Salivary mucoepidermoid carcinoma: demonstration of transcriptionally active human papillomavirus 16/18

Two Head and Neck Carcinomas With Squamous and Mucinous Components and Human Papillomavirus Associations: Maxillary Mucoepidermoid Carcinoma ex Sinonasal Schneiderian Papilloma and Tonsillar Invasive Stratified Mucin Producing Carcinoma (ISMC)

Carcinomas of the head-and-neck region with squamous and glandular/mucinous features constitute a heterogeneous group, with a significant minority of tumors showing an human papillomavirus (HPV) association. The differential diagnosis is usually between mucoepidermoid carcinoma (MEC) and adenosquamous carcinoma. We present here two tumors that exemplify both the challenges of diagnostic classification, as well as the complex relationship to HPV: (a) a low risk HPV positive/p16 negative carcinoma that is most consistent with a relatively typical intermediate grade mucoepidermoid type carcinoma with complete MEC phenotype (three cell types), originating from intranasal sinonasal papillomas with exophytic and inverted patterns, and invading surrounding maxillary compartments, and (b) a p16 and keratin 7 (KRT7) positive carcinoma of the right tonsil, characterized by stratified squamous and mucinous cell (mucocyte) features. Whereas the first tumor represents a typical MEC ex-Schneiderian papilloma, the second is morphologically most consistent with the, novel for this anatomic location, diagnosis of "invasive stratified mucin producing carcinoma" (ISMC), pointing to an analogy to similar, high-risk HPV-driven malignancies recently described in the gynecologic (GYN) and genitourinary (GU) areas. Both tumors, despite their mucoepidermoid-like features had no connection to salivary glands and lacked the MAML2 translocation typical of salivary gland MEC, pointing to a mucosal/non-salivary gland origin. Using these two carcinomas as examples, we attempt to address questions related to: (a) the histological distinction between MEC, adenosquamous carcinoma, and ISMC, (b) similarities and differences between these histological entities in mucosal sites versus morphologically similar salivary gland tumors, and (c) the role of HPV in these tumors.

Very rare tumour of the palatine tonsil: a molecular approach

Mucoepidermoid cancer (MEC) is extremely rare in the palatine tonsil with only three adequately described cases in the literature.We describe a woman in her late 70s with vague pharyngeal discomfort who underwent tonsillectomy, lymph node dissection of the neck and radiotherapy for MEC with loco-regional lymph node metastasis of the palatine tonsil. To confirm this extremely rare diagnosis and to gain deeper insight in the molecular oncogenesis, an extensive molecular study including next-generation sequencing and immunohistochemistry was performed. Immunoreactivity for p16 protein and real-time PCR showed high-risk oncogenic human papillomavirus 16 DNA and mutations in the BRAF, BARD and DNMT3A genes. Tumour mutational burden was low. After a follow-up of 7 years the patient is still alive and well without any residual or disseminated disease.

A Radiomics-Based Machine Learning Perspective on the Parotid Gland as a Potential Surrogate Marker for HPV in Oropharyngeal Cancer

BACKGROUND

In treatment of oropharyngeal squamous cell carcinoma (OPSCC), human papillomavirus status (HPV) plays a crucial role. The HPV-positive subtype tends to affect younger patients and is associated with a more favorable prognosis. HPV-associated lesions have been described in the parotid gland, which is included in routine imaging for OPSCC. This work aims to explore the ability of an ML system to classify HPV status based on imaging of the parotid gland, which is routinely depicted on staging imaging.

METHODS

Using a radiomics approach, we investigate the ability of five contemporary machine learning (ML) models to distinguish between HPV-positive and HPV-negative OPSCC based on non-contrast computed tomography (CT) data of tumor volume (TM), locoregional lymph node metastasis (LNM), and the parotid gland (Parotid). After exclusion of cases affected by streak artefacts, 53 patients (training set: 39; evaluation set: 14) were retrospectively evaluated. Classification performances were tested for significance against random optimistic results.

RESULTS

The best results are AUC 0.71 by XGBoost (XGB) for TM, AUC 0.82 by multi-layer perceptron (MLP) for LNM, AUC 0.76 by random forest (RF) for Parotid, and AUC 0.86 by XGB for a combination of all three regions of interest (ROIs).

CONCLUSIONS

The results suggest involvement of the parotid gland in HPV infections of the oropharyngeal region. While the role of HPV in parotid lesions is under active discussion, the migration of the virus from the oral cavity to the parotid gland seems plausible. The imaging of the parotid gland offers the benefit of fewer streak artifacts due to teeth and dental implants and the potential to screen for HPV in cases of an absent or unlocatable tumor. Future investigation can be directed to validation of the results in independent datasets and to the potential of improvement of current classification models by addition of information based on the parotid gland.

