Incidence of cervical lymph node metastasis and its association with outcomes in patients with adenoid cystic carcinoma. An international collaborative study

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.

Outcomes of patients in nasopharyngeal adenoid cystic carcinoma in the IMRT era: a single-center experience

OBJECTIVE

Nasopharyngeal adenoid cystic carcinoma (NACC) is a rare malignancy with special biological features. Controversies exist regarding the treatment approach and prognostic factors in the IMRT era. This study aimed to evaluate the long-term outcomes and management approaches in NACC.

METHODS

Fifty patients with NACC at our institution between 2010 and 2020 were reviewed. Sixteen patients received primary radiotherapy (RT), and 34 patients underwent primary surgery.

RESULTS

Between January 2010 and October 2020, a total of 50 patients with pathologically proven NACC were included in our analysis. The median follow-up time was 58.5 months (range: 6.0-151.0 months). The 5-year overall survival rate (OS) and progression-free survival rate (PFS) were 83.9% and 67.5%, respectively. The 5-year OS rates of patients whose primary treatment was surgery and RT were 90.0% and 67.3%, respectively (log-rank P = 0.028). The 5-year PFS rates of patients whose primary treatment was surgery or RT were 80.8% and 40.7%, respectively (log-rank P = 0.024). Multivariate analyses showed that nerve invasion and the pattern of primary treatment were independent factors associated with PFS.

CONCLUSIONS

Due to the relative insensitivity to radiation, primary surgery seemed to provide a better chance of disease control and improved survival in NACC. Meanwhile, postoperative radiotherapy should be performed for advanced stage or residual tumours. Cranial nerve invasion and treatment pattern might be important factors affecting the prognosis of patients with NACC.

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.

Occult Nodal Metastases in Individuals with Clinically Node-Negative Salivary Gland Malignancies

OBJECTIVES

Salivary gland malignancies comprise a heterogeneous group of pathologies, for which treatment of the clinically negative neck may vary depending on numerous factors. Herein we present data on occult nodal metastases (ONM) as well as survival and recurrence from a large series of cN0 salivary gland malignancies.

METHODS

Retrospective chart review was conducted on 532 patients, with 389 patients with major salivary gland cancers and 143 patients with minor salivary gland cancers. Demographic and treatment data were included and rates of ONM, overall survival, local recurrence, regional recurrence, and distant recurrence were analyzed.

RESULTS

We found that the overall rate of ONM for parotid was 27% (63/235), for submandibular/sublingual was 35% (18/52), and for minor was 15% (4/26). Analysis of ONM rate at each nodal level was also performed, finding higher rates of level IV and V ONM than prior studies. Submandibular/sublingual and minor salivary gland malignancies showed a predominance of ONMs at levels I-III. Our survival and recurrence rates were similar to those found in previous studies.

CONCLUSION

Our data also demonstrate a predominance of ONM in levels I-III for submandibular/sublingual and minor salivary gland cancers, suggesting elective dissection in these levels.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:1705-1715, 2024.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Omission of radiotherapy to lymph node level III in patients with cN0 adenoid cystic carcinoma of the major salivary gland: a single center experience

PURPOSE

Due to the rarity of adenoid cystic carcinoma (ACC) of the major salivary gland, there is no consensus on the extent of prophylactic neck irradiation (PNI) for patients with clinically negative lymph nodes (cN0) disease.

MATERIALS AND METHODS

We conducted a retrospective analysis of all patients with ACC of the major salivary gland who received treatment at our center between January 2010 and April 2020. The primary endpoint was regional failure-free survival (RRFS). Secondary endpoints included overall survival (OS), distant metastasis-free survival (DMFS), local recurrence-free survival (LRFS), and acute toxicity.

