Human Papillomavirus-Associated Oral Cavity Squamous Cell Carcinoma: An Entity with Distinct Morphologic and Clinical Features

Consensus in Oral Epithelial Dysplasia Classification: A Comparative Analysis of H&E-stained Sections With and Without p53/p16 Immunohistochemistry

Diagnosis and classification of oral epithelial dysplasia (OED) is critical to identifying and prognosticating patients at risk of squamous cell carcinoma (SCC). However, conventional 3-tiered and 2-tiered grading systems suffer from poor inter-pathologist agreement, and SCC may arise from all grades of OED. This study evaluated pathologist agreement in OED classification as p53 wildtype, p53 abnormal, and HPV-associated based on recent evidence demonstrating the utility of p53/p16 immunohistochemistry (IHC) in this setting and increased risk of p53 abnormal OED progression to SCC, regardless of histologic grade. Fifty digital biopsy specimens were evaluated for diagnosis by 18 subspecialty-trained pathologists, with OED graded utilizing 3-tiered, 2-tiered, and p53 wildtype/p53 abnormal/HPV-associated schemata. Cases were reviewed first without and subsequently with p53/p16 IHC. The cohort consisted of 8 cases of p53 wildtype, 24 cases of p53 abnormal, and 18 cases of HPV-associated OED. Inter-pathologist agreement in OED grading according to 3-tiered (κ=0.32) and 2-tiered (κ=0.39) systems by H&E was poor, but fair-to-good (κ=0.59) in classification as p53 wildtype/p53 abnormal/HPV-associated by H&E and IHC. Classification of OED as p53 wildtype, p53 abnormal, or HPV-associated using p53/p16 IHC outperformed conventional grading in this cohort enriched for p53 abnormal OED, which required correct interpretation of p53 IHC, historically deemed challenging. Routine use of IHC also identifies a wider histologic spectrum of HPV-associated OED than is currently appreciated. More work is needed to determine the efficacy of this classification system in predicting patient outcomes and in guiding management decisions in real-world cohorts.

Utility of p53 and p16 immunohistochemistry in the diagnosis of human papillomavirus-associated oral epithelial dysplasia: a retrospective study of 105 patients

AIMS

This study investigated the utility of combined p16 and p53 immunohistochemistry (IHC) for diagnosing high-risk human papillomavirus (HR HPV)-associated oral epithelial dysplasia (OED) and its associated clinical behaviour, including disease recurrence and transformation to malignancy.

METHODS AND RESULTS

The expression of p53 was evaluated in 105 cases of HR HPV-positive oral cavity OED, of which 104 were scored as positive for p16. HPV status was confirmed by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) for E6 mRNA or RNA in situ hybridization (ISH). Seven cases of p16-positive oral cavity OED with abnormal p53 expression and/or TP53 mutation and negative HPV RNA ISH were excluded. Most cases (93%) demonstrated classic HPV-associated basaloid morphology, and 7% were keratinizing. The most affected sites were the floor of the mouth/ventral tongue (61%), followed by the lateral tongue (18%) and gingiva (13%). p53 IHC showed that 76% of cases demonstrated a null-like / basal-sparing pattern, while 24% demonstrated a mid-epithelial/basal sparing pattern. Ten cases exhibited an invasive or suspicious for microinvasive component on biopsy. Dysplasia recurred in 14 cases, and a single case transformed to squamous cell carcinoma.

CONCLUSION

The combination of p16 positivity and a basal-sparing pattern of p53 is predictive of HR HPV in OED, eliminating the need for further HPV-specific testing. Although HPV OED may co-occur with invasive squamous cell carcinoma on biopsy, the transformation to malignancy is low.

Human Papillomavirus-Related Cutaneous Squamous Cell Carcinoma

The human papillomavirus (HPV) has been associated with the carcinogenesis of cutaneous squamous cell carcinoma (cSCC), especially in immunosuppressed patients. This article reviews the microbiology of HPV and its role in tissue tropism, invasion, and oncogenesis. It also describes possible HPV oncogenic ability due to the inactivation of the host p53 and retinoblastoma protein (pRb) by HPV oncoproteins E6 and E7, producing a suppression of cell cycle checkpoints and uncontrolled cell proliferation that may eventually result in invasive carcinoma. We will focus on β-HPV types and their role in epidermodysplasia verruciformis (EV), as well as α types and their ability to cause cutaneous and mucosal pathology. We also intend to examine the clinical characteristics of cSCC related to HPV and host immunosuppression conditions such as solid organ transplant in order to provide management guidelines for patients with cSCC associated with HPV based on available data. Other topics addressed in this article include particular locations of cSCC, such as nails; the prognosis; the recurrence; therapeutic modalities; and the role of HPV vaccines.

