t(6;9)(MYB‐NFIB) in head and neck adenoid cystic carcinoma: A systematic review with meta‐analysis

Outcome-oriented clinicopathological reappraisal of sinonasal adenoid cystic carcinoma with broad morphological spectrum and high MYB::NFIB prevalence

Adenoid cystic carcinoma (AdCC) is a salivary gland neoplasm that infrequently appears in the sinonasal region. The aim of this study was to evaluate the outcome and clinicopathological parameters of sinonasal AdCC. A retrospective analysis was conducted on all cases of AdCC affecting the nasal cavity or paranasal sinuses between 2000 and 2018 at the University Hospital Zurich. Tumor material was examined for morphological features and analyzed for molecular alterations. A total of 14 patients were included. Mean age at presentation was 57.7 years. Sequencing revealed MYB::NFIB gene fusion in 11/12 analyzable cases. Poor prognostic factors were solid variant (p < 0.001), histopathological high-grade transformation (p < 0.001), and tumor involvement of the sphenoid sinus (p = 0.02). The median recurrence-free survival (RFS) and OS were 5.2 years and 11.3 years. The RFS rates at 1-, 5-, and 10-year were 100%, 53.8%, and 23.1%. The OS rates at 1-, 5-, and 10- years were 100%, 91.7%, and 62.9%, respectively. In Conclusion, the solid variant (solid portion > 30%), high-grade transformation, and sphenoid sinus involvement are negative prognostic factors for sinonasal AdCC. A high prevalence of MYB::NFIB gene fusion may help to correctly classify diagnostically challenging (e.g. metatypical) cases.

Adenoid cystic carcinoma of submandibular gland: Emphasis on locoregional metastasis and prognosis

OBJECTIVES

To analyze the clinicopathological features, locoregional or distant metastasis, and prognosis of adenoid cystic carcinoma of submandibular gland (SMG-AdCC).

METHODS

The clinicopathological data of 80 patients with SMG-AdCC from January 2005 to December 2017 were analyzed retrospectively, and the relationships between different parameters of SMG-AdCC and its locoregional or distant metastasis or prognosis were analyzed.

RESULTS

As of December 2019, 41 patients (51.25%) were tumor-free, while 20 patients were found to be living with tumors. The locoregional metastasis rate of grade II-III SMG-AdCC were found to be significantly higher than that of grade I. The five-year DFS and OS rates were 70.8% and 87.1%, respectively. Univariate analysis showed that clinical size, extraglandular extension, pathological grade, pathological node (pN) status, and perineural invasion were correlated with DFS. Multivariate Cox regression analysis showed that pathological grade and extraglandular extension were independent prognostic factors for DFS; pN status and extraglandular extension were independent prognostic factors impacting OS.

CONCLUSION

The pathological grade is a risk factor for locoregional metastasis of SMG-AdCC. Pathological grade, pN status, and status of extraglandular extension are independent prognostic factors for DFS/OS in SMG-AdCC patients.

A phase 2 study of MK-2206 in patients with incurable adenoid cystic carcinoma (Alliance A091104)

BACKGROUND

Recurrent/metastatic adenoid cystic carcinoma (ACC) is a rare, incurable disease. MYB is a putative oncogenic driver in ACC that is often overexpressed through an MYB-NFIB rearrangement. The authors hypothesized that AKT inhibition with the allosteric inhibitor MK-2206 could decrease MYB expression and induce tumor regression in patients with incurable ACC (ClinicalTrials.gov identifier NCT01604772).

METHODS

Patients with progressive, incurable ACC were enrolled and received MK-2206 150 mg weekly; escalation to 200 mg was allowed. The primary end point was confirmed response. Secondary end points were progression-free survival, overall survival, and safety. An exploratory analysis evaluating the effect of MK-2206 on MYB expression was conducted in a subset of patients.

RESULTS

Sixteen patients were enrolled, and 14 were evaluable for efficacy. No confirmed responses were observed. Thirteen patients had stable disease, and one had disease progression as their best response. The median progression-free survival was 9.7 months (95% CI, 3.8-11.8 months), and the median overall survival was 18.0 months (95% CI, 11.8-29.9 months). Nine of 16 patients (56%) had at least one grade 3 treatment-related adverse event, and the most common were rash (38%), fatigue (19%), decreased lymphocyte count (13%), and hyperglycemia (13%). Twelve of 14 tumors (86%) had detectable MYB expression by immunohistochemistry, and seven of 14 tumors (50%) had an MYB-NFIB gene rearrangement. Serial biopsies revealed decreased MYB levels with MK-2206 in four of five patients.

