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

Polarized Microscopic Analysis of Picrosirius Red Stained Salivary Gland Pathologies: An Observational Study

OBJECTIVE

 Salivary gland diseases and their pathologies may affect the glandular structure including collagen, a major stromal component, in response to tissue damage or diseases. This study aimed to examine the changes in collagens in different salivary gland diseases using polarized picrosirius red staining.

MATERIALS AND METHODS

 The submandibular gland samples diagnosed as sialadenitis, chronic sclerosing sialadenitis, pleomorphic adenoma, adenoid cystic carcinoma, and mucoepidermoid carcinoma were stained with picrosirius red, Masson's trichrome, and anticollagen I staining. The quantity of collagens was examined and reported as a percentage of positive picrosirius red area. The maturity of collagens was studied with polarized light microscope and reported as a percentage of orange-red and yellow-green polarized collagens, representing the mature and immature collagens, respectively.

STATISTICAL ANALYSIS

 The % positive areas for picrosirius red representing the collagen amount among salivary gland diseases were analyzed by one-way analysis of variance with Tukey's test. The % orange-red and % yellow-green polarized areas representing the collagen maturity were analyzed by Kruskal-Wallis test and Mann-Whitney U test.

RESULTS

 The malignant tumors, adenoid cystic carcinoma (29.92) and mucoepidermoid carcinoma (26.59), had higher significant percentage of positive picrosirius red area, compared with the benign tumor (14.56), chronic sclerosing sialadenitis (10.61), and sialadenitis (7.22) (p < 0.05). The percentages of orange-red polarized areas are 48.07, 39.6, 62.67, 83.75, and 76.05 in sialadenitis, chronic sclerosing sialadenitis, pleomorphic adenoma, adenoid cystic carcinoma, and mucoepidermoid carcinoma, respectively. This percentage tended to increase in the benign and malignant lesions with statistical difference, compared with the inflammatory lesions (p < 0.05). There was no statistical difference in the percentages of yellow-green polarized areas among various salivary gland diseases. In addition, the results of Masson's trichrome and anticollagen I staining are corresponding to that of picrosirius red among various salivary gland diseases.

CONCLUSIONS

 Polarized picrosirius red demonstrated the most amounts of collagen in the malignant lesion, and represented the different maturity of collagens in each lesion group. Studying the amounts and maturity of collagen with picrosirius red for extracellular matrix alteration in salivary gland diseases along with routine hematoxylin and eosin, Masson's trichrome, and immunohistochemistry may provide a better understanding in different salivary gland pathologies.

Protein Expression of Folate Receptor Alpha in Adenoid Cystic Carcinoma of the Head and Neck

Purpose

Folate receptor alpha (FRα) is overexpressed in various cancer entities while expression in normal tissue is limited. Thus, FRα is an attractive target in cancer therapy. Currently, various therapeutic and diagnostic approaches are under investigation in clinical trials. The aim of this study was to assess the expression and clinical relevance of FRα in adenoid cystic carcinoma of the head and neck.

Patients and Methods

In this retrospective cohort study, 43 patients with adenoid cystic carcinoma (ACC) of the head and neck were included. FRα expression was analyzed in tumor tissue and tumor-free margin in a tissue microarray using immunohistochemical staining. Protein levels were correlated with clinical parameters.

Results

FRα staining was positive in 47% of ACC patients. The tumor-free margin was positive in 22%. Patients with positive tumor tissue showed positive margin staining in 55%. FRα expression was not associated with the clinical parameters (sex, age, staging, grading, perineural invasion, lymphovascular invasion).

Conclusion

FRα expression is common in ACC of the head and neck. Therefore, FRα should be further evaluated as a therapeutic target in ACC.

Breast adenoid cystic carcinoma: a report of seven cases and literature review

Background

Primary adenoid cystic carcinoma (ACC) of breast is rarely seen clinically. It is a special subtype of triple-negative breast cancer characterized by low expression of Ki-67, low malignant potential, slow progression and favorable prognosis. To date, treatment for this disease is controversial and no consensus is reached. We analyzed clinical manifestations and pathological characteristics of seven primary breast ACC cases and reported in combination with literature review to promote understanding, diagnosis and treatment of this disease.

Case presentation

We collected seven breast ACC cases pathologically diagnosed and treated in Department of breast surgery of the First Affiliated Hospital of China Medical University from January 2015 to December 2018. We organized and summarized the clinical, imaging, pathological and prognostic information and performed statistical analysis. The median age was 60 years (ranging from 54 to 64 years). Tumors of all patients were detected by immunohistochemistry. Molecular types were mostly triple negative (4/7), and Ki-67 expression was low (5/7). Lymph node metastases were absent in all patients received axillary lymph node surgery. Median follow-up time was 39 months (ranging from 25 to 68 months). There was no occurrence of relapse, distant metastasis or death.

Conclusion

Breast ACC is accompanied with favorable diagnosis, which is different from typical triple-negative breast cancer. Accurate diagnosis of ACC is particularly important.

Adenoid cystic carcinoma: A case report and review of literature

Adenoid cystic carcinoma (ADCC) is an uncommon tumor of head and neck, whose clinical patterns are characterized by slow growth, perineural invasion and distant metastasis. Cribriform, tubular and solid are the three recognized histopathological patterns which are seen in ADCC. We report a case of ADCC involving palate with an update on the current understanding of its clinical behavior, molecular biology, pathogenesis, histopathological aspect, treatment and prognosis.

Mutational and immunologic Landscape in malignant Salivary Gland Tumors harbor the potential for novel therapeutic strategies

Salivary gland carcinomas (SGC) are rare (3-6 % of all head and neck cancers) and show biological heterogeneity depending on the respective histological subtype. While complete surgical resection is the standard treatment for localized disease, chemotherapy or radiation therapy are frequently insufficient for the treatment of unresectable or metastasized SGC. Therefore, new therapeutic approaches such as molecularly targeted therapy or the application of immune checkpoint inhibition enhance the treatment repertoire. Accordingly, comprehensive analyses of the genomic landscape and the tumor-microenvironment (TME) are of crucial importance in order to optimize and individualize SGC treatment. This manuscript combines the current scientific knowledge of the composition of the mutational landscape and the TME in SGCs harboring the potential for novel (immune-) targeted therapeutic strategies.

