Systemic therapy in the management of metastatic or locally recurrent adenoid cystic carcinoma of the salivary glands: a systematic review

ID1 contributes to cell growth invasion and migration in salivary adenoid cystic carcinoma

Previous studies have reported that inhibitor of DNA binding 1 (ID1) exerts an oncogenic role in a number of tumors. In the present study, the role of ID1 in the growth, invasion and migration of salivary adenoid cystic carcinoma (SACC) cells was investigated. ID1 expression in clinical SACC samples was compared with that in normal salivary tissues using immunohistochemical staining, and the correlation between ID1 expression and clinical pathological characteristics was then determined. Subsequently, ID1 was overexpressed or silenced to investigate the effects of ID1 expression on SACC cell proliferation, invasion and migration. In addition, the gene expression levels of known ID1 target genes, including S100A9, CDKN2A and matrix metalloproteinase 1 (MMP1) was measured using reverse transcription-quantitative polymerase chain reaction to elucidate the potential mechanisms of ID1 in SACC. The results of the present study indicated that the protein expression levels of ID1 were significantly increased in the SACC tissues compared with that in the normal salivary tissues (P<0.001), and a positive correlation between ID1 expression and tumor stage (P=0.001), tumor invasion (P=0.002) and metastasis (P=0.019) in SACC was observed. Knockdown of ID1 in SACC cells significantly inhibited cell growth, invasion and migration (all P<0.01), whereas overexpression of ID1 promoted cell proliferation, invasion and migration (all P<0.01). The gene expression level of MMP1 was significantly reduced following ID1 knockdown in SACC-83 cells when compared with negative controls (P<0.05), whereas S100A9 and CDKN2A expression levels were significantly upregulated (both P<0.05). The results suggest that ID1 may regulate the growth, invasion and migration of SACC cells, and that MMP1, S100A9 and CDKN2A may serve as target genes of ID1 and mediate the effects of ID1 in SACC cells. Therefore, ID1 may present a potential target gene for the treatment of patients with SACC to inhibit cancer cell growth and metastasis.

Epiregulin Promotes Lung Metastasis of Salivary Adenoid Cystic Carcinoma

Salivary adenoid cystic carcinoma (SACC) is a peculiar malignant tumor, characterized by its slow but inexorable growth, with a high incidence of lung metastasis and poor prognosis. Here, we show the upregulated expression of EGFR ligand epiregulin in a subset of SACC cells correlates with lung metastasis and unfavorable outcome in patients with SACC. We found that upregulation of epiregulin in SACC cells induced epithelial-mesenchymal transition by regulating GLI1/E-cadherin. Elevated epiregulin increased the expression of pro-angiogenic factors, such as VEGFA, bFGF, and IL-8. We also show that epiregulin can be delivered via exosomes and was enriched in exosomes derived from epiregulin-overexpressing SACC cells. Furthermore, treating immunodeficient mice with these epiregulin-enriched exosomes greatly enhanced SACC metastasis to lung. These epiregulin-enriched exosomes significantly enhanced angiogenesis in the neighboring tumor microenvironment and increased vascular permeability in the pre-metastatic lung microenvironment in vivo. Therefore, epiregulin, as well as epiregulin-containing exosomes, may be a novel target for controlling SACC lung metastasis.

Parotid adenoid cystic carcinoma: Retrospective single institute analysis

PURPOSE

Adenoid cystic carcinoma (ACC) is a uncommon salivary malignant tumor. Our aim was to review our experience with parotid ACC, to identify clinical-pathological parameters predictive for outcome.

MATERIALS AND METHODS

We retrospectively reviewed 228 patients affected by parotid gland carcinomas surgically treated at our Institution. Forty-four ACC were included in this study. Multivariate analysis risk models were built to predict recurrence free probability (RFP), distant recurrence free probability (DRFP), overall survival (OS) and disease free survival (DFS).

RESULTS

Twenty-one patients (47.7%) died from ACC and 2.3% for other causes. The 41% presented local-regional recurrence, with a regional-RFP rate of 93%, and the 34% reported distant metastases (DM). The five and ten-year OS rates were 74% and 50%, respectively.

CONCLUSIONS

Recurrences were mainly influenced by the presence of perineural invasion and nerve paralysis, whilst female gender and age<50 were predictors for good prognosis.

Radiosensitization of Adenoid Cystic Carcinoma with MDM2 Inhibition

Purpose: Adenoid cystic carcinoma (ACC) is a rare cancer arising from the major or minor salivary gland tissues of the head and neck. There are currently no approved systemic agents or known radiosensitizers for ACC. Unlike the more common head and neck squamous cell carcinomas that frequently harbor TP53 mutations, ACCs contain TP53 mutations at a rate of <5%, rendering them an attractive target for MDM2 inhibition.Experimental Design: We report the successful establishment and detailed characterization of a TP53-WT ACC patient-derived xenograft (PDX), which retained the histologic features of the original patient tumor. We evaluated this model for response to the MDM2 inhibitor AMG 232 as monotherapy and in combination with radiotherapy.Results: AMG 232 monotherapy induced modest tumor growth inhibition, and radiation monotherapy induced a transient tumor growth delay in a dose-dependent fashion. Strikingly, combination treatment of AMG 232 with radiotherapy (including low-dose radiotherapy of 2 Gy/fraction) induced dramatic tumor response and high local tumor control rates 3 months following treatment. Posttreatment analysis revealed that although both AMG 232 and radiotherapy alone induced TP53 tumor-suppressive activities, combination therapy amplified this response with potent induction of apoptosis after combination treatment.Conclusions: These data identify that MDM2 inhibition can provide potent radiosensitization in TP53-WT ACC. In light of the absence of effective systemic agents for ACC, the powerful response profile observed here suggests that clinical trial evaluation of this drug/radiotherapy combination may be warranted to improve local control in this challenging malignancy. Clin Cancer Res; 23(20); 6044-53. ©2017 AACR.

New Developments in Salivary Gland Pathology: Clinically Useful Ancillary Testing and New Potentially Targetable Molecular Alterations

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. Ancillary testing is beginning to ameliorate some of these challenges through access to newer immunohistochemical stains and fluorescence in situ hybridization probes, which can limit differential diagnostic considerations in some cases. These ancillary testing strategies are especially useful in small biopsy samples, including aspiration cytology. Molecular techniques are also expanding our understanding of salivary gland tumor pathology and are helping to identify potential targets that may improve treatment for some of these tumors. Here, we summarize the clinical use of new immunohistochemical markers in our practice and review the current understanding of chromosomal rearrangements in salivary gland tumor pathology, emphasizing the prospects for exploiting molecular alterations in salivary gland tumors for diagnosis and targeted therapy. We find that immunohistochemistry and fluorescence in situ hybridization are powerful tools toward the diagnosis of salivary gland tumors, especially when used in a systematic manner based on morphologic differential-diagnostic considerations. As new targeted therapies emerge, it will become increasingly vital to incorporate appropriate molecular testing into the pathologic evaluation of salivary gland cancers.