CONCLUSIONS

MK-2206 failed to induce clinical responses in patients with incurable ACC. AKT inhibition may diminish MYB protein levels, although the effect was highly variable among patients. Novel approaches to target MYB in ACC are needed.

Translational Insights in the Landscape of Salivary Gland Cancers: Ready for a New Era?

Salivary gland carcinomas (SGCs) are rare neoplasms, representing less than 10% of all head and neck tumors, but they are extremely heterogeneous from the histological point of view, their clinical behavior, and their genetics. The guidelines regarding their treatment include surgery in most cases, which can also play an important role in oligometastatic disease. Where surgery cannot be used, systemic therapy comes into play. Systemic therapy for many years has been represented by polychemotherapy, but recently, with the affirmation of translational research, it can also count on targeted therapy, at least in some subtypes of SGCs. Interestingly, in some SGC histotypes, predominant mutations have been identified, which in some cases behave as "driver mutations", namely mutations capable of governing the carcinogenesis process. Targeting these driver mutations may be an effective therapeutic strategy. Nonetheless, it is not always possible to have drugs suitable for targeting driver mutations-and targeting driver mutations is not always accompanied by a clinical benefit. In this review, we will analyze the main mutations predominant in the various histotypes of SGCs.

Updated Salivary Gland Immunohistochemistry: A Review

CONTEXT.—

Salivary gland neoplasms are rare lesions in the head and neck (H&N) pathology realm. There are more than 20 malignant and 15 benign salivary gland neoplasms in the 5th edition of the World Health Organization classification of H&N tumors. These neoplasms consist of heterogeneous groups of uncommon diseases that make diagnosis and treatment challenging for the clinical team. Using an algorithmic immunohistochemical approach-defined tumor origin and type has proven to be effective and advantageous. Immunohistochemistry may be used as sort of a "diagnostic looking glass," not as a positive or negative type tool, but as an indispensable complement to a hematoxylin-eosin morphologic pattern-based approach. Furthermore, the understanding of the novel discoveries of the salivary gland gene fusions and the molecular aspects of these tumors makes the process easier and improve the diagnosis as well as treatment aspects. This review reflects our experience with more recent diagnostic antibodies, which include MYB RNA, Pan-TRK, PLAG1, LEF1, and NR4A3. Each of these is linked with a specific type of neoplasm; for example, gene fusions involving the PLAG1 and HMGA2 oncogenes are specific for benign pleomorphic adenomas, and MYB is associated with adenoid cystic carcinoma.

OBJECTIVE.—

To review these more recent antibodies, which highly enhance salivary gland neoplasm diagnosis.

DATA SOURCES.—

The study sources involved literature PubMed searches, including multiple review articles, case reports, selected book chapters, and Geisinger Medical Center cases.

CONCLUSIONS.—

Salivary gland tumors are a rare, varied group of lesions in H&N pathology. We need to have continuous readings and revisions of the molecular consequences of these fusion oncoproteins and their subsequent targets, which will eventually lead to the identification of novel driver genes in salivary gland neoplasms.

The screening, identification, design and clinical application of tumor-specific neoantigens for TCR-T cells

Recent advances in neoantigen research have accelerated the development of tumor immunotherapies, including adoptive cell therapies (ACTs), cancer vaccines and antibody-based therapies, particularly for solid tumors. With the development of next-generation sequencing and bioinformatics technology, the rapid identification and prediction of tumor-specific antigens (TSAs) has become possible. Compared with tumor-associated antigens (TAAs), highly immunogenic TSAs provide new targets for personalized tumor immunotherapy and can be used as prospective indicators for predicting tumor patient survival, prognosis, and immune checkpoint blockade response. Here, the identification and characterization of neoantigens and the clinical application of neoantigen-based TCR-T immunotherapy strategies are summarized, and the current status, inherent challenges, and clinical translational potential of these strategies are discussed.

Salivary glands adenoid cystic carcinoma: a molecular profile update and potential implications

Adenoid cystic carcinoma (ACC) is an aggressive tumor with a high propensity for distant metastasis and perineural invasion. This tumor is more commonly found in regions of the head and neck, mainly the salivary glands. In general, the primary treatment modality for ACC is surgical resection and, in some cases, postoperative radiotherapy. However, no effective systemic treatment is available for patients with advanced disease. Furthermore, this tumor type is characterized by recurrent molecular alterations, especially rearrangements involving the MYB, MYBL1, and NFIB genes. In addition, they also reported copy number alterations (CNAs) that impact genes. One of them is C-KIT, mutations that affect signaling pathways such as NOTCH, PI3KCA, and PTEN, as well as alterations in chromatin remodeling genes. The identification of new molecular targets enables the development of specific therapies. Despite ongoing investigations into immunotherapy, tyrosine kinase inhibitors, and anti-angiogenics, no systemic therapy is approved by the FDA for ACC. In this review, we report the genetic and cytogenetic findings on head and neck ACC, highlighting possible targets for therapeutic interventions.