The Epigenesis of Salivary Glands Carcinoma: From Field Cancerization to Carcinogenesis

Salivary gland carcinomas (SGCs) are a diverse collection of malignant tumors with marked differences in biological activity, clinical presentation and microscopic appearance. Although the etiology is varied, secondary radiation, oncogenic viruses as well as chromosomal rearrangements have all been linked to the formation of SGCs. Epigenetic modifications may also contribute to the genesis and progression of SGCs. Epigenetic modifications are any heritable changes in gene expression that are not caused by changes in DNA sequence. It is now widely accepted that epigenetics plays an important role in SGCs development. A basic epigenetic process that has been linked to a variety of pathological as well as physiological conditions including cancer formation, is DNA methylation. Transcriptional repression is caused by CpG islands hypermethylation at gene promoters, whereas hypomethylation causes overexpression of a gene. Epigenetic changes in SGCs have been identified, and they have been linked to the genesis, progression as well as prognosis of these neoplasms. Thus, we conduct a thorough evaluation of the currently known evidence on the involvement of epigenetic processes in SGCs.

Analysis of Human Papilloma Virus Content and Integration in Mucoepidermoid Carcinoma

Mucoepidermoid Carcinomas (MEC) represent the most common malignancies of salivary glands. Approximately 50% of all MEC cases are known to harbor CRTC1/3-MAML2 gene fusions, but the additional molecular drivers remain largely uncharacterized. Here, we sought to resolve controversy around the role of human papillomavirus (HPV) as a potential driver of mucoepidermoid carcinoma. Bioinformatics analysis was performed on 48 MEC transcriptomes. Subsequent targeted capture DNA sequencing was used to annotate HPV content and integration status in the host genome. HPV of any type was only identified in 1/48 (2%) of the MEC transcriptomes analyzed. Importantly, the one HPV16+ tumor expressed high levels of p16, had high expression of HPV16 oncogenes E6 and E7, and displayed a complex integration pattern that included breakpoints into 13 host genes including PIK3AP1, HIPI, OLFM4,SIRT1, ARAP2, TMEM161B-AS1, and EPS15L1 as well as 9 non-genic regions. In this cohort, HPV is a rare driver of MEC but may have a substantial etiologic role in cases that harbor the virus. Genetic mechanisms of host genome integration are similar to those observed in other head and neck cancers.

Mucoepidermoid carcinoma - A common neoplasm at an unusual site, mimicking a benign cyst on cytology: Diagnostic pitfall!

Mucoepidermoid carcinoma (MEC) is known to be a relatively common neoplasm of the major and minor salivary glands that can secondarily involve skin. The clinical manifestations, diagnostic cytology and histopathology of MEC presenting as a clinically benign periauricular cystic nodule have been analyzed. The challenge of accurate diagnosis can be illustrated by the fact that initially, on cytology, this tumor was misdiagnosed as a benign epidermal inclusion cyst due to the presence of mucin-filled cells which were misinterpreted as cyst macrophages. This case report emphasizes the need to include parotid tumors in the differential diagnosis of all periauricular cyst-like expansions. We also briefly discuss the reasons for false-positive cytology in this case. Delay in accurate diagnosis may result in larger surgical procedures, such as radical neck dissection, that may otherwise be avoided.

Phytochemically Derived Zingerone Nanoparticles Inhibit Cell Proliferation, Invasion and Metastasis in Human Oral Squamous Cell Carcinoma

Due to its aggressiveness and high mortality rate, oral cancer still represents a tough challenge for current cancer therapeutics. Similar to other carcinomas, cancerous invasion and metastasis are the most important prognostic factors and the main obstacles to therapy for human oral squamous cell carcinoma (OSCC). Fortunately, with the rise of the nanotechnical era and innovative nanomaterial fabrication, nanomaterials are widely used in biomedicine, cancer therapeutics, and chemoprevention. Recently, phytochemical substances have attracted increasing interest as adjuvants to conventional cancer therapy. The ginger phenolic compound zingerone, a multitarget pharmacological and bioactive phytochemical, possesses potent anti-inflammatory, antioxidant, and anticancer activities. In our previous study, we generated phytochemically derived zingerone nanoparticles (NPs), and documented their superior antitumorigenic effect on human hepatoma cells. In the present study, we further investigated the effects of zingerone NPs on inhibiting the invasiveness and metastasis of human OSCC cell lines. Zingerone NPs elicited significant cytotoxicity in three OSCC cell lines compared to zingerone. Moreover, the lower dose of zingerone NPs (25 µM) markedly inhibited colony formation and colony survival by at least five-fold compared to zingerone treatment. Additionally, zingerone NPs significantly attenuated cell motility and invasiveness. In terms of the signaling mechanism, we determined that the zingerone NP-mediated downregulation of Akt signaling played an important role in the inhibition of cell viability and cell motility. Zingerone NPs inhibited matrix metalloproteinase (MMP) activity, which was highly correlated with the attenuation of cell migration and cell invasion. By further detecting the roles of zingerone NPs in epithelial–mesenchymal transition (EMT), we observed that zingerone NPs substantially altered the levels of EMT-related markers by decreasing the levels of the mesenchymal markers, N-cadherin and vimentin, rather than the epithelial proteins, ZO-1 and E-cadherin, compared with zingerone. In conclusion, as novel and efficient phytochemically derived nanoparticles, zingerone NPs may serve as a potent adjuvant to protect against cell invasion and metastasis, which will provide a beneficial strategy for future applications in chemoprevention and conventional therapeutics in OSCC treatment.