OUP accepted manuscript

Adenoid cystic carcinoma (ACC) is a rare cancer of the head and neck that primarily occurs in the salivary glands. Sino-nasal ACC (SNACC) is a much rarer entity; this paper presents an exceedingly rare case of SNACC with both intracranial and intradural extension which was ultimately treated with palliative radiotherapy due to its extensive invasion. In addition to this, a review of the literature has been performed to delineate specific learning points for the management of intracranial SNACC.

Characterization of the MYB-inhibitory potential of the Pan-HDAC inhibitor LAQ824

A large body of work has shown that MYB acts as a master transcription regulator in hematopoietic cells and has pinpointed MYB as a potential drug target for acute myeloid leukemia (AML). Here, we have examined the MYB-inhibitory potential of the HDAC inhibitor LAQ824, which was identified in a screen for novel MYB inhibitors. We show that nanomolar concentrations of LAQ824 and the related HDAC inhibitors vorinostat and panobinostat interfere with MYB function in two ways, by inducing its degradation and inhibiting its activity. Reporter assays show that the inhibition of MYB activity by LAQ824 involves the MYB transactivation domain and the cooperation of MYB with co-activator p300, a key MYB interaction partner and driver of MYB activity. In AML cells, LAQ824-induced degradation of MYB is accompanied by expression of myeloid differentiation markers and apoptotic and necrotic cell death. The ability of LAQ824 to inhibit MYB activity is supported by the observation that down-regulation of direct MYB target genes MYC and GFI1 occurs without apparent decrease of MYB expression already after 2 h of treatment with LAQ824. Furthermore, ectopic expression of an activated version of MYB In HL60 cells counteracts the induction of myeloid differentiation by LAQ824. Overall, our data identify LAQ824 and related HDAC inhibitors as potent MYB-inhibitory agents that exert dual effects on MYB expression and activity in AML cells.

Dominant cell type analysis predicts head and neck adenoid cystic carcinoma outcomes

Traditional histological grading for predicting adenoid cystic carcinoma (ACC) outcomes is challenging and unreliable. We explored the relationship between dominant cell type (DCT) and outcomes for ACC of the head and neck to develop a new approach to predicting prognosis. Clinicopathological data were obtained from a retrospective cohort of 167 patients with primary ACC of the head and neck. Using immunohistochemistry markers to determine DCT, tumors were subclassified into three distinct subtypes, epithelial-predominant (E-ACC), myoepithelial-predominant (M-ACC), and conventional (C-ACC). Differences in clinicopathological parameters and clinical outcomes among these subtypes were then analyzed. Compared to that of M-ACC and C-ACC, E-ACC exhibited more aggressive clinicopathological features with predominantly solid components, high-grade transformation, lymphovascular invasion, tumor necrosis (TN), Ki-67 ≥ 30%, and advanced stage of disease. Both E-ACC and M-ACC could present as solid morphological forms, but E-ACC had a significantly worse prognosis than M-ACC. DCT, TN, and disease stage were independent predictors of recurrence-free survival. DCT, TN, age ≥ 50 years, and disease stage were independent predictors for overall survival. In conclusion, DCT was an independent prognostic indicator for both recurrence-free and overall survival for ACC. Our results provide a new approach to predicting prognosis in ACC and a strong pathological basis for clinically optimizing treatment.

Phase I Study of Entinostat and Nivolumab with or without Ipilimumab in Advanced Solid Tumors (ETCTN-9844)

PURPOSE

Epigenetic modulators improve immune checkpoint inhibitor (ICI) efficacy and increase CD8+ effector:FoxP3+ regulatory T cell ratios in preclinical models. We conducted a multicenter phase I clinical trial combining the histone deacetylase inhibitor entinostat with nivolumab ± ipilimumab in advanced solid tumors.

PATIENTS AND METHODS

Patients received an entinostat run-in (5 mg, weekly × 2) prior to the addition of ICIs. Dose escalation followed a modified 3+3 design [dose level (DL)1/2: entinostat + nivolumab; DL 3/4: entinostat + nivolumab + ipilimumab]. Blood and tissue samples were collected at baseline, after entinostat run-in, and after 8 weeks of combination therapy. Primary endpoints included safety and tolerability, and the recommended phase II dose (RP2D). Secondary endpoints included antitumor activity and change in tumor CD8/FoxP3 ratio pre- and post-therapy.

RESULTS

Thirty-three patients were treated across four dose levels. Treatment-related adverse events (AE) included fatigue (65%), nausea (41%), anemia (38%), diarrhea (26%), and anorexia (26%). Grade 3/4 AEs included fatigue (n = 7, 21%), anemia (n = 9, 27%), and neutropenia (n = 4, 12%). The RP2D was 3 mg entinostat weekly, 3 mg/kg every 2 weeks nivolumab, and 1 mg/kg every 6 weeks ipilimumab (max four doses). The objective response rate by RECIST 1.1 was 16%, including a complete response in triple-negative breast cancer. A statistically significant increase in CD8/FoxP3 ratio was seen following the addition of ICIs to entinostat, but not post-entinostat alone.

CONCLUSIONS

The combination of entinostat with nivolumab ± ipilimumab was safe and tolerable with expected rates of immune-related AEs. Preliminary evidence of both clinical efficacy and immune modulation supports further investigation.

Exceptional Renal Metastasis from Adenoid Cystic Carcinoma of the Nasal Cavity and Literature Review

Adenoid cystic carcinoma (ACC) is a rare malignant cancer that arises from secretory glands. Slow growth, perineural invasion, and late recurrences are the main characteristics of ACC. Only few cases of kidney metastases from ACC have been reported in the literature. We report here the case of a 66-year-old female patient who presented with bilateral renal metastases from ACC of the nasal cavity, detected 14 years after treatment of primary tumor and 6 years after metastasectomy of lung metastases. Histological examination confirmed diagnosis and the patient was treated with systemic chemotherapy. Radiological evaluation showed stability of the disease. However, a progression with occurrence of metastases in other sites (lung and bones) has been observed after 7 months. She is still receiving second-line chemotherapy. To the best of our knowledge, this is the second case of kidney metastases from ACC of the nasal cavity.

