Phase II Clinical Trial of Axitinib and Avelumab in Patients With Recurrent/Metastatic Adenoid Cystic Carcinoma

Reversible downregulation of HLA class I in adenoid cystic carcinoma

BACKGROUND

Adenoid cystic carcinoma (ACC) is a rare, but lethal cancer with low response rates to systemic therapies, such as cytotoxic chemotherapy and immune-checkpoint inhibitors (ICIs). Despite extensive clinical trials, no effective treatments for patients with recurrent or metastatic ACC are available, and ACC mortality rates remain poor.

METHODS

We employed automated multiplex immunofluorescence (mIF), single-cell RNA sequencing (scRNA-seq) Gene Expression analysis, RNA in-situ hybridization, and spatial transcriptomics analysis to characterize the immune landscape of ACC tumors, ACC metastasis, and normal tissues from regions where ACCs arise. Based on results from these studies, we treated freshly resected ACCs with interferon-γ or a stimulator of the interferon genes (STING) agonist in vitro. Additionally, we included one patient with ACC in a phase 1 clinical study of a novel STING agonist (dazostinag) plus pembrolizumab.

RESULTS

The mIF analysis revealed that ACC tumors are immunologically "cold", with few tumor-infiltrating T-lymphocytes and low programmed death-ligand 1 (PD-L1) expression. The most striking finding was a very low beta-2-microglobulin (B2M) expression in nearly all ACCs, with only focal expression found in some ACC metastases. mIF and RNA sequencing analyses of normal salivary gland and breast tissues revealed a p63+, NFIB+, basal duct cell population, with similarly low B2M/human leukocyte antigen (HLA) class I expression. Spatial transcriptomics analysis of the focally B2M-positive ACC metastases uncovered the genetic pathway driving upregulation of B2M, an interferon-γ program mediating the reintroduction of HLA-I/B2M; the significantly upregulated genes included IRF1, GBP1, and TAP1. On short-term treatment of primary ACC tissues in vitro with interferon-γ or a STING agonist, we observed strongly upregulated HLA class I/B2M expression. Moreover, treatment of a patient with recurrent, metastatic breast ACC with a STING agonist and pembrolizumab led to a partial response with a 70% tumor reduction.

CONCLUSIONS

Low B2M/HLA class I expression may explain why ACCs are immunologically cold and the lack of response to ICIs. Our findings suggest that the normal cell of ACC origin exists in a B2M/HLA-class I low state, and that pharmacologic manipulation with immune activators, such as STING agonists, can restore HLA/B2M in ACCs, as supported by the promising response observed in a patient with metastatic ACC. These findings indicate a potential path to urgently needed immunotherapies.

Phase II Study of Nivolumab and Ipilimumab for Treatment of Metastatic/Recurrent Adenoid Cystic Carcinoma (ACC) of all Anatomic Sites of Origin and Other Malignant Salivary Gland Tumors

OBJECTIVE

Dual checkpoint inhibitor therapy with nivolumab and ipilimumab has been FDA approved for a number of cancer sites. However, its role in the treatment of ACC and non-ACC salivary gland carcinomas (non-ACC SGC) is not well established.

METHODS AND ANALYSIS

We performed Simon's two-stage prospective single-institution Phase II clinical trial of nivolumab with ipilimumab. Two cohorts were analyzed: patients with metastatic/recurrent ACC and patients with non-ACC SGC. The primary endpoint was median progression-free survival (PFS); secondary endpoints were overall response rate (ORR), overall survival (OS), and toxicity.

RESULTS

Patient enrollment was prematurely terminated due to funding constraints. In total, 19 patients with ACC and 5 patients with non-ACC SGC were enrolled. The patients with ACC had a median OS of 30.0 months (95% CI 15.3-NR months), a median PFS of 8.3 months (95% CI 5.5-30.0 months), and a disease control rate (DCR) of 53% (10/19). The ORR in the ACC group was 5% (CR 0%, n = 0; confirmed PR 5%, n = 1), with one patient having continued stable disease at the time of trial conclusion. The patients with non-ACC SGC had a median OS of 10.4 months (95% CI 6.21-NR months), a median PFS of 6.21 months (95% CI 2.83-NR months), and a DCR of 40% (2/5). The ORR in this cohort was 0%.