Top Ten Differentials to Mull Over for Head and Neck Myoepithelial Neoplasms

BACKGROUND

Myoepithelial neoplasms of the salivary gland are benign or malignant neoplasms composed exclusively of neoplastic myoepithelial cells. These tumors, including the benign myoepithelioma and the malignant counterpart myoepithelial carcinoma, exhibit a wide range of cytomorphologic features and architectural patterns.

METHODS

Review.

RESULTS

Myoepithelial cells can be epithelial, plasmacytoid, clear cell, spindle cell, and/or oncocytic cell, arranging as trabeculae, solid sheets, nests, cords, and/or single cells. A stromal component is commonly but not universally present, Therefore, their differential diagnoses are quite broad, including salivary gland neoplasms especially those with a myoepithelial component, plasmacytoma, melanoma, and various mesenchymal tumors.

CONCLUSION

In this review, we summarize the characteristic histologic features, useful immunohistochemical panel, and common molecular alterations of myoepithelial tumors and their top differential diagnoses. A logical stepwise algorithmic approach and an immunohistochemical panel to include multiple myoepithelial markers are essential to establish the correct diagnosis.

High-risk subtype: Clinical manifestations and molecular characteristics of submandibular gland adenoid cystic carcinoma

Objective

Adenoid cystic carcinoma of the head and neck mainly occurs in the major salivary glands, of which the parotid gland and submandibular gland are the most common. The purpose of this study was to clarify the site-specific differences in prognosis and molecular expression characteristics of the patients and to achieve stratified risk management of the clinical prognosis.

Materials

By performing a single-centre retrospective analysis combined with analyses of the Surveillance, Epidemiology, and End Results (SEER) database, cBioPortal and GEO databases, the clinical prognostic characteristics and the differences in molecular expression patterns of ACC in the submandibular gland and parotid gland were analysed. Cox regression analysis, the chi-square test, Fisher's test and the log-rank test were used to compare the significance of differences.

Results

Compared with patients with parotid gland ACC, the submandibular gland ACC is more likely to have metastases in the cervical lymph node (21.7% vs. 3.3%) and shows a higher rate of distant metastasis within 1 year after the primary site diagnosis (47.8% vs. 23.3%), a worse overall prognosis, more frequent mutations of MYB/MYBL1 (50% vs. 25%) and abnormal upregulation of the phosphatidylinositol-3 kinase (PI3K) pathway.

Conclusions

Submandibular gland ACC is associated with site-specific early cervical lymph node metastasis and hidden distant metastasis, along with rapid progression and a poor prognosis. A high MYB/MYBL1 mutation rate and abnormal upregulation of the PI3K pathway with MYB involvement were identified.

Single-cell transcriptomic analysis of the tumor ecosystem of adenoid cystic carcinoma

Adenoid cystic carcinoma (ACC) is a malignant tumor that originates from exocrine gland epithelial cells. We profiled the transcriptomes of 49,948 cells from paracarcinoma and carcinoma tissues of three patients using single-cell RNA sequencing. Three main types of the epithelial cells were identified into myoepithelial-like cells, intercalated duct-like cells, and duct-like cells by marker genes. And part of intercalated duct-like cells with special copy number variations which altered with MYB family gene and EN1 transcriptomes were identified as premalignant cells. Developmental pseudo-time analysis showed that the premalignant cells eventually transformed into malignant cells. Furthermore, MYB and MYBL1 were found to belong to two different gene modules and were expressed in a mutually exclusive manner. The two gene modules drove ACC progression into different directions. Our findings provide novel evidence to explain the high recurrence rate of ACC and its characteristic biological behavior.

Rearrangements, Expression, and Clinical Significance of MYB and MYBL1 in Adenoid Cystic Carcinoma: A Multi-Institutional Study

Simple Summary

Adenoid cystic carcinoma (ACC) is an aggressive glandular cancer with poor prognosis that preferentially occurs in the head and neck. The MYB and MYBL1 oncogenes are main oncogenic drivers, but the true frequency and clinical significance of these alterations are unclear. Here, we have used tissue microarrays to study these genes in a multi-institutional study of close to 400 ACCs, the largest study to date. We found alterations of MYB/MYBL1 in 78% of the cases and overexpression of the MYB/MYBL1 proteins in 93% of the cases. Importantly, we show that patients with loss of one part of the MYB gene and its neighboring sequences on chromosome 6 have a significantly shorter overall survival compared to those without loss. Our study provides new knowledge about the frequency and clinical significance of MYB/MYBL1 alterations and identifies genes with tumor suppressive functions on chromosome 6 that contribute to poor prognosis in ACC.