Sphk1 promotes salivary adenoid cystic carcinoma progression via PI3K/Akt signaling

The progression of salivary adenoid cystic carcinoma (SACC) is closely related to abnormal gene expression. Herein, the role of Sphk1 in SACC was explored. Sphk1 was overexpressed in SACC tissues. In SACC cell lines, Sphk1 induced cell proliferation, inhibited apoptosis, and promoted cell migration. Moreover, Sphk1 overexpression induced up-regulation of the PI3K protein level and AKT phosphorylation level. Rescue assays further showed that activation of the Sphk1 /PI3K/Akt pathway affected various biological functions of SACC cells. Together, these findings suggested that Sphk1 promotes salivary tumorigenesis by activating the PI3K/ Akt pathway, which may provide novel intervention targets for SACC treatment.

Adenoid cystic carcinoma. An indolent but aggressive tumour. Part A: from aetiopathogenesis to diagnosis

Adenoid cystic carcinoma (ACC) is a relatively rare tumour of the minor and major salivary glands. It is uncommon in the parotid gland while it is much more frequent in the submandibular gland and in minor salivary and mucinous glands (oral cavity, oropharynx, and paranasal sinuses). ACC may also arise in secretory glands located in other tissues, such as in the tracheobronchial tree, oesophagus, breast, lungs, prostate, uterine cervix, lachrymal and Bartholin’s glands, and skin. The natural history of ACC is characterised by an indolent growth rate, a relatively low probability of regional lymph node metastases and a high likelihood of haematogenous dissemination. ACC has been traditionally subdivided into three histological groups (cribriform, tubular, and solid) based on solid components of the tumour. Some studies have shown that tumours with a solid growth component have a rapid fatal course, compared to tumours without a solid growth component, but other studies have failed to correlate growth patterns with clinical course. The purpose of this review is to analyse the very large number of studies (sometimes contradictory) on ACC. In this first part, the aetiology, epidemiology, histopathology, clinical behaviour and diagnostic workup are examined.

Comparative Proteomic Analysis to Investigate the Pathogenesis of Oral Adenoid Cystic Carcinoma

Adenoid cystic carcinoma (ACC) belongs to salivary gland malignancies commonly occurring in an oral cavity with a poor long-term prognosis. The potential biomarkers and cellular functions acting on local recurrences and distant metastases remain to be illustrated. Proteomics is the core content of precision medicine research, which provides accurate information for early detection of cancer, benign and malignant diagnosis, classification and personalized medication, efficacy monitoring, and prognosis judgment. To obtain a comprehensive regulation network and supply clues for the treatment of oral ACC (OACC), we utilized mass spectrometry-based quantitative proteomics to analyze the protein expression profile in paired tumor and adjacent normal tissues. We identified a total of 40,547 specific peptides and 4454 differentially expressed proteins (DEPs), in which HAPLN1 was the most upregulated protein and BPIFB1 was the most downregulated. Then, we annotated the functions and characteristics of DEPs in detail from the aspects of gene ontology, subcellular structural localization, KEGG, and protein domain to thoroughly understand the identified and quantified proteins. Glycosphingolipid biosynthesis and glycosaminoglycan degradation pathways showed the biggest difference according to KEGG analysis. Moreover, we confirmed 20 proteins from the ECM-receptor signaling pathway by a parallel reaction monitoring quantitative detection and 19 proteins were quantified. This study provides useful insights to analyze DEPs in OACC and guide in-depth thinking of the pathogenesis from a proteomics view for anticancer mechanisms and potential biomarkers.

Proteasome inhibitors suppress MYB oncogenic activity in a p300-dependent manner

Studies of the role of MYB in human malignancies have highlighted MYB as a potential drug target for acute myeloid leukemia (AML) and adenoid cystic carcinoma (ACC). Although transcription factors are often considered un-druggable, recent work has demonstrated successful targeting of MYB by low molecular weight compounds. This has fueled the notion that inhibition of MYB has potential as a therapeutic approach against MYB-driven malignancies. Here, we have used a MYB reporter cell line to screen a library of FDA-approved drugs for novel MYB inhibitors. We demonstrate that proteasome inhibitors have significant MYB-inhibitory activity, prompting us to characterize the proteasome inhibitor oprozomib in more detail. Oprozomib was shown to interfere with the ability of the co-activator p300 to stimulate MYB activity and to exert anti-proliferative effects on human AML and ACC cells. Overall, our work demonstrated suppression of oncogenic MYB activity as a novel result of proteasome inhibition.

68Ga-FAPI-PET/CT improves diagnostic staging and radiotherapy planning of adenoid cystic carcinomas - Imaging analysis and histological validation

BACKGROUND

Adenoid cystic carcinomas (ACCs) are rare epithelial tumors mostly situated in the head and neck region and characterized by infiltrative growth. The tumor stroma of ACCs includes cancer-associated fibroblasts (CAFs) expressing Fibroblast Activation Protein (FAP), a new target for positron emission tomography (PET) imaging. Here we describe the value of PET/ computed tomography (PET/CT) imaging using ⁶⁸Ga-labelled FAP-Inhibitors (⁶⁸Ga-FAPI-PET/CT) and their clinical potential for staging and radiotherapy planning in 12 ACC patients (7 primary, 5 recurrent).

PATIENTS AND METHODS

Patients underwent contrast enhanced staging CT (ceCT) and magnetic resonance imaging (ceMRI) before ⁶⁸Ga-FAPI - PET/CT. PET-scans were acquired 10, 60 and 180 minutes after administration of 150-250 MBq of ⁶⁸Ga-labelled FAPI tracers. SUV_max and SUV_mean values of ACCs and healthy organs were obtained using a 60% of maximum iso-contour. FAP and alpha smooth muscle actin (α-SMA) immunohistochemistry was performed in 13 cases (3 with and 10 without ⁶⁸Ga FAPI-PET/CT). Staging and radiotherapy planning based on ⁶⁸Ga-FAPI-PET/CT versus ceCT/MRI alone were compared.