Clinicopathologic and prognostic factors in adenoid cystic carcinoma of head and neck minor salivary glands: A clinical analysis of 130 cases

PURPOSE

This study was to investigate clinicopathologic characteristics and prognostic factors in adenoid cystic carcinoma of head and neck minor salivary glands.

MATERIALS AND METHODS

We conducted a retrospective review of 130 patients with adenoid cystic carcinoma of head and neck minor salivary glands that were evaluated between 2000 and 2013 in Beijng Tongren Hospital.

RESULTS

Five-year overall survival and disease-free survival rates were 80.8% and 55.6%. Local recurrence rate was 40%, regional recurrence 3.8%, and distant metastasis was 28.5%. On univariate analysis, solid histological subtype, perineural invasion, positive surgical margins and advanced stages were found to be poor prognostic indicators. On multivariate analysis, solid histological subtype and positive surgical margins were significant prognostic factors of worse overall survival.

CONCLUSIONS

Solid histological subtype and positive surgical margins were the most important predictors of poor outcome in adenoid cystic carcinoma of minor salivary glands. Surgery with postoperative radiation were recommended treatment and offered durable local control.

Risk factors and prognosis for salivary gland adenoid cystic carcinoma in southern china: A 25-year retrospective study

Adenoid cystic carcinoma (ACC) is characterized by slow growth, frequent local recurrences, and high incidence of distant metastasis (DM). The aim of this study was to evaluate predictive factors for local-regional (LR) recurrence, DM, and survival in ACC.A retrospective review of the medical records for patients with salivary glands ACC from 1990 to 2015 was performed. The clinical parameters were assessed to identify correlations with the development of LR recurrence, DM, and survival of these patients.Among 228 patients who underwent surgery as definitive treatment, 210 (92.1%) were followed up in the study. DM was detected in 64 (30.5%) patients, LR recurrence was detected in 58 (27.6%) patients. The estimated 5, 10, and 15-year overall survival rates were 84.7%, 70.8%, and 34.0%, respectively. Multivariate analysis revealed that the presence of lymphovascular invasion and a high T classification were very strong adverse factors, which independently influenced LR recurrence, DM, and survival of ACC patients. Positive/close margin and N+ status were independent risk factors for DM and LR recurrence, respectively. Survival of ACC patents was also affected by tumor location.Presence of lymphovascular invasion and a high T classification were very strong adverse factors and independent predictors for ACC patients' prognosis, which influenced LR control, DM control, and survival.

Diagnosis and Management of Malignant Salivary Gland Tumors of the Parotid Gland

Malignant parotid tumors are heterogeneous and diverse. Accurate diagnosis requires a pathologist familiar with the various histologic subtypes, immunohistochemistry stains, and common translocations. Clinical course varies according to tumor subtype, ranging from indolent, slow-growing adenoid cystic carcinoma to rapidly progressive, possibly fatal, salivary ductal carcinoma. Histologic grade is important in prognosis and therapy. Surgery remains the mainstay of treatment when negative margins can be achieved. Radiation improves locoregional control of tumors with high-risk features. Chemotherapy for parotid tumors can be disappointing. Studies of new targeted therapies have not offered significant benefits.

Activating NOTCH1 Mutations Define a Distinct Subgroup of Patients With Adenoid Cystic Carcinoma Who Have Poor Prognosis, Propensity to Bone and Liver Metastasis, and Potential Responsiveness to Notch1 Inhibitors

Purpose

Adenoid cystic carcinomas (ACCs) represent a heterogeneous group of chemotherapy refractory tumors, with a subset demonstrating an aggressive phenotype. We investigated the molecular underpinnings of this phenotype and assessed the Notch1 pathway as a potential therapeutic target.

Methods

We genotyped 102 ACCs that had available pathologic and clinical data. Notch1 activation was assessed by immunohistochemistry for Notch1 intracellular domain. Luciferase reporter assays were used to confirm Notch1 target gene expression in vitro. The Notch1 inhibitor brontictuzumab was tested in patient-derived xenografts from patients with ACC and in a patient with ACC who was enrolled in a phase I study.

Results

NOTCH1 mutations occurred predominantly (14 of 15 patients) in the negative regulatory region and Pro-Glu-Ser-Thr–rich domains, the same two hotspots seen in T-cell acute lymphoblastic leukemias, and led to pathway activation in vitro. NOTCH1-mutant tumors demonstrated significantly higher levels of Notch1 pathway activation than wild-type tumors on the basis of Notch1 intracellular domain staining ( P = .004). NOTCH1 mutations define a distinct aggressive ACC subgroup with a significantly higher likelihood of solid subtype ( P < .001), advanced-stage disease at diagnosis ( P = .02), higher rate of liver and bone metastasis ( P ≤ .02), shorter relapse-free survival (median, 13 v 34 months; P = .01), and shorter overall survival (median 30 v 122 months; P = .001) when compared with NOTCH1 wild-type tumors. Significant tumor growth inhibition with brontictuzumab was observed exclusively in the ACC patient-derived xenograft model that harbored a NOTCH1 activating mutation. Furthermore, an index patient with NOTCH1-mutant ACC had a partial response to brontictuzumab.

Conclusion

NOTCH1 mutations define a distinct disease phenotype characterized by solid histology, liver and bone metastasis, poor prognosis, and potential responsiveness to Notch1 inhibitors. Clinical studies targeting Notch1 in a genotype-defined ACC subgroup are warranted.

Systemic therapy in metastatic salivary gland carcinomas: A pathology-driven paradigm?

Salivary gland carcinomas (SGCs) represent one of the most complex tumors from a pathological point of view. According to the World Health Organization (WHO) classification (2005), twenty-four malignant histotypes are recognized, almost all characterized by specific morphological and genetic features as well as by particular clinical behavior. Loco-regional relapse and distant metastases are quite common. Distant metastases are diagnosed in 25-55% of the patients and only 20% of them are alive after 5years. Adenoid cystic carcinoma (ACC) is the most common (60%) malignant histotype observed in patients with metastatic disease, whilst the other histotypes such as mucoepidermoid carcinoma, salivary duct carcinoma, adenocarcinoma, not otherwise specified (NOS), and myoepithelial carcinoma are rarer. The most common therapeutic approach in cases of metastatic disease is systemic chemotherapy, although the results with this type of approach are poor both in terms of response rate and overall outcome. No consensus has yet been reached on what the standard regimen of chemotherapy should be in this setting. New therapies are under investigation e.g. antiangiogenic agents, histone deacetylase inhibitors, and hormonal deprivation treatment. We have focused our review on systemic treatments in ACC and in non-ACC tumors, including in this latter group all SGC histotypes other than ACC.

Clinical trial of nintedanib in patients with recurrent or metastatic salivary gland cancer of the head and neck: A multicenter phase 2 study (Korean Cancer Study Group HN14-01)

BACKGROUND

Salivary gland cancers (SGCs) are uncommon and account for less than 5% of all head and neck cancers, but they are histologically heterogeneous. No specific therapy, including targeted agents, has consistently improved clinical outcomes in recurrent/metastatic SGC. Recent studies suggest that vascular endothelial growth factor receptor (VEGFR) and platelet-derived growth factor receptor (PDGFR) play important roles in SGC. Nintedanib is a potent small-molecule, triple-receptor tyrosine kinase inhibitor (VEGFR1, VEGFR2, and VEGFR3; fibroblast growth factor receptor 1 [FGFR1], FGFR2, and FGFR3; and PDGFRα and PDGFRß). This study sought to determine the antitumor activity of nintedanib in patients with recurrent or metastatic SGC.

