Clinical Outcomes and Prognostic Factors of Adenoid Cystic Carcinoma of the Head and Neck

Nasopharyngeal Adenoid Cystic Carcinoma With Extension Into the Internal Auditory Canal: A Case Report

Adenoid cystic carcinoma (ACC) is a malignancy most commonly found in the major salivary glands. It can, however, arise from minor salivary glands throughout the upper aerodigestive tract. It is typically slow-growing and asymptomatic, though presentation varies with tumor location, pattern of infiltration, and degree of perineural invasion. ACC is characterized as an aggressive malignancy due to high rates of local recurrence and distant metastasis, with the lungs, bone, and liver commonly implicated. ACC spreading to the internal auditory canal (IAC) is highly unusual and has not been reported. We present the case of a 40 year-old male with no significant past medical history, found to have nasopharyngeal ACC that spread to the IAC resulting in multiple cranial neuropathies. The challenging location and complex path of spread along the skull base presented a significant barrier to surgery, though after completion of definitive radiation therapy, the patient experienced substantial reductions in mass effect and symptomatic relief. This report offers additional insight into the patterns of spread for ACC, emphasizing the importance of recognizing the IAC as a potential site of involvement. Early identification may significantly expedite management and prevent serious morbidities.

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.

Fluoro-2-Deoxyglucose (FDG)-Avid Adenoid Cystic Carcinoma of the Larynx: A Rare Case and Diagnostic Insight Obtained Using Positron Emission Tomography/Computed Tomography (PET/CT) Imaging

Adenoid cystic carcinoma (ACC) is a relatively uncommon tumor among head and neck cancers, with laryngeal involvement, typically subglottic, being exceptionally rare. While ACC usually originates in the salivary glands, its occurrence in the larynx is highly unusual. Laryngeal adenoid cystic carcinoma (LACC) is characterized by indolent growth, frequent perineural invasion, and a tendency for local recurrence. Moreover, distant metastasis can occur with the lungs being the most common site of metastasis. We present a case of a 28-year-old male patient with a progressively enlarging right neck mass, uncovering a rare case of infiltrative LACC invading the thyroid gland. Post thyroidectomy, the 18-fluoro-2-deoxyglucose (F-18-FDG)-positron emission tomography (PET)/computed tomography (CT) scan revealed FDG-avid right posterior subglottic residual disease with invasion into adjacent structures, including the trachea. This represents one of the few documented cases of FDG-avid LACC, contributing to the sparse literature on this rare and aggressive malignancy. This case highlights the diagnostic challenge and clinical significance of FDG-PET/CT in evaluating rare and aggressive malignancies like LACC.

The effectiveness of targeted therapy for recurrence or metastasis adenoid cystic carcinoma: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Several clinical studies have demonstrated the potential of molecular-targeted agents for the treatment of recurrent or metastatic adenoid cystic carcinoma (R/M ACC). However, there is currently no consensus regarding the efficacy of molecular-targeted agents for patients with R/M ACC. This study aimed to evaluate the therapeutic efficacy and safety of molecular-targeted agents in patients with R/M ACC and provide insights to guide clinical decision-making.

MATERIALS AND METHODS

Five databases (PubMed, Embase, Cochrane, ProQuest, and Scopus) were searched based on the search strategy and selection criteria. Primary endpoints were objective response rate (ORR) and progression-free survival (PFS). The secondary endpoints were disease control rate (DCR), overall survival (OS), metastatic sites, and adverse events (AE). Pooled estimates were calculated using a random-effects meta-analysis.

RESULTS

Finally, 28 studies, involving 849 patients, were included. The most common metastatic sites were the lungs, bones, liver, lymph nodes, and kidneys. The pooled ORR was 4.0% (95% CI, 0.7-8.8%), the pooled DCR was 80.5% (95% CI, 72.2%-87.7%). Compared with other-target drugs, multiple kinase inhibitors (MKIs) improved the ORR (pooled ORR for single-target drugs vs. MKIs: 5.9% vs. 0%). The combination of MKIs and immune checkpoint inhibitors (ICIs) had a significantly higher ORR (17.9% in the axitinib + avelumab group). The pooled median PFS and OS were 8.35 and 25.62 months, respectively. MKIs improved the median PFS compared to other-target drugs (9.43 months vs 5.06 months). In addition, the most common adverse events (AEs) were fatigue (51.6%), hypertension (44.2%), and nausea (40.0%), followed by hand-foot skin syndrome (36.8%), diarrhoea (34.4%), weight loss (34.2%), anorexia (31.8%), rash (31.7%), and headache (29.0%).

CONCLUSION

The findings of this study suggest that MKIs have a better therapeutic efficacy than single-target drugs in patients with R/M ACC. Future studies are warranted to verify the synergistic role of the combination strategy of MKIs plus ICIs, given the limited number of studies on this topic conducted and published to date.

Circulating Adenoid Cystic Carcinoma associated MYB transcripts enable rapid and sensitive detection of metastatic disease in blood liquid biopsies

Adenoid cystic carcinoma (ACC) is a rare and lethal malignancy that originates in secretory glands of the head and neck. A prominent molecular feature of ACC is the overexpression of the proto-oncogene MYB. ACC has a poor long-term survival due to its high propensity for recurrence and protracted metastasis. Currently, clinical technologies lack the efficiency to distinguish patient prognosis prior to its redevelopment. We hypothesize that metastatic ACC can be detected by monitoring tumor-specific MYB expression in patients' blood. We developed a quantitative polymerase chain reaction (qPCR) assay for MYB transcripts and screened blood samples from four patient cohorts: no history or evidence of ACC (n=23), past history of ACC and no evidence of disease (NED) for greater than three years (n=15), local ACC (n=6), and metastatic ACC (n=5). Our assay detected significantly elevated levels of MYB transcripts in the metastatic ACC cohort (p < 0.01). Receiver operating characteristic (ROC) curves comparing metastatic to NED and metastatic to local disease were significant, with p values < 0.0001 and 0.0008, respectively. Single-cell RNA sequencing (scRNA-seq) of blood from metastatic ACC identified a cluster of circulating tumor cells (CTCs) expressing MYB. Here, we report a sensitive, cost-effective, and minimally invasive diagnostic test that leverages tumor-specific signatures to screen for metastatic ACC disease, potentially enhancing detection earlier than the current clinical standard.