RESULTS

We observed elevated tracer uptake in all ACCs. Immunohistochemistry showed FAP-expressing CAFs in the tumor. Compared to conventional staging, ⁶⁸Ga-FAPI-PET/CT led to upstaging in 2/12 patients and to detection of additional metastases in 3 patients, thus in total 42% of patients had their staging altered. Moreover, ⁶⁸Ga-FAPI PET improved the accuracy of target volume delineation for radiotherapy, as compared to CT and MRI.

CONCLUSION

⁶⁸Ga-FAPI-PET/CT is a promising imaging modality for ACC, increasing the accuracy of staging exams and radiotherapy planning volumes, as compared conventional to CT and MRI.

Diagnostic discrepancy in second opinion reviews of primary epithelial neoplasms involving salivary gland: An 11-year experience from a tertiary referral center focusing on useful pathologic approaches and potential clinical impacts

AIMS

In the era of precision medicine, accurate pathologic diagnoses are crucial for appropriate management.

METHODS

We herein described the histologic features and clinical impacts of 66 salivary gland epithelial neoplasms in which the diagnosis was altered after expert review.

RESULTS

The most common revised diagnosis was that of salivary duct carcinoma (SDC, n = 12), adenoid cystic carcinoma (n = 12), and myoepithelial carcinoma (n = 10). The most common initial diagnosis was mucoepidermoid carcinoma (n = 19) with SDC being the most common revised diagnosis (7/19). Thirteen salivary gland carcinomas were initially diagnosed as benign entities, whereas five benign tumors were initially interpreted as carcinoma. The change in diagnosis was considered to be clinically significant in 65 (97%) cases.

CONCLUSIONS

Given their rarity, salivary gland neoplasms are prone to diagnostic inaccuracy and discrepancy. A constellation of histologic features and ancillary studies are useful in reaching the correct diagnosis, which can have significant clinical impacts.

Solitary Renal Metastasis Arising from a Pulmonary Adenoid Cystic Carcinoma: A Case Report and Review of the Literature

Adenoid cystic carcinoma (ACC) is a malignancy affecting the salivary glands and rarely involving the lung. Due to its rarity, primary lung ACC remains incompletely understood. We herein report the case of a 57-year-old female patient who was initially diagnosed with primary lung ACC and was treated by lobectomy. Seven years later, an abdominal computed tomography scan performed in the context of surveillance revealed the presence of a solid lesion arising from the lower pole of the left kidney. The patient underwent left partial nephrectomy, and histopathology confirmed a completely excised metastatic ACC.

Case Report: Efficacy of Pyrotinib in ERBB2 Amplification Pulmonary Adenoid Cystic Carcinoma

Primary pulmonary adenoid cystic carcinomas are salivary tumors that are low-grade malignant and prone to recurrence and metastasis. Surgery is currently the main treatment, but there is no standard with regard to postoperative adjuvant therapy. Adenoid cystic carcinoma is more sensitive to radiotherapy and patients benefit less from chemotherapy, but few studies have focused on targeted therapy, and their conclusions are inconsistent. With respect to primary pulmonary adenoid cystic carcinoma, large-scale studies cannot be conducted due to its low incidence, and studies on the targeted therapy of it are very scarce. A few case reports indicate that targeted therapy can be effective however, suggesting that it may be a good option. The current report is the first on the occurrence of human epidermal growth factor receptor 2 amplification in pulmonary adenoid cystic carcinoma. The patient was treated with pyrotinib for 6 months and achieved stable disease.

Outcome of Adenoid Cystic Carcinoma of Head and Neck After Postoperative Intensity Modulation Radiotherapy: A Single Institution Study

Objective

This study was retrospectively evaluated the outcome of postoperative intensity modulation radiotherapy (IMRT) for patients with adenoid cystic carcinoma of head and neck (ACCHN), and identified the unfavorable prognostic factors.

Methods

Fifty-five ACCHN patients treated in Sichuan Cancer Hospital between January 2007 and December 2016 were retrospectively evaluated. Median age of patient was 47 years (range, 21–73 years). Thirty-five patients were male and 20 were female. In 30 patients, tumors were located in major salivary glands (54.5%), and 25 patients in minor salivary glands (45.5%). The numbers of R0, R1, and R2 surgical resection classification patients were 22 (40.0%), 20 (36.4%), and 13 (23.6%). The median total RT dose was 62 Gy (range, 46–72 Gy), and 54.5% of patients were treated with adjuvant chemotherapy. Statistical analyses were performed using the Log rank test for univariate analysis and the Cox proportional hazard model for multivariate analysis.

Results

Median follow-up period was 68.5 months (12–132 months). The 5-year local-regional recurrence-free survival (LRRFS), distant metastasis-free survival (DMFS) and overall survival (OS) were 93.9%, 75.3% and 82.5%. In univariate analysis, T stages (p=0.025) and AJCC stages (p=0.036) were the prognostic factors for OS; Age (p=0.042), T stages (p=0.025), N stages (p=0.021), AJCC stages (p=0.021) and adjuvant chemotherapy (p=0.010) were the prognostic factors for DMFS; T stage (p=0.049) was the prognostic factor for LRRFS. In multivariate factors analyses, T stages (p=0.026), AJCC stages (p=0.028) and RT dose (p=0.025) were the significant prognosticators for OS. The most common acute toxicities over three degrees were myelosuppression (5.5%), mucositis (9.1%) and dermatitis (1.8%).

Conclusion

Postoperative IMRT seems to achieve reasonable local-regional control and OS in patients with adenoid cystic carcinoma of head and neck, with acceptable treatment relative toxicities.

Prognosis and management of recurrent and/or metastatic head and neck adenoid cystic carcinoma

Adenoid cystic carcinoma (ACC) is a rare tumor, usually arising in the salivary gland, accounting for 1% of all head and neck cancers. ACC may have a long-term poor prognosis, as about 40% of radically treated patients will recur locoregionally and up to 60% will develop distant metastasis. Factors influencing risk of recurrence have been well studied, but few data exist about prognostic factors in Recurrent/Metastatic (RM) setting. Moreover, treatment of RM ACC is often a challenge for clinicians, in the context of a rare disease, which may have an indolent clinical behavior or less frequently a quicker growth and with a paucity of available clinical trials. This review critically analyzes pathological and molecular prognostic factors in RM ACC and make an overview on actual therapeutic choices and future direction of therapy. Recognized prognostic factors in RM ACC are the presence and site of distant metastasis (lung vs other), the presence of nodal metastasis and of extranodal extension, skull base recurrence, disease free interval, lymphovascular invasion, solid histotypes and grading of disease, and the presence of mutation of NOTCH1 family, PI3K, and TP53. Due to disappointing results with chemotherapy, new approaches are under study, also on the basis of biomolecular research. Ongoing clinical trials are evaluating treatment targeting MYB and NOTCH1 alterations, immunotherapy or combination of targeted treatments and immune checkpoint inhibitors.

