Molecular differences in mucoepidermoid carcinoma and adenoid cystic carcinoma of the major salivary glands

Analysis of cells of epithelial, connective tissue and immune differentiation in HPV-positive-, HPV-negative oropharyngeal carcinoma and normal oropharyngeal tissue by immunofluorescence multiplex image cytometry: a preliminary report

BACKGROUND

Epithelial, connective tissue and immune cells contribute in various ways to the pathophysiology of HPV positive (HPV+) and HPV negative (HPV-) oropharyngeal squamous cell carcinoma (OPSCC). We aimed to investigate the abundance of these cell lineages and their coexpression patterns in patients with HPV + and HPV- OPSCC.

METHODS

We used a 4-channel immunofluorescence-microscopy technique for the simultaneous detection of three direct-conjugated antibodies (pancytokeratin, vimentin and CD45/CD18) and DAPI (4',6-Diamidin-2-phenylindole) in formalin fixed paraffin-embedded tissue samples (FFPE) of patients with HPV + and HPV- OPSCC, and of control patients. Image acquisition and analysis were performed with TissueFAXS and StrataQuest (TissueGnostics, Vienna, Austria), respectively, in tumor cell clusters/stroma in OPSCC specimens and epithelial layer/lamina propria in control specimens. Cell populations were created based on antibodies' coexpression patterns. Isotype and positive controls were examined for plausibility.

RESULTS

The proportion of cells of epithelial differentiation in tumor cell clusters was higher in HPV + OPSCC (55%) than in HPV- OPSCC samples (44%). The proportion of connective tissue cells in tumor cell cluster was lower in HPV + OPSCC patients (18%) than in HPV- OPSCC patients (26%). The proportion of immune cells in tumor cell clusters was higher in HPV + OPSCC patients (25%) than in HPV- OPSCC patients (18%). The percentage of anaplastic, potentially de-differentiated cells, was 2% in control patients, and it was higher in HPV- OPSCC (21%) than in HPV + OPSCC samples (6%).

CONCLUSIONS

This study provided the first quantitative data for the abundance of cells of epithelial, connective tissue and immune differentiation, in patients with OPSCC and control patients. The abundance of these different crucial cell populations was consistently originating from the same tissue sample. De-differentiation of tumor cells was higher in HPV- OPSCC than in HPV + OPSCC. In tumor cells clusters, the antitumoral host immune response was higher in HPV + OPSCC than in HPV- OPSCC, whereas the fibroblast response was higher in HPV- OPSCC than in HPV + OPSCC. This study contributed to the understanding of histopathologic differences between HPV + OPSCC and HPV- OPSCC patients.

The Therapeutic Landscape of Salivary Gland Malignancies-Where Are We Now?

Salivary gland malignancies (SGMs) account for less than 5% of new diagnoses in head and neck tumors. If feasible, surgery is the preferred treatment modality. Nevertheless, some malignancies have a tendency of recurrence, with possible distant metastasis. Alternative treatment strategies, such as primary radiation or chemotherapeutics, often present low response rates. As a result, there is an unmet need for novel therapeutic approaches. Nowadays, target-based therapies (e.g., small inhibitors and immunotherapy) are used by the medical oncologist for possible treatment of advanced SGMs. Based on recent published trials, some novel treatments may provide additional disease control for some patients. However, sample sizes are small, the general findings are unsatisfactory, and a lot of uncertainties remain to be elucidated. Nevertheless, research shows that patients do not benefit from blind administration of systemic treatments and therefore a more personalized approach is highly needed. The aim of this review paper is to summarize the most recent advances in the biological understanding and molecular pathways of salivary gland cancers, the association of these pathways with the current treatments used and their implications for more personalized targeted-based therapies.

Squamous Cell Carcinoma of the Submandibular Gland With Cutaneous Fistula: A Case Report and Literature Review

Squamous cell carcinoma (SCC) of salivary glands, also referred to as epidermoid carcinoma, is a very rare neoplastic tumor. It occurs as metastasis of a cutaneous or mucosal squamous carcinoma of the head and neck or as a primary SCC. In the latter case, the most known risk factor is previous irradiation to the gland. Common clinical symptoms are represented by cervical swelling and hyposialia. The treatment is essentially surgical, most often supplemented by a radical neck dissection and postoperative radiation therapy.

A 75-year-old male patient with a history of chronic smoking was consulted for a tumefaction in the right submandibular region evolving for three months. No cervical lymphadenopathy in the submandibular and superior jugulo-carotid areas was palpable. CT scan showed an enhancing heterogeneous process of the right cervical region, invading the mylohyoid and stylohyoid muscles. A biopsy-excision of the lesion has shown a keratinizing tumor with cytonuclear atypia, consistent with SCC. Radical resection of the mass was associated with the removal of the infiltrated skin. The cutaneous defect was repaired with a rhomboid flap. The patient was started on sessions of adjuvant radiotherapy and chemotherapy. Eight months postoperatively, the patient came for follow-up, with no signs of local disease.

The EGFR protein is found in ~70% of salivary neoplasms and is considered as a factor of poor prognosis and rapid proliferation. PET CT is currently the best examination to detect the existence of a concomitant malignant lesion. Diagnosis of primary SCC (PSCC) of the submandibular gland is made on histopathology. Differential diagnoses include mucoepidermoid carcinoma, lymphoepithelial carcinoma and submandibular metaplasia. There is an increased prevalence of nodal involvement in the PSCC, which justifies neck dissection (regions I, II and III of the neck). The RAS mutation leading to resistance to anti-EGFR therapies may be assessed. This would allow for a treatment depending on molecular features for metastatic PSCCs.