Targeted RNA Sequencing of Head and Neck Adenoid Cystic Carcinoma Reveals SEC16A::NOTCH1 Fusion and MET Exon 14 Skipping as Potentially Actionable Alterations

PURPOSE

Adenoid cystic carcinoma (AdCC) of the head and neck harbors MYB/MYBL1::NFIB fusions in around 60% of cases, with unfavorable long-term survival due to frequent recurrences and metastases, currently lacking effective targeted therapy. The study aims to identify actionable alterations and to elucidate the molecular underpinnings of MYB/MYBL1::NFIB-negative AdCC using a large targeted RNA sequencing panel.

METHODS AND RESULTS

We retrospectively searched our MSK-Solid Fusion clinical sequencing database for head and neck AdCC sequenced between 2016 and 2023. Of a total of 55 cases, 28 showed MYB::NFIB, 7 showed MYBL1::NFIB, and one case each harbored MYB::MPDZ (case 1) and FUS::MYB (case 2). One base of tongue tumor expressed both MYB::NFIB fusion and MET exon 14 skipping transcripts due to concurrent MET splice site mutation, D1010N (case 3). One parotid tumor lacked MYB/MYBL1 rearrangement but instead showed an in-frame SEC16A::NOTCH1 fusion that preserved the secretase cleavage site (case 4). Clinical records on 4 cases with non-canonical sequencing findings were reviewed. Distant metastases were present at the initial diagnosis (case 2) or at recurrence (cases 1, 3, and 4). Disease-related mortality occurred in cases 2 and 4 despite radiotherapy and immunotherapy.

CONCLUSIONS

The study improved the understanding of AdCC providing the first documentation of tumor clinical behavior associated with MYB::MPDZ and FUS::MYB fusions and reporting potentially actionable SEC16A::NOTCH1 fusion and MET exon 14 skipping mutation. Further research is needed to explore the therapeutic utility of MET inhibition and the efficacy of γ-secretase inhibitors against rare NOTCH1 fusions in AdCC.

Development and validation of a nomogram for predicting overall survival of head and neck adenoid cystic carcinoma

This study aimed to develop and validate a nomogram using clinical variables to guide personalized treatment strategies for adenoid cystic carcinoma of the head and neck (ACCHN). Data from 1069 patients with ACCHN diagnosed between 2004 and 2015 in the Surveillance, Epidemiology, and End Results (SEER) database were used to construct the nomogram. External validation was performed using an independent cohort of 70 patients from Fujian Cancer Hospital. Multivariate Cox regression analysis was conducted using IBM SPSS version 26.0 and R Software version 4.2.3. The concordance index (C-index) and receiver operating characteristic (ROC) curves were used to assess the predictive accuracy of the nomogram. Age, tumor site, surgery, N stage, M stage, and TNM stage were identified as independent prognostic factors through univariate and multivariate Cox analyses. The nomogram demonstrated superior predictive performance compared to the TNM staging system, effectively stratifying patients into high-risk and low-risk groups. This nomogram offers a valuable tool for predicting overall survival in patients with ACCHN and tailoring individualized treatment approaches.

Circulating Adenoid Cystic Carcinoma associated MYB transcripts enable rapid and sensitive detection of metastatic disease in blood liquid biopsies

Adenoid cystic carcinoma (ACC) is a rare and lethal malignancy that originates in secretory glands of the head and neck. A prominent molecular feature of ACC is the overexpression of the proto-oncogene MYB. ACC has a poor long-term survival due to its high propensity for recurrence and protracted metastasis. Currently, clinical technologies lack the efficiency to distinguish patient prognosis prior to its redevelopment. We hypothesize that metastatic ACC can be detected by monitoring tumor-specific MYB expression in patients' blood. We developed a quantitative polymerase chain reaction (qPCR) assay for MYB transcripts and screened blood samples from four patient cohorts: no history or evidence of ACC (n=23), past history of ACC and no evidence of disease (NED) for greater than three years (n=15), local ACC (n=6), and metastatic ACC (n=5). Our assay detected significantly elevated levels of MYB transcripts in the metastatic ACC cohort (p < 0.01). Receiver operating characteristic (ROC) curves comparing metastatic to NED and metastatic to local disease were significant, with p values < 0.0001 and 0.0008, respectively. Single-cell RNA sequencing (scRNA-seq) of blood from metastatic ACC identified a cluster of circulating tumor cells (CTCs) expressing MYB. Here, we report a sensitive, cost-effective, and minimally invasive diagnostic test that leverages tumor-specific signatures to screen for metastatic ACC disease, potentially enhancing detection earlier than the current clinical standard.

Subglottic Adenoid Cystic Carcinoma Mimicking Bronchial Asthma: A Case Report

Adenoid cystic carcinoma (ACC) is a rare type of tumor that usually originates from minor salivary glands in the oral cavity. ACC of the larynx is even rare. This case study describes a 36-year-old non-smoking male farmer who initially presented with dyspnea and was misdiagnosed with bronchial asthma. Spirometry revealed fixed airway obstruction. Further evaluation revealed a pedunculated mass obstructing the airway, which was diagnosed as ACC by histopathological examination of the biopsy specimen. The patient was treated with radiation therapy, resulting in clinical improvement after six weeks. ACC is highly invasive and slow-growing, with perineural extension and a higher risk of recurrence. Metastasis in the lungs is common. Adequate preoperative staging, including imaging with computed tomography (CT) and magnetic resonance imaging, is important for planning treatment. The role of radiation therapy with concurrent chemotherapy is still under trial.