Expression profile of circular RNA and construction of circular RNA-Micro RNA network in salivary adenoid cystic carcinoma

BACKGROUND

Circular RNAs (circRNAs) is a newly discovered type of non-coding RNA, the abnormal expression of which has been demonstrated in many types of human tumors. So they have been considered as promising candidates as diagnostic and therapeutic targets in cancer. This research aimed to screen the profile of circRNA expression in salivary adenoid cystic carcinoma (SACC).

METHODS

Using the threshold of FDR < 0.05 and fold change > 2 or < 0.5, 5 up-regulated and 26 down-regulated circRNAs were identified. The reliability of sequencing was verified by the expression detection of randomly selected circRNAs via qRT-PCR.

RESULTS

Moreover, the circRNA-miRNA system was established by bioinformatics approaches and successfully identified an interaction between circRNA ABCA13 and a cancer-related miRNA (miR-138-5p), which was also verified by qRT-PCR. Moreover, the predicted molecular interaction proved that circRNA ABCA13 may promote SACC through inhibition of miR-138-5p.

CONCLUSIONS

Collectively, this study has offered the first report about the circRNA expression profile and circRNA-miRNA network in SACC. All of the above could benefit the exploration of novel therapeutic target in SACC treatment.

Adenoid cystic carcinoma of the labium oris with rare metastasis to the pleural cavity

A 57-year-old Southeast Asian woman with a remote history of adenoid cystic carcinoma (ACC) of the right labium superius oris (upper lip) presented to the hospital with vague epigastric pain. On workup, she was found to have multiple pleural nodules. Histopathology confirmed the diagnosis of metastatic ACC. After 8 months of active surveillance, evidence of disease progression was found and the patient was started on pembrolizumab. Follow-up after starting pembrolizumab showed stable disease with no significant side effects.

Newly Identified Members of FGFR1 Splice Variants Engage in Cross-talk with AXL/AKT Axis in Salivary Adenoid Cystic Carcinoma

Adenoid cystic carcinoma (ACC) is the second most common malignancy of the salivary gland. Although characterized as an indolent tumor, ACC often leads to incurable metastatic disease. Patients with ACC respond poorly to currently available therapeutic drugs and factors contributing to the limited response remain unknown. Determining the role of molecular alterations frequently occurring in ACC may clarify ACC tumorigenesis and advance the development of effective treatment strategies. Applying Splice Expression Variant Analysis and outlier statistics on RNA sequencing of primary ACC tumors and matched normal salivary gland tissues, we identified multiple alternative splicing events (ASE) of genes specific to ACC. In ACC cells and patient-derived xenografts, FGFR1 was a uniquely expressed ASE. Detailed PCR analysis identified three novel, truncated, intracellular domain-lacking FGFR1 variants (FGFR1v). Cloning and expression analysis suggest that the three FGFR1v are cell surface proteins, that expression of FGFR1v augmented pAKT activity, and that cells became more resistant to pharmacologic FGFR1 inhibitor. FGFR1v-induced AKT activation was associated with AXL function, and inhibition of AXL activity in FGFR1v knockdown cells led to enhanced cytotoxicity in ACC. Moreover, cell killing effect was increased by dual inhibition of AXL and FGFR1 in ACC cells. This study demonstrates that these previously undescribed FGFR1v cooperate with AXL and desensitize cells to FGFR1 inhibitor, which supports further investigation into combined FGFR1 and AXL inhibition as an effective ACC therapy.This study identifies several FGFR1 variants that function through the AXL/AKT signaling pathway independent of FGF/FGFR1, desensitizing cells to FGFR1 inhibitor suggestive of a potential resistance mechanism in ACC. SIGNIFICANCE: This study identifies several FGFR1 variants that function through the AXL/AKT signaling pathway independent of FGF/FGFR1, desensitizing cells to FGFR1 inhibitor, suggestive of a potential resistance mechanism in ACC.

Adenoid cystic carcinoma of buccal mucosa: A report of two rare cases and review of literature

In the oral cavity, adenoid cystic carcinomas of the buccal mucosa are extremely rare. Minor salivary grand adenoid cystic carcinoma should receive aggressive treatment to achieve negative surgical margins to inhibit recurrence.

Chitosan/hydroxyapatite composite coatings on porous Ti6Al4V titanium implants: in vitro and in vivo studies

Purpose

Titanium implants are widely used in the treatment of dentition defects; however, due to problems such as osseointegration failure, peri-implant bone resorption, and peri-implant inflammation, their application is subject to certain restrictions. The surface modification of titanium implants can improve the implant success rate and meet the needs of clinical applications. The goal of this study was to evaluate the effect of the use of porous titanium with a chitosan/hydroxyapatite coating on osseointegration.

Methods

Titanium implants with a dense core and a porous outer structure were prepared using a computer-aided design model and selective laser sintering technology, with a fabricated chitosan/hydroxyapatite composite coating on their surfaces. In vivo and in vitro experiments were used to assess osteogenesis.

Results

The quasi-elastic gradient and compressive strength of porous titanium implants were observed to decrease as the porosity increased. The in vitro experiments demonstrated that, the porous titanium implants had no biological toxicity; additionally, the porous structure was shown to be superior to dense titanium with regard to facilitating the adhesion and proliferation of osteoblast-like MC3T3-E1 cells. The in vivo experimental results also showed that the porous structure was beneficial, as bone tissue could grow into the pores, thereby exhibiting good osseointegration.

Conclusions

Porous titanium with a chitosan/hydroxyapatite coating promoted MC3T3-E1 cell proliferation and differentiation, and also improved osseointegration in vitro. This study has meaningful implications for research into ways of improving the surface structures of implants and promoting implant osseointegration.