RESULTS

A total of 139 patients were included in the analysis. For cN0 patients, the 5-year RRFS, OS, DMFS, and LRFS were 93.2%, 90.2%, 75.7%, and 91.4%, respectively. Multivariate analysis revealed that PORT was an independent prognostic factor for RRFS and LRFS. No statistically significant differences were observed between the Level III sparing PNI group and the Standard PNI group in terms of RRFS, OS, DMFS, and LRFS. The doses delivered to the larynx and thyroid in the Level III sparing PNI group were significantly lower than those in the Standard PNI group.

CONCLUSION

In patients with cN0 ACC of the major salivary gland, PNI improves regional control, and the level III nodal region sparing radiotherapy does not increase the risk of level III recurrence, while potentially reducing toxicity.

Surgical Treatment of Carcinomas of the Oral Minor Salivary Glands-Oncological Outcome in Dependence of Tumor Entity and Therapeutic Strategies

The aim of this study was to analyze the clinical outcomes of three types of minor salivary gland carcinomas (adenoid-cystic carcinomas (ACC), adeno carcinomas not otherwise specified (AC-NOS), and mucoepidermoid carcinomas (MEC)) after primary surgical therapy. A retrospective cohort study was designed and patients with cancer of the minor oral salivary glands treated in our department in the years 2011 to 2022 were included. Clinicopathological data were evaluated to compare overall survival and progression-free survival between the entities. Eighty-one patients were included. The rates of cervical metastases were 38.9% for ACC, 25% for MEC, and 9.1% for AC-NOS. ACC exhibited significantly higher rates of local and systemic disease recurrence (p = 0.02), and the presence of neck node metastases was confirmed as an independent prognostic factor for progression-free survival (p = 0.014). Treatment success in terms of oncological outcome varied significantly between the different entities and implies different treatment regimens for each tumor entity.

Number of positive lymph nodes affects outcomes in parotid adenoid cystic carcinoma

Objectives

Survival significance of the number of positive lymph nodes (LNs) in parotid adenoid cystic carcinoma (ACC) remains unknown; thus, this study aimed to determine the impact of the number of positive LNs on the prognosis of parotid ACC.

Methods

Patients with surgically treated parotid ACC were enrolled from the SEER database. The number of positive LNs was analyzed using three models (0 vs 1+, 0 vs 1 vs 2 vs 3 vs 4 vs 4 vs 5 vs 6+, 0/1 vs 2-4 vs 5+), its hazard ratios on disease specific survival (DSS) and overall survival (OS) were assessed using univariate and multivariate Cox analyses.

Results

A total of 1,689 patients were included. In all models, the number of positive LNs was independently related to DSS and OS, model 3 had the highest C-index for DSS [0.83 (95% CI: 0.81-0.85)] and OS [0.82 (95% CI: 0.80-0.84)]. Compared with the 0/1 positive LN group, the 2-4 positive LN group had an HR of 2.81 (95% CI: 1.73-4.56) for DSS and 2.36 (95% CI: 1.58-3.54) for OS. The 5+ LN group had an HR of 20.15 (95% CI: 7.50-54.18) for DSS and 14.20 (95% CI: 5.45-36.97) for OS. No overlap existed in the 95% CI of the HR.

Conclusions

The three prognostic categories based on the number of positive LNs (0/1 vs 2-4 vs 5+) could stratify the DSS and OS in parotid ACC without overlap.

Occult neck metastases risk factors and the role of elective neck dissection in cT3-4N0 adenoid cystic carcinoma of the parotid gland

Objectives

To determine the predictor for occult neck metastases and the role of elective neck dissection (END) in cT3-4N0 parotid adenoid cystic carcinoma (ACC).

Methods

Patients with surgically treated parotid ACC were retrospectively enrolled. Predictors of occult neck metastases and the effect of END on disease specific survival (DSS), overall survival (OS), locoregional control survival (LRC), and distant metastasis free survival (DMS) were analyzed.