CONCLUSION

In patients with recurrent or metastatic ACC and non-ACC SGC, the combination of nivolumab with ipilimumab resulted in moderate disease control. Further studies are warranted to validate our findings.

TRIAL NUMBER

NCT03146650.

Current landscape and future directions of therapeutic approaches for adenoid cystic carcinoma of the salivary glands (Review)

Adenoid cystic carcinoma (ACC) of the salivary glands is the second most common type of salivary gland cancer, and is characterized by a poor prognosis and an unclear pathology. The incidence of ACC is rare, as it accounts for 10-15% of all salivary gland tumors and affects mainly patients aged between 50 and 60 years. The annual incidence rate is estimated to be ~4.5 cases per 100,000 individuals. Due to its rarity and the use of contaminated cell lines in previous investigations, the precise etiological factors underlying ACC remain poorly understood. Current treatment modalities, typically involving surgery with or without postoperative radiotherapy, often prove unsatisfactory due to the potential for local recurrence and delayed distant metastases, which may manifest 3-5 years after treatment and constitute the primary failure of existing therapeutic approaches. The indolent growth pattern, along with perineural and perivascular invasion, is potentially responsible for the delayed onset of metastases. No effective systemic therapy has been established so far. Therefore, the management of ACC represents a significant therapeutic challenge. Exploring the molecular characteristics of ACC, including the reasons behind its propensity for perineural invasion and its potential correlation with the immune system, offers promising strategies for managing ACC and could open up novel pathways for future therapeutic interventions. Currently, the use of immunotherapy in ACC treatment has shown limited effectiveness. While the exact mechanism underlying the lack of response to immunotherapy in ACC remains unknown, the low levels of tumor-infiltrating lymphocytes in these tumors may contribute to this resistance. Therefore, identifying novel targets to enhance the immune response against tumor cells is essential. The present review provides an update on clinical studies and explores novel therapeutic targets that could be effective in the therapeutic management of ACC.

Roles and therapeutic potential of the SLC family in prostate cancer-literature review

Prostate cancer (PCa) is one of the most common malignancies in men worldwide. Despite advances in treatment, many patients develop resistance to conventional therapies. Solute carrier (SLC) proteins, as transmembrane transporters, have recently emerged as potential therapeutic targets due to their role in tumor metabolism and progression. This review summarizes the key roles of six SLC proteins in PCa, including their involvement in metabolic reprogramming, regulation of signaling pathways, and effects on the tumor microenvironment. Although targeting of SLC family members in prostate cancer remains an underexplored area, the growing body of evidence suggests that it holds potential for future development.

Analysis of the Clinicopathological Characteristics, Genetic Phenotypes, and Prognostics of Primary Pulmonary and Bronchial Adenoid Cystic Carcinoma

BACKGROUND

Primary pulmonary and bronchial adenoid cystic carcinoma (PACC) is a rare, low-grade malignant tumor of the lung. However, the relationship between its clinical features, surgical prognosis, and genetic phenotype has not been fully described.

METHODS

PACC patient information was collected from the SEER, TCGA, and Zhongshan Hospital, Fudan University (FDZSH) databases. Overall survival (OS) was evaluated using the Kaplan-Meier method. Univariate and multivariate analyses through Cox proportional hazards regression identified risk factors that predicted OS. The limma and matfools packages from R were used to compare the differential genes and mutations between PACC and LUAD, respectively.

RESULTS

Two hundred and ninety-two patients, 14 patients, and 12 patients with PACC were identified from the SEER, TCGA, and FDZSH databases, respectively. The 3-, 5-, and 10-year OS of the PACC patients were 91.7%, 88.6%, and 85.0%, respectively, compared to 95.8%, 93.9%, and 93.3% for patients who underwent surgery. Race, pathological grade, M stage, regional node examination, and regional node positive were independent prognostic factors for the OS of patients who underwent surgery. The gene map of PACC and lung adenocarcinoma (LUAD) shows significant differences. Common mutations found in lung cancer were almost undetectable in PACC patients, whereas mutations in the NOTCH pathway were more common. TMB levels and PD-1/PD-L1 expressions were also lower in PACC patients.

CONCLUSION

Our study analyzed the main factors that influence the prognosis of PACC patients undergoing surgery and discovered the unique genetic phenotype of PACC.