Treatment outcomes of single-fraction stereotactic radiosurgery for adenoid cystic carcinoma: a case series of 55 patients

PURPOSE

This study aimed to analyze the treatment outcomes of single-fraction stereotactic radiosurgery (SRS) for adenoid cystic carcinoma patients.

METHODS

Retrospective analysis was conducted for 55 patients with 66 lesions. SRS intentions were categorized as definitive, adjuvant, salvage, and palliative. Tumor control was defined as local (within 50% isodose line), marginal (outside 50% isodose line), and distant (metastasis outside head/neck).

RESULTS

The median age was 60 years (range 21-85), with 53% males. Tumor origin was head/neck for 88% and trachea/lung for 12%. 61% were recurrent lesions. Median interval from diagnosis to SRS was 14 months. Preceding surgery was performed in 30%. SRS was administered as definitive (30 lesions), adjuvant (13), salvage (19), and palliative (4). SRS was used as a boost to external beam radiation therapy (EBRT) in 39%. Concurrent chemotherapy was administered in 26%. 5-, 10-, and 15-year local control rates were 60%, 33%, and 27%, respectively; local/marginal control rates were 29%, 13%, and 10%. For recurrent lesions treated with SRS without EBRT, 5-year local control rate was 14%, and local/marginal control rate was 5%. For recurrent lesions treated with SRS and EBRT, 5-year local control rate was 100%, and local/marginal control rate was 40%. The rate of distant failure after SRS was 40%. Older age and distant metastasis before SRS were negative factors for overall survival.

CONCLUSION

SRS provided a high rate of local tumor control, but marginal failure was frequent. Integrating SRS with added EBRT exhibits potential for enhancing local and local/marginal tumor control, particularly in recurrent cases.

Prognostic Significance of Primary Tumor Surgery in Adenoid Cystic Carcinoma Patients With Distant Metastases at Diagnosis: A Population-Based Database Analysis in Head and Neck Region

Purpose: Adenoid cystic carcinoma (ACC) is an aggressive cancer that often leads to poor prognosis, especially when it has metastasized. The prognostic significance of primary tumor surgery (PTS) for ACC with distant metastasis (DM) at the time of diagnosis has not been extensively studied. Methods: Using data from the surveillance, epidemiology, and end results (SEER) database from 2010 to 2019, we identified patients with ACC in head and neck region and synchronous DM. We evaluated the effect of PTS on different patterns of metastasis using Kaplan-Meier analysis, log-rank tests, and multivariate Cox regression analysis to assess the therapeutic benefit of PTS in the overall cohort and various subgroups. Results: Of the 192 identified patients with synchronous metastatic ACC of head and neck, 91 (47.4%) underwent PTS. Patients who received PTS had significantly better survival than nonsurgical patients (median overall survival: 19 vs 43 months, P = .006). Cox regression analysis also showed that PTS was associated with improved survival (HR = .46, 95% CI: 0.42-0.88; P = .028). In sub-analyses, except for patients with liver metastases [overall survival (OS), P = .107, cancer-specific survival (CSS), P = .153], PTS consistently conferred significant survival benefits in patients with bone metastases (OS, P = .041, CSS, P = .065) and lung metastases (OS, P = .016, CSS, P = .027). PTS also led to better survival in patients who did not receive radiotherapy (median OS: 13 vs 52 months, P = .007). Conclusion: Our study suggests that PTS in metastatic ACC patients of head and neck improved overall and CSS, particularly in those with bone or lung metastases and those who did not receive radiotherapy. However, further prospective studies are needed to confirm these findings, and the indications for PTS in metastatic ACC should be carefully evaluated by a multidisciplinary board.

Nectin-4 is frequently expressed in primary salivary gland cancer and corresponding lymph node metastases and represents an important treatment-related biomarker

Many locally advanced and metastatic salivary gland carcinomas (SGC) lack therapeutic targets. Enfortumab vedotin, an antibody-drug conjugate binding to Nectin-4, recently gained FDA approval for third-line urothelial carcinoma. Therefore, the aim of this study was to assess the expression of Nectin-4 in primary SGC and corresponding lymph node metastases and to correlate it with clinicopathological data. Immunohistochemical staining for Nectin-4 was performed for patients who had undergone surgery with curative intent for primary SGC of the parotid or submandibular gland in a tertiary referral center between 1990 and 2019. One hundred twenty-two primary SGC and twenty corresponding lymph node metastases were included. Nectin-4 was expressed in 80.3% of primary SGC with a mean Histo(H-)score of 61.2 and in 90.0% of lymph node metastases with a mean H-score of 75.6. A moderate or high Nectin-4 expression was found in 25.9% of salivary duct carcinomas (SaDu) and in 30.7% of adenoid cystic carcinomas (ACC). SaDu patients with a lower T-stage (p = 0.04), no loco-regional lymph node metastases (p = 0.049), no vascular invasion (p = 0.04), and no perineural spread (p = 0.03) showed a significantly higher mean Nectin-4 H-score. There was a statistical tendency towards a more favorable disease-free survival among SaDu patients with a higher Nectin-4 expression (p = 0.09). Nectin-4 is expressed in SGC and therefore represents a potential therapeutic target, especially in entities with a high rate of local recurrence and metastatic spread such as SaDu and ACC.

PSMA-targeted therapy for non-prostate cancers

Radioligand therapy (RLT) agents are demonstrating a crucial role in the clinical approach to aggressive malignancies such as metastatic castrate-resistant prostate cancer (m-CRPC). With the recent FDA approval of prostate-specific membrane antigen (PSMA)-targeted RLT for m-CRPC, the field has broadened its gaze to explore other cancers that express PSMA in the tumor parenchyma or tumor neovasculature. In this review article, we discuss current progress in the clinical use of PSMA RLTs in non-prostate cancers such salivary gland cancers, renal cell carcinoma, high grade glioma, and soft tissue sarcoma. We highlight early reports in small case series and clinical trials indicating promise for PSMA-targeted RLT and highlighting the importance of identifying patient cohorts who may most benefit from these interventions. Further study is indicated in non-prostate cancers investigating PSMA RLT dosimetry, PSMA PET/CT imaging as a biomarker, and assessing PSMA RLT safety and efficacy in these cancers.

