorly understood., Methods: We gathered a cohort of oral cavity (OC) SCC with nonkeratinizing morphology, either in the invasive or in situ carcinoma (or both), tested for p16 by immunohistochemistry and high risk HPV E6/E7 mRNA by RTPCR (reference standard for transcriptionally-active high risk HPV) and gathered detailed morphologic and clinicopathologic data., Results: Thirteen patients from two institutions were proven to be HPV-associated by combined p16 and high risk HPV mRNA positivity. All 13 patients (100%) were males, all were heavy smokers (average 57 pack/year), and most were active drinkers (9/11 or 81.8%). All 13 (100%) involved the tongue and/or floor of mouth. All had nonkeratinizing features, but maturing squamous differentiation varied widely (0-90%; mean 37.3%). Nonkeratinizing areas had high N:C ratios and larger nests, frequently with pushing borders, and minimal (or no) stromal desmoplasia. The carcinoma in situ, when present, was Bowenoid/nonkeratinizing with cells with high N:C ratios, full thickness loss of maturation, and abundant apoptosis and mitosis. HPV was type 16 in 11 patients (84.6%) and type 33 in two (15.4%). Nine patients had treatment data available. These underwent primary surgical resection with tumors ranging from 1.6 to 5.2 cm. Most had bone invasion (6/9-66.7% were T4a tumors), and most (6/9-66.7%) had extensive SCC in situ with all 6 of these patients having final margins positive for in situ carcinoma., Conclusions: HPV-associated OCSCC is an uncommon entity that shows certain distinct clinical and pathologic features. Recognition of these features may help pathologic diagnosis and could potentially help guide clinical management., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

To find if an association could be established between Human Papilloma Virus (HPV) infection and oropharyngeal cancers (OPCs) in a group of patients known to be regular users of tobacco, and to determine the impact of HPV status on clinical outcomes.Case records of 212 patients with AJCC-7 (The American Joint Committee on Cancer 7th edition) stages II-IVB non metastatic squamous cell carcinoma of the oropharynx treated using radical radiotherapy with or without chemotherapy during the years 2015-2018 were retrieved. Formalin-fixed, paraffin-embedded blocks from oropharyngeal biopsies were available for 177 patients and were evaluated for p16 expression by immunohistochemical (IHC) staining. More than 50% nuclear staining with or without cytoplasmic staining was considered HPV+ . The association between tobacco use and HPV, as well as the influence of HPV status on survival outcomes were assessed. p16 expression was found to be positive in 23(13%) patients. Significant association was found between chewable tobacco usage and HPV positivity ( p  = 0.051). The median follow up was 20.5 months (range: 3-80). 5-year Overall Survival was 43.4% and 29.8% ( p  = 0.044) in HPV+ and HPV- patients, respectively. Local control was significantly better in HPV+ patients (38.6% vs. 25.3%, p  = 0.049). There was also a trend towards improved Disease-free Survival in HPV+ patients (31 months vs. 15 months, p  = 0.078). Though less in prevalence among the Indian population, improved outcomes in HPV+ OPC patients and widely available IHC HPV assays signifies the routine implementation of p16 testing in day-to-day clinical practice., Competing Interests: Conflicts of interestThe authors declare that they have no conflict of interest., (© Association of Otolaryngologists of India 2021.)

Background: Human papillomavirus-related oropharyngeal squamous cell carcinoma (HPV-OPSCC) presents frequently as metastasis in a neck lymph node that may be cystic or necrotic. Fine-needle aspiration (FNA) biopsies are often first-line diagnostic procedures. p16 immunohistochemistry (IHC) is a surrogate marker for high-risk HPV (hrHPV) infection but can be challenging to interpret. This study evaluated the use of hrHPV in situ hybridization (ISH) in cytology cell blocks of cystic neck lesions., Methods: Twenty-four FNA cases with cell blocks and surgical correlates were evaluated. p16 IHC and hrHPV ISH were assessed on cell blocks (C-p16 and C-hrHPV ISH), and hrHPV ISH on surgical samples (S-hrHPV ISH). All results were classified as negative, positive, or equivocal., Results: Two cases were excluded because of insufficient tissue on recut. On the basis of C-hrHPV ISH cases, 12 were positive, 5 were negative, and 5 were equivocal. All 12 positive C-hrHPV ISH cases had concordant S-hrHPV ISH with no false positives. Of the 5 negative C-hrHPV ISH cases, 4 had concordant S-hrHPV ISH, and 1 had a discordant S-hrHPV ISH. Of the 5 equivocal C-hrHPV ISH cases, S-hrHPV ISH were both positive and negative. Fourteen cases were equivocal by C-p16; 9 cases were reliably classified by C-hrHPV ISH (5 positive, 4 negative; 64%)., Conclusions: C-hrHPV ISH can be reliably used, especially when positive. A negative or equivocal interpretation of C-hrHPV ISH may warrant repeat testing. Compared to C-p16, C-hrHPV ISH is more frequently diagnostic and could be helpful for HPV-OSCC diagnosis and management., (© 2021 American Cancer Society.)

The 2020 WHO classification is focused on the distinction between HPV-associated and HPV-independent squamous cell carcinoma of the lower female genital organs. Differentiating according to HPV association does not replace the process of grading; however, the WHO classification does not recommend any specific grading system. VIN are also differentiated according to whether they are HPV(p16)-associated. HPV-independent adenocarcinoma (AC) of the cervix uteri has an unfavorable prognosis. Immunohistochemical p16 expression is considered to be a surrogate marker for HPV association. HPV-associated AC of the cervix uteri is determined using the prognostically relevant Silva pattern., Competing Interests: Conflict of Interest/Interessenkonflikt The authors declare that they have no conflict of interest./Die Autorinnen/Autoren geben an, dass kein Interessenkonflikt besteht., (The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commecial purposes, or adapted, remixed, transformed or built upon. ( https://creativecommons.org/licenses/by-nc-nd/4.0/ ).)