PSCC of major salivary glands is a very rare lesion with local and general aggressiveness. The diagnosis is based on a combination of clinical examination, MRI, fine needle aspiration and histological examination. Immunotherapy constitutes a ground of research to treat metastatic and advanced pathological cases.

Beyond Surgical Treatment in Adenoid Cystic Carcinoma of the Head and Neck: A Literature Review

Introduction

Adenoid cystic carcinoma (AdCC) is a rare tumour as it accounts for about 10% of all salivary gland neoplasms. It occurs in all age groups with a predominance of women, but no risk factors have been identified to date. Although AdCC behaves as a slow-growing tumour, it is characterized by multiple and late recurrences. Therefore, we aim to update the knowledge of the treatment options in advanced and recurrent cases.

Materials and Methods

We performed a systematic literature review to provide a synthesis of the practical knowledge required for AdCC non-surgical management. Altogether, 99 out of the 1208 available publications were selected for analysis.

Results

AdCC is described as a basaloid tumour consisting of epithelial and myoepithelial cells. Immunohistochemistry is useful for diagnosis (PS100, Vimentin, CD117, CKit, muscle actin, p63) and for prognosis (Ki67). Identified mutations could lead to therapeutic opportunities (MYB-NFIB, Notch 1). The work-up is mainly based on neck and chest CT scan and MRI, and PET-CT with 18-FDG or PSMA can be considered. Surgical treatment remains the gold standard in resectable cases. Post-operative intensity modulated radiotherapy is the standard of care, but hadron therapy may be used in specific situations. Based on the available literature, no standard chemotherapy regimen can be recommended.

Conclusion

There is currently no consensus on the use of chemotherapy in AdCC, either concomitantly to RT in a postoperative setting or at a metastatic stage. Further, the available targeted therapies do not yet provide significant tumour response.

Evaluation of HER2/neu expression in different types of salivary gland tumors: a systematic review and meta-analysis

This study is a systematic review and meta-analysis to assess the overexpression rate of HER2 in patients with salivary gland tumors. We included peer-reviewed publications from 1995 to 2020, indexed in medical databases, using search terms such as "human epidermal growth factor receptor 2 (HER2)" and "salivary gland tumors", and extracted relevant data. The extracted data were analyzed with RevMan 5.3 software. Intra-and intergroup post hoc analyses of outcome variables were performed using t-tests, and the rates of HER2 positivity among studies were evaluated. 80 studies were included in the analysis. The positive rates of HER2 ranged from 3.3% to 84.0% and 1% to 9% in malignant and benign subtypes, respectively. The highest HER2 overexpression rate among malignant tumors was in salivary ductal carcinomas (SDC), with a 45% positive rate (CI 95%: 21.9-70.3%). Mucoepidermoid carcinoma (MEC) had the highest positive rate of 84% (CI 95%: 74.1-90.0%). Among benign salivary gland tumors, the highest rate was found in myoepithelioma, with a positive rate of 9% (CI 95%: 1.7-33.6%). The highest rate of HER2 overexpression is present in malignant subtypes of salivary gland tumors, more specifically in salivary ductal carcinoma, mucoepidermoid carcinomas, salivary duct carcinoma in situ, and carcinoma ex pleomorphic adenoma.

Oral Cancer Stem Cells: Therapeutic Implications and Challenges

Head and neck squamous cell carcinoma (HNSCC) is currently one of the 10 most common malignancies worldwide, characterized by a biologically highly diverse group of tumors with non-specific biomarkers and poor prognosis. The incidence rate of HNSCC varies widely throughout the world, with an evident prevalence in developing countries such as those in Southeast Asia and Southern Africa. Tumor relapse and metastasis following traditional treatment remain major clinical problems in oral cancer management. Current evidence suggests that therapeutic resistance and metastasis of cancer are mainly driven by a unique subpopulation of tumor cells, termed cancer stem cells (CSCs), or cancer-initiating cells (CICs), which are characterized by their capacity for self-renewal, maintenance of stemness and increased tumorigenicity. Thus, more understanding of the molecular mechanisms of CSCs and their behavior may help in developing effective therapeutic interventions that inhibit tumor growth and progression. This review provides an overview of the main signaling cascades in CSCs that drive tumor repropagation and metastasis in oral cancer, with a focus on squamous cell carcinoma. Other oral non-SCC tumors, including melanoma and malignant salivary gland tumors, will also be considered. In addition, this review discusses some of the CSC-targeted therapeutic strategies that have been employed to combat disease progression, and the challenges of targeting CSCs, with the aim of improving the clinical outcomes for patients with oral malignancies. Targeting of CSCs in head and neck cancer (HNC) represents a promising approach to improve disease outcome. Some CSC-targeted therapies have already been proven to be successful in pre-clinical studies and they are now being tested in clinical trials, mainly in combination with conventional treatment regimens. However, some studies revealed that CSCs may not be the only players that control disease relapse and progression of HNC. Further, clinical research studying a combination of therapies targeted against head and neck CSCs may provide significant advances.

PCP4/PEP19 and HER2 Are Novel Prognostic Markers in Mucoepidermoid Carcinoma of the Salivary Gland

Simple Summary

Mucoepidermoid carcinoma (MEC) is the most common malignancy of all salivary neoplasms, and no effective treatment strategy for MEC has been established other than resection. In this study, we showed that Purkinje cell protein (PCP) 4/peptide (PEP) 19 and human epidermal growth factor receptor 2 (HER2) are predicted to play important roles in the pathogenesis and progression of MEC. The detection of PCP4/PEP19 and HER2 may be useful for providing more effective treatments against MEC.