METHODS

This open-label, multicenter, phase 2, single-arm study was conducted at 11 hospitals in South Korea. Patients with pathologically confirmed recurrent and/or metastatic SGC for whom at least 1 line of systemic chemotherapy had failed were enrolled. Nintedanib was given orally at 200 mg twice a day until disease progression or unacceptable toxicity. The primary endpoint was the response rate. The secondary endpoints were progression-free survival, overall survival, toxicity, and the disease-control rate. The Simon 2-stage minimax design was used.

RESULTS

The median age of the patients was 54 years, 60% were female, and 95% had an Eastern Cooperative Oncology Group performance status of 0 or 1. The majority of the patients had adenoid cystic carcinoma (65%), and 40% received at least 2 prior rounds of chemotherapy. After 20 patients were enrolled, the study was stopped because no responders were observed at stage I. There were no partial responses, but the disease-control rate was 75% (15 of 20). The median duration of stable disease was 8.2 months (range, 1.76-12.36 months). At the time of the data cutoff, with a median follow-up of 9.5 months, the median overall survival had not been reached, and the progression-free survival rate at 6 months was 60% (95% confidence interval, 0.34-0.79). Grade 3 adverse events included liver enzyme elevation (25%) and nausea/vomiting (5%). Four patients who required a dose reduction because of a grade 3 liver enzyme elevation showed no further grade 3 events.

CONCLUSIONS

Single-agent nintedanib did not yield a partial response but did achieve a 75% disease-control rate with long-term stabilization in SGC patients. Because of the high rate and long duration of disease control with a good safety profile, further investigation is warranted. Cancer 2017;123:1958-1964. © 2017 American Cancer Society.

Activating NOTCH1 Mutations Define a Distinct Subgroup of Patients With Adenoid Cystic Carcinoma Who Have Poor Prognosis, Propensity to Bone and Liver Metastasis, and Potential Responsiveness to Notch1 Inhibitors

Purpose Adenoid cystic carcinomas (ACCs) represent a heterogeneous group of chemotherapy refractory tumors, with a subset demonstrating an aggressive phenotype. We investigated the molecular underpinnings of this phenotype and assessed the Notch1 pathway as a potential therapeutic target. Methods We genotyped 102 ACCs that had available pathologic and clinical data. Notch1 activation was assessed by immunohistochemistry for Notch1 intracellular domain. Luciferase reporter assays were used to confirm Notch1 target gene expression in vitro. The Notch1 inhibitor brontictuzumab was tested in patient-derived xenografts from patients with ACC and in a patient with ACC who was enrolled in a phase I study. Results NOTCH1 mutations occurred predominantly (14 of 15 patients) in the negative regulatory region and Pro-Glu-Ser-Thr-rich domains, the same two hotspots seen in T-cell acute lymphoblastic leukemias, and led to pathway activation in vitro. NOTCH1-mutant tumors demonstrated significantly higher levels of Notch1 pathway activation than wild-type tumors on the basis of Notch1 intracellular domain staining ( P = .004). NOTCH1 mutations define a distinct aggressive ACC subgroup with a significantly higher likelihood of solid subtype ( P < .001), advanced-stage disease at diagnosis ( P = .02), higher rate of liver and bone metastasis ( P ≤ .02), shorter relapse-free survival (median, 13 v 34 months; P = .01), and shorter overall survival (median 30 v 122 months; P = .001) when compared with NOTCH1 wild-type tumors. Significant tumor growth inhibition with brontictuzumab was observed exclusively in the ACC patient-derived xenograft model that harbored a NOTCH1 activating mutation. Furthermore, an index patient with NOTCH1-mutant ACC had a partial response to brontictuzumab. Conclusion NOTCH1 mutations define a distinct disease phenotype characterized by solid histology, liver and bone metastasis, poor prognosis, and potential responsiveness to Notch1 inhibitors. Clinical studies targeting Notch1 in a genotype-defined ACC subgroup are warranted.

Primary adenoid cystic carcinoma of the trachea with thyroid invasion: a case report and literature review

Primary adenoid cystic carcinoma (ACC) of the trachea with thyroid invasion is very rare. In this report, we present a 46-year-old man with primary ACC of the trachea with thyroid invasion. ACC invasion of the thyroid is very rare and is easily misdiagnosed. The patient sought consultation due to a 6-month history of dysphagia and associated dyspnea. A contrast-enhanced computed tomography scan obtained at the time of admission revealed bilateral thyroid masses and tracheal wall thickening. The thyroid masses were fused to the trachea and the esophagus without discernible borders, intraoperatively. Frozen pathology suggested poorly differentiated cancer, and a bilateral partial thyroidectomy was performed. Postoperative pathology revealed primary tracheal ACC with thyroid invasion. The patient died 1 month after surgery. We have also summarized the literature on the clinical presentation, diagnosis, and treatment of thyroid-invasive ACC.

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.

Combination chemotherapy of carboplatin and paclitaxel for advanced/metastatic salivary gland carcinoma patients: differences in responses by different pathological diagnoses

BACKGROUND

A standard chemotherapy for recurrent/metastatic salivary gland cancers has not been established. Combination chemotherapy of carboplatin and paclitaxel should be evaluated as a treatment option.

METHODS

This study retrospectively reviewed salivary gland cancer patients who received combination chemotherapy of carboplatin and paclitaxel. The differences in objective responses and in the prognoses according to the different pathological diagnoses were evaluated.

RESULTS

A total of 38 patients were enrolled in the study; of them, 18 had salivary duct carcinomas (SDCs), nine had adenoid cystic carcinomas (ACCs), and 11 had other pathological diagnoses. Objective responses were observed in 15 (39%) patients. The median progression-free survival (PFS) was 6.5 months, and the median overall survival (OS) was 26.5 months. ACC patients had relatively low response rates (9%), but there were no significant differences in PFS or OS compared to other sub-types. The treatment was well tolerated, with few adverse events.

CONCLUSION

Salivary gland cancer patients showed a moderate clinical response to the combination chemotherapy of carboplatin and paclitaxel. The objective response rates differed according to the pathological diagnoses, but there were no significant differences in prognoses.

Immune Profiling of Adenoid Cystic Carcinoma: PD-L2 Expression and Associations with Tumor-Infiltrating Lymphocytes

Adenoid cystic carcinoma (ACC) is among the most lethal salivary gland tumors, with no treatments for metastatic disease that prolong survival. We examined tissue from 28 primary and metastatic ACC deposits obtained from 21 patients for infiltrating immune cells and PD-L1/PD-L2 expression and determined mRNA profiles of over 1,400 oncogenic and immune-related genes. We also assessed the effect of chemoradiation on immune mediators in a patient who had serial biopsies available. Most tumors expressed PD-L2 but had few infiltrating immune cells. Lack of immune-cell infiltrate was associated with expression of genes in the β-catenin/Wnt and PI3K pathways. Additionally, certain transcripts linked to growth and invasion were differentially expressed among primary and metastatic deposits. Chemoradiation appeared to increase CD8(+) effector T cells, decrease regulatory T cells, and promote a systemic humoral response. These data suggest a potential role for PD-L2 inhibition and immune modulation as treatment for patients with ACC. Cancer Immunol Res; 4(8); 679-87. ©2016 AACR.