Human oncogenic viruses: a focus on head and neck carcinogenesis: a systematic review and meta-analysis

OBJECTIVE

This systematic review aimed at identifying oncoviruses associated with head and neck malignant neoplasms (HNC).

STUDY DESIGN

Five databases and grey literature sources were searched following PRISMA guidelines. The risk of bias in individual studies was analyzed using the Joanna Briggs Institute checklist, and the certainty of evidence was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluation tool.

RESULTS

One hundred and 19 studies were included in the qualitative synthesis. Gathered results of 57 studies were combined in a meta-analysis revealing a significant link between oncoviruses and the development of head and neck cancer, with the most common viruses identified were human papillomavirus (HPV)-16, HPV-18, and Epstein-Barr virus. More studies are needed to clarify the association of human cytomegalovirus and Merkel Cell Polyomavirus with HNC.

CONCLUSIONS

Although the role of viruses in cancer onset has been studied for years, our results demonstrated using a meta-analysis that these viruses are associated with HNC.

CMTM6 status predicts survival in head and neck squamous cell carcinoma and correlates with PD-L1 expression

We retrospectively analyzed 129 treatment-naïve head and neck squamous cell carcinomas (HNSCCs) for the expression of programmed death ligand 1 (PD-L1), CKLF-like MARVEL transmembrane domain-containing 6 (CMTM6), tumor-infiltrating leukocytes (TILs), and tumor-associated macrophages (TAMs). We evaluated the relationships among these markers, human papilloma virus (HPV) status, and overall survival (OS). PD-L1 and CMTM6 (combined positive score (CPS) ≥ 1 and ≥ 5) were detected in ~ 70% of HNSCCs. HPV status had insignificant effects on marker expression. Most PD-L1-positive cases showed concomitant CMTM6 expression with comparable staining patterns. While PD-L1 and CMTM6 mRNA expression levels correlated with PD-L1 and CMTM6 protein status, no significant correlation was observed for PD-L1 and CMTM6 mRNA expression. Tumors expressing PD-L1 (p < 0.0001) and/or CMTM6 (p < 0.05) were associated with the best OS. A high density of TILs (p < 0.01), CD8+ T cells (p < 0.001), and CD68/CD163 ratio > 1 were prognostically relevant. In addition to HPV status, PD-L1 and CD8+ T cells, CMTM6 was identified as an independent prognostic factor using a multivariate Cox regression analysis. PD-L1 and CMTM6 correlated with TILs and CD8+ cells but not with HPV. Our results identified CMTM6 as an important interaction partner in the crosstalk between TILs, CD8+ T cells, and PD-L1, which mediates anticancer efficacy. Assessments of CMTM6 may be helpful for prognostic prediction, and it may serve as a reliable biomarker for immunotherapy selection.

Uncommon and Challenging Phenotypes of High-Risk Human Papillomavirus-Associated Head and Neck Carcinomas Revealed by High-Throughput Studies

BACKGROUND

HPV- associated squamous cell carcinoma (SCC) is uncommon in non-oropharynx sites and not well characterized. This study aims to investigate uncommon phenotypes of HPV-associated head and neck carcinoma, the prevalence and morphologic spectrum of HPV-associated SCC in the oral cavity, larynx and hypopharynx.

METHOD

P16 immunostaining and HPV E6/7 in situ hybridization (ISH) were performed on tissue microarrays comprised of SCCs from different anatomic sites: oropharynx (n = 270), hypopharynx (n = 52), oral cavity (n = 95) and larynx (n = 123). Tumors were classified as HPV-associated based on a positive E6/7 ISH testing. RNA sequencing was performed on several selected cases.