Objectives: The Lower Anogenital Squamous Terminology (LAST) recommendations classify human papillomavirus-associated squamous lesions into low- and high-grade squamous intraepithelial lesions (LSILs/HSILs). Our study aimed to assess interobserver agreement among 6 experienced pathologists in assigning 40 anal lesions previously diagnosed as anal intraepithelial neoplasia 2 (AIN 2) to either HSIL or non-HSIL categories., Methods: Agreement based on photomicrographs of H&E alone or H&E plus p16 immunohistochemistry was calculated using κ coefficients., Results: Agreement was fair based on H&E alone (κ = 0.42; 95% confidence interval [CI], 0.34-0.52). Adding p16 improved agreement to moderate (κ = 0.55; 95% CI, 0.54-0.62). On final diagnosis, 21 cases (53%) had unanimous diagnoses, and 19 (47%) were divided. When designating p16 results as positive or negative, agreement was excellent (κ = 0.92; 95% CI, 0.83-0.95). Among variables (staining location, extent, and intensity), staining of the basal/parabasal layers was a consistent feature in cases with consensus for positive results (20/20). Of the 67 H&E diagnoses with conflicting p16 results, participants modified 32 (48%), downgrading 23 HSILs and upgrading 9 non-HSILs., Conclusions: Although p16 increased interobserver agreement, disagreement remained considerable regarding intermediate lesions. p16 expression, particularly if negative, can reduce unwarranted HSIL diagnoses and unnecessary treatment., (© American Society for Clinical Pathology, 2020. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The lungs are a common site of metastasis of head and neck (H&N) squamous cell carcinomas (SCC). This study attempts to define p16 immunoexpression and presence of HPV in primary SCC of the lung and determine their usefulness in discriminating between primary lung SCC and metastasis from HPV-associated oropharyngeal primary. Pathology archives were searched for patients with SCC of the lung without SCC elsewhere. Tissue microarray was constructed and immunohistochemistry performed using anti-p40 and anti-p16 antibodies. All cases were tested for HPV viral proteins E6/E7 by RNA in situ hybridization (ISH) and available positive cases for HPV DNA by polymerase chain reaction (PCR). Eight of 25 (32%) showed cytoplasmic and nuclear expression of p16: 2 (8%) strong and 2 (8%) moderate in > 70% of tumor cells; 1 (4%) strong, 1 (4%) moderate, and 1 (4%) weak in 50-70% of tumor cells; 1 (4%) weak in < 50% of tumor cells. E6/E7 mRNA ISH was negative in all cases. Seven of 8 (87.5%) p16-expressing cases were available for testing by HPV PCR; all were negative for HPV DNA. A retrospective control group of 12 patients with possible SCC metastatic to lung was also identified; high-risk HPV DNA was present in 3, confirming metastasis. p16 expression in lung SCC is not uncommon and may not discriminate between primary pulmonary SCC and metastasis from HPV-associated oropharyngeal primary. Confirmatory HPV testing (high risk HPV DNA or E6/E7 mRNA) is recommended to differentiate metastasis from oropharyngeal primary from two separate primaries.

Objective: Accurate determination of human papilloma virus (HPV) status is critical when identifying patients with oropharyngeal squamous cell carcinoma (OPSCC) who may be candidates for de-escalation trials. In this study we investigated whether local p16 screening, by immunohistochemistry (IHC), has high positive predictive value (PPV) for HPV status in a good prognosis HPV positive OPSCC (HPVOPSCC) population treated on a clinical trial., Methods and Materials: Patients enrolled on the TROG 12.01 randomised trial for good prognosis HPVOPSCC were randomised based on local p16 IHC testing but subsequently had central p16 IHC and HPV RNA in situ hybridisation (HPV RNA ISH) testing. Correlations between the local and central p16 and central HPV RNA ISH were studied. The main outcome was the positive predictive value (PPV) of local pathology laboratory testing of p16., Results: 176/182 patients had samples available for central testing. 172/176 were evaluable for central testing of p16, and all were confirmed to be p16 positive (172/172, 100%, 95% CI = [97.9%, 100%]). Similarly, 100% of those evaluable for HPV RNA ISH (155/155, 100%, 95% CI = [97.6%, 100%]) were confirmed HPV positive, indicating p16 overexpression driven by transcriptionally active HPV and a PPV of 100% for local p16 testing., Conclusions: Our results validate the suitability of local pathology laboratory p16 testing alone, in populations with a high attributable fraction of OPSCC due to HPV, to screen and enrol low risk HPVOPSCC patients onto de-intensification trials. This obviates the need for upfront more complex and expensive HPV assays and/or central laboratory testing., Competing Interests: Declaration of Competing Interests Richard Young - institutional grant from Roche; Ben Solomon - personal fees from Merck Sharp & Dohme, personal fees from Bristol-Myers Squibb, grants and personal fees from Roche, grants from Regeneron, personal fees from AstraZeneca, grants and personal fees from Pfizer, personal fees from Genentech, personal fees from Loxo Oncology; Christopher Angel - institutional grant from Roche; Sandro Porceddu - personal fees from Merck Sharp & Dohme, personal fees from Merck, personal fees from Celgene; Danny Rischin - grants from Merck Sharp & Dohme, grants from Merck, grants from Bristol-Myers Squibb, grants from GSK, grants from Roche, grants from Regeneron, grants from Amgen, grants and personal fees from MSD, Trial Steering Committees and/or Advisory Boards (all uncompensated) - MSD, Merck, Bristol-Myers Squibb, GSK, Regeneron; June Corry, Christopher Wratten, Andrew Macann, James Jackson, and Alan Herschtal - no disclosures., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Human papillomavirus (HPV) has become a critical prognostic biomarker in oropharyngeal squamous cell carcinoma (OPSCC). While retrospective studies suggest that p16 immunohistochemistry and even HPV RNA in situ hybridization work well on tissues and tumors from a variety of labs and various fixation conditions, no formal study of fixation conditions has been performed to date. We took surgically resected specimens from three p16 and HPV RNA in situ hybridization positive OPSCC patients, divided their fresh tumors into small pieces, and varied the time to formalin fixation as 1, 3, 6, 24, and 48 h. Tumors were either held moistened at room temperature or were refrigerated. After fixation and processing, routine hematoxylin and eosin slides were generated and p16 immunohistochemistry and RNA in situ hybridization performed. All three tumors were nonkeratinizing and had strong and diffuse p16 expression at immediate fixation, which, surprisingly, remained positive for all fixation times and conditions and despite significant degeneration at the later points for two of the patients while for one, the nuclear signal dropped out of most cells at early and mid time points, particularly at room temperature, causing false negatives. HPV RNA in situ hybridization stayed positive in all specimens up to 48 h of cold ischemic time refrigerated and even at room temperature, except for overtly autolyzed tumor regions. These findings help to establish that, at least for standard nonkeratinizing, p16 and HPV RNA strongly positive OPSCC patients, and using the most common tests in clinical practice, relatively lenient time to fixation may be acceptable if it cannot be avoided. However, for some patients, p16 immunohistochemistry may be sensitive to signal loss with autolysis. HPV RNA in situ hybridization, in particular, seems remarkably resistant to pretest cold ischemic times.