Homeobox transcription factor engrailed homeobox 1 is a possible diagnostic marker for adenoid cystic carcinoma and polymorphous adenocarcinoma

Diagnostic utility of a homeobox transcription factor, engrailed homeobox 1 (En1) in the histopathology of salivary gland neoplasms was studied. The expression of En1 was immunohistochemically examined in 51 cases of adenoid cystic carcinoma (AdCC) and 143 cases of other salivary gland neoplasms. In all 51 AdCCs, En1 was expressed in 30-100% of tumor cells. In eight of nine polymorphous adenocarcinomas (PACs), En1 was expressed in 40-100% of tumor cells. Less than 5% of tumor cells expressed En1 in three of 12 epithelial-myoepithelial carcinomas, one of 17 basal cell adenomas (BCAs), and one of 34 pleomorphic adenomas (PAs). Among 55 other carcinoma cases, 1-30% of tumor cells expressed En1 in three salivary duct carcinomas (SDCs) ex PA. None of the myoepitheliomas and Warthin tumors expressed En1. When the cut-off value of the percentage of En1-expressing cells was set to 25%, all 51 AdCCs, eight of nine PACs and one SDC ex PA were En1-positive and the others were En1-negative. En1 is expressed consistently in AdCCs, frequently in PACs, but rarely in other salivary gland neoplasms. En1 is a possible diagnostic marker for AdCC and PAC in the histopathology of salivary gland neoplasms.

Adenoid Cystic Carcinoma of the Larynx: A SEER Database Review

BACKGROUND

Adenoid cystic carcinoma (AdCC) of the larynx is an uncommon malignancy of the head and neck with very little literature discussing treatment paradigms and prognostic factors influencing survival.

METHODS

This retrospective cohort study uses data obtained from the Surveillance, Epidemiology and End Result database comprising of patients diagnosed with laryngeal AdCC from 1978 to 2016.

RESULTS

A total of 89 records were analyzed. High histologic grade was a significant negative prognostic factor compared to low histologic grade disease for overall survival (OS; 5-year OS: 35.7% vs 90.5%, P < .005) and disease-specific survival (DSS; 5-year DSS: 38.7% vs 95.2%, P < .005). No differences in OS (5-year OS: 88.9% vs 76.4%, P = .287) or DSS (5-year DSS: 100% vs 79.1%, P = .159) were noted between patients with early versus late American Joint Committee on Cancer (AJCC) stage disease. No differences in DSS was noted in cohorts treated with just definitive surgery versus surgery and adjuvant radiation (5-year DSS: 92.9% vs 74.3%, P = .140) even when stratified for late stage disease (5-year DSS: 100% vs 78.6%, P = .290) or high-grade histology (5-year DSS: 100% vs 83.3%, P = .773).

CONCLUSIONS

Histologic grade may be a more significant prognostic factor than AJCC stage for survival in laryngeal AdCC. Treatment with surgery and radiation may provide no additional survival advantage compared to just definitive surgery in these patients, although further study is warranted.

Therapeutic implications of immune-profiling and EGFR expression in salivary gland carcinoma

BACKGROUND

Data relating to the efficacy of immune checkpoint inhibitors (ICI) for salivary gland carcinomas (SGC) is gradually evolving with responses varying among different histotypes. To address these disparities, this retrospective analysis examined the prevalence of recognized biomarkers of response to ICI; namely programmed death-1 (PD-1), programmed death-ligand 1 (PD-L1), combined positive score (CPS), epidermal growth factor receptor (EGFR), and microsatellite instability (MSI) in patients with SGC with an aim to determine any prognostic or survival benefits and stratify the use of ICI in this disease.

PATIENTS AND METHODS

Of 52 patients with primary SGC eligible for this study, the most common histological types were adenoid cystic carcinoma (n = 17, 33%), salivary duct carcinoma (n = 14, 27%), mucoepidermoid carcinoma (n = 11, 21%), and acinic cell carcinoma (n = 6, 11%). Immunohistochemistry (IHC) was performed using the Ventana Discovery Ultra auto-staining platform for EGFR, PD-1, PD-L1, and mismatch repair (MMR) proteins. CPS ≥1 defined PD-L1 positive cases and log-rank testing was performed to examine the relationship between PD-L1 expression status and disease-free survival (DFS) and overall survival (OS).

RESULTS

CPS positivity was seen in 9 (17.3%) patients, none of which were adenoid cystic carcinoma. All 52 (100%) cases expressed retained MMR proteins inferring microsatellite stability (MSS) and EGFR expression was identified in 45 of 52 (86.5%) patients. CPS positivity (score ≥1) was significantly associated with advanced pathological T status (P = .021), advanced pathological N status (P = .006), high histological tumor grade (P = .045), and positive histological margin (P = .023). Patients with PD-L1 positivity in tumor cells did not have an inferior 3-year OS (P = .93).

CONCLUSION

The data from this retrospective study highlighting the uniform microsatellite stability alongside the low prevalence of CPS positivity suggests that only a minority of SGC patients may benefit from ICI therapy alone. The high rates of EGFR expression in SGC may be a target to augment immune checkpoint therapy response.

Perineural Invasion in Adenoid Cystic Carcinoma of the Salivary Glands: Where We Are and Where We Need to Go

Adenoid cystic carcinoma of the salivary gland (SACC) is a rare malignant tumors of the head and neck region, but it is one of the most common malignant tumors that are prone to perineural invasion (PNI) of the head and neck. The prognosis of patients with SACC is strongly associated with the presence of perineural spread (PNS). Although many contributing factors have been reported, the mechanisms underlying the preferential destruction of the blood-nerve barrier (BNB) by tumors and the infiltration of the tumor microenvironment by nerve fibers in SACC, have received little research attention. This review summarizes the current knowledge concerning the characteristics of SACC in relation to the PNI, and then highlights the interplay between components of the tumor microenvironment and perineural niche, as well as their contributions to the PNI. Finally, we provide new insights into the possible mechanisms underlying the pathogenesis of PNI, with particular emphasis on the role of extracellular vesicles that may serve as an attractive entry point in future studies.