Abstract

Adenoid cystic carcinoma (ACC) is an aggressive head and neck malignancy characterized by a t (6;9) translocation resulting in an MYB–NFIB gene fusion or, more rarely, an MYBL1 fusion. The true frequency and clinical significance of these alterations are still unclear. Here, we have used tissue microarrays and analyzed 391 ACCs and 647 non-ACC salivary neoplasms to study the prevalence, expression, and clinical significance of MYB/MYBL1 alterations by FISH and immunohistochemistry. Alterations of MYB or MYBL1 were found in 78% of the cases, of which 62% had MYB alterations and 16% had MYBL1 rearrangements. Overexpression of MYB/MYBL1 oncoproteins was detected in 93% of the cases. MYB split signal, seen in 39% of the cases, was specific for ACC and not encountered in non-ACC salivary tumors. Loss of the 3′-part of MYB was enriched in grade 3 tumors and was a significant independent prognostic biomarker for overall survival in multivariate analyses. We hypothesize that loss of the 3′-part of MYB results from an unbalanced t(6;9) leading to an MYB–NFIB fusion with concomitant loss of the segment distal to the MYB breakpoint in 6q23.3. Our study provides new knowledge about the prevalence and clinical significance of MYB/MYBL1 alterations and indicates the presence of genes with tumor suppressive functions in 6q23.3-qter that contribute to poor prognosis and short overall survival in ACC.

MYB-NFIB fusion transcript in Adenoid Cystic Carcinoma: current state of knowledge and future directions

Adenoid cystic carcinoma (ACC) is the most common type of salivary gland cancer that can also arise in other primary sites. Regardless of the site, most ACC cases carry a recurrent chromosomal translocation - t(6;9)(q22-23;p23-24) - involving the MYB oncogene and the NFIB transcription factor. Generally, a long sequence of MYB is fused to the terminal exons of NFIB, yet the break can occur in different exons for both genes, resulting in multiple chimeric variants. The fusion status can be determined by a number of methods, each of them with particular advantages. In vitro and in vivo studies have been conducted to understand the biological consequences of MYB-NFIB translocation, and such findings could contribute to improving the current inefficient therapeutic options for disseminated ACC. This review provides a discussion on relevant evidence in the context of ACC MYB-NFIB translocations to determine the current state of knowledge and discuss future directions.

Analysis of Human Papillomavirus (HPV) and Polyomaviruses (HPyVs) in Adenoid Cystic Carcinoma (AdCC) of the Head and Neck Region Reveals Three HPV-Positive Cases with Adenoid Cystic-like Features

An aetiological role of human papillomavirus (HPV) and/or human polyomaviruses (HPyVs) has been proposed in adenoid cystic carcinoma (AdCC). Moreover, HPV-related multiphenotypic carcinoma (HMSC) was recently introduced as an emerging entity of the sinonasal region. Here, we primarily want to study the role of HPV/HPyV in a large AdCC cohort and, secondly, possibly identify and characterize HMSC. Tumour DNA from 68 patients initially diagnosed with AdCC between 2000 and 2012 was, therefore, tested for 27 HPV types and 10 HPyVs. HPV DNA-positive samples were micromorphologically re-evaluated, further stained for p16^INK4a, S100, p63 and CD117 and tested for the presence of the MYB-NFIB fusion transcript. Notably, no samples were HPyV-positive, while one sinonasal and two tonsillar carcinomas were HPV- and p16-positive. After re-evaluating the micromorphology, immunohistochemistry and presence of fusion transcripts, all tumours had the same appearance and fitted within the diagnosis of HMSC, but in all these three cases, the morphology of the HMSC and basaloid squamous cell carcinoma was overlapping. We conclude that HPV and HPyV have no major role in AdCC. However, based on our data, we also suggest that HMSC should be considered as a basaloid variant of squamous cell carcinoma, and not its own entity, until better characterized.