A Primary Parotid Mucosa-Associated Lymphoid Tissue Non-Hodgkin Lymphoma in a Patient With Sjogren Syndrome

The salivary gland tumors are rare entities and the majority of these are benign. However, there are some entities such as prior neck radiation, certain infections, and systemic diseases which should raise the clinical suspicion for a malignant lesion. Patients with Sjogren syndrome are at increased risk for a salivary gland neoplasm, specifically non-Hodgkin lymphoma. While clinical findings play an important role in the initial workup, imaging plays a critical role in the diagnosis and management. This case describes a patient with Sjogren syndrome who presented with a left face mass where imaging was able to confidently diagnose her with a suspicious parotid neoplasm with lymphoma as the favored diagnosis. After histological evaluation, she was diagnosed with primary parotid mucosa-associated lymphoid tissue (MALT) non-Hodgkin lymphoma after which she went on to non-operative management.

Incidence and survival trends of parotid malignancies over 42 years

BACKGROUND

There is a paucity of information regarding the incidence and survival of parotid malignancies over time.

METHODS

The Surveillance, Epidemiology, and End Results population-based cancer registry was queried for parotid malignancies from 1973 to 2015.

RESULTS

The age-adjusted incidence of parotid malignancies has increased by 58.1% (7.87-12.44 per 1 000 000). Analysis of histologic type revealed an increased annual percent change (APC) of acinar cell carcinoma (1.38) and squamous cell carcinoma (1.58), but decreased APC of adenoid cystic carcinoma (-1.63) and adenocarcinoma NOS (-0.86) (P < .05). The disease-specific survival of mucoepidermoid carcinoma, adenocarcinoma NOS, and squamous cell carcinoma significantly improved (P < .05) over time.

CONCLUSION

The incidence of parotid cancer is rising steadily since 1973, while the incidence of overall head and neck cancer has decreased. Further research is necessary to understand the etiology, risk factors, and pathophysiology of parotid cancer to curb its rising incidence.

LEVEL OF EVIDENCE

4.

The current markers of cancer stem cell in oral cancers

Head and neck cancer (HNC) constitute 5% of all reported cancers. Among all, the oral cavity cancer is the most frequent type of HNC which accounts for over half of HNC cases. Mouth cancer ranks the sixth leading cause of cancer-related mortality. Generally, conventional chemotherapy has shown success at decreasing relapse and metastasis rates and improves the overall prognosis. Recently, target therapy and targeted drug delivery systems have been introduced as promising treatments. The elimination of efficiency of current therapeutic strategies due to the spared cancer stem cells that cause chemotherapy resistance, relapse and metastasis. Inefficiency methodologies in the elimination of all cancer cells in the body are a major problem that remained to be resolved before to confront the new cancer therapies. Many studies imply to cancer stem cell markers as important agents for targeted anti-cancer as well as improving chemotherapy efficiencies. The potentials of targeted cancer therapy led us to search for novel markers in the mouth cancer stem cells especially in rare cancers. The aimed of this research was, first a comprehensive critical review of the previous studies on the markers of cancer stem cells in oral cancers including oral squamous cell carcinoma, salivary gland cancers, and to highlight the most common cancer stem cell markers which have potential to be exploited as indicators for the preneoplastic lesion malignancy, oral cancer progression, and/or treatment prognosis.

Poorly differentiated neuroendocrine carcinoma of the head and neck: human papillomavirus tumour status/p16 status and impact on overall survival

AIMS

Poorly differentiated neuroendocrine carcinoma (PDNEC) of the head and neck is a rare high-grade neuroendocrine neoplasm. Human papillomavirus (HPV) status and p16 status are as yet unclear among PDNECs, owing to a lack of statistical analysis. The objective of the present study was therefore to evaluate their potential clinicopathological associations, and their prognostic impact on overall survival in PDNECs of the head and neck, regardless to HPV genotype.

METHODS AND RESULTS

All cases of PDNEC of the head and neck between 1998 and 2019 were identified from the database of the Lyon university hospital pathology department (n = 21); for these cases, p16 immunohistochemistry and HPV in-situ hybridisation were performed. Published cases of PDNEC of the head and neck with assessment of HPV status and p16 status were identified in PubMed (n = 57). Local and published cases were pooled for analysis. HPV positive (HPV+) tumour status was found to be significantly associated with oropharyngeal localisation (P < 0.001) and overexpression of p16 (P < 0.001). Multivariate analysis, adjusted on tumour site, histological subtype, p16 status, HPV status, and source of the case, showed that oropharyngeal localisation [hazard ratio (HR) 3.031, 95% confidence interval (CI) 1.257-7.310] and being a small-cell variant (HR 2.859, 95% CI 1.150-7.109) were significant predictors of worse overall survival; HPV+ tumour status was associated with better overall survival (HR 0.388, 95% CI 0.146-0.995).