Efficacy and toxicity of sorafenib in patients with adenoid cystic carcinoma of the head and neck: a case series of five patients

INTRODUCTION

Adenoid cystic carcinoma (ACC) of the head and neck is a rare malignancy of the salivary glands that accounts for approximately 10% of salivary gland carcinoma. Despite aggressive local therapy, local recurrence and distant metastases occur frequently. Response rates (RR) to potential curative and palliative chemotherapy are limited, so new strategies are needed.

CASE REPORTS

We describe five case reports of patients with unresectable locally advanced or metastatic ACC of the head and neck who have been treated with sorafenib, a multi-tyrosine kinase inhibitor (mTKI).

RESULTS

In this case series, we found that three out of five patients treated with sorafenib survived, respectively, 16, 35 and 35 months. Two patients showed a partial response (PR) and one patient had a prolonged stable disease (SD) for almost three years. Grade 3 adverse events (AE) occur under sorafenib so adequate toxicity management is essential. This retrospective case series hints towards the possibility of clinical benefit for treating ACC patients with sorafenib. Efficacy of sorafenib should be studied in a prospective-randomized clinical trial which is a challenging task due to the rarity of the disease.

A middle-aged man with adenoid cystic lung carcinoma: not every dyspnoea is the novel coronavirus, even during a pandemic

Background:

A middle-aged gentleman presenting with dyspnoea was presumptively assumed to be a novel coronavirus suspect.

Findings:

Nasopharyngeal and oropharyngeal swabs were reported negative, and clinico-radiological workup revealed a case of adenoid cystic carcinoma (ACC) of the lung with metastases to the contralateral lung and the lumbar vertebrae.

Conclusion:

ACC is a rare malignancy of exocrine glands. Most commonly found in the minor salivary glands, they may rarely occur in other sites. Primary ACC of the lung is a rare histologic subtype that is encountered infrequently in clinical practice for which standard guidelines do not exist.

Long-term outcomes of patients in different histological subtypes of primary nasopharyngeal adenocarcinoma: A single-center experience with 71 cases

OBJECTIVE

This study is aimed to evaluate the long-term outcomes and management approaches in different histological subtypes of primary nasopharyngeal adenocarcinoma (NPAC).

MATERIALS AND METHODS

71 patients with NPAC at our institution between 1984 and 2016 were reviewed, including adenoid cystic carcinoma (ACC) in 43 patients, mucoepidermoid carcinoma (MEC) in 17 patients, and primary traditional adenocarcinoma (AC) in 11 patients. 37 patients received primary radiotherapy and 34 patients underwent primary surgery.

RESULTS

The median time of follow-up was 77 months. The 5-year overall survival rate (OS), locoregional failure-free survival rate (LRFFS) and distant metastasis failure-free survival rate (DFFS) were 69.9%, 67.1% and 77.9%, respectively. Patients who received combined modality therapy had better 5-year OS (73.7% vs 66.2%, p = 0.065) and LRFFS (73.1% vs 64.5%, p = 0.047) than patients receiving single modality therapy. Regarding the different histological subtypes, the survival rates of patients with ACC undergoing primary radiotherapy and primary surgery were similar (5-year OS 82.3% vs 68.8%, LRFFS 70.0% vs 70.8%, p＞0.05). As to patients with MEC and AC, those who underwent primary surgery achieved better 5-year OS (75.6% vs 45.5%, p = 0.001) and LRFFS (70.6%% vs 57.1%, p = 0.014) than those who received primary radiotherapy. Multivariate analyses indicated that histological subtypes and radiotherapy technique were independent factors for OS.

CONCLUSIONS

The optimal treatment policy for NPAC remained the combination of radiotherapy and surgery. For patients with ACC, radiotherapy could be considered as the primary treatment. Surgery was suggested to be the primary treatment in patients with MEC and AC.

Analysis of the clinicopathological characteristics and prognosis of adenoid cystic carcinoma of the intraoral minor salivary glands: a retrospective study of 40 cases

The clinicopathological aspects and prognostic factors of 40 patients with adenoid cystic carcinoma (ACC) of the intraoral minor salivary glands, treated between 2007 and 2017 at a single institution, were evaluated retrospectively. Twenty-six were female and 14 were male, and they ranged in age from 26 to 81 years (median 55 years). ACC occurred mainly in the palate, with 54.8% of cases presenting T3-T4 lesions. Curative surgery was performed in all patients, and 62.5% of patients were treated with postoperative adjuvant radiotherapy. In the final analysis, positive surgical margins were noted in 57.5% of cases and perineural invasion in 70%. Follow-up was at least 13 months (range 13-141 months, median 59 months). Nineteen patients (47.5%) developed recurrent disease after initial surgery and nine patients had died at the end of follow-up. The 5- and 10-year overall survival rates were 88.3% and 25.6%, respectively. The 5- and 10-year disease-free survival rates were 75.6% and 34.0%, respectively. Patients with a tumour size >4cm and those with positive surgical margins showed a significantly higher risk of local recurrence. Elective neck dissection is suggested for patients with clinically positive lymph nodes or a locally advanced tumour, especially those undergoing microvascular reconstruction. The survival analysis results are similar to those reported previously in the literature.

KIT/PDGFRA/KDR amplification defines a novel molecular subtype of adenoid cystic carcinoma patients who may benefit from treatment with tyrosine kinase inhibitors

Background

Adenoid cystic carcinoma (ACC) is a rare cancer with an aggressive phenotype and the high incidence of recurrence and distant metastasis severely affects the overall survival of ACC patients. Understanding the molecular mechanisms that drives ACC could improve the treatment and outcomes of patients with this disease.

Methods

Actionable genetic alterations in 52 surgically resected ACC tissue samples were identified using targeted next generation sequencing (NGS). Expression of c-KIT/PDGFRα/VEGFR2 was assessed by immunohistochemistry (IHC). Sunitinib, a multi-targeted small molecule inhibitor of receptor tyrosine kinases (RTKs), was used off-label in one ACC patient harboring the KIT/PDGFRA/KDR amplification.

Results

Potentially actionable genetic alterations were detected in 61.5% (32/52) of patients. In addition to the common actionable targets identified in NOTCH signaling and FGF/PI3K pathway, multiple novel gene fusions were detected in 7.7% (4/52) of ACC patients. Specifically, the KIT/PDGFRA/KDR amplification was identified in 2 of 52 (3.8%) cases and triple positive c-KIT/PDGFRα/VEGFR2 by IHC was associated with a significantly higher likelihood of distant metastasis. Furthermore, an advanced ACC patient with the KIT/PDGFRA/KDR amplification and who was positive for three encoded proteins showed a partial response to sunitinib.