Abstract

Mucoepidermoid carcinoma (MEC) is one of the most common malignant salivary gland carcinomas, but no effective treatment strategy has been established other than surgical resection. Purkinje cell protein (PCP) 4/peptide (PEP) 19 is a calmodulin-binding antiapoptotic peptide that is expressed and inhibits apoptosis in human breast cancer cells. Human epidermal growth factor receptor 2 (HER2) is an epidermal growth factor that has been implicated in the pathogenesis of many carcinomas, particularly breast and gastric carcinomas. In the present study, we performed immunohistochemical analyses of samples from 73 patients who underwent surgical resection for MEC of the salivary gland using antibodies against PCP4/PEP19 and HER2. PCP4/PEP19 expression was related to better prognosis, while HER2 expression was associated with worse prognosis. Patients that were PCP4/PEP19-positive and HER2-negative showed similar outcomes to PCP4/PEP19 and HER2 alone. Therefore, PCP4/PEP19 and HER2 are predicted to play important roles in the pathogenesis and progression of MEC.

Primary squamous cell carcinoma of major salivary gland: "Sapienza Head and Neck Unit" clinical recommendations

Primary squamous cell carcinoma of salivary gland (SCG) is an extremely rare type of malignant salivary gland tumor, which in turn results in scarcity of data available regarding both its treatment and associated genetic alterations. A retrospective analysis of 12 patients with primary SCG was conducted, along with analysis of the association between treatment, clinical/pathological characteristics, and outcomes. Most patients (8) were staged IVa, with the majority of them (10) having G3 fast growing cancer. Local and systemic recurrence were reported in only three out of nine parotid cases (0 out of 2 submandibular SCGs). In two out of eight patients local relapse occurred after integrated treatment, while recurrence occurred in two out of three patients undergoing exclusive surgery. Five patients eventually died. Treatment of resectable disease must be aggressive and multimodal, with achievement of loco-regional control in order to reduce rate of recurrence and improve outcomes. Metastatic disease would require a therapeutic strategy tailored to the molecular profile in order to improve the currently disappointing results.

Claudin expression is maintained in mucoepidermoid carcinoma of the salivary gland

OBJECTIVE

The aim of the present study was to investigate the expression of claudin-1, -3, -4, -5 and -7 proteins in mucoepidermoid carcinoma of oral cavity and analyze whether EGF may interfere in the expression of the genes that encode claudins using in vitro models.

MATERIAL AND METHODS

Using immunohistochemistry, the expression of claudins was searched in 36 histologically graded cases of mucoepidermoid carcinoma. The association of expression of claudins with clinical-pathological parameters was evaluated. An in vitro step investigated the influence of EGF on gene expression of claudins by real time RT-PCR technique.

RESULTS

Claudin-1, -3, -4, -5, and -7 were highly expressed in most mucoepidermoid carcinomas. These expressions were compared with clinicopathological parameters. High expression of claudin-1 was associated with patients over 40 years-old (p = 0.05) and Caucasians (p = 0.024). In vitro experiments demonstrated a tendency for Claudin gene expression increase after EGF stimulus.

CONCLUSIONS

The expression of claudins is maintained in mucoepidermoid carcinoma cells and EGF could be related with this expression. Our results point out to a fundamental biological importance to CLDNs in normal and neoplastic tissue. The expression patterns of CLDNs does not yet allow a clinical application, but the biological knowledge will ground evidence to new studies towards possible target-therapies.

Molecular landscape of salivary gland cancers

Accurate diagnosis of salivary gland tumors can be challenging because of the many diagnostic entities, the sometimes extensive morphologic overlap, and the rarity of most tumor types. The current understanding of molecular rearrangements in salivary gland tumor pathology, emphasizes the prospects for exploiting molecular alterations in salivary gland tumors for diagnosis and targeted therapy. As new targeted therapies emerge, it will become increasingly vital to incorporate appropriate molecular testing into the pathologic evaluation of salivary gland cancers.

Metallothionein Expression and its Influence on the In Vitro Biological Behavior of Mucoepidermoid Carcinoma

Mucoepidermoid carcinoma (MEC) is the most common tumor in the salivary glands, often presenting with recurrence and metastasis due to its high invasive capacity. Metallothionein (MT), a zinc storage protein that supplies this element for protease activity, is probably related to mucoepidermoid carcinoma behavior. This prompted us to characterize a cell line derived from mucoepidermoid carcinoma and to correlate metallothionein expression with transforming growth factor-α (TGF-α), tumor necrosis factor-α (TNF-α) and matrix metalloproteinases (MMPs). Transcriptomic analysis and cytogenetic assays were performed to detect the expression of genes of interest and cellular chromosomal alterations, respectively. MEC cells with a depleted metallothionein 2A (MT2A) gene were subjected to Western blot to correlate metallothionein expression with growth factors and MMPs. Additionally, cells with depleted MT were subjected to migration and invasion assays. The transcriptomic study revealed reads mapped to cytokeratins 19 and AE1/AE3, α-smooth muscle actin, vimentin, and fibronectin. Cytogenetic evaluation demonstrated structural and numerical alterations, including the translocation t(11;19)(q21;p13), characteristic of MEC. Metallothionein depletion was correlated with the decreased expression of TGF-α and MMP-9, while TNF-α protein levels were augmented. Migration and invasion activity were diminished after metallothionein silencing. Our findings suggest an important role of MT in MEC invasion, through the regulation of proteins involved in this process.