CONCLUSIONS

HPV+ tumour status was associated with oropharyngeal PDNECs and with a better prognosis.

Human Papillomavirus Testing in Head and Neck Carcinomas: Guideline From the College of American Pathologists

Context Human papillomavirus (HPV) is a major cause of oropharyngeal squamous cell carcinomas, and HPV (and/or surrogate marker p16) status has emerged as a prognostic marker that significantly impacts clinical management. There is no current consensus on when to test oropharyngeal squamous cell carcinomas for HPV/p16 or on which tests to choose. Objective To develop evidence-based recommendations for the testing, application, interpretation, and reporting of HPV and surrogate marker tests in head and neck carcinomas. Design The College of American Pathologists convened a panel of experts in head and neck and molecular pathology, as well as surgical, medical, and radiation oncology, to develop recommendations. A systematic review of the literature was conducted to address 6 key questions. Final recommendations were derived from strength of evidence, open comment period feedback, and expert panel consensus. Results The major recommendations include (1) testing newly diagnosed oropharyngeal squamous cell carcinoma patients for high-risk HPV, either from the primary tumor or from cervical nodal metastases, using p16 immunohistochemistry with a 70% nuclear and cytoplasmic staining cutoff, and (2) not routinely testing nonsquamous oropharyngeal carcinomas or nonoropharyngeal carcinomas for HPV. Pathologists are to report tumors as HPV positive or p16 positive. Guidelines are provided for testing cytologic samples and handling of locoregional and distant recurrence specimens. Conclusions Based on the systematic review and on expert panel consensus, high-risk HPV testing is recommended for all new oropharyngeal squamous cell carcinoma patients, but not routinely recommended for other head and neck carcinomas.

MAML2 Rearrangements in Variant Forms of Mucoepidermoid Carcinoma: Ancillary Diagnostic Testing for the Ciliated and Warthin-like Variants

Mucoepidermoid carcinoma (MEC) is the most common salivary gland malignancy. Recent studies have shown that most MECs harbor gene fusions involving MAML2-an alteration that appears to be specific for MEC, a finding that could be diagnostically useful. While most cases of MEC are histologically straightforward, uncommon variants can cause considerable diagnostic difficulty. We present 2 variants of MEC for which MAML2 studies were crucial in establishing a diagnosis: a previously undescribed ciliated variant, and the recently described Warthin-like variant. All cases of ciliated and Warthin-like MEC were retrieved from the archives of The Johns Hopkins Hospital. Break-apart fluorescence in situ hybridization for MAML2 was performed on all cases. One ciliated MEC and 6 Warthin-like MECs were identified. The ciliated MEC presented as a 4.6 cm cystic lymph node metastasis originating from the tongue base in a 47-year-old woman. The Warthin-like MECs presented as parotid masses ranging in size from 1.2 to 3.3 (mean, 2.7 cm) in 4 women and 2 men. The ciliated MEC consisted of macrocystic spaces punctuated by tubulopapillary proliferations of squamoid cells and ciliated columnar cells. The Warthin-like MECs were comprised of cystic spaces lined by multilayered oncocytic to squamoid cells surrounded by a circumscribed cuff of lymphoid tissue with germinal centers. In these cases, the Warthin-like areas dominated the histologic picture. Conventional MEC, when present, represented a minor tumor component. MAML2 rearrangements were identified in all cases. Warthin-like MEC, and now a ciliated form of MEC, are newly described variants of a common salivary gland carcinoma. Unfamiliarity with these novel forms, unanticipated cellular features (eg, cilia), and morphologic overlap with mundane benign processes (eg, developmental ciliated cysts, Warthin tumor) or other carcinomas (eg, ciliated human papillomavirus-related carcinoma) may render these variants susceptible to misdiagnosis. These unusual variants appear to consistently harbor MAML2 fusions-a finding that establishes a clear link to conventional MEC and provides a valuable adjunct in establishing the diagnosis.

Mucoepidermoid carcinoma of the posterior-lateral border of tongue: a rare presentation

Mucoepidermoid carcinoma (MEC) is the most common malignant tumour of the major and minor salivary glands. Minor salivary glands are scattered in different areas of the oral cavity such as palate, retromolar area, floor of the mouth, buccal mucosa, lips and tongue, but so far, only a few lingual MEC cases have been documented in the literature and most of the studies have shown a predilection for base and dorsum of the tongue. We report a rare case of MEC involving the posterior-lateral border of the tongue.