The evolving role of molecular pathology in the diagnosis of salivary gland tumours with potential pitfalls

Salivary gland tumors are diagnostically challenging owing to the morphological diversity within any tumor type and overlapping histomorphology and immunohistochemistry amongst different tumours. In past two decades, rapid progress has been made in the field of understanding the pathogenesis of these tumours with the discovery of many tumour specific translocations and rearrangements. This includes CRTC1-MAML2 and CRTC-MAML2 in mucoepidermoid carcinoma, MYBNFIB and MYBL1-NFIB fusions in adenoid cystic carcinoma, PLAG1 and HMGA2 in pleomorphic adenoma, ETV6-NTRK3 in secretory carcinoma, NR4A3 rearrangements in acinic cell carcinoma, PRKD1 mutations in polymorphous adenocarcinoma and EWSR1-ATF1 in clear cell carcinoma. This review is a lens for progress made till date in the molecular pathology of salivary gland tumours with a special focus on their role as diagnostic tools and implications on clinical management of the patient as prognostic and predictive markers.

Treatment of Recurrent or Metastatic Adenoid Cystic Carcinoma

PURPOSE OF REVIEW

Adenoid cystic carcinoma (ACC) is a rare and heterogeneous malignancy of secretory glands. Recurrence after curative-intent treatment is common, and approximately 40% of patients develop metastatic disease, for which consensus is lacking regarding therapeutic approaches. Here, we review the available therapies for recurrent/metastatic (R/M) ACC and offer our perspectives on future treatment options.

RECENT FINDINGS

Proteogenomic studies of ACC revealed two molecular subtypes with therapeutic implications: ACC-I (37% of cases) and ACC-II (63%); each has distinct disease biology and prognosis. Molecular drivers, such as NOTCH1, have emerged as potential therapeutic targets for ACC-I and are being explored in clinical trials. Despite its biological heterogeneity, treatment for R/M ACC is not personalized and limited to cytotoxic agents and VEGFR inhibitors, which produce modest responses and significant toxicity. The increasing understanding of ACC's molecular biology might guide the development of biomarkers for patient selection and new therapies development.

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.

Fusion-Positive Salivary Gland Carcinomas

Salivary gland tumors are a rare, heterogeneous group of neoplasms that pose significant diagnostic challenges for the histopathologist. Histopathological diagnosis relies primarily on morphological assessment, with ancillary special stains and immunohistochemistry. In recent years, new defining genomic alterations have been characterized in these tumors. In particular, they include gene fusions which have shown to be tightly tumor-type specific, and thus valuable for use in diagnostically challenging cases. These discoveries also help in refining tumor classification. Furthermore, such genetic alterations may have prognostic as well as potentially therapeutic implications in the era of personalized medicine. This review aims at providing a summary of the most recent updates in this field.

Management of Salivary Gland Malignancy: ASCO Guideline

PURPOSE

To provide evidence-based recommendations for practicing physicians and other healthcare providers on the management of salivary gland malignancy.

METHODS

ASCO convened an Expert Panel of medical oncology, surgical oncology, radiation oncology, neuroradiology, pathology, and patient advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 2000 through 2020. Outcomes of interest included survival, diagnostic accuracy, disease recurrence, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 293 relevant studies to inform the evidence base for this guideline. Six main clinical questions were addressed, which included subquestions on preoperative evaluations, surgical diagnostic and therapeutic procedures, appropriate radiotherapy techniques, the role of systemic therapy, and follow-up evaluations.

RECOMMENDATIONS

When possible, evidence-based recommendations were developed to address the diagnosis and appropriate preoperative evaluations for patients with a salivary gland malignancy, therapeutic procedures, and appropriate treatment options in various salivary gland histologies.Additional information is available at www.asco.org/head-neck-cancer-guidelines.

Nomogram for predicting the survival rate of primary pulmonary mucoepidermoid carcinoma patients: a retrospective study based on SEER database

Background

Primary pulmonary mucoepidermoid carcinoma (PMEC) is a rare malignant tumor, and the clinical manifestations lack specificity. The study evaluates the prognostic factors and constructs a practicable nomogram to estimate the individualized survival status for PMEC patients.

Methods

Surveillance, Epidemiology, and End Results (SEER) database was used to selected eligible patients between 1975 and 2016. The baseline characteristics including age, sex, race, marital status, tumor stage, differentiated degree, tumor laterality, primary tumor site, tumor size, lymph node metastases status, distant metastases status, surgery, chemotherapy, and radiation. We identified independent variables to build 3-, 5-, 10-year overall survival (OS) and cancer-specific survival (CSS) nomograms by univariate and multivariate analyses.