Heterogeneous immune landscapes and macrophage dynamics in primary and lung metastatic adenoid cystic carcinoma of the head and neck

Introduction

Recurrent or metastatic adenoid cystic carcinoma (ACC) of the head and neck is rare and highly aggressive. Due to the ineffectiveness of immune checkpoint therapies, this study aims to investigate the tumor immune microenvironment of primary tumor tissues and lung metastatic tissues and to comprehend the challenges of immunotherapy.

Methods

We analyzed RNA sequencing data and constructed immune landscapes from 25 primary tumors and 34 lung metastases. The data were then validated by immunohistochemistry and single-cell sequencing analysis.

Results

Compared to adjacent normal tissues, both primary and lung metastatic ACC showed low immune infiltration. Lung metastases had higher immune infiltration levels and antigen presentation scores but also higher T cell exclusion and dysfunction scores. Single-cell sequencing data and immunohistochemistry revealed abundant immunosuppressive tumor-associated macrophages in lung metastases. Patients with high M2 macrophage infiltration had shorter lung metastasis-free survival.

Discussion

Primary and lung metastatic ACC exhibit heterogeneous tumor immune microenvironments. Higher immune cell infiltration in lung metastases is countered by the presence of suppressive tumor-associated macrophages, which may limit effective anti-tumor responses.

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

IMPORTANCE

Recurrent/metastatic adenoid cystic carcinoma (R/M AdCC) presents a clinical challenge with limited treatment options, particularly in the face of unsatisfactory efficacy from current therapeutic approaches. This review underscores the unmet clinical needs in managing R/M AdCC, emphasising the imperative for novel therapeutic strategies to address this critical gap.

OBJECTIVE

The primary objective of this review is to comprehensively analyse and assess trials investigating therapeutic approaches for R/M AdCC. Emphasis is placed on endpoints such as tumour response rates and progression-free survival. The specific interventions, populations, and outcomes examined in these trials will be detailed to provide a focused and informative systematic review.

EVIDENCE REVIEW

The systematic search spanned databases, including PubMed, EMBASE, and the Cochrane database of systematic reviews. Employing terms like "Carcinoma, Adenoid Cystic" and "trial," the search focused on English full-text articles from April 1, 2010, to August 9, 2023. Inclusion criteria encompassed studies with patients having R/M AdCC, involving drug interventions. Study quality was assessed using the Newcastle-Ottawa Scale for retrospective studies, Cochrane ROBINS-I tool for non-randomised trials, and the ROB-2 tool for randomised controlled trials.

FINDINGS

A total of 46 trials involving 1244 patients are included in this review, encompassing a variety of therapeutic approaches for R/M AdCC. Targeted therapies, particularly Apatinib at 500 mg, exhibit efficacy with a 47.1% objective response rate (ORR). Conversely, immunotherapeutic agents demonstrate suboptimal performance, with an overall ORR ranging from 0 to 18%. While Apatinib shows promise, the review underscores the imperative for a thorough exploration of drugs targeting unique mechanisms in the immunologically cold nature of R/M AdCC.

CONCLUSIONS AND RELEVANCE

Substantial progress in systemic therapy for R/M AdCC is evident, driven by early-phase clinical trials, particularly with promising outcomes in VEGF-2 inhibitors. However, challenges persist, notably in immunotherapy due to the cancer's immunologically cold nature. Ongoing research, prioritising early-stage trials, is crucial, emphasising exploration of emerging therapies like cell therapy and antibody-drug conjugates. Transitioning to Phase III trials is essential for more precise therapeutic insights. Collaborative efforts and a focus on personalised precision medicine are vital for overcoming challenges and advancing our understanding of treatment efficacy in this rare cancer.

Systemic therapies for salivary gland cancer: Adenoid cystic carcinoma. REFCOR recommendations by the formal consensus method

OBJECTIVE

To determine the therapeutic indications for systemic medical treatment in the management of adenoid cystic carcinoma (ACC) according to the clinical situation.

MATERIALS AND METHODS

The French Network of Rare Head and Neck Tumors (REFCOR) formed a steering group, which drafted a narrative review of the literature published on Medline and proposed recommendations. The level of adherence to the recommendations was then assessed by a rating group, according to the formal consensus method.

RESULTS

ACCs are rare tumors and there is currently insufficient evidence to indicate chemotherapy at the localized stage. At the metastatic stage, progression is often slow. In case of oligometastatic ACC, local treatment should be discussed. The most often indolent nature of polymetastatic ACC can allow management by active surveillance. Molecular screening is recommended, for abnormalities potentially accessible to targeted therapy.