A molecular guide to systemic therapy in salivary gland carcinoma

Salivary gland carcinomas (SGC) are a rare and variable group of head and neck cancers with historically poor response to cytotoxic chemotherapy and immunotherapy in the recurrent, advanced, and metastatic settings. In the last decade, a number of targetable molecular alterations have been identified in SGCs including HER2 upregulation, androgen receptor overexpression, Notch receptor activation, NTRK gene fusions, and RET alterations which have dramatically improved treatment outcomes in this disease. Here, we review the landscape of precision therapy in SGC including current options for systemic management, ongoing clinical trials, and promising future directions.

Fulminant Adenoid Cystic Carcinoma of the Maxillary Sinus - A Rare Finding: Case Report

BACKGROUND

The most common malignant tumor of the small salivary glands in the head and neck region is adenoid cystic carcinoma (ACK). The most common localization of ACK is the hard palate. ACK does not show any sex predisposition and is mainly diagnosed in middle-aged patients.

CASE REPORT

The present case report describes a fulminant ACK in the rare localization of maxillary sinus in a 36-year old male. The subsequent surgical treatment consisted of a radical hemimaxillectomy using an extraoral approach according to Weber-Fergusson-Dieffenbach and ipsilateral neck dissection. A magnetic epithesis was used for initial defect coverage of the maxillary bone accompanied by an obturator prosthesis. The surgical treatment was then followed by adjuvant proton therapy.

CONCLUSION

This case report shows how individual patient care can be provided according to the latest therapy standards of ACK in the rare localization of the maxillary sinus.

Transcriptomic insights into adenoid cystic carcinoma via RNA sequencing

Background: The aim of this study was to investigate the underlying mechanisms of adenoid cystic carcinoma (ACC) at the transcriptome level. Materials and methods: We obtained paired tumor and normal salivary gland tissues from 15 ACC patients, which were prepared for RNA sequencing. Results: Gene enrichment analysis revealed that the upregulated pathways were mainly involved in axonogenesis, and the downregulated pathways were mainly related to leukocyte migration, the adaptive immune response, lymphocyte-mediated immunity, and the humoral immune response. T-cells, B-cells and NK cells showed low infiltration in ACC tissues. In addition to the gene fusions MYB-NFIB and MYBL1-NFIB, a new gene fusion, TVP23C-CDRT4, was also detected in 3 ACC tissues. PRAME was significantly upregulated in ACC tissues, while antigen-presenting human leukocyte antigen (HLA) genes were downregulated. Conclusion: We found a new gene fusion, TVP23C-CDRT4, that was highly expressed in ACC. PRAME may be an attractive target for ACC immunotherapy.

Role of postoperative radiotherapy in resected adenoid cystic carcinoma of the head and neck

PURPOSE

Although postoperative radiotherapy (PORT) is demonstrably effective in local control of head and neck adenoid cystic carcinoma (HNACC), its application is controversial and the subset of patients who would benefit most from PORT is unknown. Herein, we analyzed the data of HNACC patients to clarify the role of PORT.

METHODS

We retrospectively reviewed 187 patients with nonmetastatic HNACC who underwent surgical resection between 2005 and 2019. The study endpoints were locoregional failure-free survival (LRFFS), progression-free survival (PFS), and overall survival (OS). Subgroup analysis and recursive partitioning analysis (RPA) were performed to identify patients most likely to benefit from PORT.

RESULTS

With a median follow-up of 84.7 months, the 5-year LRFFS, PFS, and OS were 70.0%, 52.6%, and 86.4%, respectively. Survival was significantly shorter in patients who experienced local failure than in those who did not (5-year OS: 88.1% vs. 80.5%, P = 0.001). The local failure rate was significantly lower in patients who underwent PORT (16.9% vs. 31.0%, P = 0.021), despite the high frequency of adverse factors. Especially, significant decreases in local failure and similar OS rates could be obtained after PORT among patients with positive margins, T2-4 stage disease, and minor salivary gland tumors. The RPA model for PFS categorized patients into four groups according to three prognostic factors (T-stage, location, and sex). The RPA model for LRFFS and OS suggested three groups based on two factors (T-stage, margin for LRFFS; T-stage, grade 3 for OS).

CONCLUSION

PORT could prevent dismal survival, while significantly reducing local failures in high-risk HNACC patients.

Approaches to the Management of Metastatic Adenoid Cystic Carcinoma

High rates of recurrence and distant metastasis are a foremost challenge in the management of adenoid cystic carcinoma (ACC), occurring in approximately 40% of all ACC patients. Despite the morbidity and mortality resulting from recurrent/metastatic (R/M) disease, there are no FDA-approved systemic agents for these patients. In this review, we summarize pertinent ACC pathophysiology and its implications for different systemic treatment regimens in R/M ACC. We review the evidence for the most widely used systemic agents - cytotoxic chemotherapy and tyrosine kinase inhibitors (TKIs) targeting VEGFR - in addition to immune checkpoint inhibitors and non-TKI biologic agents. Exciting emerging targets for R/M ACC, including inhibitors of Notch signaling, stemness, PRMT5, and Axl, are also discussed. Lastly, we review local therapies for small-volume lung disease in patients with oligometastatic ACC, specifically pulmonary metastasectomy and stereotactic body radiation therapy (SBRT). Future development of targeted molecular agents which exploit the underlying biology of this disease may yield novel therapeutic options to improve clinical outcomes in patients with R/M ACC.