Clinical and molecular insights into adenoid cystic carcinoma: Neural crest-like stemness as a target

OBJECTIVES

This review surveys trialed therapies and molecular defects in adenoid cystic carcinoma (ACC), with an emphasis on neural crest-like stemness characteristics of newly discovered cancer stem cells (CSCs) and therapies that may target these CSCs.

DATA SOURCES

Articles available on Pubmed or OVID MEDLINE databases and unpublished data.

REVIEW METHODS

Systematic review of articles pertaining to ACC and neural crest-like stem cells.

RESULTS

Adenoid cystic carcinoma of the salivary gland is a slowly growing but relentless cancer that is prone to nerve invasion and metastases. A lack of understanding of molecular etiology and absence of targetable drivers has limited therapy for patients with ACC to surgery and radiation. Currently, no curative treatments are available for patients with metastatic disease, which highlights the need for effective new therapies. Research in this area has been inhibited by the lack of validated cell lines and a paucity of clinically useful markers. The ACC research environment has recently improved, thanks to the introduction of novel tools, technologies, approaches, and models. Improved understanding of ACC suggests that neural crest-like stemness is a major target in this rare tumor. New cell culture techniques and patient-derived xenografts provide tools for preclinical testing.

CONCLUSION

Preclinical research has not identified effective targets in ACC, as confirmed by the large number of failed clinical trials. New molecular data suggest that drivers of neural crest-like stemness may be required for maintenance of ACC; as such, CSCs are a target for therapy of ACC.

SOD2 deregulation enhances migration, invasion and has poor prognosis in salivary adenoid cystic carcinoma

This study aimed to investigate the role of SOD2 in the progression and metastasis of salivary adenoid cystic carcinoma (SACC). We analyzed the expression of SOD2 in 50 SACC patients. Then, the effects and mechanism of SOD2 on cell metastasis in a pair of different metastatic potential cell lines was investigated. SOD2 was deregulated in patients with SACC. Up-regulation of SOD2 was associated with distant metastasis and reduced overall survival and disease free - survival. Compared to SACC-83 cells (lower metastasis ability), SACC-LM cells (higher metastasis ability) had higher SOD2 activity and intracellular H2O2 concentrations, and protein levels of pERK1/2 and Slug, but had similar catalase protein level and activity. In SACC-LM, reducing the expression of SOD2 by SiRNA inhibited the metastasis ability and reduced the SOD2 activities, intracellular H2O2 concentrations, and protein levels of pERK1/2 and Slug. These effects were revised in SACC-83 after SOD2 overexpression. Moreover, in SACC-83, treated with H2O2, the metastasis was enhanced accompanied by increased protein levels of pERK1/2 and Slug. We confirmed that SOD2 play an important role in the development and prognosis of SACC and SOD2-dependent production of H2O2 contributes to metastasis of SACC through the ERK-Slug signaling pathway.

Autocrine epiregulin activates EGFR pathway for lung metastasis via EMT in salivary adenoid cystic carcinoma

Salivary adenoid cystic carcinoma (SACC) is characterized by invasive local growth and a high incidence of lung metastasis. Patients with lung metastasis have a poor prognosis. Treatment of metastatic SACC has been unsuccessful, largely due to a lack of specific targets for the metastatic cells. In this study, we showed that epidermal growth factor receptors (EGFR) were constitutively activated in metastatic lung subtypes of SACC cells, and that this activation was induced by autocrine expression of epiregulin (EREG), a ligand of EGFR. Autocrine EREG expression was increased in metastatic SACC-LM cells compared to that in non-metastatic parental SACC cells. Importantly, EREG-neutralizing antibody, but not normal IgG, blocked the autocrine EREG-induced EGFR phosphorylation and the migration of SACC cells, suggesting that EREG-induced EGFR activation is essential for induction of cell migration and invasion by SACC cells. Moreover, EREG-activated EGFR stabilized Snail and Slug, which promoted EMT and metastatic features in SACC cells. Of note, targeting EGFR with inhibitors significantly suppressed both the motility of SACC cells in vitro and lung metastasis in vivo. Finally, elevated EREG expression showed a strong correlation with poor prognosis in head and neck cancer. Thus, targeting the EREG-EGFR-Snail/Slug axis represents a novel strategy for the treatment of metastatic SACC even no genetic EGFR mutation.

The landscape of gene fusions and somatic mutations in salivary gland neoplasms - Implications for diagnosis and therapy

Recent studies of the genomic landscape of salivary gland tumors have provided important insights into the molecular pathogenesis of these tumors. The most consistent alterations identified include a translocation-generated gene fusion network involving transcription factors, transcriptional coactivators, tyrosine kinase receptors, and other kinases. In addition, next-generation sequencing studies of a few subtypes of salivary neoplasms have revealed hotspot mutations in individual genes and mutations clustering to specific pathways frequently altered in cancer. Although limited, these studies have opened up new avenues for improved classification and targeted therapies of salivary gland cancers. In this review, we summarize the latest developments in this field, focusing on tumor types for which clinically important molecular data are available.

Cytogenetic and immunohistochemical biomarker profiling of therapy-relevant factors in salivary gland carcinomas

OBJECTIVES

There is currently no established algorithm for the molecular profiling of therapy-relevant defects in salivary gland carcinomas (SGC). HER2 overexpression in a subfraction of SGC and low frequencies of EGFR mutations are known. Here, we established receptor and cell signalling profiles of 17 therapy-relevant factors and propose a molecular diagnostic algorithm for SGC.

MATERIALS AND METHODS

Formalin-fixed and paraffin-embedded tissue samples from SGC (n = 38) were analysed with immunohistochemistry and fluorescence in situ hybridisation (FISH).

RESULTS

Two or more expressed receptors and/or receptor gene amplification were detectable in eight of 38 (21%) tumours: HER2 3+/AR 1+, HER3 gene amplification/AR 1+/EGFR 1+, ER 3+/AR 1+, EGFR 2+/PR 1+ and EGFR 2+/PR 1+/AR 1+. No FGFR1-3, MET, ALK1, ROS1, RET, BRAF nor VEGFA defects were detectable, and ERCC1 was not overexpressed. No PD1+ tumour-infiltrating T cells were detectable.

CONCLUSION

Personalised therapy of patients with salivary gland carcinomas should include HER2 and EGFR signalling testing and, in negative cases, evaluation of rare potential target molecules. ERCC1 and PD1 do not appear to be reliable markers for the decision for or against chemotherapy or immunotherapy, respectively.

VEGF and Ki-67 Overexpression in Predicting Poor Overall Survival in Adenoid Cystic Carcinoma

PURPOSE

The purpose of this study was to evaluate potential prognostic factors in patients with adenoid cystic carcinoma (ACC).

