The Immune Landscape of Chinese Head and Neck Adenoid Cystic Carcinoma and Clinical Implication

Tumor immune microenvironment in adenoid cystic carcinoma of the lacrimal gland: relationship with histopathology and prognosis

PURPOSE

To quantitatively investigate the pathological subtypes of lacrimal gland adenoid cystic carcinoma (LGACCs), the tumor immune microenvironment in each pathological subtype, and the relation to survival.

METHODS

In this retrospective study, the tumor subtype was determined by H&E staining. Multiplex immunochemistry was performed to define specific immune cells. The tumor immune microenvironment (TIME) was sketched by sequential image scanning and reconstructed by a cytometry platform.

RESULTS

Eighteen patients with adequate paraffin blocks diagnosed with LGACC from 2012 to 2021 were included in this study. Thirteen patients out of the eighteen patients (72.2%)showed a mixture of different pathological subtypes. Each pathological subtype took different percentages on different tumors. The cribriform was the most common subtype, taking an overall percentage of 39%. The rest of the pathological subtypes were tubular (19%), basaloid (17%), cribriform and tubular mixture (C + T) 14%. The sclerosing and comedocarcinomic subtypes were the least seen in LGACC, taking a percentage of 11% altogether. Patients with cribriform dominant component had better overall survival than the non-cribriform dominant patients. Patients with basaloid dominant component had worse clinical outcomes than the non-basaloid dominant ones. The TIME showed high immunogenicity in the tumor margin but declined in the tumor areas. Pathological subtypes rather than individual differences determined the TIME phenotype. The cribriform subtype possessed more immune cell infiltration than other pathological subtypes.

CONCLUSIONS

LGACC is composed of multiple pathological subtypes. Each pathological subtype takes different percentages on different tumors, which is related to the prognosis. TIME pattern in LGACC varies among different pathological subtypes, which could indicate novel strategies in immunotherapy.

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.

Outcomes in Adenoid Cystic Carcinoma: A 14-Year Analysis

Background Adenoid cystic carcinoma (ACC) is a rare malignancy characterized by slow progression, local recurrence, and distant metastases. This study aims to evaluate the demographic patterns, clinical presentations, outcomes, and survival trends of patients with ACC. Methods A retrospective analysis of 14 patients diagnosed with ACC from 2010 to 2024 at a tertiary cancer center in the United Arab Emirates was conducted. Data on demographics, presenting symptoms, clinical outcomes, tumor characteristics, recurrence patterns, and survival were analyzed. Kaplan-Meier survival analysis was performed to evaluate survival trends. Results The cohort was predominantly male (64.3%, n=9) with a mean age of 38.9 years. An enlarging mass in the neck (50%, n=7) was the most common presenting symptom. Local recurrence and distant metastases were observed in 42.9% (n=6) of patients each, with the lungs being the most frequent site of metastases (83.3%, n=5). Advanced-stage disease (Stage III/IV) was common (64.3%, n=9). Overall survival was 85.7% (n=12) over a mean follow-up of 4.3 years. Smoking was associated with poorer survival trends, though not statistically significant (HR=7.0, p=0.083). Conclusion ACC predominantly affects middle-aged individuals and is associated with high rates of local recurrence and distant metastases, especially to the lungs. Although survival trends varied by gender, smoking, and metastases, these differences were not statistically significant, underscoring the need for larger studies to better elucidate prognostic factors.

Primary tracheal adenoid cystic carcinoma: A case report and analysis of the tumor immune microenvironment using single cell RNA sequencing

BACKGROUND

Tracheal adenoid cystic carcinoma (ACC) is a slow growing yet aggressive malignancy with high rates of local recurrence as well as distant metastasis. Tracheal ACC exhibit a low mutation burden along with high mutational diversity, and generally do not respond well to chemotherapeutics.

METHODS

We present a rare case of primary tracheal ACC initially presenting with nonspecific cervicalgia and globus sensation that was ultimately treated with tracheal resection followed by chemoradiation. Immune profiling of intratumoral T-cell receptor (TCR) repertoire was subsequently performed using single cell RNA sequencing (scRNAseq).

RESULTS

We describe a rare case of primary tracheal adenoid cystic carcinoma highlighting several management principles as well as providing new insights into intratumor T cell populations.