Human papillomavirus (HPV) in oropharyngeal squamous cell carcinoma (SCC) is a well-known cause and prognostic indicator, and the utility of p16 as a surrogate marker for HPV status has been established. P16 and its relationship with HPV have not been defined in sinonasal malignancy nor has a link with outcomes been established. Patients with sinonasal SCC from 2011 to 2017 were identified from our pathology database. P16 immunohistochemistry and HPV RNA in situ hybridization were performed on tissue specimens. Forty-seven patients were included. Disease-free survival for p16+ patients was significantly higher than p16- patients (P = .043). Fewer HPV+ patients died (P = .052) or experienced recurrence (P = .0437). Odds ratio between p16 and HPV status was 14.19 (95% CI: 1.72, 442.03). Our findings demonstrate improved survival in both the p16+ and HPV+ groups and a positive association between p16 and HPV. There may be similar potential for modifying classification for HPV+ sinonasal SCC., (© 2020 Wiley Periodicals, Inc.)

Evidence from current studies show that squamous cell carcinomas at oral and oropharyngeal sites are distinct and unique, with their own separate etiopathogenesis, treatment, and prognosis. The aim of this work is to correlate p16 immunohistochemical expression with histomorphological features suggestive of HPV infection in oral and oropharyngeal squamous cell carcinoma. A total of 50 consecutive biopsy cases of oral squamous cell carcinoma (OSCC) and 50 consecutive biopsy cases of oropharyngeal squamous cell carcinoma (OPSCC) were evaluated for features suggestive of HPV infection like focal basaloid appearance, nests, and lobules of tumor cells with pushing borders, absence of stromal reaction, central necrosis, focal lymphoepithelial morphology, presence of koilocytes, and non-keratinizing or hybrid morphology. Immunostaining was performed using p16 monoclonal antibody (clone mouse 16P04). Only cases showing a moderate (2+) to high intensity (3+) staining in more than 75% cells were taken as p16 immunopositive. The histological features were correlated with p16 immunopositivity. A total of 18/50 (36%) cases of oral squamous cell carcinoma and 27/50 (54%) cases of oropharyngeal squamous cell carcinoma were p16 immunopositive. On statistical analysis, only nests/lobules with pushing borders were found to have a significant correlation with p16 immunopositivity ( P value = 0.0012) for OSCC cases. For OPSCC cases, four histological features namely nests and lobules with pushing borders ( P value = 0.0001), focal basaloid appearance ( P value = 0.0041), lymphoepithelial morphology ( P value = 0.0029), and non-keratinizing/hybrid morphology ( P value = 0.0141) had a significant correlation with p16 immunopositivity. Histomorphological features are more helpful in predicting p16 immunopositivity in OPSCC than OSCC., Competing Interests: Conflict of InterestThe authors declare that they have no conflict of interest., (© Indian Association of Surgical Oncology 2020.)

Background: p16 immunohistochemistry is widely used to diagnose human papillomavirus (HPV)-related squamous neoplasms of cervix, anogenital, head, and neck tissues. The incidence of these HPV-related squamous neoplasms is markedly increased in the HIV-infected population. Ocular surface squamous neoplasia (OSSN) is also more common in HIV-infected patients. However, the expression pattern of p16 in OSSN among HIV-infected patients is unclear. Here, we examined the expression of p16 in OSSN surgical excisions collected from a large HIV-infected cohort from -Mozambique., Methods: OSSN surgical tissue specimens were collected from 75 Mozambican patients. Formalin-fixed, paraffin-embedded tissue blocks from these OSSNs were sectioned, stained with hematoxylin and eosin (H&E), and p16 expression by immunohistochemistry. H&E slides were reviewed to determine if OSSNs were noninvasive conjunctival intraepithelial neoplasms or invasive squamous cell carcinomas (SCC). Cases were classified as p16 positive or negative based on diffuse nuclear and cytoplasmic expression of p16 in neoplastic cells., Results: p16 positivity was found in a minority of OSSN cases (14/75). p16 positivity was significantly associated with the invasive SCC type of OSSN in HIV-infected patients ( p value of 0.026)., Conclusions: The majority of OSSNs in our HIV-infected cohort do not express p16. However, those cases that are p16-positive are significantly more likely to be the invasive SCC form of OSSN. We propose that p16 expression may identify more aggressive OSSNs in HIV-infected populations., Competing Interests: The authors have no conflicts of interest to declare., (Copyright © 2019 by S. Karger AG, Basel.)