Rare Case of Primary Adenoid Cystic Carcinoma of the Lung With Bilateral Kidney and Liver Metastasis

Adenoid cystic carcinoma (ACC) is a rare epithelial tumor that is found in the salivary glands. It is typically slow-growing and follows an indolent course. While it can hematogenously spread to the lungs, distant metastases are rarely reported. Primary ACC in the lung is not common and makes up only 0.04-0.2% of all primary lung tumors. In addition, metastasis of the ACC to liver and bilateral kidneys is not common frequently documented. In this case report, we present a patient with unusual metastases of ACC, as well as non-specific symptoms that warrant discussion for ACC as potential differentials in the appropriate clinical setting.

Metastatic Adenoid Cystic Carcinoma: Genomic Landscape and Emerging Treatments

OPINION STATEMENT

Adenoid cystic carcinoma (ACC) is a heterogeneous cancer that commonly develops in the salivary glands. Approximately 40 to 50% of patients with ACC develop recurrence and/or metastasis. Although most patients with ACC have slow-growing disease, a subset experiences aggressive disease with early visceral and/or bone metastasis. Thus far, there is no consensus on the best time to start palliative treatment in patients with indolent disease. The only systemic therapies available for recurrent or metastatic ACC are cytotoxic agents and multikinase inhibitors targeting vascular endothelial growth factor receptor, and both types of therapy have modest activity. Studies integrating proteomics, genomics, and clinical data have revealed distinct molecular ACC subtypes, ACC-I and ACC-II, with ACC-I generally associated with more aggressive disease biology. ACC-I tumors were enriched for NOTCH1-activating mutation and upregulation of MYC and MYC targets, while ACC-II tumors exhibited upregulation of TP63 and receptor tyrosine kinases. These findings highlight the importance of patient selection for surveillance and targeted therapy development in ACC. In recent clinical trials of targeted therapy in ACC, patients are being selected according to tumor molecular profile (e.g., presence of NOTCH-activating mutations), which represents a major advance in the field. Ongoing collaborative research focusing on the development of novel therapeutic strategies for ACC patients based on disease biology will increase the drug armamentarium and improve survival outcomes for these patients in dire need.

Therapeutic bronchoscopy followed by sequential radiochemotherapy in the management of life-threatening tracheal adenoid cystic carcinoma: a case report

Background

Adenoid cystic carcinoma of the lung is a distinctive salivary-gland-type malignant epithelial neoplasm that rarely presents as a primary tumor of the respiratory tract. Complete surgical resection remains the treatment of choice for adenoid cystic carcinoma. We present a case of large ACC tumors that caused severe central airway obstruction and were effectively treated with therapeutic bronchoscopy followed by radiotherapy and chemotherapy.

Case presentation

A 31-year-old Malay Indonesian female patient who was a nonsmoker and had no family history of cancer was admitted to the emergency ward because of worsening breathlessness accompanied by stridor since 1 week prior. Chest computed tomography revealed segmental atelectasis of the left lung; a mass on the left main bronchus, with infiltrates in segments 1, 2, and 3 of the left lung; and consolidation in the left inferior lobe, with narrowing of the main left bronchus. Lobulated masses obstructing almost the entire distal trachea up to the carina and the entire left main bronchus were found on bronchoscopy. Owing to the large tumors causing severe central airway obstruction, the medical team decided to perform central airway mass removal through rigid bronchoscopy. A neodymium-doped yttrium-aluminum-garnet laser was used first to facilitate mass shrinkage. After the laser treatment, mechanical mass removal using a rigid scope was performed. The tracheal and carinal lumens were opened to > 50% of their diameter, with the left main bronchus lumen opened only slightly. After the treatment, the patient was stable, and no stridor was found. Adjuvant intensity-modulated radiotherapy and chemotherapy were performed after the therapeutic bronchoscopy. At the end of the entire treatment, reevaluation by thoracic computed tomography scan and bronchoscopy revealed no remaining mass.

Conclusions

In cases of nonresectable large adenoid cystic carcinoma tumors with life-threatening central airway obstruction, therapeutic bronchoscopy followed by sequential radiochemotherapy might achieve a complete response outcome.

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.

Graphene-containing metal-organic framework nanocomposites for enhanced microwave ablation of salivary adenoid cystic carcinoma

Salivary adenoid cystic carcinoma (SACC), one of the most common malignant tumors in the head and neck region, is characterized by high postoperative recurrence rate and poor prognosis. Microwave (MW) ablation possesses advantages in preserving SACC patients' facial aesthetics and oral function, but unfortunately, it suffers from low therapeutic efficacy due to the limited MW-thermal efficiency. Moreover, the insufficient thermal ablation may aggravate hypoxic state in tumors, which is deleterious to the treatment of residual tumors and aggressive tumors. Hence, MW ablation has been rarely applied in treating head and neck tumors in recent years. To minimize the unfavorable outcomes and maximize the therapeutic effects of MW ablation, a MW sensitizer coupled with a self-sufficient oxygen nanoagent was employed for the first time in MW ablation to treat head and neck tumors. We prepared a graphene-containing metal-organic framework (ZIF67@Gr-PEG), which exhibited excellent MW thermal conversion ability endowed by the incorporated Gr and showed in situ oxygen generation capacity derived from the ZIF67 matrix. In an animal experiment, ZIF67@Gr-PEG-based MW ablation with a temperature up to 66.1 °C exhibited a high tumor ablation rate. More importantly, insufficient MW ablation-induced high expressions of HIF-1α and VEGF were observed in our experiment, whereas the levels of tumor hypoxia and angiogenesis were efficiently decreased in MW ablation with the assistance of ZIF67@Gr-PEG nanocomposites (NCs). Notably, our strategy for MW ablation not only evidences the great potential of ZIF67@Gr-PEG but also promotes the translation of thermotherapeutic graphene from basic research to clinical practice.

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.