A Rare Case of Mucoepidermoid Carcinoma of Parotid with Mandibular Metastasis

Mucoepidermoid carcinoma is the most common malignant tumor of salivary gland. Majority of the salivary gland tumors arise in parotid gland with maximum being of benign nature. Although Mucoepidermoid carcinoma accounts for less than 10% of all tumors of the salivary gland, it constitutes approximately 30% of all malignant tumors of the salivary gland. It is characterized by a mixed pattern of the two main cell types: epidermoid and mucus-producing cells. Metastasis from salivary gland malignancy is infrequent and predominantly found in bone, lung, liver and lymph nodes. We are presenting a rare case of metastasis of mucoepidermoid carcinoma of parotid gland to the contralateral mandible.

Particular aspects in the cytogenetics and molecular biology of salivary gland tumours - current review of reports

Salivary gland tumours are a group of lesions whose heterogeneity of biological and pathological features is widely reflected in the molecular aspect. This is demonstrated by an increasing number of studies in the field of genetics of these tumours.

The aim of this study was to collect the most significant scientific reports on the cytogenetic and molecular data concerning these tumours, which might facilitate the identification of potential biomarkers and therapeutic targets. The analysis covered 71 papers included in the PubMed database. We focused on the most common tumours, such as pleomorphic adenoma, Warthin tumour, mucoepidermoid carcinoma, and others. The aim of this study is to present current knowledge about widely explored genotypic alterations (such as PLAG1 gene in pleomorphic adenoma or MECT1 gene in mucoepidermoid carcinoma), and also about rare markers, like Mena or SOX10 protein, which might also be associated with tumourigenesis and carcinogenesis of these tumours.

Systemic therapy for recurrent or metastatic salivary gland malignancies

Salivary gland carcinomas are notoriously resistant to therapy and no standard of care exists. Due to the rarity of these malignancies, various histologies, and wide ranging clinical behavior it has been difficult to standardize systemic therapy. We have reviewed clinical prospective studies in the last 15 years with salivary gland malignancies involving cytotoxic chemotherapy and biologic agents including targeted therapies such as anti-HER-2, anti-EGFR therapies, and therapies directed at c-kit. Although the results of most trials are modest at best, there has been an increase in studies for salivary cancer in recent years and there are several promising treatment approaches in evolution. Every effort should be made to treat salivary gland malignancies under a clinical protocol and/or at a large multidisciplinary practice with clinicians experienced in treating these malignancies.

Expression of E-cadherin in normal oral mucosa, in oral precancerous lesions and in oral carcinomas

Objective:

The aim of the present study was to assess the expression of E-cad in oral precancerous lesions and conditions and oral carcinomas in comparison with normal mucosa.

Materials and Methods:

Total of 50 samples were selected for the study and were categorized into five groups and 10 samples in each group as Group I-oral leukoplakia (OL), Group II-oral lichen planus (OLP), Group III-oral submucous fibrosis (OSMF), Group IV-oral squamous cell carcinoma (OSCC) and Group V-normal oral mucosa (NOM) as control group. All the samples were assessed for the expression of E-cad by immunohistochemical study.

Results:

Upon assessing the expression of E-cad in OL, OSMF, OLP and OSCC, as majority of the samples with OSCC (90%), OL (80%), OLP (70%) and OSMF (60%) showed mild to moderate expression of E-cad staining, which was suggestive of reduction in dysplastic cells on comparison to NOM cells. This difference in expression and variation of E-cad upon comparison with normal mucosa was statistically significant (P < 0.001).

Conclusion:

There is significant (P < 0.001) variation of expression of E-cad with the histopathological dysplasia of the oral precancerous lesions and conditions, and the tumor differentiation of the oral cancers. However, there was no correlation of the degree of loss of expression of E-cad with the degree of dysplasia or the tumor differentiation of oral cancers. We conclude with our study that, there is a variation in the expression of E-cad but its value as a prognostic marker is questionable.

Phase II study of gefitinib in patients with advanced salivary gland cancers

BACKGROUND

The purpose of this study was to determine the antitumor activity of the epidermal growth factor receptor (EGFR) inhibitor gefitinib in patients with recurrent/metastatic salivary gland cancer.

METHODS

We conducted a phase II study in adenoid cystic carcinoma (ACC) and non-ACC. Gefitinib was administered 250 mg orally daily. The primary endpoint was tumor response. Secondary endpoints included progression-free survival (PFS), overall survival (OS), and disease control rates. EGFR and human epidermal growth factor receptor 2 (HER2) expression were evaluated and correlated with outcomes.

RESULTS

Thirty-seven patients were enrolled in this study, and 36 were evaluable (18 with ACC and 18 with non-ACC). No responses were observed. Median PFS was 4.3 months and 2.1 months, and median OS was 25.9 months and 16 months for patients with ACC and non-ACC, respectively. The disease control rate at 8 weeks was higher in patients with ACC. No unexpected toxicities occurred. EGFR and HER2 overexpression did not correlate with outcomes.

CONCLUSION

We did not observe significant clinical activity of gefitinib in advanced salivary gland cancer. NCT00509002.

Epidermal growth factor receptor (EGFR) in salivary gland carcinomas: potentials as therapeutic target

AIMS

Epidermal growth factor (EGFR) is involved in angiogenesis, cell differentiation, proliferation and progression of many cancers and is an important therapy target in lung and colorectal cancer. To determine the potential applicability of EGFR targeted therapies, EGFR status of over 800 salivary gland tumors of different entities were analyzed on DNA and protein level by FISH and IHC.

MATERIALS AND METHODS

A tissue microarray was constructed from 721 carcinomas and 205 adenomas of the salivary gland. EGFR expression and EGFR gene copy number was assessed by means of immunohistochemistry and fluorescence in situ hybridization (FISH). EGFR mutation analysis of exon 19 and 21 was performed in a subset of 107 carcinomas.