Results

Occult neck metastases occurred in 35 (19.7%) of the 178 patients undergoing an END. The tumor stage [p=0.011, 4.215 (1.387–10.435)] and intra-parotid lymph node metastasis [p=0.032, 3.671 (1.693–8.775)] were related to the possibility of occult neck metastases independently. The END group had better 10-year LRC than the observation group (56% vs. 43%, p=0.002) and also better 10-year DMS than the observation group (43% vs. 32%, p<0.001). The two groups had similar 10-year DSS (40% vs. 33%, p=0.230) and OS (31% vs. 23%, p=0.094) rates. Furthermore, the Cox model confirmed that END was independently associated with better LRC rate [p=0.022, 2.576 (1.338–6.476)] and better DMS [p=0.011, 2.343 (1.274–7.462)].

Conclusions

Occult neck metastases in cT3-4N0 parotid ACC was not common. A T4 tumor with intra-parotid lymph node metastasis had the highest possibility of occult neck metastases. END had no effect on DSS or OS but significantly decreased the risk of locoregional recurrence and distant metastasis.

Clinical Prediction Nomograms to Assess Overall Survival and Disease-Specific Survival of Patients with Salivary Gland Adenoid Cystic Carcinoma

Aim

Salivary gland adenoid cystic carcinoma (SACC) is the second highest incidence of malignant salivary gland tumor. The purpose of this study was to establish nomograms combined with SACC patients based on the Surveillance, Epidemiology, and End Results (SEER) database.

Methods

Patients with SACC were included in the SEER∗Stat Database from 2004 to 2016. The least absolute shrinkage and selection operator (LASSO) Cox regression analysis was applied to filter potential prognostic clinical variables. Multivariate analysis from the Cox proportional hazards model was performed to determine the independent prognostic factors on overall survival (OS) and disease-specific survival (DSS), applied to develop nomograms. The Schönfeld residual test verified the proportional hazard assumption. The discrimination and consistency of nomograms was assessed and validated according to concordance index (C-index), receiver operating characteristic (ROC) curves, and calibration curves using an internal 1,000 times bootstrap resampling. The nomogram's net clinical benefit was assessed through decision curve analysis (DCA).

Results

A total of 658 patients with SACC were included. Age, T stage, N stage, M stage, histologic grade, and surgery were independent prognostic factors for OS and DSS. Based on these independent prognostic factors, nomograms were developed to predict 3-, 5-, and 10-year OS and DSS. In the validation of 1,000 times bootstrap resampling, the C-index and ROC curves had good discriminatory ability. The calibration curves indicated excellent consistency between the predicted and actual survival results in the nomograms. The DCA curves demonstrated that the nomograms had good clinical benefit and were superior to the TNM stage and other variables.

Conclusions

Two nomograms developed in this study precisely predicted the 3-, 5-, and 10-year OS and DSS rates of patients with SACC in accordance with independent prognostic factors, and their clinical value is better than TNM staging, providing a prognostic reference for other SACC patients.

Occult Neck Metastases in Head and Neck Adenoid Cystic Carcinoma: A Systematic Review and Meta-Analysis

Introduction: Adenoid cystic carcinoma (AdCC) is a rare tumor whose clinical course is burdened by local recurrence and distant dissemination. Lymph node metastasis is not believed to be common and its clinical impact is controversial. The aim of this study was to determine: (1) the prevalence of occult metastasis at diagnosis in cN0 head and neck AdCC, (2) its prognostic role, and (3) the consequent need to perform elective neck dissection (END). Material and Methods: A systematic review and meta-analyses following PRISMA guidelines was performed. PubMed, Embase, and Central databases were questioned up to July 2021 to identify studies reporting on the prevalence of occult neck metastases in head and neck AdCC. A single-arm meta-analysis was then performed to determine the pooled prevalence of occult lymph node metastases among the retained studies. Results: Of the initial 6317 studies identified, 16 fulfilled the inclusion criteria, and they were included in the meta-analysis. Of a population of 7534 patients, 2530 cN0 patients were treated with END, which revealed 290/2530 cases of occult metastases (pN+/cN0). Meta-analysis of the results of END in the 16 studies estimated an overall prevalence of occult metastases at diagnosis of 17%. No further subgroup analysis was possible to identify factors influencing lymph node involvement and the prognostic role of END. Conclusions: Taking 20% as an historically proposed cut off, a 17% prevalence of occult metastases represents a borderline percentage to get a definitive conclusion about the indication to END for head and neck AdCC. A more advanced UICC stage, an oropharyngeal minor salivary glands origin, and a high-grade transformation are factors to be considered in a comprehensive patient’s tailored therapeutic strategy. Multicenter prospective studies are the key to finding stronger recommendations on this topic.