MATERIALS AND METHODS

A total of 68 patients who underwent curative surgery and had available tissue were enrolled in this study. Their medical records and pathologic slides were reviewed and immunohistochemistry for basic fibroblast growth factor, fibroblast growth factor receptor (FGFR) 2, FGFR3, c-kit, Myb proto-oncogene protein, platelet-derived growth factor receptor beta, vascular endothelial growth factor (VEGF), and Ki-67 was performed. Univariate and multivariate analysis was performed for determination of disease-free survival (DFS) and overall survival (OS).

RESULTS

In univariate analyses, primary site of nasal cavity and paranasal sinus (p=0.022) and Ki-67 expression of more than 7% (p=0.001) were statistically significant factors for poor DFS. Regarding OS, perineural invasion (p=0.032), high expression of VEGF (p=0.033), and high expression of Ki-67 (p=0.007) were poor prognostic factors. In multivariate analyses, primary site of nasal cavity and paranasal sinus (p=0.028) and high expression of Ki-67 (p=0.004) were independent risk factors for poor DFS, and high expression of VEGF (p=0.011) and Ki-67 (p=0.011) showed independent association with poor OS.

CONCLUSION

High expression of VEGF and Ki-67 were independent poor prognostic factors for OS in ACC.

Adding concurrent chemotherapy to postoperative radiotherapy improves locoregional control but Not overall survival in patients with salivary gland adenoid cystic carcinoma-a propensity score matched study

PURPOSE

To compare the long-term outcomes in patients with salivary gland adenoid cystic carcinoma (SGACC) treated with post-operative chemoradiotherapy (POCRT) versus post-operative radiotherapy (PORT).

METHODS

We retrospectively reviewed the records of 91 SGACC patients treated with surgery followed by PORT (n = 58) or POCRT (n = 33) between 2000 and 2013. Treatment outcomes between groups were compared using propensity score matching (1:1 nearest neighbor).

RESULTS

The median radiation dose was 66 Gy, and patients were followed up for a median of 71 months. Cisplatin-based concurrent regimens were the most commonly used chemotherapy schedules. In the entire study cohort, patients undergoing POCRT showed a trend toward higher locoregional control (LRC) rates than those treated with PORT alone at both 5 and 8 years (97 and 97 % versus 84 and 79 %, respectively; P = .066). Distant metastases were the most common form of treatment failure and occurred in 31 (34 %) patients (PORT, n = 17; POCRT, n = 14). After propensity score matching (33 pairs), patients receiving POCRT had 5- and 8 year LRC rates of 97 and 97 %, respectively, compared with 79 and 67 % for patients treated with PORT alone (P = .017). The two groups did not differ significantly in terms of distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS). However, a significantly better opioid-requiring pain-free survival (ORPFS) was achieved in POCRT group (P = .038). Subgroup analyses revealed that patients with stage III - IV disease (P = .040 and .017), positive surgical margins (P = .011 and .050), or perineural invasion (P = .013 and .035) had significantly higher 5- and 8 year LRC and ORPFS when treated with POCRT, respectively.

CONCLUSIONS

In SGACC patients, adding concurrent chemotherapy to PORT may increase LRC and ORPFS rates, particularly in presence of stage III - IV disease, positive surgical margins, or perineural invasion. However, no significant differences in DMFS, DFS, and OS were observed.

Adenoid cystic carcinoma of the submandibular gland with rare metastasis to the sternum in a 52-year-old male

Adenoid cystic carcinoma (ACC) is a rare tumor, described as being one of the most biologically destructive tumors of the head and neck. It is the most common malignancy that affects the minor salivary glands. Lung and bones are the most common regions of ACC distant metastasis. To the best of our knowledge, herein, we report the first ever case of latent isolated sternal metastasis from ACC in a 52-year-old gentleman, who was diagnosed to have ACC of the submandibular gland, excised 10 years ago.

Adenoid Cystic Carcinoma of the Lung with an EGFR Mutation

An 80-year-old woman was referred to our hospital due to the presence of a mass that was identified on a chest X-ray. A further investigation demonstrated advanced adenoid cystic carcinoma of the lungs. Anti-cancer chemotherapy with docetaxel was carried out and the lesion remained as stable disease. Subsequently, pleural effusion was detected, and an investigation of the pleural effusion revealed the existence of malignant cells with an epidermal growth factor (EGFR) mutation. Gefitinib was administered and the pleural effusion resolved. This is the first case of a positive EGFR mutation of adenoid cystic carcinoma of the lung with a favorable response to an EGFR-tyrosine kinase inhibitor.

Adenoid cystic carcinoma: current therapy and potential therapeutic advances based on genomic profiling

Adenoid cystic carcinoma (ACC) is a rare cancer with high potential for recurrence and metastasis. Efficacy of current treatment options, particularly for advanced disease, is very limited. Recent whole genome and exome sequencing has dramatically improved our understanding of ACC pathogenesis. A balanced translocation resulting in the MYB-NFIB fusion gene appears to be a fundamental signature of ACC. In addition, sequencing has identified a number of other driver genes mutated in downstream pathways common to other well-studied cancers. Overexpression of oncogenic proteins involved in cell growth, adhesion, cell cycle regulation, and angiogenesis are also present in ACC. Collectively, studies have identified genes and proteins for targeted, mechanism-based, therapies based on tumor phenotypes, as opposed to nonspecific cytotoxic agents. In addition, although few studies in ACC currently exist, immunotherapy may also hold promise. Better genetic understanding will enable treatment with novel targeted agents and initial exploration of immune-based therapies with the goal of improving outcomes for patients with ACC.

Head and neck adenoid cystic carcinoma: A prospective multicenter REFCOR study of 95 cases

OBJECTIVES

To describe the clinical, histological and therapeutic characteristics of a prospective multicenter series of 95 head and neck adenoid cystic carcinoma patients, and to determine any prognostic factors for disease-free survival.

PATIENTS AND METHODS

Ninety-five patients with adenoid cystic carcinoma were included in the Réseau d'Expertise Français Des Cancers ORL Rares (REFCOR, French Rare Head and Neck Cancer Expert Network) database between 2009 and 2012. The primary site was the salivary glands in 39 cases, sinus cavities (including hard palate) in 36 cases, pharynx-larynx-trachea in 14 cases, and lips and oral cavity in 4 cases. The tumor was stage I in 15% of cases, stage II in 23%, stage III in 26% and stage IV in 36%. Nine patients had cervical lymph node involvement and 5 had metastases at diagnosis. Fifty-six percent of patients were managed by surgery with postoperative radiation therapy. During follow-up, 3 patients died, 9 developed metastases and 12 showed recurrence or local progression.

RESULTS

Mean follow-up was 18 months. On univariate analysis, disease-free survival correlated with T stage (P=0.05), N stage (P=0.003), resection margins (P=0.04), lymph node involvement on histology (P=0.01), and absence of chemotherapy (P=0.03). On multivariate analysis, disease-free survival correlated with T stage (P=0.01), N stage (P=0.09) and surgery (P=0.005).