RESULT

66% oropharynx SCCs (OPSCCs) were HPV-associated; all were p16/HPV testing concordant except one which was p16 negative. The p16-/HPV + OPSCC resembled similar gene expression signature with p16+/HPV + OPSCCs by transcriptome analysis. 6/95 (6%) oral cavity SCCs were HPV-associated, all from male patients and 5/6 (83%) arose from the floor of mouth. Morphologically, 3/6 (50%) showed keratinizing SCC and 5/6 (83%) demonstrated HPV-associated squamous dysplasia in adjacent mucosa. 1/123 (less than 1%) larynx SCCs and 0/52 hypopharynx SCCs were HPV-associated.

CONCLUSION

Although uncommon, p16 negative HPV-associated OPSCC can occur, emphasizing the importance of judicious HPV testing. The morphology of HPV-associated oral cavity SCCs may deviate from prototypic nonkeratinizing SCC, making them difficult to recognize. Presence of HPV-associated squamous dysplasia could serve as a morphologic clue.

Histologic spectrum and outcome of Human papillomavirus (HPV)-associated oral cavity squamous cell carcinoma: a single center experience and a survey of The Cancer Genome Atlas (TGCA) cohort

While high-risk human papillomavirus (HPV) serves as an essential pathogen and an important prognostic and predictive biomarker for oropharyngeal squamous cell carcinoma, it occurs at low frequency (2.2-6%) in oral cavity squamous cell carcinoma (OCSCC). To date, the pathologic features of HPV-associated OCSCC (HPV( +)-OCSCC) have been sparsely reported and its prognosis is not well-defined. We herein described detailed clinicopathologic features and outcomes of a retrospective series of 27 HPV( +)-OCSCC, including 13 from Memorial Sloan Kettering Cancer Center (MSKCC) and 14 from The Cancer Genomic Atlas program (TCGA). The frequency of HPV positivity in OCSCC was 0.7% in MSKCC cohort and 4.9% in TCGA cohort. Although HPV( +)-OCSCC was predominantly non-keratinizing (in 81%) with various degree of maturation, its histologic spectrum was expanded to include keratinizing subtype (19%), adenosquamous carcinoma (7%), and papillary architecture (subtype, 7%). HPV( +)-OCSCC predominantly affected male patients (male:female ratio = 12.5:1) and (ex) smokers (77%). It might occur in mandibular mucosa, floor of mouth, tongue, retromolar trigone, buccal mucosa, maxillary mucosa, or hard palate. In oral cavity, positivity of HPV by RNA in situ hybridization was required, and p16 immunohistochemistry alone was insufficient to confirm the HPV + status. The positive predictive value of p16 immunopositivity in detecting HPV infection was 68%. HPV-positivity did not appear to affect outcomes, including disease specific survival and progression free survival in OCSCC.

High incidence of HPV infection in minors with oral squamous cell carcinoma

BACKGROUND

Oral squamous cell carcinoma in minors is considered to be a distinct entity from OSCC in older patients, with an uncertain etiology. Human papillomavirus (HPV) infection may trigger the initiation and promote the progression of OSCC, but these roles have not been firmly established.We aimed to explore the correlation between HPV infection and the development of oral squamous cell carcinoma in minors and know the characteristics of OSCC in young patients more thoroughly.

METHOD

From January 2013 to December 2022,6 cases of OSCC aged < 15 years were selected from the Department of Oral Pathology, Peking University School of Stomatology, Beijing, China. All cases underwent testing for high-risk HPV mRNA infection using the RNA scope technique, and immunohistochemical staining was performed to investigate the expression of p16, pan-cytokeratin (CK), CK5/6, CK7, CK8/18, epidermal growth factor receptor (EGFR), p53, and Ki-67. Furthermore, we reviewed the literature on OSCC in patients aged < 21 years.

CONCLUSIONS

Minors OSCC is associated with HPV infection, and that p16 can serve as an immunohistochemical marker of HPV positivity.