CONCLUSIONS

Primary tracheal ACC is most commonly treated with surgical resection followed by adjuvant therapy. Further characterization of the tumor immune microenvironment is necessary to better understand ACC disease biology and to identify potential therapeutic targets.

The genetic and immune features of salivary gland secretory carcinoma with high-grade transformation

OBJECTIVES

To compare the clinicopathological, molecular, and immune features of conventional and high-grade transformation (HGT) secretory carcinoma (SC) in salivary glands.

MATERIALS AND METHODS

The clinicopathological data of 88 cases including 74 conventional SCs and 14 SCs with HGT were reviewed. Targeted next-generation sequencing was performed in 11 SCs with HGT and 7 conventional SCs. The level of PD-L1 and CD8+ TILs was determined by immunohistochemistry.

RESULTS

Compared with the conventional group, the rates of nodal metastasis, local recurrence, distant metastasis and mortality were significantly higher in the HGT cohort. Mutations of ARID1A/B, KMT2A, HOXD13, NRG1 and ETV6 genes were identified in HGT SCs. A recurrent E307G mutation in GATA6 gene was also observed in two cases. Two deceased HGT patients with distant metastasis harboured NOTCH3 mutations. ETV6-RET translocation was prone to occur in the HGT SCs. Additionally, PD-L1 expression was low, and CD8+ TILs were sparse in most HGT cases.

CONCLUSION

Our findings reveal novel gene alterations involved in the progression of HGT in SCs. Most HGT SCs patients cannot benefit from PD-L1 blocking and may be approached with a distinct treatment strategy including the lymph node dissection and application of molecular target drugs in precision oncology.

Exploring Immunological Effects and Novel Immune Adjuvants in Immunotherapy for Salivary Gland Cancers

Salivary gland cancer (SGC) is rare and comprises over 20 histological subtypes. Recently, clinical experience regarding immunotherapies for SGCs has been accumulating, yet their efficacy remains controversial. Understanding the tumor microenvironment (TME), including the expression of immune checkpoint molecules in SGC, is crucial to optimizing immunotherapy. In this review, we demonstrate that high-grade mucoepidermoid carcinoma and salivary duct carcinoma generally exhibit immune-hot TME with high immune cell infiltration, frequent genetic mutations, and robust immune checkpoint molecule expression. In contrast, adenoid cystic carcinomas exhibit an immune-cold TME. While the reported efficacy of immune checkpoint inhibitors (ICIs) for SGCs is generally poor, several studies showed promising clinical efficacy of ICIs, with an objective response rate ranging from 20.0-33.3%, indicating that ICIs might be beneficial for a specific population of SGC. Molecule-targeted therapies including anti-human epidermal growth factor receptor 2 and anti-androgen receptor therapies have shown promising clinical efficacy against SGC. Recent evidence indicates that these molecules could be targets for antigen-specific immunotherapies including chimeric antigen receptor-T therapy and cancer vaccines. This review discusses the current understanding and future directions of immunotherapies for SGCs, including ongoing clinical trials.

The evolving landscape of salivary gland tumors

Salivary gland cancers are a rare, histologically diverse group of tumors. They range from indolent to aggressive and can cause significant morbidity and mortality. Surgical resection remains the mainstay of treatment, but radiation and systemic therapy are also critical parts of the care paradigm. Given the rarity and heterogeneity of these cancers, they are best managed in a multidisciplinary program. In this review, the authors highlight standards of care as well as exciting new research for salivary gland cancers that will strive for better patient outcomes.

[Misdiagnosis of adenoid cystic carcinoma of oropharynx: a case report]

Adenoid cystic carcinoma usually occurs in the salivary glands of the head and neck. It is a malignant tumor with a high degree of malignancy, resistance to radiotherapy and chemotherapy and poor prognosis. The clinical course of adenoid cystic carcinoma is slow and easy to be misdiagnosed. The main diagnosis and treatment means are individualized and precise treatment under the multi-disciplinary consultation mode, that is, surgical treatment and radiotherapy and chemotherapy. Adenoid cystic carcinoma is prone to relapse and hematologic metastasis, and the traditional radiotherapy and chemotherapy based therapies have not achieved satisfactory efficacy in the past three decades. How to detect, diagnose and treat early is an urgent task faced by clinicians.