CONCLUSION

ACCs are rare tumors for which there are currently few effective medical treatments. It is therefore recommended to include patients in clinical trials.

Adenoid cystic carcinoma: insights from molecular characterization and therapeutic advances

Adenoid cystic carcinoma (ACC) is a malignant tumor primarily originating from the salivary glands, capable of affecting multiple organs. Although ACC typically exhibits slow growth, it is notorious for its propensity for neural invasion, local recurrence, and distant metastasis, making it a particularly challenging cancer to treat. The complexity of ACC's histological and molecular features poses significant challenges to current treatment modalities, which often show limited effectiveness. Recent advancements in single-cell RNA-sequencing (scRNA-seq) have begun to unravel unprecedented insights into the heterogeneity and subpopulation diversity within ACC, revealing distinct cellular phenotypes and origins. This review delves into the intricate pathological and molecular characteristics of ACC, focusing on recent therapeutic advancements. We particularly emphasize the insights gained from scRNA-seq studies that shed light on the cellular landscape of ACC, underscoring its heterogeneity and pathobiology. Moreover, by integrating analyses from public databases, this review proposes novel perspectives for advancing treatment strategies in ACC. This review contributes to the academic understanding of ACC by proposing novel therapeutic approaches informed by cutting-edge molecular insights, paving the way for more effective, personalized therapeutic approaches for this challenging malignancy.

Vascular Endothelial Growth Factor Receptor Inhibitors for Recurrent or Metastatic Adenoid Cystic Carcinoma: A Systematic Review and Meta-Analysis

Importance

There is no systemic therapy for recurrent or metastatic adenoid cystic carcinoma (ACC) approved by the US Food and Drug Administration.

Objective

To examine the efficacy, safety, and tolerability of vascular endothelial growth factor receptor (VEGFR) inhibitors in recurrent or metastatic ACC.

Data Sources

PubMed, Embase, and Cochrane Library were systematically searched for studies of VEGFR inhibitors in recurrent or metastatic ACC from database inception to August 31, 2023.

Study Selection

Inclusion criteria were prospective clinical trials of recurrent or metastatic ACC treated with VEGFR inhibitors, reporting at least 1 outcome of interest specifically for ACC. Of 1963 identified studies, 17 (0.9%) met inclusion criteria.

Data Extraction and Synthesis

The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) reporting guideline was followed to extract data. Data were pooled using a random-effects generalized linear mixed model with 95% CIs.

Main Outcomes and Measures

The primary efficacy outcome was best overall response to VEGFR inhibitors, including objective response, stable disease, or progressive disease (PD). Safety and tolerability outcomes included incidence of grade 3 or higher adverse events, rates of exit from trial due to PD or drug-related toxic effects, and dose reduction rate (DRR).

Results

A total of 17 studies comprising 560 patients with recurrent or metastatic ACC treated with 10 VEGFR inhibitors were included. The objective response rate was 6% (95% CI, 3%-12%; I2 = 71%) and stable disease was the most frequent best overall response (82%; 95% CI, 74%-87%; I2 = 67%). The 6-month disease control (defined as objective response and stable disease) rate was 54% (95% CI, 45%-62%; I2 = 52%). The rate of grade 3 or higher adverse events was 53% (95% CI, 42%-64%; I2 = 81%) and of DRR was 59% (95% CI, 40%-76%). Most patients (57%; 95% CI, 44%-70%; I2 = 83%) continued therapy until PD; 21% (95% CI, 15%-28%; I2 = 62%) of patients suspended therapy for toxic effects. In subgroup analysis by specific VEGFR inhibitor, the objective response rate was 14% (95% CI, 7%-25%; I2 = 0%), stable disease rate was 76% (95% CI, 63%-85%; I2 = 0%), proportion treated until PD was 61% (95% CI, 14%-94%; I2 = 94%), and DRR was 78% (95% CI, 66%-87%; I2 = 39%) with lenvatinib. Corresponding axitinib results were objective response rate of 8% (95% CI, 4%-15%; I2 = 0%) and stable disease rate of 85% (95% CI, 72%-92%; I2 = 69%), with 73% (95% CI, 63%-82%; I2 = 0%) of patients treated until PD, and the DRR was 22% (95% CI, 12%-38%; I2 = 77%). Rivoceranib had the highest objective response rate (24%; 95% CI, 7%-57%) but high heterogeneity among studies (I2 = 95%) and the lowest rate of patients who continued therapy until PD (35%; 95% CI, 20%-55%; I2 = 90%).