Results

A total of 438 PMEC patients met our selection criteria. In multivariate analysis, age, tumor stage, differentiated grade, tumor size, lymph node metastases status, distant metastases status, surgery and radiation were involved in the nomogram. The C-index (0.887 (95% CI: 0.863-0.911), calibrate plots and ROC curves (AUC =0.941, 0.951, 0.935 for 3-, 5-, 10-year OS, respectively) indicated the satisfied accuracy and practicability of our nomograms. Compared to TNM system, our model also showed a superior prediction (IDI =0.167, 0.171, 0.172, P<0.001).

Conclusions

We built OS (CSS) nomograms that can accurately estimate individualized survival time and identify the risk classification of PMEC.

Molecular Pathology of Salivary Gland Neoplasms: Diagnostic, Prognostic, and Predictive Perspective

Salivary gland neoplasms are an uncommon and widely heterogeneous group of tumors. In recent years, there has been considerable progress in efforts to reveal the molecular landscape of these tumors, although it is still limited and appears to be only the tip of the iceberg. Genomic aberrations, especially specific chromosomal rearrangements including CRTC1-MAML2 and CRTC3-MAML2 in mucoepidermoid carcinoma, MYB-NFIB and MYBL1-NFIB fusions in adenoid cystic carcinoma, PLAG1 and HMGA2 alterations in pleomorphic adenoma and carcinoma ex pleomorphic adenoma, ETV6-NTRK3 and ETV6-RET in secretory carcinoma, EWSR1-ATF1 and EWSR1-CREM in clear cell carcinoma, provide new insights into the molecular pathogenesis of various salivary gland neoplasms and help to better classify them. These genetic aberrations primarily serve as diagnostic tools in salivary gland tumor diagnosis; however, some also have promise as prognostic or predictive biomarkers. This review summarizes the latest developments in molecular pathology of salivary gland tumors with a focus on distinctive molecular characteristics.

The utility of TP53 and PIK3CA mutations as prognostic biomarkers in salivary adenoid cystic carcinoma

OBJECTIVES

Despite wide excision and post-operative irradiation, loco-regional and/or metastatic recurrence is a significant clinical problem in salivary adenoid cystic carcinoma (SACC). Reliable biomarkers are required to tailor post-treatment surveillance to patients at highest risk of recurrence. We sought to determine the utility of TP53 and PIK3CA mutations as prognostic biomarkers in SACC.

MATERIALS AND METHODS

DNA was extracted from archival tumour blocks of 145 SACC patients from 66 UK referral centres and sequenced for TP53 and PIK3CA mutations. Clinical, pathological and outcome data were analysed to determine the impact of the genomic alterations on disease recurrence and overall survival (OS).

RESULTS

TP53 and PIK3CA mutations were identified in 8% (10/121 successful analyses) and 2% (3/121) of cases, respectively. There were too few PIK3CA mutations in this cohort for informative further analysis. TP53-mutated SACC had significantly shorter median OS (5.3 vs. 16.3 years, p = 0.019) and lower 10-year survival (48% vs. 81%) compared with TP53 wild-type ACC. Solid-pattern histopathology was more frequent in TP53-mutated SACC (50% vs. 15%, p = 0.27).

CONCLUSION

TP53-mutated recurrent and metastatic SACC was associated with shorter OS, which was significant when combined with published genomic data sets. Stratifying by TP53 status, in addition to established clinical, pathological and genomic biomarkers, may usefully inform follow-up strategy.

Salivary Gland Carcinoma: Novel Targets to Overcome Treatment Resistance in Advanced Disease

Salivary gland carcinomas (SGCs) account for <5% of head and neck malignant neoplasms, further subcategorized in over 20 histological subtypes. For the most part, treatment for advanced disease is guided by morphology. SGCs in general respond poorly to a wide array of standard chemotherapy, with short durability, and significant toxicity. More recently, next-generation sequencing provided significant input on the molecular characterization of each SGC subtype, not only improving diagnostic differentiation between morphologically similar tumor types but also identifying novel driver pathways that determine tumor biology and may be amenable to targeted therapy. Among the most common histological subtype is adenoid cystic carcinoma, which often harbors a chromosome translocation resulting in an MYB-NFIB oncogene, with various degrees of Myb surface expression. In a smaller subset, NOTCH1 mutations occur, conferring a more aggressive pattern and potential sensitivity to Notch inhibitors. Salivary duct carcinomas may overexpress Her-2 and androgen receptors, with promising clinical outcomes after exposure to targeted therapies approved for other indications. Secretory carcinoma, previously known as mammary analog secretory carcinoma, is distinguished by an ETV6-NTRK3 fusion that can both help differentiate it from its morphologically similar acinar cell carcinoma and make it susceptible to Trk inhibitors. In the present article, we discuss the molecular abnormalities, their impact on tumor biology, and therapeutic opportunities for the most common SGC subtypes and review published and ongoing clinical trials and future perspectives for this rare disease.