RESULTS

Positive immunohistochemical staining (definition?) for EGFR was shown in 324 of 663 (48.9%) salivary gland carcinomas. The frequency was dependent on the tumor entity and ranged from 17.9% (30 of 168 cases) positive immunostaining in acinic cell adenocarcinomas to 85.7% (42 of 49 cases) in Warthin tumors. No EGFR amplification was found by FISH. EGFR mutation analysis of Exon 19 and 21 in 107 salivary gland carcinomas revealed mutations in two acinic cell adenocarcinomas.

CONCLUSION

EGFR protein expression is common in salivary gland tumors but is not associated with gene amplification. Activating mutations of EGFR are rare. Nonetheless, selected cases of patients with salivary gland carcinomas might potentially benefit of anti-EGFR therapy.

Systemic therapy in the management of metastatic or advanced salivary gland cancers

Salivary gland cancers are very rare tumors. They are characterized by a histologic heterogeneity and a poor outcome. According to this rarity, few prospective data are available to date. No standard recommendations could be held for the use of systemic therapy in these tumors. Several case reports and small studies have investigated the contribution of different agents of chemotherapy. With the extension of molecular biology approach in oncology several signaling pathways have been discovered in different cancers including salivary gland cancers; thus a number of targeted therapies have been investigated. This paper reviewed exhaustively the studies investigating the role of systemic therapies (chemotherapy, targeted therapy, hormone therapy) in salivary gland cancers.

Systemic therapy in the management of metastatic or advanced salivary gland cancers

Salivary gland cancers are very rare tumors. They are characterized by a histologic heterogeneity and a poor outcome. According to this rarity, few prospective data are available to date. No standard recommendations could be held for the use of systemic therapy in these tumors. Several case reports and small studies have investigated the contribution of different agents of chemotherapy. With the extension of molecular biology approach in oncology several signaling pathways have been discovered in different cancers including salivary gland cancers; thus a number of targeted therapies have been investigated. This paper reviewed exhaustively the studies investigating the role of systemic therapies (chemotherapy, targeted therapy, hormone therapy) in salivary gland cancers.

Novel therapeutic strategies for malignant salivary gland tumors: lessons learned from breast cancer

Malignant salivary gland tumors (MSGTs) account for 2–6% of all head and neck cancers. Despite the rarity, MSGTs have been of great interest due to a wide variety of pathological features and high metastasis rates resulting in poor prognosis. Surgical resection followed by radiation therapy represents the main treatment of this malignancy. Adjuvant therapy is reserved for the management of local recurrence, no longer amenable to additional local therapy, and for metastasis. Based on the studies from other types of tumors, particularly breast cancer, the expression and function of sex steroid hormone receptors in cancer have been extensively studied and applied to diagnosis and treatment. Although a number of studies in MSGTs have been published, the rationale for hormone therapy is still controversial due to the disparate results and insufficient number of cases. However, some recent reports have demonstrated that certain salivary gland neoplasms are similar to breast cancer, not only in terms of the pathological features, but also at the molecular level. Here, we shed light on the biological similarity between MSGTs and certain types of breast cancer, and describe the potential use of hormone and additional therapies for MSGTs.

Activation of the EGFR/ERK pathway in high-grade mucoepidermoid carcinomas of the salivary glands

Background:

Mucoepidermoid carcinoma (MEC) shows differences in biological behaviour depending mainly on its histological grade. High-grade tumours usually have an aggressive biological course and they require additional oncological treatment after surgery.

Methods:

In a series of 43 MECs of the salivary glands, we studied the epidermal growth factor receptor (EGFR) gene by using dual-colour chromogenic in situ hybridisation (CISH). Moreover, we assessed the protein expressions of the EGFR and the activated extracellular signal-regulated kinases (pERK1/2) by using immunohistochemistry. These results were correlated with the histological grade of the tumours and the outcome of the patients.

Results:

The CISH study demonstrated a high-EGFR gene copy number, with balanced chromosome 7 polysomy, in 8 out of 11 high-grade MECs (72.7%), whereas 27 low-grade and 15 intermediate-grade tumours had a normal EGFR gene copy number (P<0.001). The EGFR gene gains correlated with disease-free interval (P=0.003) and overall survival of the patients (P=0.019). The EGFR protein expression had a significant correlation with the histological grade of the tumours but not with the outcome of the patients. The pERK1/2 expression correlated with histological grade of tumours (P<0.001), disease-free interval (P=0.004) and overall survival (P=0.001).

Conclusions:

The EGFR/ERK pathway is activated in high-grade MECs with aggressive behaviour. Patients with these tumours who require oncological treatment in addition to surgery could benefit from EGFR and mitogen-activated protein kinase pathway inhibitors.

Immunohistochemical expression of the oncogenic molecules active Stat3 and survivin in benign and malignant salivary gland tumors

OBJECTIVE

Signal transducer and activator of transcription 3 (Stat3) and survivin have been shown to exert oncogenic effects in various human neoplasms. The purpose of this study was to evaluate the expression of tyrosine phosphorylated (active) Stat3 and survivin in various benign and malignant salivary gland tumors (SGTs).

STUDY DESIGN

Eighty-six SGTs (65 malignant and 21 benign tumors of various histopathologic subtypes) were immunohistochemically stained with antisurvivin or anti-phosphorylated tyrosine-705 (p-tyr) Stat3 antibodies. Immunohistochemical reactivity was graded in a semiquantitative manner; a combined score of immunohistochemical positivity (0-6) was calculated for each tumor by adding the individual scores for percentage of tumor cells (0-3) and intensity of staining (0-3).