Conclusions and Relevance

This systematic review and meta-analysis found that VEGFR inhibitors were associated with high rates of disease stabilization in recurrent or metastatic ACC. Of 10 included VEGFR inhibitors, lenvatinib and axitinib were associated with the best combined and consistent efficacy, safety, and tolerability profiles, substantiating their inclusion in treatment guidelines.

Adenoid Cystic carcinoma of minor salivary glands (AdCCmSG): a multidisciplinary update

INTRODUCTION

Adenoid cystic carcinoma of minor salivary glands (AdCCmSG) represents a 'rarity in the rarity,' posing a clinical challenge in lack of standardized, evidence-based recommendations. At present, AdCCmSG management is mostly translated from major salivary gland cancers (MSGCs). Ideally, AdCCmSG diagnostic-therapeutic workup should be discussed and carried out within a multidisciplinary, high-expertise setting, including pathologists, surgeons, radiation oncologists and medical oncologists.

AREAS COVERED

The present review provides an overview of epidemiology and pathologic classification. Moreover, the most recent, clinically relevant updates in the treatment of AdCCmSG (Pubmed searches, specific guidelines) are critically discussed, aiming to a better understanding of this rare pathologic entity, potentially optimizing the care process, and offering a starting point for reflection on future therapeutic developments.

EXPERT OPINION

The management of rare cancers is often hindered by limited data and clinical trials, lack of evidence-based guidelines, and hardly represented disease heterogeneity, which cannot be successfully tackled with a 'one-size-fits-all' approach. Our goal is to address these potential pitfalls, providing an easy-to-use, updated, multidisciplinary collection of expert opinions concerning AdCCmSG management as of today's clinical practice. We will also cover the most promising future perspectives, based on the potential therapeutic targets highlighted within AdCCmSG's molecular background.

High-grade salivary carcinomas: A current insight on diagnostic pathology and the key to clinical decision making

High-grade carcinomas of the salivary glands are a group of several tumor entities with highly malignant histologic appearances, and have an aggressive biological behavior accompanied by poor a prognosis. In general, they require more intensive treatment than low- or intermediate-grade carcinomas. High-grade salivary carcinomas are rare and the microscopic features often overlap between different tumor types, making an appropriate diagnosis challenging in daily practice settings. However, with recent rapid advances in molecular pathology and molecular-targeted therapy in this field, there is a growing need to properly classify tumors, rather than just diagnosing the cases as "high-grade carcinomas". This leads to specific treatment strategies. In this article, we review representative high-grade salivary gland carcinomas, including salivary duct carcinoma and its histologic subtypes, high-grade mucoepidermoid carcinoma, solid-type adenoid cystic carcinoma, and high-grade transformation of low- or intermediate-grade carcinomas, and discuss their differential diagnoses and clinical implications. Other rare entities, such as neuroendocrine carcinoma, NUT carcinoma, and metastatic carcinoma, should also be considered before diagnosing high-grade carcinoma, NOS. Of these tumors, salivary duct carcinoma has received the most attention because of its strong association with androgen deprivation and anti-HER2 therapies. Other tumor-type-specific treatments include anti-TRK therapy for high-grade transformation of secretory carcinoma, but further therapeutic options are expected to be developed in the future. It should be emphasized that detailed histological evaluation with adequate sampling, in addition to the effective use of molecular ancillary tests, is of the utmost importance for a suitable diagnosis.

Molecular Profiling and the Impact of Treatment on Outcomes in Adenoid Cystic Carcinoma Type I and II

PURPOSE

Adenoid cystic carcinoma (ACC) is an uncommon salivary gland cancer with no approved therapies available to treat advanced, incurable disease. Recent molecular profiling efforts have identified two important subtypes: the more aggressive ACC-I is characterized by Notch pathway alterations and MYC amplification whereas ACC-II demonstrates a more indolent phenotype and TP63 overexpression.