Prognostic value of human papillomavirus infection and p53, p16, epidermal growth factor receptor and p34cdc2 expression in patients with salivary adenoid cystic carcinoma

The aim of this study was to explore the correlation between HPV infection, p53, p16, epidermal growth factor receptor (EGFR), p34^cdc2 protein expression and prognosis in patients with adenoid cystic carcinoma of salivary gland. Totally 78 cases of adenoid cystic carcinoma of salivary gland specimens were selected from January 1, 2004 to December 31, 2013 in Tangshan Union Hospital. PCR-reverse dot blot hybridization was used to detect infection of human papilloma virus (HPV), and SP immunohistochemical method was adopted to detect the expression of p53, p16, EGFR and p34^cdc2 protein in the carcinoma tissues. Clinical data were collected and the patients were followed up. Results showed that the infection rate of HPV in adenoid cystic carcinoma tissues was 0% (0/78). The expression rate of p53, p16, EGFR and p34^cdc2 protein in carcinoma tissues were 75.6% (59/78), 57.7% (45/78), 60.1% (47/78) and 64.1% (50/78), respectively. Expression of p53, p16, EGFR and p34^cdc2 proteins was not significantly correlated with patients' age, gender, disease location, TNM classification and histological type (P > 0.05). Kaplan-Meier analysis showed that EGFR-positive patients had a lower median overall survival than EGFR-negative ones (58 months vs. 75 months, respectively. P = 0.001). The result of median progression-free survival was virtually the same for both EGFR-positive and EGFR-negative patients (43 months vs. 49 months, respectively. P = 0.002). p34^cdc2-positive patients had a lower median overall survival than p34^cdc2-negative ones (61 months vs. 71 months, respectively. P = 0.027). Median progression-free survival was also almost the same for both p34^cdc2-positive and p34^cdc2-negative patients (44 months vs. 51 months, respectively. P = 0.011). Cox regression analysis showed that expression of EGFR and p34^cdc2 was independent risk factors for the prognosis of patients with adenoid cystic carcinoma of salivary gland (relative risk = 13.199, 11.466, P < 0.001). In conclusion, HPV infection is not detected in salivary adenoid cystic carcinoma tissues. p53, p16, EGFR and p34^cdc2 protein are positively expressed in most salivary adenoid cystic carcinoma tissues. p16 is unsuitable as a surrogate for HPV infection status in patients with adenoid cystic carcinoma of salivary gland. Expression of EGFR and p34^cdc2 is independent risk factors in the prognosis of patients with salivary gland adenoid cystic carcinoma. Patients with EGFR or p34^cdc2 positive expression should be followed up closely.

Human Papillomavirus-Associated Neoplasms of the Head and Neck

Human papillomavirus (HPV) is an essential causal factor in a subset of head and neck neoplasms, most notably oropharyngeal squamous cell carcinoma, for which HPV infection has important diagnostic, prognostic, and therapeutic implications. This article summarizes the current understanding of HPV-associated neoplasms of the head and neck, including the recently described carcinoma with adenoid cystic-like features. Salient clinical, gross, and microscopic features are discussed, and the utility of specific ancillary studies is highlighted.

A Case-Control Study of Risk Factors for Salivary Gland Cancer in Canada

Aim. To assess the effect of various lifestyle risk factors on the risk of salivary gland cancer in Canada using data from a population-based case-control study. Methods. Data from a population-based case-control study of 132 incident cases of salivary gland cancer and 3076 population controls were collected through self-administered questionnaire and analysed using unconditional logistic regression. Results. Four or more servings/week of processed meat product was associated with an adjusted odds ratio (OR) and corresponding 95% confidence interval (CI) of 1.62 (1.02–2.58). Nonsignificantly increased ORs were also related to obesity, >7 drinks/week of alcohol consumption, and occupational exposure to radiation. Furthermore, nonsignificantly decreased ORs were found to be associated with high education level (>12 years) (OR = 0.65), high consumption of spinach/squash (OR = 0.62) and all vegetables/vegetable juices (OR = 0.75), and >30 sessions/month of recreational physical activity (OR = 0.78). Conclusions. This study suggests positive associations with consumption of processed meat, smoking, obesity, alcohol drinking, and occupational exposure to radiation as well as negative associations with higher education, consumption of spinach/squash, and physical activity, which suggest a role of lifestyle factors in the etiology of salivary gland cancer. However, these findings were based on small number of cases and were nonsignificant. Further larger studies are warranted to confirm our findings.

Prevalence and associated survival of high-risk HPV-related adenoid cystic carcinoma of the salivary glands