Conclusions

A total of 61.5% of ACC patients were found to harbor at least one actionable genetic alteration via a targeted NGS in this study. The KIT/PDGFRA/KDR amplification as well as triple positive c-KIT/PDGFRα/VEGFR2 defined a distinctive molecular phenotype that was characterized by distant metastasis. Clinical trials investigating the application of RTKs in ACC patients with the KIT/PDGFRA/KDR amplification or triple positive c-KIT/PDGFRα/VEGFR2 are warranted.

The Utility of MYB Immunohistochemistry (IHC) in Fine Needle Aspiration (FNA) Diagnosis of Adenoid Cystic Carcinoma (AdCC)

Differentiating adenoid cystic carcinoma (AdCC) from other basaloid neoplasm in a fine needle aspiration (FNA) sample can be challenging. Activation of MYB in AdCC by the fusion transcript MYB-NFIB has been recently demonstrated in salivary gland and other organs. The aim of this study is to evaluate the utility of MYB immunohistochemistry (IHC) in distinguishing AdCCs and other basaloid neoplasm in cytology specimens. Eighteen FNA cases, from salivary gland and other sites, and their subsequent surgical resection specimens were included in the study. Eight cases were confirmed AdCC on resection. MYB IHC was performed on slides made from cytology cell block and surgical resection paraffin blocks. Percentage and intensity of nuclear staining in tumor cells was scored as 0 to 3. The staining results were concordant between cytology specimens and their corresponding surgical resection tumors. Strong diffuse nuclear staining (score 3, N = 5) was exclusively observed in AdCC, both in cytology and surgical specimens. Only one pleomorphic adenoma and one poorly differentiated basaloid carcinoma were positive for MYB staining (score 1 to 2). Any degree of nuclear MYB labeling was seen in 100% AdCC cases (N = 8/8) compared with of 20% (N = 2/10) of all other non-AdCC cases (P = < 0.001). The sensitivity and specificity of any degree MYB positivity for AdCC in cytology specimen is 100% and 78%. The sensitivity and specificity of strong diffuse MYB labeling (score 2 to 3) for AdCC is 83% and 100% in cytology specimen. Strong diffuse nuclear staining of MYB is valuable in supporting a cytologic diagnosis of AdCC. However, weak and focal labeling of MYB should be interpreted with caution as it can be seen in benign and other malignant basaloid lesions.

Tumor immune microenvironment and mutational analysis of tracheal adenoid cystic carcinoma

Background

Tracheal adenoid cystic carcinoma (TACC) is the second most common type of cancer in bronchial tumors with poor prognosis. Studies on the genomic profiles and tumor immune microenvironment (TIME) of TACC are still relatively rare.

Methods

Here, we performed whole-exome sequencing (WES), T cell repertoire (TCR) sequencing, and immunohistochemistry (IHC) on the resected tumors and matched peripheral blood leukocytes (PBLs) samples from 25 TACCs collected from April-2010 to Mar-2019.

Results

WES results revealed that LPAR3 and ALPI were recurrently mutated genes, with no classical lung cancer drivers in TACCs (n=8). The median tumor mutation burden (TMB) was 3.67, lower than other solid tumors. Unexpectedly, one patient showed high microsatellite instability (MSI). Recurrent copy number variations (CNVs) affected genes commonly involved in p53, cell cycle, and PI3K-Akt signaling pathways. For TCR estimators of 13 PBLs, the median clonality and Shannon index was 0.15 and 7.02, respectively. Shannon index showed marginally negative association with age (Pearson r =−0.53, P=0.062). Clonotype number and Shannon index of 7 TACC tissues were significantly lower than those of lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) (Mann-Whitney test, both P<0.001, both P<0.001). Furthermore, programmed cell death 1 ligand 1 (PD-L1), a vital player in TIME, was negative (tumor proportion score, TPS <1%) in all samples (n=14). Patients with less clonotypes had longer progression-free survival (PFS) than those with more PFS (15.0 vs. 9.5 months, P<0.001, HR 12.5, 95% CI: 0.2–675.7). In particular, the clinical and molecular characteristics of one TACC patient receiving immunotherapy have been explained in detail.

Conclusions

In summary, despite the existence of one patient with MSI-H and chromosome instability, TACC was characterized by a lack of common drivers of lung cancer, negative PD-L1 expression, and low CD3+ and CD8+ T cell infiltration.

Overexpression of gasdermin D promotes invasion of adenoid cystic carcinoma

OBJECTIVE

To investigate the relationship between gasdermin D (GSDMD) expression and the invasion of adenoid cystic carcinoma (ACC).

METHODS

Immunohistochemistry (IHC) was used to examine GSDMD expression in tumours and adjacent non-cancerous (ANC) tissues from 33 patients with salivary ACC patients and in tumour samples from 29 patients with pleomorphic adenoma (PA). Lentiviral infection was used to stably overexpress GSDMD in ACC-LM and ACC-83 cells (GSDMD-ov cells), which were subjected to transwell and scratch tests to assess their invasive abilities compared to control cells. Cells overexpressing GSDMD were treated with siRNA targeting GSDMD, and their invasive ability was subsequently examined.

RESULTS

GSDMD expression was significantly higher in ACC tissues than in corresponding ANC tissues (P<0.001). After 24 hours, both the ACC-83 and ACC-LM GSDMD-ov cell lines had more cells that moved through the membrane than did the control cells (P<0.05). For the wound healing experiment, the diameter of the wound in the GSDMD-ov cell lines was smaller than that of the control cells (P<0.001) after 24 hours. The ACC cell lines expressing high GSDMD showed stronger metastatic ability than did the control.

CONCLUSION

GSDMD was highly expressed in ACC tissues compared to ANC tissues, and high GSDMD expression promoted the invasion of ACC cells. These findings suggest that GSDMD expression is related to the invasion of ACC. Our data indicate that we may be able to use GSDMD as an indicator of the invasive or metastatic potential of tumour cells in future research.