EXPERIMENTAL DESIGN

This retrospective observational cohort study involved de-identified samples from 438 patients with ACC with tumor samples sent for commercially-available molecular profiling (Caris Life Sciences). Next-generation whole-exome and whole-transcriptomic sequencing was performed on primary and metastatic samples. Immunostaining for PD-L1 and RNA deconvolution (quanTIseq) was used to explore the tumor immune microenvironment (TME). Real-world clinical and survival outcome metrics were extracted from insurance claims data.

RESULTS

MYC expression was 1.61-fold higher (39.8 vs. 24.7; P < 0.0001) among NOTCH1-mutant ACC-I tumors, whereas MYB/L1 fusion rates were similar among ACC-I/II. The median B-cell fraction in the TME was higher among ACC-II (7.1% vs. 5.8%; P < 0.01), although infiltrating T cells subsets were low among either ACC subgroup (both <1%). When pooling systemic treatment categories, ACC-I patients had worse outcomes with available therapies (HR, 3.06; 95% confidence interval, 1.65-5.68; P < 0.01), with no significant difference in overall survival between ACC-I/II based on chemotherapy or VEGFR tyrosine kinase inhibitor exposure in smaller subsets.

CONCLUSIONS

We confirmed the previously reported associations with MYC and TP63 in the prognostically relevant subgroups of ACC-I and -II, respectively, and report immunologic differences among these subtypes. Survival outcomes are comparatively worse in ACC-I regardless of treatment type.

Molecular Aspects of Mucoepidermoid Carcinoma and Adenoid Cystic Carcinoma of the Salivary Gland

BACKGROUND

Salivary gland tumors (SGTs) are rare and highly heterogeneous lesions, making diagnosis a challenging activity. In addition, the small number of studies and samples evaluated difficults the determination of prognosis and diagnosis. Despite the solid advances achieved by research, there is still an intense need to investigate biomarkers for diagnosis, prognosis and that explain the evolution and progression of SGTs.

METHODS

We performed a comprehensive literature review of the molecular alterations focusing on the most frequent malignant SGTs: mucoepidermoid carcinoma and adenoid cystic carcinoma.

RESULTS

Due to the importance of biomarkers in the tumorigenenic process, this review aimed to address the mechanisms involved and to describe molecular and biomarker pathways to better understand some aspects of the pathophysiology of salivary gland tumorigenesis.

CONCLUSIONS

Molecular analysis is essential not only to improve the diagnosis and prognosis of the tumors but also to identify novel driver pathways in the precision medicine scenario.

Adenoid cystic carcinoma of the retromolar pad region: A case report

INTRODUCTION

Adenoid cystic carcinoma (ACC) is one of the most common salivary gland malignancies, mostly occurs in the major and minor salivary glands in the oral and maxillofacial region. The development of ACC in the retromolar pad is extremely rare, which limits establishing proper diagnosis and management.

PRESENTATION OF CASE

A patient described a 2-month history of finding a mass behind the lower left posterior teeth. Based on the physical examination and radiographic findings, we got an initial impression of a benign mucocele, the nature of which was to be investigated further. Pathological examination of the resected tissue resulted in a diagnosis of ACC. Follow-up visits showed no recurrence during the subsequent 54 months.

DISCUSSION

In cases with an uncertain diagnosis based on medical history, clinical features and imaging examinations, it is important to proceed carefully with the possibility of a tumor in mind.

CONCLUSION

ACC in the retromolar pad is rare and can be easily misdiagnosed. Clinical, radiographic, and pathological evidence confirm a definitive diagnosis. Long-term follow-up is important for the full analysis of ACC treatment.

First Use of AXL Targeting in Metastatic, Refractory, Adenoid Cystic Carcinoma: A Case Report

First use of AXL-targeting in adenoid cystic carcinoma (ACC); with positive results, ACC now included in AXL studies.