Spatial Immunoprofiling of Adenoid Cystic Carcinoma Reveals B7-H4 Is a Therapeutic Target for Aggressive Tumors

PURPOSE

Adenoid cystic carcinoma (ACC) is a heterogeneous malignancy, and no effective systemic therapy exists for metastatic disease. We previously described two prognostic ACC molecular subtypes with distinct therapeutic vulnerabilities, ACC-I and ACC-II. In this study, we explored the ACC tumor microenvironment (TME) using RNA-sequencing and spatial biology to identify potential therapeutic targets.

EXPERIMENTAL DESIGN

Tumor samples from 62 ACC patients with available RNA-sequencing data that had been collected as part of previous studies were stained with a panel of 28 validated metal-tagged antibodies. Imaging mass cytometry (IMC) was performed using the Fluidigm Helios CyTOF instrument and analyzed with Visiopharm software. The B7-H4 antibody-drug conjugate AZD8205 was tested in ACC patient-derived xenografts (PDX).

RESULTS

RNA deconvolution revealed that most ACCs are immunologically "cold," with approximately 30% being "hot." ACC-I tumors with a poor prognosis harbored a higher density of immune cells; however, spatial analysis by IMC revealed that ACC-I immune cells were significantly restricted to the stroma, characterizing an immune-excluded TME. ACC-I tumors overexpressed the immune checkpoint B7-H4, and the degree of immune exclusion was directly correlated with B7-H4 expression levels, an independent predictor of poor survival. Two ACC-I/B7-H4-high PDXs obtained 90% complete responses to a single dose of AZD8205, but none were observed with isotype-conjugated payload or in an ACC-II/B7-H4 low PDX.

CONCLUSIONS

Spatial analysis revealed that ACC subtypes have distinct TMEs, with enrichment of ACC-I immune cells that are restricted to the stroma. B7-H4 is highly expressed in poor-prognosis ACC-I subtype and is a potential therapeutic target.

Systemic and Targeted Therapies in Adenoid Cystic Carcinoma

OPINION STATEMENT

Adenoid cystic carcinoma (ACC) is an often-indolent type of salivary gland cancer (SGC). A subset of patients develops progression or aggressive disease warranting systemic therapy in the recurrent/metastatic (R/M) setting. We recommend genomic testing for all patients with R/M disease to aid with prognostication and eligibility for potential experimental therapies. Here, we review the currently available treatment options (cytotoxic chemotherapies and vascular endothelial growth factor receptor (VEGFR)-targeting tyrosine kinase inhibitors (TKIs)). Based on limited data, we nominate regimens which may have more favorable efficacy profiles. Among the cytotoxic chemotherapies, several regimens are acceptable when incorporating a platinum agent. Among the VEGFR-targeting TKIs, lenvatinib and axitinib are the preferred options. Larger, randomized studies prioritizing combinations with mechanistic synergism are needed. Predictive biomarkers are critical, as there is currently little evidence to guide sequencing of available options for individual patients. Immunotherapy is an available option, but has been associated with only modest benefit in ACC. We go on to review other therapies that have been studied and nominate those with promise based on early clinical data.

Exploring the role of neutrophil-to-lymphocyte ratio and blood chemistry in head and neck adenoid cystic carcinomas treated with carbon ion radiotherapy

BACKGROUND AND PURPOSE

In recent years, there is an emerging interest in the prognostic role of chemistry blood biomarkers in oncological patients but their role in adenoid cystic carcinomas (ACCs) is still unknown. This study aims to assess the prognostic significance of baseline neutrophil-to-lymphocyte ratio (NLR) and blood chemistry in a series of head and neck ACC patients treated with carbon ion radiotherapy (CIRT).

MATERIAL AND METHODS

We retrospectively retrieved the data of 49 consecutive head and neck ACC patients treated with CIRT. Univariable and multivariable Cox proportional hazard regression (Cox-ph) analyses were performed to look for a potential association of NLR, and other blood biomarker values, with disease-free survival (DFS), Local Control (LC), Metastasis Free Survival (MFS) and overall survival (OS).

RESULTS

No significant association between NLR > 2,5 and DFS, LC, MFS and OS was found with univariable analysis although a trend was reported for DFS (Hazard ratio [HR]: 2,10, 95 % CI: 0,85 - 5,08, p-value = 0,11). Patients with hemoglobin (hb) ≤ 14 g/dL showed significantly better DFS, MFS and OS. Multivariable regression Cox-ph analysis for DFS, adjusted for margin status, clinical target volume and Absolute Number of Monocytes, reported the following statistically significant HRs, for both NLR > 2,5 and hb > 14 g/dL respectively: 4,850 (95 % CI = 1,408 - 16,701, p = 0,012) and 3,032 (95 % CI = 1,095 - 8,393, p = 0,033). Moreover, hb > 14 with HR = 3,69 (95 % CI: 1,23 - 11,07, p-value = 0,02), was a negative independent prognostic predictor for MFS.