RESULTS

Survivin was immunohistochemically detected in all studied benign and malignant SGTs; p-tyr Stat3 was also detected in the majority (91%) of SGTs. The average combined scores for survivin and p-tyr Stat3 immunohistochemical expression in the studied malignant SGTs was 4.40 and 3.35, respectively; the corresponding combined scores for survivin and p-tyr Stat3 in the studied benign SGTs were 4.37 and 3.22, respectively. No statistically significant differences (P > .05) in p-tyr Stat3 or survivin expression were detected between the benign and malignant groups, or among the various examined histopathologic subtypes of SGTs. In contrast, normal salivary gland tissues revealed only weak and focal survivin or p-tyr Stat3 immunoreactivity, mainly localized to ductal and mucous cells.

CONCLUSIONS

Our data indicate an almost universal expression of activated Stat3 and survivin in benign and malignant SGTs. Considering the well established proliferative and antiapoptotic properties of these molecules and their functional interrelationship, selective targeting techniques against Stat3 and/or survivin may represent promising therapeutic strategies against neoplasms of salivary gland origin.

Overexpression of EGFR and absence of C-KIT expression correlate with poor prognosis in salivary gland carcinomas

AIMS

To evaluate the prognostic impact of expression of receptor tyrosine kinases epidermal growth factor receptor (EGFR), HER2, and C-KIT in relation to established clinicopathological parameters in salivary gland carcinomas.

METHODS AND RESULTS

Immunohistochemistry for EGFR, HER2, C-KIT and the proliferation marker Ki67 was performed in 101 cases of salivary gland carcinoma and related to long-term clinical follow-up. Immunopositivity of C-KIT was common in adenoid cystic carcinoma (92%). Lack of C-KIT expression occurred in salivary duct carcinoma (P < 0.001) and was associated with high-grade tumours (P = 0.002), positive lymph nodes (P = 0.002) and high expression of Ki67 (P = 0.001). HER2 was typically expressed in salivary duct carcinomas (83%), but was not associated with any other parameter. EGFR overexpression occurred independently of histological type and clinical parameters. On univariate survival analysis, overexpression of EGFR (P = 0.011) and lack of C-KIT (P = 0.014) were associated with worse prognosis, whereas HER2 was of no prognostic significance. On multivariate analysis, the strongest negative predictor of survival was high proliferative activity measured by Ki67 (P = 0.002), followed by presence of residual tumour (P = 0.006), overexpression of EGFR (P = 0.026) and advanced tumour stage (P = 0.041).

CONCLUSIONS

The expression of receptor tyrosine kinases confers additional prognostic impact on disease-specific survival. EGFR overexpression is an independent negative prognostic factor.

Cetuximab in the treatment of metastatic mucoepidermoid carcinoma of the salivary glands: a case report and review of literature

Introduction

Patients with metastatic mucoepidermoid carcinoma of salivary glands have a poor outcome. The epidermal growth factor receptor protein is overexpressed in approximately 70% of mucoepidermoid carcinoma patients and may represent a therapeutic target. However, whether treatment with anti-epidermal growth factor receptor agents is effective is unclear and clinical trials are difficult due to the rarity of the disease. Here we assessed the activity of cetuximab in mucoepidermoid carcinoma on a molecular basis.

Case presentation

We present the case of a 40-year old Caucasian man with a mucoepidermoid carcinoma of the major salivary glands who developed distant bone and visceral metastases despite platinum-based chemotherapy. Epidermal growth factor receptor was overexpressed and fluorescence in situ hybridization analysis demonstrated a chromosome 7 polysomy. The patient was treated with the monoclonal antibody cetuximab in combination with cisplatin. After 11 doses of cetuximab, the patient developed brain metastases but evidence of response was documented at all extracranial metastatic sites.

Conclusion

This case report indicates that cetuximab can be active in mucoepidermoid carcinoma and may restore sensitivity to cisplatin in platinum-treated patients. Cetuximab does not cross the blood brain barrier and may select a metastatic clone to home the central nervous system while responding at other sites.

Salivary gland-type lung carcinomas: an EGFR immunohistochemical, molecular genetic, and mutational analysis study

Salivary gland-type lung carcinomas are uncommon neoplasms of the lung, the two most common being adenoid cystic carcinoma and mucoepidermoid carcinoma. Although they usually have an indolent behavior, adenoid cystic carcinomas can be more aggressive, with 5-year survival as low as 55%. Unfortunately, these tumors do not respond well to chemotherapy. In contrast to the most common subtypes of lung carcinomas, epidermal growth factor receptor studies have not been carried out in this group of tumors. Herein we report a series of 24 cases (12 adenoid cystic and 12 mucoepidermoid carcinomas) tested for epidermal growth factor receptor protein expression, epidermal growth factor receptor gene copy gains, and epidermal growth factor receptor gene mutational status, through immunohistochemistry, fluorescence in situ hybridization, and sequencing of the exons 18-21, respectively. Overall, 91 and 92% of the adenoid cystic carcinomas and mucoepidermoid carcinomas expressed epidermal growth factor receptor protein. Chromosome 7 polysomy occurred in 25% of the cases (four adenoid cystic carcinomas and two mucoepidermoid carcinomas). No epidermal growth factor receptor gene amplification was detected and no mutation was found in exons 18-21 of the epidermal growth factor receptor gene. Immunoexpression of epidermal growth factor receptor in salivary gland-type lung carcinomas is not related to epidermal growth factor receptor gene copy number or mutational status.

Salivary gland cancers: current treatments, molecular characteristics and new therapies

Salivary gland cancers are relatively rare and quite diverse. Current therapy relies on local ablation. There are few large clinical trials or randomized trials to guide treatment, especially for metastatic disease. This article reviews the epidemiology, staging, molecular characteristics, and treatment evidence for the most common types of salivary cancers and suggests potential future diagnostic and treatment directions. Progress in understanding the molecular and cell biology of salivary gland cancers may lead to the development of targeted therapies in these rare tumors. Multidisciplinary and multi-institutional collaborative studies are needed to help improve survival in salivary gland cancers.