MYB-NFIB Translocation by FISH in Adenoid Cystic Carcinoma of the Head and Neck in Nigerian Patients: A Preliminary Report

Adenoid cystic carcinoma (AdCC) is a relatively rare malignancy of head and neck sites such as the salivary glands, lacrimal gland, sinonasal region, and pharynx and may arise in other exocrine glands. The oncologic event in AdCC is the translocation between MYB proto-oncogene transcription factor (MYB) and nuclear factor I/B (NFIB) resulting in t(6;9)(q22-23;p23-24). We carried out a preliminary evaluation of MYB-NFIB translocation by fluorescence in-situ hybridization on seven archived formalin-fixed paraffin-embedded tissues of AdCC of Nigerian patients and its clinicopathologic features. Only 3 of the 7 cases were successfully hybridized, all featuring MYB-NFIB translocations with a range of 14.7-83.3% of translocated cells in 60 cells examined. The 3 translocation positive cases were located in the maxillary sinus, buccal mucosa and parotid. Their morphologic appearances were cribriform-solid (1) & cribriform (2) and classified as grades III (1) & I (2), respectively. These patients may potentially benefit from MYB-targeted anti-neoplastic therapy.

Prognostic importance of RUNX1 expression for head and neck adenoid cystic carcinoma

OBJECTIVE

In the present study, we aimed to investigate the prognostic value of RUNX1 expression in 76 patients with adenoid cystic carcinoma (ACC).

MATERIALS AND METHODS

All cases were arranged in tissue microarray blocks and submitted to immunohistochemistry against RUNX1. These results were statistically correlated with clinicopathologic features, including age, gender, tumour site, tumour size, lymph node status, AJCC clinical stage, distant metastasis, treatment, recurrences, follow-up, histologic pattern, vascular and neural invasion, all of which obtained from patient's medical records.

RESULTS

RUNX1 was expressed in the nuclei of tumour cells, with a mean of 18.1% of positivity. Nuclear RUNX1 expression was significantly associated with AJCC clinical stage (p < .0001), solid histologic pattern (p < .0001), vascular invasion (p < .0001) and presence of local recurrence (p < .0001). Using univariate and multivariate analyses, RUNX1 nuclear expression was significantly associated with a lower disease-free survival (p < .0001 and p = .028, respectively) and disease-specific survival (p < .0001 and p = .018, respectively) rates.

CONCLUSION

In summary, RUNX1 nuclear expression may represent an indicator of unfavourable outcome for patients affected by head and neck ACC.

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.

Prognostic value of CRTC1-MAML2 translocation in salivary mucoepidermoid carcinoma: Systematic review and meta-analysis

The presence of the CRTC1-MAML2 translocation has been described in mucoepidermoid carcinoma (MEC) as a predictor of better survival rates. However, the real prognostic value of the translocation has been debated due to recent controversial findings. The aim of this study was to perform a systematic review to understand the prognostic potential of the CRTC1-MAML2 translocation in MEC. An electronic search was carried out using the MEDLINE/PubMed, EMBASE and Scopus databases. Articles that assessed the association between the CRTC1-MAML2 translocation and survival of MEC patients were selected for the systematic review. Ten published articles were included in the qualitative synthesis. The prevalence of the translocation varied from 33.7% to 69.7%. Seven studies observed a significant association between the presence of the CRTC1-MAML2 translocation and a favourable clinical outcome, which could improve disease-free, disease-specific or overall survival. Five studies were included in the quantitative synthesis. Fixed-effects model confirmed that translocation-positive patients have a decreased risk of death (combined odds ratio 0.08, 95% confidence interval - 0.03-0.23, P < .00001). The detection of the CRTC1-MAML2 translocation appears to be useful as a prognostic factor in MEC. However, the level of evidence is not as high as it could be once important limitations were found in the published studies.