A Contemporary Review of Molecular Therapeutic Targets for Adenoid Cystic Carcinoma

Simple Summary

Adenoid cystic carcinoma (ACC) is a salivary malignancy known for slow growth, a propensity for perineural spread, local recurrence following resection, and indolent distant metastases. Current treatments in recurrent/metastatic (R/M) ACC are generally of limited impact and often palliative in nature. Herein, we review the preclinical and clinical literature on molecular alterations in ACC with the potential for targeted therapeutics. We further review other molecular targets of ongoing investigation and active clinical trials for patients with ACC, offering a contemporary summary and insight into future therapeutic strategies.

Abstract

ACC is a rare malignant tumor of the salivary glands. In this contemporary review, we explore advances in identification of targetable alterations and clinical trials testing these druggable targets. A search of relevant articles and abstracts from national meetings and three databases, including PubMed, Medline, and Web of Science, was performed. Following keyword search analysis and double peer review of abstracts to ensure appropriate fit, a total of 55 manuscripts were included in this review detailing advances in molecular targets for ACC. The most researched pathway associated with ACC is the MYB–NFIB translocation, found to lead to dysregulation of critical cellular pathways and thought to be a fundamental driver in a subset of ACC disease pathogenesis. Other notable molecular targets that have been studied include the cKIT receptor, the EGFR pathway, and NOTCH1, all with limited efficacy in clinical trials. The ongoing investigation of molecular abnormalities underpinning ACC that may be responsible for carcinogenesis is critical to identifying and developing novel targeted therapies.

Laryngeal adenoid cystic carcinoma: a rare case report

Laryngeal adenoid cystic carcinomas (LACC) are extremely rare and only account for less than 1% of all malignant laryngeal tumors. This tumor commonly occurs in the subglottic region of larynx, so dyspnea and hoarseness are its most common presenting symptoms. Adenoid cystic carcinoma is characterized by slow progression, late recurrence, and late distant metastasis. Total or partial laryngectomy is its treatment. Although it does not respond to radiotherapy completely, adjuvant radiotherapy or chemotherapy may be considered. In this study, we report a 41 year-old man, who had a rare recurrence of LACC, and we evaluate his clinical and pathologic characteristics.

First experiences with 177Lu-PSMA-617 therapy for recurrent or metastatic salivary gland cancer

Background

Advanced salivary gland cancers become difficult to treat when they are technically irresectable and radiotherapy limits are exceeded. There is also an unmet need to improve palliative systemic therapy. Salivary glands depict the Prostate-Specific Membrane Antigen (PSMA) on ⁶⁸Ga-PSMA-PET/CT, a transmembrane protein that is targeted for diagnosis and treatment of advanced prostate cancer. Some salivary gland carcinomas also express PSMA.

Methods

This study aimed to retrospectively evaluate the effectiveness of ¹⁷⁷Lu-PSMA-617 therapy for recurrent or metastatic salivary gland cancers, as a last resort treatment. Patients with serious tumour-related discomfort for whom no regular option was available were selected and critically re-assessed by the tumour board. Radionuclide therapy eligibility was confirmed when tumour targeting was greater than liver SUVmax on ⁶⁸Ga-PSMA-PET/CT. The protocol aimed at four cycles of 6.0–7.4 GBq ¹⁷⁷Lu-PSMA-617 every 6–8 weeks. Clinical response was evaluated by questionnaires and radiological response by ⁶⁸Ga-PSMA-PET/CT.

Results

Six patients were treated with ¹⁷⁷Lu-PSMA: four adenoid cystic carcinomas, one adenocarcinoma NOS and one acinic cell carcinoma. In two patients, radiological response was observed, showing either stable disease or a partial response, and four patients reported immediate relief of tumour-related symptoms. Most reported side effects were grade 1–2 fatigue, nausea, bone pain and xerostomia. Four patients prematurely discontinued therapy: three due to disease progression and one due to demotivating (grade 1) side-effects.

Conclusions

Palliative ¹⁷⁷Lu-PSMA therapy for salivary gland cancer may lead to rapid relief of tumour-associated discomfort and may even induce disease stabilization. It is safe, relatively well tolerated and can be considered when regular treatment options fail.

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

Objective

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

Methods

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

Results

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

Conclusion

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

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

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

Prognostic Factors and Survival in Adenoid Cystic Carcinoma of the Head and Neck: A Retrospective Clinical and Histopathological Analysis of Patients Seen at a Cancer Center

Adenoid cystic carcinoma (AdCC) is a rare malignancy that accounts for approximately 1% of all head and neck cancers. This neoplasm is characterized by slow but often relentless growth and dissemination. Our aim was to retrospectively evaluate the clinical-pathological features of patients diagnosed with head and neck AdCC and to identify possible prognostic factors. This retrospective observational study analyzed 87 cases of AdCC of the head and neck. Clinical parameters (tumor size, lymph node and distant metastasis, clinical stage, and survival) were obtained from the records. Survival curves were constructed using the Kaplan-Meier method. A p value ≤ 0.05 was considered significant. There was a slight predominance of cases diagnosed in female patients (54%). The mean age at diagnosis was 51.5 years. Analysis using Cox's proportional hazards model considering 10-year disease-specific survival identified histologic pattern and presence of perineural invasion as independent prognostic variables. Primary tumor size and distant metastasis were prognostic predictors of 5- and 10-year disease-free survival. Detailed analysis of the association between clinical-pathological parameters and prognosis can assist professionals with cancer treatment planning and adequate patient management. Considering the long-term aggressive behavior of AdCC, rigorous patient follow-up is important to identify possible locoregional or distant recurrences.

Tumor with slow-developing and recurring lumps of the external ear with skull base and lung metastasis: A case report

The present case report describes a rare case of recurring lumps on the external ear in a 46-year-old Chinese male with a history of >10 years, who presented with large irregular red lumps on the right temple and with lung and skull base metastasis. The patient had a lesion in the right auricle and experienced recurrence following surgical resection. A thorough systemic evaluation revealed no other obvious abnormalities. The patient was diagnosed with adenoid cystic carcinoma (ACC), a slow-growing form of high-grade adenocarcinoma, and refused any further treatment at the present hospital (The First Affiliated Hospital of Army Medical University). At 2 years post-follow-up, the patient had become more frail but was in good spirits. The present study indicated that ACC is a low-grade and commonly slow-developing malignancy that primarily arises from a salivary gland, with recurring and metastatic characteristics.