Management and outcome of patients with mucoepidermoid carcinoma of major salivary gland origin: a single institution's 30-year experience

BACKGROUND

Mucoepidermoid carcinoma (MEC) is one of the most frequent epithelial malignancies of the salivary glands. Prediction of clinical outcome of MEC is challenging.

MATERIAL AND METHODS

We retrospectively reviewed 52 cases of MEC of major salivary gland origin diagnosed at the Department of Otolaryngology-Head and Neck Surgery, Helsinki University Central Hospital, Helsinki, Finland, during a 30-year period of 1976 to 2005. Criteria used for diagnosis were those of World Health Organization classifications valid at each time point, and criteria for grading were those recommended by Armed Forces Institute of Pathology fascicle (1996). Since 1993, the degree of cell proliferation was used at our institution as an adjunct tool when grading MEC. The majority of cases occurred in the parotid gland (n = 47, 90%) followed by the submandibular gland (n = 5, 10%).

RESULTS

We had 39% high-grade (HG), 14% intermediate-grade (IMG), and 44% low-grade (LG) MECs. T categories were T1, n = 18; T2, n = 16; T3, n = 9; T4, n = 9. Forty-nine (94%) patients were treated with curative intent. These patients underwent surgery, and 24 (49%) patients received postoperative radiotherapy. Follow-up time varied from 6 months to 9 years. Forty-five percent of HG-MEC patients and 67% of IMG-MEC patients developed locoregional failures or distant metastases during a 3-year follow-up as opposed to none of the LG-MEC patients. Of MEC patients with N0 neck, two HG-MEC patients and one IMG-MEC (8%) patient developed regional recurrence during follow-up.

CONCLUSIONS

Patient outcome in the different grades of MEC suggests a need for overview of the treatment protocol, especially with regard to LG-MEC and IMG-MEC. The apparently unusual occurrence of locoregional failures and metastases in LG-MEC suggests a restrictive approach in surgical management. However, the frequent occurrence of such failures in IMG-MEC warrants an aggressive approach with these tumors.

Cancer mucoépidermoïde des glandes salivaires: signification pronostique des marqueurs tumoraux

INTRODUCTION

Mucoepidermoid carcinoma is one of the most frequent malignant lesions of salivary glands. The treatment is based on clinical, paraclinical and histological data. Several studies on the prognostic value of molecular markers for these cancers were made with contradictory results. The aim of this retrospective study was to analyze the prognostic value of molecular markers of salivary gland mucoepidermoid carcinoma.

MATERIAL AND METHODS

Sixteen patients were treated for mucoepidermoid carcinoma of principal and/or accessory salivary glands between 1994 and 2003. An immunohistochemical study of archive specimen was performed. Nine markers were specifically studied: 4 proteins/oncoproteins (p53, bcl2, c-erb-B2 and cd117), 2 markers of proliferation (PCNA and Ki67), 1 growing factor receptor (EGFR), 1 epithelial adhesion molecule (E-cadherin), and 1 angiogenic cytokine (PDGF).

RESULTS

Nine men and 7 women were included, with a mean age of 43.7 years (14-80). The mean diameter of tumors was 3.1 mm (1-14), and the parotid gland was the most frequent location. The mean global survival rate was 57.3 months with a median of 55 months. The 2 to 5 years survival expectation rate were 82.5% and 46.4% respectively. The mean survival rate for women was superior to that of men (P=0.043). The expression of p53 and the high expression rate of EFGR were bad prognostic factors (respectively P=0.049 and P=0.012). The expression of PCNA was linked to the location (mainly the salivary gland) and to the diameter of the tumor (respectively P=0.037 and P=0.029). The degree of EFGR positivity and the histological grade were linked (P=0.027).

DISCUSSION

The strong expression of EGFR was statistically linked to the histological tumor grade. The degree of PCNA positivity seemed to be associated to the preferential location in the main salivary glands and to the diameter of the tumor. The strong expression of p53 and EGFR were bad prognostic factors. These retrospective results need to be confirmed by prospective randomized and larger studies. EGFR and p53 were significant negative prognostic factors. EGFR was highly correlated to the histological grade, making it an interesting target for further investigation.

Insights into a complex group of neoplastic disease: advances in histopathologic classification and molecular pathology of salivary gland cancer

Cancers of major and minor salivary glands represent a histopathologic challenge in two major respects. The first challenge is the complexity of morphologic features and overlapping of histologic patterns in the different tumor entities many of which are relatively rare. The number of separate tumor entities to be considered in differential diagnosis has greatly increased in the two latest WHO classification systems 12 (Table I). The second challenge is prognostication based on histopathology. The clinical experience is that behavior of some salivary gland carcinomas does not correlate well with their histopathologic classification, and that tumors classified within the same category may exhibit quite different clinical outcomes. However, recent advances in histopathological classification have been combined with new tools in immunohistochemical diagnosis and prognostication including cell-proliferation markers, myoepithelial antigens, matrix metalloproteinases, steroid receptors, growth factors and their receptors. These have improved our possibilities for more specific choices in the treatment of a variety of salivary gland carcinomas. This paper will give an overview on recent developments in histopathological classification, prognostication, and molecular pathology of salivary gland cancer.