Background: The rise in human papillomavirus (HPV) infection rates over the last few decades in the USA has contributed to a significant increase in the overall incidence of patients diagnosed with squamous cell carcinoma of the head and neck. These head and neck carcinomas develop in the oropharynx, with more than 90% of them caused by infection with high-risk HPV type 16. Patients diagnosed with HPV-induced oropharyngeal squamous cell carcinomas (OPSCCs) have a better prognosis and treatment response than those diagnosed with head and neck cancers caused by alcohol consumption and tobacco use. To identify patients with HPV-positive OPSCC, new guidelines recommend positive staining of oropharyngeal tissues for p16 INK4a (p16) by immunohistochemistry (IHC). Herein we discuss the testing algorithm that was adopted to address discrepant results between p16 IHC and a DNA in situ hybridization (ISH) test used routinely to diagnose HPV-positive OPSCC patients., Methods: A DNA polymerase chain reaction (PCR) test that amplifies HPV16 and HPV18 E7 was developed to aid in the diagnosis of HPV-positive OPSCC in a subset of patients. Specimens from these patients stained positive for p16 by an IHC test, but negative for high-risk HPV by a commercial DNA ISH test. Moreover, these results did not match the histopathological characteristics of the specimens, nor the clinical presentations of the patients., Results: Of 21 patients' specimens that were tested for p16 by IHC, 11 specimens showed concordant results with the high-risk HPV 16/18 DNA ISH test. Whereas, in eight p16 IHC positive specimens, HPV viral DNA was not detected by HPV16/18 DNA ISH, and two specimens were not tested by DNA ISH. When these eight p16 IHC positive specimens with discrepant p16 IHC and DNA ISH results were further tested by DNA PCR, six specimens showed concordance with p16 IHC with positive results for HPV16 E7, while two specimens were negative for HPV16 E7 by DNA PCR. All tested specimens were negative for HPV18 E7 by DNA PCR. Thus, the addition of the HPV16 and HPV18 E7 DNA PCR test identified a significant number of false negative test results by the HPV16/18 DNA ISH test and likely several false positive results by p16 IHC., Conclusions: Inclusion of an HPV16 E7 DNA PCR test improved the robustness of HPV-associated OPSCC diagnosis in patients with discrepant results from p16 IHC staining and a DNA ISH test, and identified patients for proper management with less misclassification., Competing Interests: The authors have declared no conflict of interest., (Copyright 2020, Perera et al.)

Human papilloma virus (HPV)-related squamous cell carcinoma (SCC) is biologically unique and has a better prognosis than conventional SCC of the head and neck. p16 immunohistochemistry emerged as a valuable surrogate marker for HPV in oropharyngeal SCC. The criteria for a positive p16 result in tissue specimens are well established. However, there is no consensus regarding interpreting p16 staining in cell blocks and other cytology specimens. This review discusses the current evidence on p16 testing in cytology specimens and also highlights other methods for HPV testing, including DNA and RNA in situ hybridization, as well as other molecular HPV tests., (© 2019 S. Karger AG, Basel.)

Objective: The main objective of this study was to analyze the presence of human papillomavirus (HPV) by polymerase chain reaction (PCR) in invasive squamous cell carcinomas of the oral cavity., Materials and Methods: A selection was made of 155 cases of squamous cell carcinoma of the oral cavity treated at the University Hospital of Geneva. HPV detection was performed at the Laboratory of Molecular Pathology using a PCR technique followed by in situ hybridization of the viral DNA. Sections were studied for the immunohistochemical expression of P16 INK4a ., Results: The presence of HPV-DNA was found in 3.3% of the cases (95% CI: 1.3%-7.5%). The only HPV genotype found was HR-HPV 16. In contrast, 7.7% (95% CI: 1.3%-7.5%) of the cases showed an overexpression of the P16 INK4a . We found no significant differences in age, sex, or tobacco and alcohol consumption in relation to the P16 INK4a or HPV positivity., Conclusions: Human papillomavirus is rarely associated with squamous cell carcinomas of the oral cavity. Our results suggest that an overexpression of the P16 INK4a protein, even in the absence of the virus, is linked to an increase in the survival of the patient., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd. All rights reserved.)

Background: We investigated the survival of patients with a p16-positive N3 oropharyngeal squamous cell carcinoma (OPSCC) and the prognostic significance of patient, tumor, and treatment characteristics., Methods: We retrospectively reviewed the data of patients treated at our Cancer Center for a p16-positive N3 OPSCC between 2003 and 2016. End points were overall survival (OS) and progression-free survival (PFS)., Results: A total of 29 patients were included. The 5-year OS and PFS were 67.5% and 59.1%, respectively. Smoking history above 10 pack-years and the absence of human papillomavirus DNA were associated with worse OS (P = .02 and P = .03, respectively) and PFS (P = .02 and P = .02, respectively). Induction chemotherapy or radical neck dissection were not associated with different treatment outcomes., Conclusion: Patients with an N3 p16-positive oropharyngeal cancer in our series had a 5-year OS rate of 67.5%. Smoking history and viral DNA were prognostic factors associated with survival., (© 2018 Wiley Periodicals, Inc.)

Background: Nasopharyngeal carcinoma (NPC) is related to Epstein-Barr virus (EBV) in endemic areas; however, the role of viruses in nonendemic countries is unclear. Our nationwide study investigated the prevalence and prognostic significance of EBV and human papillomaviruses (HPVs) in Finnish NPC tumors., Methods: We analyzed samples from 150 patients diagnosed between 1990 and 2009. Viral status was determined using EBV and HPV RNA in situ hybridizations, and p16 immunohistochemistry. Patient and treatment characteristics were obtained from patient records., Results: In our white patient cohort, 93 of 150 (62%) patients were EBV-positive and 21/150 (14%) patients were HPV-positive with no coinfections. Thirty-six (24%) tumors were negative for both viruses. The 5-year disease-specific survival for patients with EBV-positive, HPV-positive, and EBV/HPV-negative tumors was 69%, 63%, and 39%, respectively. In multivariable-adjusted analysis, overall survival was better among patients with EBV-positive (P = .005) and HPV-positive (P = .03) tumors compared to patients with EBV/HPV-negative tumors., Conclusions: In our low-incidence population, EBV and HPV are important prognostic factors for NPC., (© 2018 The Authors. Head & Neck published by Wiley Periodicals, Inc.)

Background: p16 has often been found to be overexpressed in patients oral squamous cell carcinoma (OSCC), but its prognostic value between anatomic subsites is still unclear., Objective: The aim of this study was to investigate the diagnostic and prognostic values of p16 in OSCC originating from tongue, gingiva or buccal mucosa., Methods: A total of 147 OSCC patients with tumors arising from the tongue, gingiva or buccal mucosa were enrolled in this study. p16 expression was detected using immunohistochemistry (IHC), and the presence of HPV16 was determined by real-time PCR in p16 positive patients. The correlation of p16 expression with the clinical parameters was evaluated., Results: Only one p16 positive patient with a cut off value of 25% and 75% was HPV16 positive. Although overall survival (OS), recurrence free survival (RFS) and metastasis free survival (MFS) had no significant differences between the p16 positive and negative patients, p16 negative patients (cut off value 25%) had more RFS in the buccal mucosa cancer (p= 0.03) than the p16-positive patients., Conclusions: The prevalence of HPV16 in Chinese OSCC patients was low. p16 overexpression decoupled from HPV infection was not a prognostic marker for OSCC patients except for patients with the buccal mucosa cancer.