Prostate-specific membrane antigen (PSMA) expression in adenoid cystic carcinoma of the head and neck

BACKGROUND

Treatment options for advanced head and neck adenoid cystic carcinoma (AdCC) are limited. Prostate-Specific Membrane Antigen (PSMA), a transmembrane protein that is known for its use in diagnostics and targeted therapy in prostate cancer, is also expressed by AdCC. This study aimed to analyse PSMA expression in a large cohort of primary, recurrent and metastasized AdCC of the head and neck.

METHODS

One hundred ten consecutive patients with histologically confirmed AdCC in the period 1990-2017 were included. An analysis was made of clinical details, revised pathology and semiquantitative immunohistochemical expression of PSMA on tissue microarray and whole slides. Associations of PSMA expression with clinicopathological parameters were explored and survival was analysed by multivariate Cox-proportional Hazard analysis.

RESULTS

PSMA expression was present in 94% of the 110 primary tumours, with a median of 31% positive cells (IQR 15-60%). Primary tumours (n = 18) that recurred (n = 15) and/or had metastases (n = 10) demonstrated 40, 60 and 23% expression respectively. Expression was not independently related to increased pathological stage, tumour grade, and the occurrence of locoregional recurrence or metastasis. After dichotomization, only primary tumour PSMA expression ≤10% appeared to be associated with reduced 10-years recurrence-free survival (HR 3.0, 95% CI 1.1-8.5, p = .04).

CONCLUSIONS

PSMA is highly expressed in primary, recurrent and metastatic AdCC of the salivary and seromucous glands. PSMA expression has no value in predicting clinical behaviour of AdCC although low expression may indicate a reduced recurrence-free survival. This study provides supporting results to consider using PSMA as target for imaging and therapy when other diagnostic and palliative treatment options fail.

Expression of inhibitors of apoptosis proteins in salivary gland adenoid cystic carcinoma: XIAP is an independent marker of impaired cause-specific survival

Objectives

Inhibitors of apoptosis proteins are crucial to carcinogenesis since their expression results in evasion of apoptosis. Overexpression of inhibitors of apoptosis has repeatedly been associated with resistance to treatment and poor prognosis in various cancers. The role of inhibitors of apoptosis in adenoid cystic carcinoma of the salivary gland is still unclear. The aim of this study was to investigate the expression of inhibitors of apoptosis and their potential prognostic value in adenoid cystic carcinoma.

Design, setting and participants

Forty‐nine patients, diagnosed with adenoid cystic carcinoma of the salivary gland between 1996 and 2016, were retrospectively included in this study. The expression of cIAP1, cIAP2, XIAP, Birc6, Livin and Survivin was assessed using immunohistochemistry, and their association of survival and prognosis was evaluated during a median follow‐up of 6.4 years.

Main outcome measure

Cause‐specific survival and recurrence‐free survival rates.

Results

XIAP, cIAP2, Livin and nuclear Survivin showed high expression levels in adenoid cystic carcinoma in most patients. There was no significant association of cIAP1, cIAP2, Livin, Birc6 and Survivin with outcome. However, high XIAP expression was associated with worse cause‐specific survival and worse response to radiotherapy and proved to be an independent marker in multivariable analysis.

Conclusion

Our data indicate that high expression of XIAP may be used as a prognosticator for poor survival and poor response to radiotherapy in adenoid cystic carcinoma patients.

Primary Adenoid Cystic Carcinoma of the Upper Anterior Mediastinum Mimicking a Thyroid Tumor: A Case Report and Review of Literature

Primary adenoid cystic carcinoma (ACC) of the upper anterior mediastinum mimicking a thyroid tumor has rarely been seen in clinical practice and lacks a standard of care therapy. Here, we report a 47-year old female patient with an ACC originated from the upper anterior mediastinum presenting as a thyroid gland tumor. The patient received gross surgical resection of the tumor and underwent post-surgical chemotherapy and radiotherapy. The patient was free from local recurrence 3-years following initial treatment, but developed multiple lung metastases. She remains under clinical observation without discomfort and is still followed as an outpatient. Here, we also summarized recent reports of similar cases with hope to provide some experience for future clinical practice.

Laryngeal adenoid cystic carcinoma: Three cases reports

INTRODUCTION

Laryngeal adenoid cystic carcinoma (LACC) is an extremely rare malignant neoplasm. The etiology of LACC remains unknown, and it is characterized by multiple recurrences, slow progression, and late distant metastasis. This study aimed to provide more information regarding the characteristics, diagnosis, and treatment of LACC by analyzing 3 clinical cases and reviewing the literature on this topic.

PATIENT CONCERNS

Here, we present all 3 cases of LACC within the period between 2010 and 2019. Dyspnea was the most commonly observed symptom in these patients, followed by hoarseness, pharyngeal paresthesia, and difficulty swallowing.

DIAGNOSIS

All patients were pathologically confirmed as LACC.

INTERVENTIONS

All the patients underwent a combined therapy of surgical resection plus external irradiation.

OUTCOMES

The follow-up time was between 2 and 6 years; no local recurrence occurred in any of the 3 patients. Lung metastasis was found in 1 patient 6 years after surgery.

CONCLUSION

LACC is usually a slowly progressing cancer; the main treatment methods are surgery and radiotherapy, and the adequate radiotherapy dose should usually be greater than 60 Gy. The 5-year disease-specific survival rate is high; however, distant metastasis may still occur in patients with LACC even beyond 5 years after treatment. Therefore, patients with LACC require long-term surveillance.