CONCLUSIONS

Pre-treatment NLR and hb values seem to be independent prognostic predictor for clinical outcomes in head and neck ACC patients. If their role will be validated in a larger prospective cohort, they might be worthwhile for a pre-treatment risk stratification in patients treated with CIRT.

Single-cell RNA sequencing identifies a paracrine interaction that may drive oncogenic notch signaling in human adenoid cystic carcinoma

Salivary adenoid cystic carcinoma (ACC) is a rare, biologically unique biphasic tumor that consists of malignant myoepithelial and luminal cells. MYB and Notch signaling have been implicated in ACC pathophysiology, but in vivo descriptions of these two programs in human tumors and investigation into their active coordination remain incomplete. We utilize single-cell RNA sequencing to profile human head and neck ACC, including a comparison of primary ACC with a matched local recurrence. We define expression heterogeneity in these rare tumors, uncovering diversity in myoepithelial and luminal cell expression. We find differential expression of Notch ligands DLL1, JAG1, and JAG2 in myoepithelial cells, suggesting a paracrine interaction that may support oncogenic Notch signaling. We validate this selective expression in three published cohorts of patients with ACC. Our data provide a potential explanation for the biphasic nature of low- and intermediate-grade ACC and may help direct new therapeutic strategies against these tumors.

Salivary gland cancers in elderly patients: challenges and therapeutic strategies

Salivary gland carcinomas (SGCs) are the most heterogeneous subgroup of head and neck malignant tumors, accounting for more than 20 subtypes. The median age of SGC diagnosis is expected to rise in the following decades, leading to crucial clinical challenges in geriatric oncology. Elderly patients, in comparison with patients aged below 65 years, are generally considered less amenable to receiving state-of-the-art curative treatments for localized disease, such as surgery and radiation/particle therapy. In the advanced setting, chemotherapy regimens are often dampened by the consideration of cardiovascular and renal comorbidities. Nevertheless, the elderly population encompasses a broad spectrum of functionalities. In the last decades, some screening tools (e.g. the G8 questionnaire) have been developed to identify those subjects who should receive a multidimensional geriatric assessment, to answer the question about the feasibility of complex treatments. In the present article, we discuss the most frequent SGC histologies diagnosed in the elderly population and the relative 5-years survival outcomes based on the most recent data from the Surveillance, Epidemiology, and End Results (SEER) Program. Moreover, we review the therapeutic strategies currently available for locoregionally advanced and metastatic disease, taking into account the recent advances in precision oncology. The synergy between the Multidisciplinary Tumor Board and the Geriatrician aims to shape the most appropriate treatment pathway for each elderly patient, focusing on global functionality instead of the sole chronological age.

Comparative proteomic and clinicopathological analysis of breast adenoid cystic carcinoma and basal-like triple-negative breast cancer

Background

Adenoid cystic carcinoma (ACC) is a rare type of triple-negative breast cancer that has an indolent clinical behavior. Given the substantial overlapping morphological, immunohistochemical, and molecular features with other basal-like triple-negative breast cancer (BL-TNBC), accurate diagnosis of ACC is crucial for effective clinical treatment. The integrative analysis of the proteome and clinicopathological characteristics may help to distinguish these two neoplasms and provide a deep understanding on biological behaviors and potential target therapy of ACC.

Methods

We applied mass spectrometry-based quantitative proteomics to analyze the protein expression in paired tumor and adjacent normal breast tissue of five ACC and five BL-TNBC. Bioinformatic analyses and the clinicopathological characteristics, including histological features, immunohistochemistry, and FISH results, were also collected to get comprehensive information.

Results

A total of 307 differentially expressed proteins (DEPs) were identified between ACC and BL-TNBC. Clustering analysis of DEPs clearly separated ACC from BL-TNBC. GSEA found downregulation of the immune response of ACC compared with BL-TNBC, which is consistent with the negative PD-L1 expression of ACC. Vesicle-mediated transport was also inhibited, while ECM organization was enriched in ACC. The top upregulated proteins in DEPs were ITGB4, VCAN, and DPT. Moreover, in comparison with normal breast tissue, ACC showed elevated ribosome biogenesis and RNA splicing activity.