CONCLUSION

The essential issue in adenoid cystic carcinoma is long-term control. The present results confirm that the reference attitude is radical surgical resection for optimal local control. Adjuvant radiation therapy did not emerge as a prognostic factor. This study also provides a starting-point for translational studies in pathology and genetics.

Notch2 signaling contributes to cell growth, invasion, and migration in salivary adenoid cystic carcinoma

Many studies have explored whether the Notch signaling pathway has a tumor-suppressive or an oncogenic role in various tumors; however, the role of the Notch signaling pathway in salivary adenoid cystic carcinoma (SACC) is still unknown. In this study, we attempt to define the role of Notch2 signaling in cell growth, invasion, and migration in SACC. We compared Notch2 expression in clinical SACC samples with that of normal samples by using immunohistochemical staining. Then, we down-regulated Notch2 expression to observe the effect of Notch2 on proliferation, invasion, migration, and the expression of known target genes of Notch signal pathway. According to our results, Notch2 expression was higher in SACC tissues compared with normal tissues. Knockdown of Notch2 inhibited cell proliferation, invasion, and migration in vitro and down-regulated the expression of HEY2 and CCND1. The results of this study suggest that Notch2 has an essential role in the cell growth, invasion, and migration of SACC. Notch2 may therefore be a potential target gene for the treatment of SACC by interfering with cell growth and metastasis.

Metastatic Salivary Gland Tumors: A Single-Center Study Demonstrating the Feasibility and Potential Clinical Benefit of Molecular-Profiling-Guided Therapy

We evaluated the use of molecular profiling (MP) for metastatic salivary gland adenoid cystic carcinoma (SACC), for which there is no standard treatment. MP (Caris Molecular Intelligence) was performed on biopsy samples from all metastatic SACC patients attending a tertiary medical center between 2010 and 2013 (n = 14). Treatment was selected according to the biomarkers identified. Findings were compared with all similarly diagnosed patients treated in the same center between 1996 and 2009 (n = 9). For each patient, MP identified 1-13 biomarkers associated with clinical benefit for specific therapies (most commonly low/negative TS, low ERCC1). Eleven patients (79%) received MP-guided treatment (2 died prior to treatment initiation, 1 opted not to be treated), with complete response in 1, partial response (PR) in 3, and stable disease in 4. In the historical controls, 2 patients (22%) were treated (1 had PR). Median (range) progression-free survival in the first line after MP was 8.2 months (1.4-49.5+). Median (range) overall survival from diagnosis of metastatic disease was 31.3 (1.4-71.1+) versus 14.0 (1.5-116) months in the historical controls. In conclusion, MP expands treatment options and may improve clinical outcomes for metastatic SACC. In orphan diseases where randomized trials cannot be performed, MP could become a standard clinical tool.

Slug silencing inhibited perineural invasion through regulation of EMMPRIN expression in human salivary adenoid cystic carcinoma

Salivary adenoid cystic carcinoma (SACC) is the most frequent salivary gland malignancy with a unique characteristic that has been named perineural invasion (PNI). EMMPRIN is a transmembrane glycoprotein that has been demonstrated to promote PNI in SACC. Slug, one of the most effective promoters of the epithelial-to-mesenchymal transition (EMT), has been found to be associated with PNI in SACC. The aim of the present study was to investigate the roles and relationships of Slug, EMMPRIN, and E-cadherin in the PNI process of SACC. The expression levels of Slug, EMMPRIN, and E-cadherin in 115 primary SACC cases were statistically analyzed by immunohistochemistry. Simultaneously, the SACC cell line SACC-83 was transfected with recombinant plasmids of silencing Slug (si-Slug) and/or silencing EMMPRIN (si-EMMPRIN). The functions of Slug and EMMPRIN in the EMT and PNI process were assessed by reverse transcription PCR (RT-PCR), western blotting, morphological observation, scratch test, migration assay, and in vitro perineural invasion assay. The immunohistochemical statistics revealed that the high expression of Slug and EMMPRIN and the low expression of E-cadherin were significantly associated with the PNI of SACC (P < 0.05). Slug expression was significantly associated with EMMPRIN expression (P < 0.05), and Slug expression and EMMPRIN expression were both significantly negatively associated with E-cadherin expression (P < 0.05). Slug and EMMPRIN silencing both significantly inhibited EMMPRIN expression but promoted E-cadherin expression in SACC-83 cells (P < 0.01). The series of in vitro assays revealed that silencing of Slug, EMMPRIN, or both induced cell morphology changes and inhibited tumor cell motility and PNI ability in SACC-83 cells (P < 0.01). These results suggested that Slug silencing could inhibit the EMT process by downregulating EMMPRIN and then upregulating E-cadherin in the PNI process of SACC. The present study indicated that Slug and EMMPRIN are potential biomarkers and therapeutic targets for the diagnosis and treatment of PNI in human SACC.

Anti-tumor effect of inhibition of IL-6 signaling in mucoepidermoid carcinoma

Mucoepidermoid carcinoma (MEC) is the most frequent malignant salivary gland cancer. Response to chemoradiotherapy is modest, and therefore radical surgery remains the standard-of-care. Emerging evidence suggests that Interleukin (IL)-6 signaling correlates with the survival of cancer stem cells and resistance to therapy. Here, we investigated whether inhibition of IL-6 receptor (IL-6R) signaling with tocilizumab (humanized anti-human IL-6R antibody) sensitizes MEC to chemotherapy using human mucoepidermoid carcinoma cell lines (UM-HMC) and correspondent xenograft models. In vitro, we observed that tocilizumab inhibited STAT3 phosphorylation but had no measurable effect in MEC cell viability (UM-HMC-1,-3A,-3B). In contrast, the anti-tumor effect of single agent tocilizumab on MEC xenografts was comparable to paclitaxel or cisplatin. Combination of tocilizumab with cisplatin or paclitaxel enhanced the inhibitory effect of chemotherapy on xenograft growth (P < 0.05), time to failure (P < 0.01), decreased vascular endothelial growth factor (VEGF) expression and tumor microvessel density (P < 0.05) without added systemic toxicities. Notably, tocilizumab decreased the fraction of MEC cancer stem cells (ALDH(high)CD44(high)) in vitro, and prevented paclitaxel-induced increase in the fraction of cancer stem cells in vivo (P < 0.05). Collectively, these findings demonstrate that tocilizumab enhances the anti-tumor effect of conventional chemotherapy in preclinical models of mucoepidermoid carcinoma, and suggest that patients might benefit from combination therapy with an inhibitor of IL-6R signaling and chemotherapeutic agent such as paclitaxel.

Adjuvant chemoradiotherapy versus with radiotherapy alone for locally advanced salivary gland carcinoma among older patients

BACKGROUND

The majority of patients with locally advanced salivary gland carcinoma will die of the disease even after curative surgery. Few studies on adjuvant therapy have been conducted. In this study, we compared adjuvant chemoradiotherapy (CRT) with adjuvant radiotherapy among the older patient population.

METHODS

Surveillance, Epidemiology, and End Results (SEER)-Medicare database (1992-2009) was analyzed. Eligible cases were those receiving curative surgery followed by adjuvant therapy. Outcomes were overall survival and toxicity.