Clinically Integrated Molecular Diagnostics in Adenoid Cystic Carcinoma

Adenoid cystic carcinoma is a rare but aggressive type of salivary gland malignancy. This article addresses the need for more effective, biomarker‐informed therapies in rare cancers, focusing on clinical utility and financial sustainability of integrated next‐generation sequencing in routine practice.

Background.

Adenoid cystic carcinoma (ACC) is an aggressive salivary gland malignancy without effective systemic therapies. Delineation of molecular profiles in ACC has led to an increased number of biomarker‐stratified clinical trials; however, the clinical utility and U.S.‐centric financial sustainability of integrated next‐generation sequencing (NGS) in routine practice has, to our knowledge, not been assessed.

Materials and Methods.

In our practice, NGS genotyping was implemented at the discretion of the primary clinician. We combined NGS‐based mutation and fusion detection, with MYB break‐apart fluorescent in situ hybridization (FISH) and MYB immunohistochemistry. Utility was defined as the fraction of patients with tumors harboring alterations that are potentially amenable to targeted therapies. Financial sustainability was assessed using the fraction of global reimbursement.

Results.

Among 181 consecutive ACC cases (2011–2018), prospective genotyping was performed in 11% (n = 20/181; n = 8 nonresectable). Testing identified 5/20 (25%) NOTCH1 aberrations, 6/20 (30%) MYB‐NFIB fusions (all confirmed by FISH), and 2/20 (10%) MYBL1‐NFIB fusions. Overall, these three alterations (MYB/MYBL1/NOTCH1) made up 65% of patients, and this subset had a more aggressive course with significantly shorter progression‐free survival. In 75% (n = 6/8) of nonresectable patients, we detected potentially actionable alterations. Financial analysis of the global charges, including NGS codes, indicated 63% reimbursement, which is in line with national (U.S.‐based) and international levels of reimbursement.

Conclusion.

Prospective routine clinical genotyping in ACC can identify clinically relevant subsets of patients and is approaching financial sustainability. Demonstrating clinical utility and financial sustainability in an orphan disease (ACC) requires a multiyear and multidimensional program.

Implications for Practice.

Delineation of molecular profiles in adenoid cystic carcinoma (ACC) has been accomplished in the research setting; however, the ability to identify relevant patient subsets in clinical practice has not been assessed. This work presents an approach to perform integrated molecular genotyping of patients with ACC with nonresectable, recurrent, or systemic disease. It was determined that 75% of nonresectable patients harbor potentially actionable alterations and that 63% of charges are reimbursed. This report outlines that orphan diseases such as ACC require a multiyear, multidimensional program to demonstrate utility in clinical practice.

Distinctive clinicopathological features and disease‑specific survival of adenoid cystic carcinoma and adenoid basal carcinoma in the lower female genital tract

Adenoid cystic carcinomas (ACCs) and adenoid basal carcinomas (ABCs) in the lower female genital tract are very rare. Data on the clinicopathologic features and survival outcomes of ACCs and ABCs in the lower female genital tract are limited to case reports and small case series studies. The present study systemically analyzed 233 cases, including 84 cervical ACCs, 78 cervical ABCs and 71 vulvar ACCs, to identify clinicopathologic features and survival factors in a population‑based Surveillance, Epidemiology and End Results (SEER) study. Whereas cervical ACCs and ABCs tend to occur in the elderly (median, 72 and 69 years, respectively), vulvar ACCs commonly occurred in patients a decade younger (median, 59 years). The majority of patients with cervical ABC had localized disease and almost all received surgery. In contrast, cervical and vulvar ACC patients tended to have higher stage disease, and a significant proportion of these patients received radiotherapy, with or without surgery. The 5‑year cause‑specific survival (CSS) rates for patients with cervical ACC were 69.3%, vulvar ACC 87.7% and cervical ABC 96.6%. The 5‑year overall survival (OS) rate for patients with cervical ACC was 59.2%, significantly worse than that of cervical ABC (88.3%; P=0.002) and vulvar ACC (81.2%; P=0.01). Increased age and high stage were significantly associated with a worse prognosis in patients with cervical and vulvar ACCs by univariate and multivariate analysis (P<0.05). Tumor stage was the only significant factor associated with 5‑year overall survival in patients with cervical ABC (P<0.05). The present data demonstrated that the distinctive clinicopathologic features and survival outcomes differed significantly among ACCs and ABCs in the lower female genital tract, thus providing a rationale for location/pathologic type‑based treatment modalities.

Cervical lymph node metastases in salivary gland adenoid cystic carcinoma: a systematic review and meta-analysis

Background

The purpose of this research was to determine whether neck dissection is necessary for the adenoid cystic carcinoma (ACC) of head and neck.

Materials and methods

This article screened the abstract and full-text papers that investigated salivary gland primary ACC of head and neck. Two independent reviewers searched for articles published before October 2017 in three databases (Web of Science, PubMed, and Ovid), having no limits in date and language. Statistical data were analyzed statistically by Review Manager 5.3.

Results

In total, 18 studies involving 2993 patients were included in the analysis. Of the 2993 patients, 473 patients had cervical lymph node metastasis, with a merge frequency of 16% (95% CI: 13-19). Among included articles, only 4 involved cervical lymph node occult metastases, with a merge frequency of 14% (95% CI: 9-20). There were 5 articles containing minor salivary glands (MiSGs) involving 370 patients of which 92 patients had cervical lymph node metastases and the merge frequency was 25% (95% CI: 11-38). Moreover, there were 4 studies on major salivary glands involving 904 patients of which 158 patients had cervical lymph node metastases and the merge frequency was 17% (95% CI: 15-20).

Conclusion

Elective neck dissection is unnecessary for all patients with salivary gland ACC of head and neck. Moreover, compared with major salivary glands, MiSGs have a higher cervical lymph node metastases rate in ACC. The overall cervical lymph node metastases rate of MiSGs is 25%, which is enough to attract our attention. Therefore, we suggest that neck dissection might be applied to ACC of MiSGs.