Utilization of p53 and p16 Immunohistochemistry in the Classification of Human Papillomavirus-Associated, p53 Wild-Type, and p53 Abnormal Oral Epithelial Dysplasia

p53 immunohistochemistry (IHC) has recently been shown to be a clinically useful marker for predicting risk of progression to invasive squamous cell carcinoma in oral epithelial dysplasia (OED). The literature supports the use of p53 IHC as a marker to identify TP53 mutation in in situ and invasive vulvar lesions and as a surrogate marker for high-risk human papillomavirus (HPV) infection, but there is little documentation for similar use in OED. The purpose of this study was to determine whether p53 IHC is a reliable surrogate marker for detecting both TP53 mutation and high-risk HPV infection in OED. We studied 57 cases of OED (11 mild, 18 moderate, and 28 severe), and all were stained for p16 and p53 IHC. High-risk HPV RNA in situ hybridization (ISH) was performed in selected cases (all p16-positive cases and all OED showing abundant apoptotic cells and karyorrhectic cells; N = 27). Targeted next-generation sequencing (NGS) was performed in 33 p16-negative cases and all high-risk HPV RNA ISH-negative cases (N = 36). We identified 21 cases with p53 basal sparing patterns (mid-epithelial and markedly reduced [null-like]), 14 cases with p53 wild-type patterns (scattered basal and patchy basal/parabasal), and 22 cases with p53 abnormal patterns (18 overexpression, 3 null, and 1 novel cytoplasmic pattern). Among cases with p53 basal sparing patterns, 20 were positive for p16 (20/21, 95%), and all were positive for high-risk HPV RNA ISH (21/21, 100%). The 36 sequenced cases had IHC patterns concordant with TP53 mutation status in 92% (33/36) of lesions. This study demonstrates that p53 IHC expression patterns are sensitive and specific for detection of both high-risk HPV infection and TP53 mutation. Coupled with selective p16 IHC testing, this IHC panel can accurately subclassify OED into HPV-associated, p53 wild-type (conventional), and p53 abnormal OED.

Predictive value of CDKN2A/p16INK4a expression in the malignant transformation of oral potentially malignant disorders: Systematic review and meta-analysis

BACKGROUND

Management of oral potentially malignant disorders (OPMDs) is still challenging. Despite the diagnostic ascertainment by bioptic examination, this method is poorly informative of the prognosis and subsequent malignant transformation. Prognosis is based on histological findings by grading of dysplasia. Immunohistochemical expression of p16INK4a has been investigated in different studies, with controversial results. In this scenario, we systematically revised the current evidence about p16INK4a immunohistochemical expression and the risk of malignization of OPMDs.

MATERIAL AND METHODS

After a proper set of keywords combination, 5 databases were accessed and screened to select eligible studies. The protocol was previously registered on PROSPERO (Protocol ID: CRD42022355931). Data were obtained directly from the primary studies as a measure to determine the relationship between CDKN2A/P16INK4a expression and the malignant transformation of OPMDs. Heterogeneity and publication bias were investigated by different tools, such as Cochran's Q test, Galbraith plot and Egger and Begg Mazumdar's rank tests.

RESULTS

Meta-analysis revealed a twofold increased risk to malignant development (RR = 2.01, 95% CI = 1.36-2.96 - I2 = 0%). Subgroup analysis did not highlight any relevant heterogeneity. Galbraith plot showed that no individual study could be considered as an important outlier.

CONCLUSION

Pooled analysis showed that p16INK4a assessment may arise adjunct tool to dysplasia grading, leading to an optimized determination of the potential progression to cancer of OPMDs. The p16INK4a overexpression analysis by immunohistochemistry techniques has a multitude of virtues that may facilitate its incorporation in the day-to-day prognostic study of OPMDs.

Association between human papillomavirus and oral cancer: a literature review

HPV plays a vital role in the development of cervical cancers and oropharyngeal cancers, but it is controversial whether HPV is involved in oral cancer development and to what extent. In this review, the clinical characteristics, diagnosis, treatment, and prognosis of HPV-positive oral cancers are summarized, and the mechanisms of HPV-related oral cancer development are discussed. HPV DNA positivity rates are 20-30% in oral squamous cell carcinoma (OSCC), and HPV16 is the most common high-risk HPV. E6/E7 mRNA positivity rates are 2-6% in OSCC. Detection of both high-risk HPV DNA and E6/E7 mRNA is recommended to determine the presence of active HPV, in agreement with high-risk HPV infection in OSCC. Surgical treatment is the first-line therapy for HPV-positive and -negative oral cancer, but there is no unified view about the prognosis of HPV-positive OSCC patients. HPV16 may play a vital role in malignant transformation in oral epithelial dysplasia, and a model of synergistic carcinogenic impact of HPV and tobacco smoking is predicted. Additionally, it is hypothesized that there are different HPV-associated oral cancers, such as integrated HPV DNA-positive OSCC with stable E6/E7 expression and episomal HPV DNA-positive OSCC. In summary, the role of HPV in oral carcinogenesis seems to be limited because of the low E6/E7 positivity in OSCCs; however, episomal HPV DNA may play a vital role in the malignant transformation of HPV-positive oral premalignant lesions. Further investigation is required to promote new insights into the role of episomal HPV DNA in oral carcinogenesis.