RESULTS

Analyses included 741 patients: 641 patients (86.5%) received adjuvant radiotherapy and 100 (13.5%) received adjuvant CRT. The median overall survival was 41.0 months with adjuvant radiotherapy and 24 months with CRT. Both multivariable and propensity score-adjusted analyses indicated that adjuvant CRT was associated with an increased mortality (hazard ratio [HR]: 1.39; 95% confidence interval [CI]: 1.07-1.79 and HR: 1.49; 95% CI: 1.14-1.94, respectively). Toxicity rates were significantly higher in the CRT group.

CONCLUSION

Treatment with adjuvant CRT was associated with an increased mortality and toxicity when compared to adjuvant radiotherapy alone. © 2015 Wiley Periodicals, Inc. Head Neck 38: 863-870, 2016.

Outcomes and prognostic factors in modern era management of major salivary gland cancer

OBJECTIVES

There is a dearth of prospective evidence regarding cancer of the major salivary glands. Outcomes and management of major salivary gland are based largely on retrospective series spanning many decades and changes in surgical, radiation, imaging and systemic therapy strategies and technique. We sought to report contemporary patterns of relapse and prognostic factors for major salivary gland cancer.

MATERIALS AND METHODS

112 patients with major salivary gland cancers underwent resection with or without adjuvant therapy between January 1997 and September 2010. Outcomes were documented with follow-up until December 2014. Survival was calculated by the Kaplan-Meier method. Log-rank test and Cox proportional hazards regression were performed with locoregional control (LRC), distant control (DC) and overall survival (OS) as the primary outcome variables.

RESULTS

Median follow-up was 55.1 months. Rates of LRC for stage I/II and III/IV at five years were 95.7% and 61.9% respectively. Rates of DC at five years for stage I/II and III/IV were 93% and 56.9% respectively. Multivariate analysis identified larger tumor size, clinical nerve involvement and in parotid cancers, advanced T stage, no adjuvant radiation, and older age at diagnosis to be associated with increased risk of locoregional recurrence (all p<0.05). Distant metastasis was associated with sublingual site, degree of clinical nerve involvement, high grade, tumor size and in parotid tumors additionally deep lobe involvement on multivariate analysis (all p<0.05).

CONCLUSION

Several prognostic factors were identified that may help guide decisions regarding adjuvant therapy. DM remains a significant concern in the management of this disease.

Phase 2 study of dovitinib in patients with metastatic or unresectable adenoid cystic carcinoma

BACKGROUND

The objective of this study was to evaluate the efficacy and safety of dovitinib in patients with adenoid cystic carcinoma (ACC).

METHODS

ACC patients with documented disease progression within the past 12 months were eligible. Patients received oral dovitinib (500 mg once daily for 5 consecutive days followed by a 2-day rest every week) until disease progression or unacceptable toxicities. The primary endpoint was the probability of 4-month progression-free survival (PFS). Metabolic response was evaluated with positron emission tomography (PET)/computed tomography (CT) scans performed at the baseline and after 8 weeks of treatment.

RESULTS

Between September 2011 and April 2013, 32 patients with metastatic and/or unresectable ACC were enrolled in this prospective, multicenter trial. The 4-month PFS probability was 80.4%, and the median PFS was 6.0 months (95% confidence interval, 4.4-7.6 months). Tumor shrinkage was observed in 22 patients (68.8%), and 1 patient had a confirmed partial response. The disease control rate was 96.9%. Among 26 patients with PET/CT scans both before and after treatment (at 8 weeks), the metabolic activity of ACC was reduced in 13 patients (50.0%), and 5 patients (19.2%) achieved a metabolic partial response, which was defined as a ≥25% reduction in maximum standardized uptake values. Common grade 3 and 4 adverse events were asthenia (50.0%) and neutropenia (25.0%).

CONCLUSIONS

Dovitinib shows modest antitumor activity in the treatment of ACC.

Adenoid cystic carcinoma: A review of recent advances, molecular targets, and clinical trials

Background

Adenoid cystic carcinoma (ACC) is a rare tumor of secretory glands. In this study, recent advances in molecular characterization and in therapeutics are reviewed.

Methods

A search of articles in PubMed and of abstracts from national meetings was performed regarding ACC.

Results

Recent genetic analyses found that recurrent chromosome 6:9 translocations in ACC generate an MYB:NFIB gene fusion resulting in overexpression of the MYB oncoprotein. Several other frequent mutations are recently published that may be relevant for drug development. Several trials of targeted drugs are reviewed. Some agents delay tumor progression, but tumor responses remain rare.

Conclusion

ACCs have a characteristic chromosomal translocation, but also frequently pick up additional mutations. Clinical research is limited by the rarity and slow growth of ACC. Several ongoing trials are testing agents that inhibit fibroblast growth factor receptor signaling or other signaling pathways. Novel treatments based on the recently sequenced tumor genome are under development. © 2015 The Authors Head & Neck Published by Wiley Periodicals, Inc. 38: 620–627, 2016

Role of hypoxia-inducible factor-1α and CD146 in epidermal growth factor receptor-mediated angiogenesis in salivary gland adenoid cystic carcinoma

Adenoid cystic carcinoma (AdCC) of the salivary gland in the head and neck is characterized by indolent yet persistent growth, multiple local recurrences and early hematogenous metastasis. Considering the possible association between the epidermal growth factor receptor (EGFR) signaling pathway and angiogenesis in various types of cancer and the overexpression of EGFR in AdCC, it is reasonable to examine the correlation between angiogenesis and the EGFR signaling pathway in this carcinoma. In the present study, the expression of EGFR, CD31, CD146 and hypoxia-inducible factor-1α (HIF-1α) were evaluated by immunohistochemical staining with tissue microarray containing normal salivary gland (NSG), pleomorphic adenoma (PMA) and AdCC tissues. Pearson's correlation coefficient was conducted to demonstrate the correlation between EGFR, CD31, CD146 and HIF-1α. To determine their similarity and intimacy, hierarchical analysis was performed with Cluster 3.0 and then visualized using TreeView software. Immunohistochemical results of tissue microarrays were quantified, revealing that the expression of EGFR, CD146 and HIF-1α increased in AdCC compared with in PMA and NSG tissues. The association between the expression of EGFR and CD31 was significant and positive. The expression of CD146 and HIF-1α was positively correlated with EGFR and CD31, respectively. These findings suggest that the EGFR signaling pathway has a vital role in AdCC progression and may be associated with HIF-1α-mediated angiogenesis. These results may enhance our understanding of the mechanism underlying AdCC progression and provide potential clinical therapeutic strategies based on the inhibition of EGFR.

Adenoid cystic carcinoma of the head and neck--An update

This article provides an update on the current understanding of adenoid cystic carcinoma of the head and neck, including a review of its epidemiology, clinical behavior, pathology, molecular biology, diagnostic workup, treatment and prognosis. Adenoid cystic carcinoma is an uncommon salivary gland tumor that may arise in a wide variety of anatomical sites in the head and neck, often with an advanced stage at diagnosis. The clinical course is characterized by very late recurrences; consequently, clinical follow-up should extend at least >15 years. The optimal treatment is generally considered to be surgery with postoperative radiotherapy to optimize local disease control. Much effort has been invested into understanding the tumor's molecular biological processes, aiming to identify patients at high risk of recurrence, in hopes that they could benefit from other, still unproven treatment modalities such as chemotherapy or biological therapy.