Cystic squamous cell carcinoma (SCC) of the lateral neck is considered metastatic human papilloma-virus (HPV)-related oropharyngeal SCC (HPV-OPSCC) until proven otherwise. P16 immunohistochemistry is diffusely positive in those carcinomas and is used as a surrogate marker of active human papillomavirus (HPV) infection. Thyroglossal duct cysts (TDC) are one of the differential diagnoses for cystic neck lesions. SCC arising from TDC is extremely rare. In this study, we report a p16-positive cystic SCC located in the midline neck. Radiologic features and the presence of thyroid tissue in the cyst wall indicated that it was a TDC. The morphologic features of the lesion raised the question: is the carcinoma metastatic HPV-OPSCC? The HPV confirmative test, high-risk HPV RNA in situ hybridization, was negative. We then studied p16 immunohistochemistry in the squamous epithelium of benign TDC and found that rare benign TDC can show diffuse and strong p16 positivity., (Published by Elsevier Inc.)

Oral papillary squamous cell carcinoma (PSCC) is an unusual variant of squamous cell carcinoma with a better prognosis. The most common location of PSCC in the oral cavity is the gingiva and buccal mucosa, and it is exceedingly rare in the tongue. Herein, we present a case of PSCC in an 85-year-old male with a history of heart transplant and long-term use of immunosuppression medication. A verrucous pedunculated mass measuring 3.5 cm in the greatest dimension was present on the tip of tongue and a partial glossectomy was performed. Histological diagnosis was well differentiated PSCC with focal and minimal stalk invasion. No vascular nor perineural invasion was identified. Based on the current WHO and AJCC oral cancer staging system, the tumor stage was T2N0M0. The tumor cells were focally positive for p16, but in situ hybridization was negative for low-risk HPV (types 6 and 11) and high-risk HPV (types 16, 18, 31, 33 and 51). To the best of our knowledge, this is the first documented case of PSCC present on the tip of tongue in patients with long-term immune suppression. The pathogenesis, stage and prognosis of this entity are discussed. More case studies with long-term follow up are needed to achieve an accurate tumor stage and definite prognosis., (Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Objectives: The objectives were to determine the prevalence of human papillomavirus (HPV) in mobile tongue cancer (MTC) and evaluate associations and survival., Materials and Methods: Patients who underwent surgical resection as primary treatment for MTC (n = 127) were retrospectively evaluated. Formalin-fixed paraffin-embedded (FFPE) specimens were assessed for p16 and p53 by immunohistochemistry; for HPV DNA by nested multiplex polymerase chain reaction (PCR) using two pairs of consensus primers (MY09-MY11 and GP5+-GP6+); and for E6 and E7 oncogenes from 13 high-risk HPV types (16, 18, 31, 33, 35, 39, 45, 52, 56, 58, 59, 66, and 68) by real-time reverse transcription PCR (RT-PCR)., Results: There were 18 (14.2%) p16-positive, 45 (35.4%) p53-positive, 9 (7.1%) HPV DNA-positive, and 7 (5.5%) E6 and/or E7 mRNA-positive tumors, but the correlation of all pairs was poor. There was no demographic or histopathologic association with HPV status. Cause-specific survival was significantly better with p16-positive than with p16-negative tumors (p = .037)., Conclusions: The prevalence of HPV and p16 positivity was relatively low and p16 status was a poor surrogate marker for HPV status. The results showed the importance of p16 expression in prognosticating mobile tongue cancer.

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., (© 2017 The Authors International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.)

Follicular dendritic cell sarcoma is a rare mesenchymal neoplasm that most commonly occurs in cervical lymph nodes. It has histologic and clinical overlap with the much more common p16-positive human papillomavirus (HPV)-related squamous cell carcinoma of the oropharynx, which characteristically has nonkeratinizing morphology and often presents as an isolated neck mass. Not surprisingly, follicular dendritic cell sarcomas are commonly misdiagnosed as squamous cell carcinoma. Immunohistochemistry is helpful in separating the 2 entities. Follicular dendritic cell sarcoma expresses dendritic markers such as CD21 and CD23 and is almost always cytokeratin negative. However, in many cases of HPV-related oropharyngeal carcinoma, only p16 immunohistochemistry as a prognostic and surrogate marker for HPV is performed. p16 expression in follicular dendritic cell sarcoma has not been characterized. Here, we investigate the expression of p16 in follicular dendritic cell sarcoma and correlate it with retinoblastoma protein expression. A pilot study of dendritic marker expression in HPV-related oropharyngeal squamous cell carcinoma was also performed. We found that 4 of 8 sarcomas expressed p16 with strong and diffuse staining in 2 cases. In 2 of the 4 cases, p16 expression corresponded to loss of retinoblastoma protein expression. Dendritic marker expression (CD21 and CD23) was not found in HPV-related oropharyngeal squamous cell carcinomas. As such, positive p16 immunohistochemistry cannot be used as supportive evidence for the diagnosis of squamous cell carcinoma as strong and diffuse p16 expression may also occur in follicular dendritic cell sarcoma. Cytokeratins and dendritic markers are critical in separating the two tumor types., (Copyright © 2017 Elsevier Inc. All rights reserved.)

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., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The clinical and pathologic characteristics of human papillomavirus (HPV)-related premalignant lesions in the upper aerodigestive tract have not been adequately studied. There are a few reports of oral cavity HPV-related severe dysplasia with unique morphology (prominent apoptosis/karyorrhexis imparting a 'bowenoid' appearance) and a single case report of HPV-related squamous cell carcinoma in situ with nonkeratinizing histology distinct from the 'bowenoid' pattern that extensively involved the upper aerodigestive tract. The aim of this study was to characterize the morphologic and clinical features of HPV-related severe dysplasia/carcinoma in situ. All cases of upper aerodigestive tract severe dysplasia/carcinoma in situ (111 cases from 98 patients) at Washington University from July 2012 to March 2015 were categorized into histologic types: keratinizing, nonkeratinizing, mixed or 'bowenoid'. There were 83 (85 %) patients with keratinizing, 3 (3 %) nonkeratinizing and 12 (12 %) mixed patterns. The previously reported 'bowenoid' morphology was not identified. All 3 (100 %) nonkeratinizing and 6 (50 %) mixed cases were p16 and HPV RNA in situ hybridization (RNA ISH) positive (100 % concordance between p16 and RNA ISH). Only 2 of 73 keratinizing cases were p16 positive, 1 of which was also HPV RNA ISH positive (1.4 % of keratinizing cases HPV-related). Thus, nonkeratinizing morphology was a strong predictor of transcriptionally-active HPV in severe dysplasia/carcinoma in situ. HPV-related cases most commonly occurred in the floor of mouth and were frequently extensive (≥4 cm) or unresectable.