Conclusion

This study provides evidence that ACC presents a substantially different proteomic profile compared with BL-TNBC and promotes our understanding on the molecular mechanisms and biological processes of ACC, which might be useful for differential diagnosis and anticancer strategy.

Prognostic role of PD-L1 expression in patients with salivary gland carcinoma: A systematic review and meta-analysis

Background

Although programmed cell death-ligand 1 (PD-L1) has been recognized as a potential marker in several cancers, the relationship between PD-L1 expression and survival in patients with salivary gland carcinoma (SGC) has remained unclear. We aimed to evaluate the association of PD-L1 expression with clinicopathological features and prognosis in SGC patients.

Methods

The databases Ovid Medline, PubMed, Scopus, and EMBASE were searched for relevant studies that detected PD-L1 expression in SGC. The meta-analysis was performed according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA), and the reporting recommendations for tumor marker prognostic studies (REMARK) was used to assess the quality of research eligible for this meta-analysis. Included studies were assessed using the Quality in Prognosis Studies (QUIPS) tool. Odds ratios (ORs) with 95% confidence interval (CI) were calculated to estimate the correlation between PD-L1 expression and clinicopathological features. Hazard ratios (HRs) with 95% CI were applied to assess the association between PD-L1 expression and survival outcomes of patients.

Results

A total of ten studies (including 952 patients with SGC) were evaluated. The meta-analysis showed that positive PD-L1 expression in SGC was significantly associated with male patients, older age, Tumor stage, lymph node metastasis, high pathological grade, and non-adenoid cystic carcinoma subtype. The pooled data demonstrated that high PD-L1 expression was associated with poor overall survival and disease-free survival. There was no significant correlation between PD-L1 expression and progression-free survival or disease-specific survival of SGC patients.

Conclusion

According to the meta-analysis, positive PD-L1 expression may play an important role as an effective marker of poor prognosis in patients with SGC. However, large-scale, prospective investigations are still needed to confirm the findings. The assessment of PD-L1 expression may aid in the personalized management of SGC.

Development of a Novel Immune-Related Gene Signature to Predict Prognosis and Immunotherapeutic Efficiency in Gastric Cancer

Background: Gastric cancer (GC) is the fifth most common malignancy and the third leading cause of tumor-related deaths globally. Herein, we attempted to build a novel immune-related gene (IRG) signature that could predict the prognosis and immunotherapeutic efficiency for GC patients.

Methods: The mRNA transcription data and corresponding clinical data of GC were downloaded from The Cancer Genome Atlas (TCGA) database as the training group and the GSE84437 data set as the testing cohort, followed by acquisition of IRGs from the InnateDB resource and ImmPort database. Using the univariate Cox regression analysis, an IRG signature was developed. Several immunogenomic analyses were performed to illustrate the associations between the immune risk score and tumor mutational burden, immune cell infiltrations, function of immune infiltration, clinical characteristics, immune subtype, and immunotherapeutic response.

Results: The analysis of 343 GC samples and 30 normal samples from the TCGA database gave rise to 8,713 differentially expressed genes (DEGs) and 513 differentially expressed immune-related genes (DEIRGs) were extracted. The novel IRG signature contained eight DEIRGs (FABP4, PI15, RNASE2, CGB5, INHBE, RLN2, DUSP1, and CD36) and was found to serve as an independent predictive and prognostic factor for GC. Then, the GC patients were separated into the high- and low-risk groups based on the median risk score, wherein the low-risk group presented a better prognosis and was more sensitive to immunotherapy than did the high-risk group. According to the time-dependent ROC curves and AUCs, the immunotherapeutic value of the signature was better than the Tumor Immune Dysfunction and Exclusion (TIDE) and T-cell inflammatory signature (TIS) scores. In addition, the AUCs of the risk score for predicting 1-, 2-, and 3-year OS were 0.675, 0.682, and 0.710, respectively, which indicated that the signature had great predictive power.

Conclusion: This study presents a novel IRG signature based on the tumor immune microenvironment, which could improve the prediction of the prognosis and immunotherapeutic efficiency for GC patients. The powerful signature may serve as novel biomarkers and provide therapeutic targets for precision oncology in clinical practice.