Abnormal p53 Immunohistochemical Patterns Shed Light on the Aggressiveness of Oral Epithelial Dysplasia

The diagnosis of oral epithelial dysplasia is based on the degree of architectural and cytologic atypia in the squamous epithelium. The conventional grading system of mild, moderate, and severe dysplasia is considered by many the gold standard in predicting the risk of malignant transformation. Unfortunately, some low-grade lesions, with or without dysplasia, progress to squamous cell carcinoma (SCC) in short periods. As a result, we are proposing a new approach to characterize oral dysplastic lesions that will help identify lesions at high risk for malignant transformation. We included a total of 203 cases of oral epithelial dysplasia, proliferative verrucous leukoplakia, lichenoid, and commonly observed mucosal reactive lesions to evaluate their p53 immunohistochemical (IHC) staining patterns. We identified 4 wild-type patterns, including scattered basal, patchy basal/parabasal, null-like/basal sparing, mid-epithelial/basal sparing, and 3 abnormal p53 patterns, including overexpression basal/parabasal only, overexpression basal/parabasal to diffuse, and null. All cases of lichenoid and reactive lesions exhibited scattered basal or patchy basal/parabasal patterns, whereas human papillomavirus-associated oral epithelial dysplasia demonstrated null-like/basal sparing or mid-epithelial/basal sparing patterns. Of the oral epithelial dysplasia cases, 42.5% (51/120) demonstrated an abnormal p53 IHC pattern. p53 abnormal oral epithelial dysplasia was significantly more likely to progress to invasive SCC when compared to p53 wild-type oral epithelial dysplasia (21.6% vs 0%, P < .0001). Furthermore, p53 abnormal oral epithelial dysplasia was more likely to have dyskeratosis and/or acantholysis (98.0% vs 43.5%, P < .0001). We propose the term p53 abnormal oral epithelial dysplasia to highlight the importance of utilizing p53 IHC stain to recognize lesions that are at high risk of progression to invasive disease, irrespective of the histologic grade, and propose that these lesions should not be graded using the conventional grading system to avoid delayed management.

Oral Cavity Squamous Cell Carcinoma: An Update of the Pharmacological Treatment

Oral cavity squamous cell carcinoma (OCSCC) represents a serious health and socio-economic problem in different geographical areas of the world. It is characterized by a high rate of mortality, recurrence and metastasis. Despite the therapeutic strategies implemented for its management and resolution, currently the survival estimate for locally advanced disease is about 50%. The available therapeutic options comprise surgery and pharmacological treatment. Recently, an increased emphasis has been placed on the drugs that might be of benefit in this life-threatening disease. Therefore, the aim of this present review was to offer a general survey of the current available pharmacological treatment for OCSCC. The PubMed database was used to retrieve the papers using "OCSCC" as the search terms. We limited our search to the last 5 years to give a more updated and recent picture of the state of the art, including preclinical and clinical investigations. We found that 77 out of 201 papers were on the surgical treatment of OCSCC, 43 out of 201 focused on the radiotherapy and 81 out of 201 underwent evaluation for the aim of our review. We excluded the case reports, editorial letters, observational studies and papers written in languages other than English. A total of 12 articles were included in the final review. Our results showed that nanotechnologies use to enhance the efficacy of anticancer drugs such as: cisplatin, paclitaxel, cetuximab, EGFR antagonists, MEK1/2 and immune check inhibitors combination could have promising anti-cancer activity. However, the paucity of available data on drugs suggests the urgent need to improve the pharmacological armamentarium for OCSCC treatment.