Objectives: Human papillomavirus (HPV) has emerged as a driving cause of head and neck cancer, but investigations outside the West are limited. A p16 immunohistochemistry is a commonly used biomarker for HPV cancers. We sought to investigate the pathology and rates of HPV head and neck oropharyngeal cancer in Japan via p16 immunohistochemistry at 2 institutions in Japan., Methods: Fifty-nine oropharyngeal specimens from 2 university hospitals in Japan were examined for morphology and p16 immunohistochemistry. The rate of p16 positivity was then determined, and the 2 groups were compared for differences in age, smoking history, gender, and stage of presentation and mortality., Results: The rate of p16 positivity among the oropharyngeal specimens was 29.5%. There were important differences in the pathology compared to morphology usually seen in the US. The patients with p16+ cancer tended to be younger. There was no significant difference in smoking status. Patients with p16+ cancers trended toward better survival., Conclusion: There appears to be a geographical difference in HPV rates of oropharyngeal cancers with persistently lower rates in Asian countries when compared to Western Europe and the US. Conclusions about HPV head and neck squamous cell carcinoma (HNSCC) in Western countries may not be generalizable across the globe at this time.

Human papillomavirus (HPV), especially HPV16 genotype, is associated with oropharyngeal squamous cell carcinoma (OPSCC). We aim to determine the prevalence and characterize the high-risk (HR)-HPV genotypes in head and neck SCC (HNSCC) in a South-East Asian multi-ethnic society in Singapore and examine its prognostic significance.159 HNSCC archival tissue samples were retrieved and tumour DNA was screened for 18 HR-HPV genotypes using a PCR-based assay (Qiagen, digene HPV genotyping RH test). P16 protein overexpression was identified using immunohistochemistry (IHC). Statistical correlation between clinical outcomes were performed between HPV-positive and negative HNSCC patients.Six HR-HPVs (HPV16, 18, 31, 45, 56, 68) were detected in 90.6% of HNSCC; and 79.9% had multiple HPV genotypes detected. HPV31 and HPV45 were the most prevalent (79.2% and 87.4%, respectively); and HPV16 was predominantly found in OPSCC (p < 0.001). HPV-DNA PCR assay yielded a high sensitivity (96%) but low specificity (11%) when compared to p16 immunohistochemistry as the reference standard.P16-positive HNSCC was predominantly observed in OPSCC (73.7%; p = 0.005); and p16-positive OPSCC exhibited improved overall survival compared to p16-negative OPSCC (p = 0.022). Similarly, smoking and alcohol consumption were poor prognostic factors of overall survival (p = 0.007; p = 0.01) in OPSCC patients.HR-HPVs were identified in 90.6% of HNSCC patients using the HPV-DNA PCR assay. This test had a poor specificity when compared to p16 IHC; making it an unreliable detection technique in selecting patients for radiation dose de-escalation treatment protocol. P16-positive tumor was predominantly found in the oropharynx these patients demonstrated better overall survival than those with p16-negative OPSCC.

Background: Human Papillomavirus (HPV) is a cause of oropharyngeal squamous cell carcinoma (OPSCC), but its pathogenic role in larynx squamous cell carcinoma (LSCC) remains unclear., Material and Methods: A single-institutional, retrospective case-series was performed to estimate the etiological fraction (EF) for HPV in LSCC. Eligible cases included 436 consecutive cases of LSCC diagnosed (2005-2014) at The Ohio State University Medical Center. HPV DNA presence was detected by consensus primer PCR (Inno-LiPa) and HPV type-specific qPCR. HPV E6/E7 mRNA expression was detected by type-specific qRT-PCR. Tumor p16 expression was evaluated by immunohistochemistry (IHC)., Results: HPV DNA was detected by Inno-LiPa in 54 of 404 (13.4%, 95% CI 10.2-17.1) evaluable samples but was confirmed by HPV type-specific qPCR in only 14 (3.5%, 95% CI 1.9-5.7). Only 7 of 404 (1.7%, 95% CI 0.7-3.5) LSCC were positive for HPV E6/E7 mRNA expression, including HPV16 (n=4) and 1 each for 11, 26 and 33. In the HPV11-positive tumor, Sanger sequencing discovered 6 nucleotide mutations in the upstream regulation region, E6 and E7. Of 404 LSCC, 18 had strong and diffuse p16 expression. In comparison to a gold standard of HPV E6/E7 mRNA expression, p16 expression had a sensitivity of 71.4% (95% CI 29.0-96.3), specificity of 96.7% (95% CI 94.5-98.3), positive-predictive-value (PPV) of 27.8% (95% CI 9.7-53.5) and negative-predictive-value of 99.5% (95% CI 98.1-99.9)., Conclusion: The EF for HPV in LSCC is low (1.7%) in a geographic region with high EF for OPSCC. Low-risk HPV may rarely cause LSCC. Finally, p16 expression has poor PPV for HPV in LSCC., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

There is limited information regarding the incidence of p16 expression, its association with human papillomavirus (HPV) and prognosis in oral cavity squamous cell carcinoma (OSCC). The role of p16 in OSCC is evaluated in 215 cases using tissue microarrays (TMAs). p16 immunohistochemistry and HPV in situ hybridisation were performed on TMAs following histopathology review of 215 patients with OSCC in the Sydney Head and Neck Cancer Institute database. Thirty-seven (17.2%) cases showed p16 expression without association with HPV. p16 expression significantly decreased with increasing pT category (p=0.002). p16 expression was associated with longer disease-specific survival on univariable analysis (p=0.044) but not on multivariable analysis adjusting for depth of invasion. Amongst patients receiving adjuvant radiotherapy, patients with p16 expression had significantly longer disease-free and overall survival. p16 expression was seen in early stage OSCCs and was associated with better survival following surgery and radiotherapy. While not an independent predictor of survival, p16 may mediate its effects by contributing to reduced proliferative capacity, leading to smaller tumour size and lower invasive potential., (Copyright © 2016. Published by Elsevier B.V.)