Ongoing challenges in the treatment of adenoid cystic carcinoma of the head and neck

BACKGROUND

Adenoid cystic carcinoma is a malignant tumour of major and minor salivary glands. Distant metastasis and poor survival are persistent in the literature, with recent publications aimed at understanding molecular pathogenesis and development of pharmaceutical therapeutic options.

AIM

Provide an update of recent studies in the management of adenoid cystic carcinoma of the head and neck.

METHODS

Literature search using Medline, Scopus, Google Scholar, the Cochrane Database of Systematic Reviews and the Cochrane central register of controlled trials for articles on adenoid cystic carcinoma from January 2005 to January 2015.

CONCLUSION

Adenoid cystic carcinoma is characterized by a slow growing mass, with distant metastasis independent of local or regional control. Primary tumour resection remains the preferred option with radiotherapy having an adjuvant role. Recent advances have been made with novel targeted therapies however, limited to clinical trials and advanced disease.

Induction of autophagy-dependent cell death by the survivin suppressant YM155 in salivary adenoid cystic carcinoma

Adenoid cystic carcinoma (ACC) is one of the most common malignancies of the major and minor salivary glands. However, the molecular mechanism underlying the aggressive growth of human salivary ACC remains unclear. In the present study, we showed that survivin, which belongs to the family of inhibitors of apoptosis, is closely related to the high expression of CDK4 and cyclin D1 in human ACC specimens. By employing the small-molecule drug YM155, we found that the inhibition of survivin in ACC cells caused significant cell death and induced autophagy. Chloroquine, an autophagy inhibitor, prevented cell death induced by YM155, suggesting YM155-induced autophagy contributed to the cell death effects in ACC cells. More importantly, evidence obtained from a xenograft model using ACC-2 cells proved the occurrence of YM155-induced autophagy and cell death in vivo was correlated with the suppression of Erk1/2 and S6 activation as well as increased TFEB nuclear translocation. Taken together, our results indicate YM155 is a novel inducer of autophagy-dependent cell death and possesses therapeutic potential in ACC.

Airway compromise due to adenoid cystic carcinoma obstructing the distal trachea: a review of current management and clinical trials

An 84-year-old man presented with a 2-month history of intermittent stridor and worsening difficulty in breathing. Chest X-ray and flexible nasendoscopy were unremarkable but following further deterioration a CT scan revealed an obstructing lesion in the distal trachea. Bronchoscopy revealed an infiltrative tumour arising 3 cm above the carina causing 90% obstruction. The mass was biopsied and surgically debrided to leave a patent airway. Histological analysis revealed a diagnosis of adenoid cystic carcinoma. Transthoracic surgical resection was unsuccessful and the patient continues to be effectively managed with periodic bronchoscopic debulking and radiotherapy. This case highlights the diagnostic and therapeutic dilemmas posed by distal tracheal lesions and the need for specialist input for effective management.

Inhibition of survivin reduces HIF-1α, TGF-β1 and TFE3 in salivary adenoid cystic carcinoma

In the present study, we explored the expression and correlation of survivin with HIF-1α, TGF-β1 and TFE3 in adenoid cystic carcinoma (AdCC). The expression of survivin, HIF-1α, TGF-β1 and TFE3 was assessed by immunohistochemical staining of a tissue microarray containing tissue samples of normal salivary gland (NSG), pleomorphic adenoma (PA) and AdCC. Correlation analysis of these proteins revealed that increased survivin expression was associated with the overexpression of HIF-1α (P<0.001, r = 0.5599), TGF-β1 (P<0.001, r = 0.6616) and TFE3 (P<0.001, r = 0.7747). The expression of survivin, HIF-1α, TGF-β1 and TFE3 was not correlated with the pathological type of human AdCC (P>0.05). Selective inhibition of survivin by YM155 and siRNA significantly reduced human SACC-83 cell proliferation, with the corresponding decrease in expression of HIF-1α, TGF-β1 and TFE3. The data indicate that the overexpression of survivin in AdCC is related to HIF-1α, TGF-β1 and TFE3. We hypothesize from these findings that the inhibition of survivin may be a novel strategy for neoadjuvant chemotherapeutic and radiosensitive treatment of AdCC.

A multicenter phase II study of everolimus in patients with progressive unresectable adenoid cystic carcinoma

BACKGROUND

The aim of this study was to examine the efficacy and safety of everolimus in patients with progressive unresectable adenoid cystic carcinoma (ACC).

METHODS

Histologically confirmed ACC patients with documented disease progression within 12 months prior to the study entry were eligible. Everolimus was given at a dose of 10 mg daily until progression or occurrence of unacceptable toxicities. The primary endpoint was a 4-month progression-free survival (PFS).

RESULTS

A total of 34 patients were enrolled. The 4-month PFS probability was 65.5% (95% one-sided confidence interval [CI], 47.7 to infinity). Median PFS duration was 11.2 months (95% CI, 3.6 to 15.8). Complete or partial response was not achieved. Twenty-seven (79.4%, 95% CI, 63.2 to 89.6) patients showed stable disease (SD). Tumor shrinkage within SD criteria was observed in 15 patients (44.1%) and SD lasting 6 months was observed in 13 patients (38.2%). Four patients had disease progression. Among the 18 patients with both pre- and post-treatment (at 8 weeks) FDG-PET scans available, 8 patients (44.4%) showed a partial metabolic response, defined as a ≥25% reduction in maximum standardized uptake values (SUVmax). The most common adverse events were stomatitis, anemia, asthenia, and leukopenia. No unexpected everolimus related toxicities were reported.

CONCLUSIONS

Everolimus showed promising efficacy and good tolerability in progressive unresectable ACC.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT01152840.

High expression of SOX2 is associated with poor prognosis in patients with salivary gland adenoid cystic carcinoma

Sex determining region Y-BOX2 (SOX2), one of the key members of the SOX family, is a transcription factor that is involved in the maintenance of embryonic stem cell pluripotency and in multiple developmental processes. Recent studies have shown that SOX2 is aberrantly expressed in several types of tumors. The present study aimed to investigate the clinicopathological and prognostic significance of SOX2 in adenoid cystic carcinoma (ACC) of salivary gland. In this study, the expression of SOX2 in ACC tissues and matched adjacent non-cancerous tissues was measured by immunohistochemistry, western blot, and quantitative polymerase chain reaction. High SOX2 expression occurred in approximately 62.6% of primary ACC. In addition, high expression of SOX2 was significantly associated with T classification (p=0.003) and distant metastasis (p=0.002). The 5-year overall survival (OS) and disease-free survival (DFS) in patients with high SOX2 expression is poorer than those with low SOX2 expression. When adjusted by multivariate analysis, high SOX2 expression, together with distant metastasis, was an independent prognostic factor. The findings of the present study provide evidence that SOX2 represents a potential novel prognostic biomarker for ACC patients.