Current diagnosis and treatment of salivary gland-type tumors of the lung

Salivary gland-type tumors of the lung are thought to originate from the submucosal exocrine glands of the large airways. Due to their rare occurrence, reports of their study are limited to small-scale or case reports. Therefore, daily clinical practices often require a search for previous reports. In the last 20 years, several genetic rearrangements have been identified, such as MYB::NF1B rearrangements in adenoid cystic carcinoma, CRTC1::MAML2 rearrangements in mucoepidermoid carcinoma, EWSR1::ATF1 rearrangements in hyalinizing clear cell carcinoma and rearrangements of the EWSR1 locus or FUS (TLS) locus in myoepithelioma and myoepithelial carcinoma. These molecular alterations have been useful in diagnosing these tumors, although they have not yet been linked to molecularly targeted therapies. The morphologic, immunophenotypic, and molecular characteristics of these tumors are similar to those of their counterparts of extrapulmonary origin, so clinical and radiologic differential diagnosis is required to distinguish between primary and metastatic disease of other primary sites. However, these molecular alterations can be useful in differentiating them from other primary lung cancer histologic types. The management of these tumors requires broad knowledge of the latest diagnostics, surgery, radiotherapy, bronchoscopic interventions, chemotherapy, immunotherapy as well as therapeutic agents in development, including molecularly targeted agents. This review provides a comprehensive overview of the current diagnosis and treatment of pulmonary salivary gland tumors, with a focus on adenoid cystic carcinoma and mucoepidermoid carcinoma, which are the two most common subtypes.

Salivary gland carcinoma: Towards a more personalised approach

Salivary Gland carcinomas (SGCs) are rare tumors accounting for less than 1% of all cancers with 21 histologically diverse subtypes. The rarity of the disease presents a challenge for clinicians to conduct large size randomized controlled trials. Surgery and radiotherapy remain the only curative treatment for localized disease, whereas treatments for recurrent and metastatic disease remain more challenging with very disappointing results for chemotherapy. The different histological subtypes harbor various genetic alterations, some pathognomonic with a diagnostic impact for pathologists in confirming a difficult diagnosis and others with therapeutic implications regardless of the histologic subtype. Current international guidelines urge pathologists to identify androgen receptor status, HER-2 expression that could be determined by immunohistochemistry, and TRK status in patients with non-adenoid cystic salivary gland carcinoma that are eligible to initiate a systemic treatment, in order to offer them available targeted therapies or refer them to clinical trials based on their mutational profile. A more advanced molecular profiling by next generation sequencing would offer a larger panel of molecular alterations with possible therapeutic implications such as NOTCH, PI3K, BRAF, MYB, and EGFR. In the following review, we present the most common genetic alterations in SGCs as well as actionable mutations with the latest available data on therapeutic options and upcoming clinical trials.

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.

Exploring the Therapeutic Potential of Triptonide in Salivary Adenoid Cystic Carcinoma: A Comprehensive Approach Involving Network Pharmacology and Experimental Validation

BACKGROUND

Salivary Adenoid Cystic Carcinoma (ACC) is characterized by a highly invasive and slow-growing pattern, and its etiology remains unidentified. Triptonide (TN) has demonstrated efficacy as a pharmacotherapeutic agent against ACC. Nonetheless, the specific targets and mechanism of molecular action underlying the effectiveness of TN in treating ACC have not been elucidated.

OBJECTIVES

By integrating network pharmacology within laboratory experiments, this research delves into the prospective targets and molecular mechanisms associated with the application of TN in treating ACC.

METHODS

Initially, pertinent targets associated with TN against ACC were acquired from public databases. Subsequently, a combination of network pharmacology and bioinformatics analysis was utilized to screen the top 10 hub targets and key signal pathways of TN-treating ACC. Finally, in vitro experiments involving various molecular assays were conducted to evaluate the biological phenotypes of cells following TN treatment, encompassing assessments of apoptosis levels, plate migration, and other parameters, thereby validating pivotal genes and pathways.

RESULTS

A total of 23 pertinent targets for TN in relation to ACC were identified, with the top 10 hub genes being MAPK8, PTGS2, RELA, MAPK14, NR3C1, HDAC1, PPARG, NFKBIA, AR, and PGR. There was a significant correlation between the TNF signaling pathway and the treatment of ACC with TN. In vitro experiments demonstrated that TN treatment elevated RELA phosphorylation while concurrently reducing MAPK14 phosphorylation and inducing G2/M arrest. TN exhibited the ability to enhance the apoptosis rate through increased caspase-3 activity, elevated levels of Reactive Oxygen Species (ROS), mitochondrial dysfunction, and inhibition of cell migration.

CONCLUSION

There is a potential therapeutic role for TN in the treatment of ACC through the activation of the TNF signaling pathway. Among the identified candidates, MAPK8, HDAC1, PTGS2, RELA, NR3C1, PPARG, NFKBIA, AR, and PGR emerge as the most pertinent therapeutic targets for TN in the context of ACC treatment.