Adenoid cystic carcinoma (SACC) is a rare malignancy, but a frequent subtype in minor and major salivary glands. The molecular alterations or biomarkers that underlie its development and progression as well as therapy outcomes are poorly characterized. The main study goal was to investigate reliable biomarkers and patient-related factors that may have impact on recurrence and long-term survival of SACC. The prevalence of human papilloma virus (HPV) in SACC was determined by HPV-DNA genotyping and p16 immunostaining. Epithelial growth factor receptor (EGFR), p53 and Ki-67 expression were also evaluated. Twenty-eight (42%) of 67 patients were HPV-DNA positive. Kaplan-Meier analysis indicated that SACC patients with metastases (P=0.03) had a poor overall survival (OS) and a shorter recurrence-free survival (P<0.001). Positive resection margins significantly predicted shorter recurrence-free survival (P=0.01). In the multivariate analysis, non-metastatic disease (P=0.033) and p16 positivity (P=0.005) have shown their prediction value for OS while non-metastatic disease (P=0.002), HPV positivity (P=0.041) and negative resection margin predicted a better recurrence-free survival. The present study documents for the first time the positivity for HPV infection and overexpression of certain markers (p16, Ki-67, EGFR and p53) used in diagnostics in SACC as well as characterizes clinical entities. These factors might be exploited in the future as biomarkers for its prognostic value. Using the clinical and pathological basis for predicting different outcomes could significantly facilitate SACC stratification and potentially directing treatment.

Genetic alterations in salivary gland cancers

Salivary gland cancers are an incredibly heterogeneous group of tumors that include 24 histologically distinct tumor types. The use of new genetic methods has paved the way for promising advancements in our understanding of the molecular biology underlying each type of tumor. The objective of this review was to highlight common oncogenes, tumor suppressor genes, and cytogenetic and epigenetic changes associated with the most common tumor types: mucoepidermoid carcinoma, adenoid cystic carcinoma, salivary duct carcinoma, mammary analogue secretory carcinoma, hyalinizing clear cell carcinoma, carcinoma ex pleomorphic adenoma, and acinic cell carcinoma. Recent insights into the pathogenesis of each cancer subtype have helped better define and classify these tumors. Further research in salivary gland cancers should focus on determining the key genes involved in the tumorigenesis of each distinct malignancy and identifying individualized chemotherapies directed at these targets. Cancer 2016;122:1822-31. © 2016 American Cancer Society.

HPV Infection, but Not EBV or HHV-8 Infection, Is Associated with Salivary Gland Tumours

Benign and malignant salivary gland tumours are clinically heterogeneous and show different histology. Little is known about the role of human herpes virus 8 (HHV-8), Epstein-Barr virus (EBV), and human papillomavirus (HPV) infection in salivary gland neoplasms. We investigated the presence of the three viruses in formalin-fixed, paraffin-embedded tissue samples in a cohort of 200 different salivary gland tumours. We performed EBV-LMP-1 and HHV-8 and p16 immunohistochemistry, a specific chip based hybridization assay for detection and typing of HPV and a chromogenic in situ hybridization for EBV analysis. Only one case, a polymorphic low-grade carcinoma, showed HHV-8 expression and one lymphoepithelial carcinoma was infected by EBV. In 17 cases (9%) moderate or strong nuclear and cytoplasmic p16 expression was detected. The HPV type was investigated in all of these cases and additionally in 8 Warthin's tumours. In 19 cases HPV type 16 was detected, mostly in Warthin's tumour, adenoid cystic carcinoma, and adenocarcinoma NOS. We concluded that HHV-8 infection and EBV infection are not associated with salivary gland cancer, but HPV infection may play a role in these tumour entities.

P16 and HPV discordance in metastatic carcinoma of cervical lymph nodes of unknown primary

The prognostic utility of HPV in oropharyngeal squamous cell carcinoma (OPSCC) and non-OPSCC as has been well documented. Currently, a standardized IHC scoring system does not exist and is needed to define HPV positivity. We have recently seen a patient that provides a caution in using p16 status as a diagnostic aid.

Mucoepidermoid Carcinoma in a 33-Year-Old White Man

PATIENT DEMOGRAPHICS

A 33-year-old white man.

CHIEF COMPLAINT

Longstanding bump on the roof of the mouth.

TREATMENT

The patient was referred to an oral maxillofacial surgeon for a pathology consultation. The patient had been experiencing pain on both sides of his jaw, but the oral mass was not painful (Image 1).

MEDICAL HISTORY

The patient has no history of smoking, is slightly overweight with a body mass index of 26.5, and has no systemic or chronic medical conditions.

EXAMINATION FINDINGS

On initial examination by the oral surgeon, the vital signs of the patient were normal. An indurated lesion was noted on the left hard palate of the patient. Suspecting a benign lesion or possible carcinoma/neoplasm, the oral surgeon scheduled and performed an excisional biopsy (Image 2). The mass was sent for pathological processing.

POSTOPERATIVE CARE

This included a diet of soft foods, with daily rinsing using 0.12% chlorhexidine gluconate, with a follow-up appointment made for 2 weeks later.

PRINCIPAL LABORATORY FINDINGS

Figure 1; Image 3; Image 4.