Detecting MYB and MYBL1 fusion genes in tracheobronchial adenoid cystic carcinoma by targeted RNA-sequencing

Primary tracheobronchial adenoid cystic carcinoma is rare, accounting for less than 1% of all lung tumors. Many adenoid cystic carcinomas have been reported to have a specific chromosome translocation t(6;9)/MYB-NFIB. More recently, t(8;9)/MYBL1-NFIB gene fusion was reported in salivary gland adenoid cystic carcinomas which lacked a t(6;9)/MYB-NFIB. Two prior studies showed t(6;9)/MYB-NFIB in tracheobronchial adenoid cystic carcinoma; however, only rare cases of MYBL1 rearrangement have been reported in this carcinoma. In this study, we used targeted RNA sequencing to investigate fusion genes in tracheobronchial adenoid cystic carcinoma at our institution. Fusions of either MYB or MYBL1 genes were detected in 7 of 7 carcinomas. Three cases had MYB-NFIB, and 3 had MYBL1-NFIB. The remaining case showed a rare MYBL1-RAD51B fusion. These findings suggest that rearrangement involving MYB or MYBL1 is a hallmark of tracheobronchial adenoid cystic carcinoma.

Kallikrein-Related Peptidase mRNA Expression in Adenoid Cystic Carcinoma of Salivary Glands: A Polymerase Chain Reaction Study

Kallikrein-related peptidases (KLKs) are a group of 15 serine proteases implicated in a variety of biological processes. Aberrant expression of KLKs has been associated with the development of certain cancers. However, the role of KLKs in salivary tumors has not been extensively studied. This study evaluated the expression of KLKs in both adenoid cystic carcinoma (ACC) and normal salivary gland tissue. We isolated total RNA from 39 formalin-fixed, paraffin-embedded samples, which included 24 ACCs and 15 normal salivary gland tissues. Complementary DNA, synthesized by reverse transcription, was combined with gene specific kallikrein primers (KLK1-KLK15) to allow for quantitative real-time PCR. Data was normalized to a β-actin housekeeping gene. Relative quantification analysis was performed using the ΔCq method. KLK1-KLK15 expression was observed in both tissue types. However, KLK1, KLK8, KLK11, and KLK14 were found to be downregulated in ACC. We propose that this may represent a multi-parametric panel providing diagnostic and prognostic information.

Mass spectrometry-based proteome profile may be useful to differentiate adenoid cystic carcinoma from polymorphous adenocarcinoma of salivary glands

OBJECTIVE

The aim of this study was to determine the proteome of adenoid cystic carcinoma (AdCC) and polymorphous adenocarcinoma (PAc) and to identify a protein signature useful in distinguishing these two neoplasms.

STUDY DESIGN

Ten cases of AdCC and 10 cases of PAc were microdissected for enrichment of neoplastic tissue. The samples were submitted to liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the proteomics data were analyzed by using the MaxQuant software. LC-MS/MS spectra were searched against the Human UniProt database, and statistical analyses were performed with Perseus software. Bioinformatic analyses were performed by using discovery-based proteomic data on both tumors.

RESULTS

LC-MS/MS analysis identified 1957 proteins. The tumors shared 1590 proteins, and 261 were exclusively identified in AdCC and 106 in PAc. Clustering analysis of the statistically significant proteins clearly separated AdCC from PAc. Protein expression 10 times higher in one group than in the other led to a signature of 16 proteins-6 upregulated in AdCC and 10 in PAc. A new clustering analysis showed reverse regulation and also differentiated both tumors.

CONCLUSIONS

Global proteomics may be useful in discriminating these two malignant salivary neoplasms that frequently show clinical and microscopic overlaps, but additional validation studies are still necessary to determine the diagnostic potential of the protein signature obtained.

c-MYB and DMTF1 in Cancer

The c-Myb gene encodes a transcription factor that regulates cell proliferation, differentiation, and apoptosis through protein-protein interaction and transcriptional regulation of signaling pathways. The protein is frequently overexpressed in human leukemias, breast cancers, and other solid tumors suggesting that it is a bona fide oncogene. c-MYB is often overexpressed by translocation in human tumors with t(6;7)(q23;q34) resulting in c-MYB-TCRβ in T cell ALL, t(X;6)(p11;q23) with c-MYB-GATA1 in acute basophilic leukemia, and t(6;9)(q22-23;p23-24) with c-MYB-NF1B in adenoid cystic carcinoma. Antisense oligonucleotides to c-MYB were developed to purge bone marrow cells to eliminate tumor cells in leukemias. Recently, small molecules that inhibit c-MYB activity have been developed to disrupt its interaction with p300. The Dmp1 (cyclin D binding myb-like protein 1; Dmtf1) gene was isolated through its virtue for binding to cyclin D2. It is a transcription factor that has a Myb-like repeat for DNA binding. The Dmtf1 protein directly binds to the Arf promoter for transactivation and physically interacts with p53 to activate the p53 pathway. The gene is hemizygously deleted in 35-42% of human cancers and is associated with longer survival. The significances of aberrant expression of c-MYB and DMTF1 proteins in human cancers and their clinical significances are discussed.