Many patients with human papillomavirus (HPV)-related head and neck squamous cell carcinoma present initially with cervical nodal metastasis. Fine needle aspiration (FNA) of the nodal disease might be the only diagnostic material available for p16 immunohistochemistry (IHC) and HPV testing. The current study aims to evaluate p16 IHC in FNA and establish guidelines for its interpretation. The percentage and intensity of p16 IHC staining were examined in 60 matched FNA and surgical cases. Cytomorphologic features were included in the analysis. p16 IHC staining was correlated with the results seen in the surgical specimens and with HPV in situ hybridization (ISH). Analysis of different thresholds demonstrated that the threshold of 10% p16 tumor cell positivity had the best overall concordance rate with surgical p16 IHC (κ = 0.650) and with FNA HPV-ISH (κ = 0.714). Applying the recommended p16 positivity threshold for surgical specimens (70%) on FNA materials resulted in low sensitivity (39%) and low negative predictive value (26%). In comparison with p16 IHC in surgical specimens, 6/46 FNA cases (13%) were falsely negative for p16. All 6 cases were associated with necrotic background, two (33%) lacked large tumor clusters, and one (17%) had low cellularity. The recommended threshold for p16 IHC on surgical specimens should not be used in cytology materials. The cutoff value for p16 immunostain in FNA specimens showing best results in our series is 10%. When p16 IHC is negative in FNA specimens, a repeat stain on a surgical specimen is recommended to avoid a false-negative diagnosis., (Copyright © 2016 Elsevier Inc. All rights reserved.)

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.

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., (© American Society for Clinical Pathology, 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Purpose: Identifying intraepithelial sebaceous carcinoma cells in small periocular biopsies can be difficult, particularly in the conjunctiva. The goal of this study was to evaluate p53 and p16 immunohistochemistry as potential markers of intraepithelial sebaceous carcinoma., Procedures: A total of 25 tumors, including 4 recurrent lesions, were stained for p16 and p53, with intensity scored as negative, weak, moderate or strong., Results: Expression of p16 was detected in intraepithelial sebaceous carcinoma cells in 24 of the 25 cases (96%), with only 1 case showing weak immunoreactivity. Intraepithelial p53 immunoreactivity was present in 17 of 25 tumors (68%), but was weak in 3 cases. Expression levels remained relatively stable in primary and recurrent tumors, but varied in a few cases between intraepithelial and subepithelial sites., Conclusions: Intraepithelial sebaceous carcinomas stained for p53 and p16 demonstrated moderate to strong immunoreactivity in 100% of cases for at least one of these proteins, suggesting that together they are useful markers for determining the extent of tumor spread. Of the two, p16 was immunoreactive in more cases than p53.

Background: Human papillomavirus (HPV)-positive oropharyngeal cancer is associated with improved survival and treatment response as compared to HPV-negative cancers. P16 overexpression is widely accepted as a surrogate marker for HPV positivity., Methods: A total of 92 serum samples from 75 head and neck squamous cell carcinoma (HNSCC) patients were examined for HPV16 and 18 E7 antibodies by ELISA. Available tissue was tested for HPV-DNA by PCR, and p16 immunohistochemistry was obtained from a deidentified database., Results: Of 75 HNSCC patients, 25 were HPV E7 seropositive. Seropositivity was strongly associated with cancers of the oropharynx, and correlated with positive p16 immunohistochemistry (IHC) and HPV-DNA. Post-treatment serum was available in a limited subset of patients, revealing a decrease in antibody titers following response to treatment., Conclusions: HPV E7 seropositivity correlated with positive tumor HPV-DNA and p16 expression, and was strongly associated with cancers of the oropharynx. E7 serology warrants further study as a potential biomarker in HPV-positive HNSCC., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: Infection with high-risk human papillomavirus (HPV) is linked to a sub-group of squamous cell oropharyngeal tumors (OPSCC). Our aim was to compare an HPV Polymerase Chain Reaction (PCR) assay and p16(INK4A) expression status by immunohistochemistry (IHC) as a surrogate marker., Materials and Methods: This was a retrospective study considering patients affected by squamous cell oropharyngeal tumors. All included samples were processed for IHC for p16(INK4A) and tested by PCR for detection of HPV DNA and HPV genotyping., Results: A total of 84 patients affected by squamous cell oropharyngeal tumors were included and tested. A significant positive correlation was found between HPV PCR and p16(INK4A) IHC but the agreement was poor (k coefficient of 0.25). In fact, the sensitivity of p16(INK4A) IHC positivity in detecting HPV PCR positivity was low (28.21%, 95% confidence interval=16.54% - 43.78%)., Conclusion: Positivity of p16(INK4A) by IHC had a low sensitivity in detecting HPV DNA and our results suggest the need at least to test p16(INK4A) IHC- negative samples using HPV PCR to increase detection accuracy and provide valuable information for the clinical management of these patients., (Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)

Summary Akin to cervical cancer in sexually-active women, men who have sex with men (MSM) are predisposed to anal cancers, especially those with HIV co-infection. This cross-sectional study endeavored to assess the prevalence of anal dysplasia using Pap smears and p16 immunostaining amongst Indian MSM. A total of 31 consecutive HIV-positive and 34 HIV-negative MSM, from a cohort of sexually transmitted infection clinic attendees, underwent anal cytological evaluation with Pap smear and p16 staining. Chi square test and coefficient of correlation were used for comparison. Eighteen (27.7%) had abnormal anal cytology; increased in HIV-positive as compared to HIV-negative men (35% versus 20%, p = 0.180). Similarly, both low-grade (25.8% versus 17.6%) and high-grade lesions (8.3% versus 4.8%) were comparable in HIV-positive and HIV-negative group. Thirteen (20%) smears were p16-positive with a sensitivity and specificity for anal dysplasia of 72.3% and 100%, respectively. Anal cytology may be used to screen for anal dysplasia in MSM irrespective of HIV status. Furthermore, the addition of p16, with greater specificity for high-grade lesions, may improve diagnostic accuracy especially for high-grade lesions. A larger study to further corroborate these observations is warranted., (© The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.)