Gnathic and peripheral ameloblastomas lack human papillomavirus DNA

Human papillomavirus (HPV) has been associated with a variety of head and neck neoplasms, including squamous cell carcinomas and Schneiderian papillomas. Ameloblastomas can arise from either the gnathic bones or peripheral soft tissues. Peripheral sinonasal ameloblastomas share clinical features with Schneiderian papillomas. A small number of reports have described detection of HPV DNA within ameloblastomas. However, Most of these cases was reported in the 1990s, used the polymerase chain reaction technique, and only examined gnathic tumors. The current study was designed to determine whether low- or high-risk HPV DNA could be detected in gnathic or peripheral ameloblastomas using in situ hybridization. Twenty-nine examples of gnathic osseous and peripheral head and neck ameloblastomas were obtained from the authors' archives (University of Virginia and the Johns Hopkins Hospital). High-risk HPV DNA was not detected in any of the 29 tumors analyzed. Low-risk HPV DNA was identified in only 1 tumor, which was peripheral in origin, and from an immunocompromised patient. We believe that the HPV in this case represents a background "passenger" infection. This study demonstrates that HPV of either high- or low-risk subtypes is unlikely to play a role in the pathogenesis of sinonasal ameloblastomas.

The protective effect of p16(INK4a) in oral cavity carcinomas: p16(Ink4A) dampens tumor invasion-integrated analysis of expression and kinomics pathways

A large body of evidence shows that p16(INK4a) overexpression predicts improved survival and increased radiosensitivity in HPV-mediated oropharyngeal squamous cell carcinomas.(OPSCC). Here we demonstrate that the presence of transcriptionally active HPV16 in oral cavity squamous cell carcinomas does not correlate with p16(INK4a) overexpression, enhanced local tumor immunity, or improved outcome. It is interesting that HPV-mediated oropharyngeal squamous cell carcinomas can be categorized as having a 'nonaggressive' invasion phenotype, whereas aggressive invasion phenotypes are more common in HPV-negative squamous cell carcinomas. We have developed primary cancer cell lines from resections with known pattern of invasion as determined by our validated risk model. Given that cell lines derived from HPV-mediated oropharyngeal squamous cell carcinomas are less invasive than their HPV-negative counterparts, we tested the hypothesis that viral oncoproteins E6, E7, and p16(INK4a) can affect tumor invasion. Here we demonstrate that p16(INK4a) overexpression in two cancer cell lines (UAB-3 and UAB-4), derived from oral cavity squamous cell carcinomas with the most aggressive invasive phenotype (worst pattern of invasion type 5 (WPOI-5)), dramatically decreases tumor invasiveness by altering expression of extracellular matrix remodeling genes. Pathway analysis integrating changes in RNA expression and kinase activities reveals different potential p16(INK4a)-sensitive pathways. Overexpressing p16(INK4a) in UAB-3 increases EGFR activity and increases MMP1 and MMP3 expression, possibly through STAT3 activation. Overexpressing p16(INK4a) in UAB-4 decreases PDGFR gene expression and reduces MMP1 and MMP3, possibly through STAT3 inactivation. Alternatively, ZAP70/Syk might increase MUC1 phosphorylation, leading to the observed decreased MMP1 expression.

Trends in head and neck cancers in England from 1995 to 2011 and projections up to 2025

BACKGROUND

The magnitude of the growing burden of oropharyngeal cancers (OPC), a sub-set of head and neck cancers (HNC), is unknown in England.

METHODS

Data were extracted from population-based cancer registries in England. The burden of HNC overall and by anatomic site was described from 1995 to 2011. Projections of future rates up to 2025 were estimated using flexible age-period-cohort modelling.

RESULTS

HNC increased by 59% between 1995 and 2011 in England. Projections indicate that the number of HNC cases will increase by 55% from 2011, totalling 11,748 new cases in 2025, ranking HNC as the sixth most common cancer. Of the anatomic sites, OPC is projected to account for 35% of HNC with the largest rate increase (annual percentage change, +7.3% for men and +6.2% for women between 2011 and 2025), predominantly affecting males <60years. This projected burden is equivalent to a 239% increase in number of OPC cases. Incidence of the oral cavity, salivary glands and palate are projected to rise at lower rates, whereas rates of the nasopharynx, hypopharynx and larynx remain relatively stable or decreasing.

CONCLUSION

The substantial recent and predicted future significant increase in OPC highlights the need for prioritising the provision of cancer services for the considerable burden of OPC patients and survivors and cancer control strategies.

Expression of cyclin-dependent kinase inhibitor 2A 16, tumour protein 53 and epidermal growth factor receptor in salivary gland carcinomas is not associated with oncogenic virus infection

It is known that human papillomavirus (HPV) infection can cause squamous cell neoplasms at several sites, such as cervix uteri carcinoma and oral squamous carcinoma. There is little information on the expression of HPV and its predictive markers in tumours of the major and minor salivary glands of the head and neck. We therefore assessed oral salivary gland neoplasms to identify associations between HPV and infection-related epidermal growth factor receptor (EGFR), cyclin-dependent kinase inhibitor 2A (CDKN2A/p16) and tumour protein p53 (TP53). Formalin-fixed, paraffin-embedded tissue samples from oral salivary gland carcinomas (n=51) and benign tumours (n=26) were analysed by polymerase chain reaction (PCR) analysis for several HPV species, including high-risk types 16 and 18. Evaluation of EGFR, CDKN2A, TP53 and cytomegalovirus (CMV) was performed by immunohistochemistry. Epstein–Barr virus (EBV) was evaluated by EBV-encoded RNA in situ hybridisation. We demonstrated that salivary gland tumours are not associated with HPV infection. The expression of EGFR, CDKN2A and TP53 may be associated with tumour pathology but is not induced by HPV. CMV and EBV were not detectable. In contrast to oral squamous cell carcinomas, HPV, CMV and EBV infections are not associated with malignant or benign neoplastic lesions of the salivary glands.