Systemic therapy in the palliative management of advanced salivary gland cancers

Cancers of the salivary glands are unusual lesions that vary widely in their histologic appearance and molecular characteristics. Likewise, there is a wide spectrum of biologic behavior, ranging from low-grade, minimally invasive tumors, to highly lethal malignancies. There are few data on the role of systemic therapies in the management of these cancers, and chemotherapy is generally reserved for the palliative management of advanced disease that is not amenable to local therapies such as surgery and/or radiation. The majority of patients for whom systemic therapy is considered will have either adenoid cystic carcinoma, mucoepidermoid carcinoma, or high-grade adenocarcinoma. This article will review the available literature regarding the use of palliative chemotherapy for patients with advanced salivary gland cancer of these histologies, with an emphasis on the potential role of targeted agents. There is a need for a determined, coordinated effort to conduct high-quality clinical trials in patients with these rare cancers.

Salivary gland adenoid cystic carcinoma: A review of chemotherapy and molecular therapies

Adenoid cystic carcinoma (ACC) accounts for about 1% of all head and neck malignancies. It has a tendency for a prolonged clinical course, with local recurrences and distant metastases sometimes occurring many years after presentation. Standard treatment for salivary gland ACC is surgery and post-operative radiotherapy. The aim of this review was to examine the reported efficacy of various chemotherapy regimens and molecular therapies on recurrent/metastatic salivary gland ACC. One hundred and fourteen publications were reviewed on chemotherapy as well as possible molecular targets of therapy, including KIT, epidermal growth factor receptor (EGFR), human epidermal growth receptor-2 (HER-2), oestrogen and progesterone receptors, proliferating cell nuclear antigen (PCNA), Ki-67 and the p53, bcl-2 and SOX-4 genes. Reported response rates to combination chemotherapy are low and response duration generally short lived. The response to molecular therapies is low also. More research into novel molecular targets is needed.

Parotid carcinoma: expression of kit protein and epidermal growth factor receptor

OBJECTIVES

Our aim is to investigate the expression of kit protein (KIT) and epidermal growth factor receptor (EGFR) in parotid carcinomas in order to correlate the expression to histology and prognosis. Further we want to perform mutation analysis of KIT-positive adenoid cystic carcinomas.

PATIENTS AND METHODS

Formalin-fixed paraffin-embedded sections from 73 patients with parotid gland carcinomas were used for the study. The sections were stained with both KIT and EGFR polyclonal antibodies. Twelve KIT-positive adenoid cystic carcinomas were examined for c-kit mutation in codon 816.

RESULTS

Of all carcinomas 25% were KIT-positive and 79% were EGFR-positive. Ninety-two percentage of the adenoid cystic carcinomas were KIT-positive. None of the adenoid cystic carcinomas had mutations in codon 816 of the c-kit gene.

CONCLUSION

Neither KIT- nor EGFR-expression seem to harbour significant prognostic information. Adenoid cystic carcinomas express KIT, but no mutations in codon 816 of the c-kit gene were identified.

Unexpected rapid progression of metastatic adenoid cystic carcinoma during treatment with imatinib mesylate

BACKGROUND

There is a lack of effective treatment for metastatic adenoid cystic carcinoma (ACC), a usually indolent tumor. We studied the efficacy of imatinib mesylate, a potent inhibitor of KIT tyrosine kinase, in patients with KIT-positive metastatic ACC.

METHOD

Five patients with lung metastasis were treated in a pilot study with imatinib 400 mg by mouth twice a day. Mutations of c-kit and platelet-derived growth factor receptor (PDGFR)-alpha in tumors from these patients were analyzed.

RESULTS

Disease progression was noted in three of five patients during the short treatment periods, ranging from 2 to 3 weeks. Three patients died of disease within 6 months. No detectable mutations were found in c-kit and PDGFR-alpha.

CONCLUSION

We observed an unexpected high progression rate of metastatic ACC within short periods during imatinib treatment. Use of imatinib to treat cancers without c-kit or PDGFR-alpha mutation should be approached with caution.

Salivary gland neoplasms

Treatment and cure of salivary gland neoplasms requires surgical intervention in most cases. For parotid neoplasms, the most common surgical procedure performed is the superficial parotidectomy with facial nerve preservation. Postoperative radiation therapy is indicated in high-grade salivary gland malignancies and malignancies with increased risk of locoregional recurrence. Primary radiation, including neutron beam techniques, may play a role in certain histologic types or nonoperative candidates. Chemotherapy has yet to result in improvements in survival or quality of life in the treatment of salivary gland malignancy. Advances in radiation therapy techniques, including intensity-modulated radiation therapy, provide opportunities for reduced morbidity.

Cadherin and catenin expression in mucoepidermoid carcinoma: correlation with histopathologic grade, clinical stage, and patient outcome

BACKGROUND

Alteration of cadherin and catenin expression is associated with loss of differentiation, acquisition of an invasive phenotype, and poor prognosis in many types of cancers. The roles of cadherins and catenins in mucoepidermoid carcinoma (MEC) are not fully understood.

METHODS

Based on immunohistochemical studies, the expressions of E-, N-, and P-cadherins and alpha-, beta-, and gamma-catenins in MEC were investigated, and correlations with clinicopathologic parameters were evaluated.

RESULTS

These six molecules were strongly expressed in normal ductal epithelium but increased or decreased immunoreactivities of those proteins in MEC were frequently observed, especially for E-cadherin and alpha-catenin. The immunoactivity of beta-catenin showed significant correlation with grade (P = 0.05) and stage (P < 0.0001). beta-Catenin expressions are also correlated with gamma-catenin expression (P = 0.006) according to cross-table analysis. Survival analysis indicated that stage, grade, and beta-catenin expressions had significant correlation with survival.

CONCLUSION

Aberrant beta-catenin expression may play an important role in the histologic differentiation and tumor staging of MEC.