Much recent attention has highlighted a subset of head and neck squamous cell carcinomas (HNSCCs) related to human papillomavirus (HPV) that has an epidemiologic, demographic, molecular and clinical profile which is distinct from non-HPV-related HNSCC. The clinical significance of detecting HPV in a HNSCC has resulted in a growing expectation for HPV testing of HNSCCs. Although the growing demand for routine testing is understandable and appropriate, it has impelled an undisciplined approach that has been largely unsystematic. The current state of the art has now arrived at a point where a better understanding of HPV-related tumorigenesis and a growing experience with HPV testing can now move wide scale, indiscriminant and non-standardized testing towards a more directed, clinically relevant and standardized approach. This review will address the current state of HPV detection; and will focus on why HPV testing is important, when HPV testing is appropriate, and how to test for the presence of HPV in various clinical samples. As no single test has been universally accepted as a best method, this review will consider the strengths and weaknesses of some of the more commonly used assays, and will emphasize some emerging techniques that may improve the efficiency of HPV testing of clinical samples including cytologic specimens., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Recent studies have reported that p16 protein overexpression qualifies as a surrogate marker identifying an oncogenic human papillomavirus (HPV) infection in oropharyngeal squamous cell carcinoma (OPSCC). However, there is still a percentage of OPSCCs that are positive for p16 immunohistochemistry (p16 IHC) but lack HPV DNA. The objective of this study was to characterize this group at the molecular level by performing sensitive HPV DNA- and RNA-based PCR methods and genetic profiling. All patients diagnosed with an OPSCC in the period 2000-2006 in two Dutch university medical centers were included (n = 841). The presence of HPV in a tumor sample was tested by p16 IHC followed by an HPV DNA GP5+/6+ PCR. p16 IHC scored positive in 195 samples, of which 161 were HPV DNA-positive and 34 (17%) HPV DNA-negative. In the latter group, a SPF10-LiPA25 assay, an HPV16 type-specific E7 PCR and an E6 mRNA RT-PCR were performed. Next, ten of these cases were further analyzed for loss of heterozygosity (LOH) of 15 microsatellite markers at chromosome arms 3p, 9p and 17p. Of the 34 p16-positive but PCR-negative OPSCCs, two samples tested positive by SPF10 assay, HPV16 E7 PCR and HPV16 E6 mRNA RT-PCR. Three samples tested positive by SPF10 assay but negative by the HPV16-specific assays. Nine of ten cases that were tested for LOH showed a genetic pattern comparable to that of HPV-negative tumors. This study categorizes p16-positive but HPV DNA-negative OPSCCs as HPV-negative tumors based on genetic profiling. This study highlights the importance of performing HPV testing in addition to p16 IHC for proper identification of HPV-associated OPSCCs., (© 2013 UICC.)

Confirmation of human papillomavirus (HPV) as a causative agent for a subset of biologically and clinically distinct squamous cell carcinomas of the head and neck (HNSCC) has resulted in a growing need and expectation for HPV testing of head and neck cancers. At the same time, opportunities to obtain tissue samples for HPV testing are diminishing: The sensitivity of HPV-related HNSCC to chemotherapy and ionizing radiation has limited the role of surgical resection, and diagnostic tissue biopsies/resections may not be available in a substantial portion of patients with small or occult primaries. Into this quandary steps the cytopathologist. Fine needle aspirates of metastatic HNSCCs and brushes of oropharyngeal cancers provide a valuable substrate for HPV analysis. These cytologic specimens are suitable for standard tissue-based methods of HPV detection such as immunoperoxidase and in situ hybridization, but the expanding demands for biomarker analysis of these limited samples is driving the development of alternative assays that eliminate the requirement for high cellularity and complex specimen processing. Various liquid phase assays already in widespread use for HPV analysis of cervical cancer risk may be directly transferrable to the head and neck context. Implementation of these assays may abrogate the current need for tissue acquisition of HNSCCs via a more aggressive surgical procedure., (Copyright © 2013 Wiley Periodicals, Inc.)

Background: Oropharyngeal squamous cell carcinoma (OPSCC) is associated with the sexually transmitted human papillomavirus (HPV), smoking and alcohol. In Greenland, a high rate of HPV-induced cervical cancer and venereal diseases are found, which exposes the population for high risk of HPV infection. In Greenland, only girls are included in the mandatory HPV vaccination program., Objective: To investigate the annual incidence of OPSCC and the proportion of HPV-associated OPSCC (HPV+ OPSCC) in Greenland in 1994-2010., Design: At Rigshospitalet, University of Copenhagen, we identified all Greenlandic patients diagnosed and treated for OPSCC from 1994 to 2010. Sections were cut from the patient's paraffin-embedded tissue blocks and investigated for p16 expression by immunohistochemistry. HPV analyses were performed with 2 sets of general HPV primers and 1 set of HPV16-specific primer. HPV+ OPSCC was defined as both >75% p16+ cells and PCR positive for HPV., Results: Of 26 Greenlandic patients diagnosed with OPSCC, 17 were males and 9 were females. The proportion of HPV+ OPSCC in the total study period was 22%, without significant changes in the population in Greenland. We found an increase in the proportion of HPV+ OPSCC from 14% in 1994-2001 to 25% in 2002-2010 (p=0.51). Among males from 20 to 27% (p=0.63) and in females from 0 to 20% (p=0.71). The annual OPSCC incidence increased from 2.3/100,000 (CI=1.2-4.2) in 1994-2001 to 3.8/100,000 (CI=2.4-6.2) in 2002-2010: among males from 2.4/100,000 (CI=1.0-5.7) to 5.0/100,000 (CI=2.9-8.9)., Conclusion: Even though the population is at high risk of HPV infection, the proportion of 22% HPV+ OPSCC in the total study period is low compared to Europe and the United States. This might be explained by our small study size and/or by ethnic, geographical, sexual and cultural differences. Continuing observations of the OPSCC incidence and the proportion of HPV+ OPSCC in Greenland are needed.