Salivary mucoepidermoid carcinoma revisited

Clinicopathological features, prognosis and therapeutic strategies for mucoepidermoid carcinoma originating in salivary and salivary-type glands of the head and neck are reviewed. We emphasise histopathological aspects, appraise the value of histochemistry, electron microscopy, immunohistochemistry and cytophotometry, and discuss histogenesis and characteristic gene translocations. We additionally consider possible diagnostic difficulties, problems related to histological grading and accuracy of existing literature, and areas of controversy or uncertainty which may benefit from further investigations.

Mucoepidermoid carcinoma does not harbor transcriptionally active high risk human papillomavirus even in the absence of the MAML2 translocation

High risk human papillomavirus (HPV) is firmly established as an important cause of oropharyngeal carcinoma. Recent studies have also implicated HPV as a cause of mucoepidermoid carcinoma (MEC)-a tumor of salivary gland origin that frequently harbors MAML2 translocations. The purpose of this study was to determine the prevalence of transcriptionally active HPV in a large group of MECs and to determine whether HPV infection and the MAML2 translocation are mutually exclusive events. Break-apart fluorescence in situ hybridization for MAML2 was performed on a tissue microarray containing 92 MECs. HPV testing was performed using RNA in situ hybridization targeting high risk HPV mRNA E6/E7 transcripts. Of the 71 MECs that could be evaluated by FISH, 57 (80 %) harbored the MAML2 rearrangement. HPV was not detected in any of the 57 MECs that contained a MAML2 rearrangement, in any of the 14 MECs that did not contain the rearrangement, or in any of the 21 MECs where MAML2 status was unknown. High risk HPV does not appear to play any significant role in the development of MEC. It neither complements nor replaces MAML2 translocation in the tumorigenesis of MEC.

African Americans with oropharyngeal carcinoma have significantly poorer outcomes despite similar rates of human papillomavirus-mediated carcinogenesis

We examined racial disparities among 102 oropharyngeal carcinoma (OPC) patients (30 African Americans and 72 whites) comparing rates of transcriptionally active human papillomavirus (HPV)16/18 and p16(INK4a) overexpression, with times to disease progression and disease-specific survival (DSS). Expression of HPV16/18 transcripts was assessed by reverse transcription and polymerase chain reaction using type-specific E6/E7 primers; p16(INK4a) was evaluated by immunohistochemistry. African Americans were significantly more likely to present with high T stage disease and receive nonsurgical treatment. HPV16/18 was present in 63% of patients; no racial differences were observed. Silenced p16(INK4a) in OPC was significantly more common in African Americans (15/24) than in whites (20/69) (P = .004) and in HPV16+ African Americans (6/24) than in HPV+ whites (2/42) (P = .023). Kaplan-Meier analysis for DSS revealed a protective effect for p16(INK4a) overexpression (P = .0028; hazard ratio [HR], 0.23), HPV16+ (P = .036; HR, 0.38), and whites (P = .0039; HR, 0.27). Shorter DSS was associated with primary definitive chemoradiation (P = .019; HR, 3.49) and T3/T4 disease (P = .0001; HR, 7.75). A protective effect with respect to disease progression was observed for HPV16+ (P = .007; HR, 0.27), whites (P = .0006; HR, 0.197), and p16(INK4a) overexpression (P = .0001; HR, 0.116). African Americans with OPC experience poorer outcomes likely due to p16(INK4a) silencing, higher T stage, and nonsurgical treatment but not lower rates of transcriptionally active HPV16/18.

The sinonasal tract: another potential "hot spot" for carcinomas with transcriptionally-active human papillomavirus

While high risk human papillomavirus (HPV) is well established as causative and clinically important for squamous cell carcinoma (SCC) of the oropharynx, its role in non-oropharyngeal head and neck SCC is much less clearly elucidated. In the sinonasal region, in particular, although it is a relatively uncommon site for SCC, as many as 20 % of SCC harbor transcriptionally-active high risk HPV. These tumors almost always have a nonkeratinizing morphology and may have a better prognosis. In addition, specific variants of SCC as well as other rare carcinoma types, when arising in the sinonasal tract, can harbor transcriptionally-active HPV. This article reviews the current literature on HPV in sinonasal carcinomas, attempts to more clearly demonstrate what tumors have it and how this relates to possible precursor lesions like inverted papilloma, and discusses the possible clinical ramifications of the presence of the virus.