Nivolumab plus ipilimumab in advanced salivary gland cancer: a phase 2 trial

Salivary gland cancers (SGCs) are rare, aggressive cancers without effective treatments when metastasized. We conducted a phase 2 trial evaluating nivolumab (nivo, anti-PD-1) and ipilimumab (ipi, anti-CTLA-4) in 64 patients with metastatic SGC enrolled in two histology-based cohorts (32 patients each): adenoid cystic carcinoma (ACC; cohort 1) and other SGCs (cohort 2). The primary efficacy endpoint (≥4 objective responses) was met in cohort 2 (5/32, 16%) but not in cohort 1 (2/32, 6%). Treatment safety/tolerability and progression-free survival (PFS) were secondary endpoints. Treatment-related adverse events grade ≥3 occurred in 24 of 64 (38%) patients across both cohorts, and median PFS was 4.4 months (95% confidence interval (CI): 2.4, 8.3) and 2.2 months (95% CI: 1.8, 5.3) for cohorts 1 and 2, respectively. We present whole-exome, RNA and T cell receptor (TCR) sequencing data from pre-treatment and on-treatment tumors and immune cell flow cytometry and TCR sequencing from peripheral blood at serial timepoints. Responding tumors universally demonstrated clonal expansion of pre-existing T cells and mutational contraction. Responding ACCs harbored neoantigens, including fusion-derived neoepitopes, that induced T cell responses ex vivo. This study shows that nivo+ipi has limited efficacy in ACC, albeit with infrequent, exceptional responses, and that it could be promising for non-ACC SGCs, particularly salivary duct carcinomas. ClinicalTrials.gov identifier: NCT03172624 .

The Efficacy of Immunotherapy and Clinical Utility of Comprehensive Genomic Profiling in Adenoid Cystic Carcinoma of Head and Neck

Background and Objectives: Adenoid cystic carcinoma (ACC) of the head and neck is generally slow-growing but has a high potential for local recurrence and metastasis to distant organs. There is currently no standard pharmacological treatment for recurrent/metastatic (R/M) ACC, and there are cases in which immune checkpoint inhibitors (ICIs) are administered for ACC according to head and neck squamous cell carcinoma (HNSCC). However, the efficacy of ICIs for ACC remains unclear, and the predictive biomarkers need to be elucidated. Materials and Methods: The Center for Cancer Genomics and Advanced Therapeutics (C-CAT) database enabled the retrospective but nationwide analysis of 263 cases of ACC of the head and neck. Then, we examined and reported four cases of ACC that received ICIs and comprehensive genomic profiling (CGP) in our institution. Results: The C-CAT database revealed that 59 cases out of 263 received ICIs, and the best response was 8% of objective response rate (ORR) and 53% of disease control rate (DCR) (complete response, CR 3%, partial response, PR 5%, stable disease, SD 44%, progressive disease, PD 19%, not evaluated, NE 29%). The tumor mutational burden (TMB) in ACC was lower overall compared to HNSCC and could not be useful in predicting the efficacy of ICIs. Some cases with MYB structural variants showed the response to ICIs in the C-CAT database. A patient with MYB fusion/rearrangement variants in our institution showed long-term stable disease. Conclusions: ICI therapy is a potential treatment option, and the MYB structural variant might be a candidate for predictive biomarkers for immunotherapy in patients with R/M ACC.

Current management and future challenges in salivary glands cancer

Salivary gland cancers (SGCs) are rare, accounting for less than 5% of all malignancies of the head and neck region, and are morphologically heterogeneous. The diagnosis is mainly based on histology, with the complementary aid of molecular profiling, which is helpful in recognizing some poorly differentiated, borderline, or atypical lesions. Instrumental imaging defines the diagnosis, representing a remarkable tool in the treatment plan. Ultrasound and magnetic resonance are the most common procedures used to describe the primary tumour. The treatment of SGCs is multimodal and consists of surgery, radiotherapy, and systemic therapy; each treatment plan is, however, featured on the patient and disease's characteristics. On 24 June 2022, in the meeting "Current management and future challenges in salivary gland cancers" many experts in this field discussed the state of the art of SGCs research, the future challenges and developments. After the meeting, the same pool of experts maintained close contact to keep these data further updated in the conference proceedings presented here. This review collects the insights and suggestions that emerged from the discussion during and after the meeting per se.