Is prophylactic neck irradiation indicated for patients with cN0 Adenoid cystic carcinoma of the paranasal sinuses?

PURPOSE

To study the prevalence of nodal metastases in sinonasal adenoid cystic carcinoma (SNACC) and to evaluate whether prophylactic neck irradiation (PNI) should be performed in patients with clinical N0 (cN0) disease.

PATIENTS AND METHODS

Between April 1992 and November 2020, 166 patients with SNACC who had undergone radiotherapy at our department were retrospectively analyzed. The median follow-up time was 71.3 months.

RESULTS

Among 166 cases of SNACC, a total of 13 (7.8%) had retropharyngeal or cervical nodal metastasis and 93% (12/13) cases occurred in patients with advanced T stage (T3-T4). Levels VIIa, Ib, and IIa were the most common sites of initial nodal involvement. Only 1.2% (2/166) of patients presented late neck recurrence. Lymph node metastasis independently predicted a poor progression-free survival (PFS) (P = 0.017) but had no impact on overall survival (OS) (P = 0.38). PNI was performed on 36% (55/153) of cN0 patients. The OS (P = 0.42), PFS (P = 0.59), nodal recurrence-free survival (NRFS) (P = 0.46) and distant metastasis-free survival (DMFS) (P = 0.63) rates showed no significant difference between cases with and without PNI. Furthermore, cN0 patients with T4b (P = 0.53; P = 0.61), tumor origin from maxillary sinus (P = 0.55; P = 0.53) or nasopharynx involvement (P = 0.56; P = 0.60) showed no extended OS or PFS associated with PNI.

CONCLUSIONS

Regardless of the T stage or the site of origin, prophylactic neck irradiation (PNI) for cN0 patients did not provide any benefit on OS and PFS, suggesting that its application on such patients is not warranted unless there is clinical suspicion.

Current opinions on diagnosis and treatment of adenoid cystic carcinoma

Adenoid cystic carcinoma (ACC) is a rare malignant tumor derived mainly from the salivary glands, representing approximately 1% of all headandneck carcinomasand 10% of all salivary gland neoplasms. ACC displays a paradoxical behavioral combination of an indolent growth pattern but an aggressive progression, with local recurrence and distant metastasis. The propensity of ACC of the head and neck (ACCHN) for perineural invasion and its anatomical location, especially if it extends to the nasal cavity and paranasal sinuses, facilitates tumor involvement in the surrounding structures, such as the orbit, pterygopalatine fossa, Meckel'scave, and cavernous sinus, which can lead to skull base involvement and intracranial extension. Despite advances in molecular mechanisms and diagnostic imaging, ACC treatment remainschallenging due to the lack ofconsensuson treatment patterns. In this review, we aimed toprovideanupdatedinsight intothe understanding of ACCHN by focusing on clinical behavior, imaging diagnosis, pathological features, and therapeutic strategies. We reviewed the molecular mechanisms, especially in ACCHN with perineural invasion, and elaborated on treatment options, including chemotherapy, targeted therapies, and immunotherapy, to establish a comprehensive understanding of ACC to arrive at a policy for proper diagnosis, preoperative evaluation, and therapeutic strategies.

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

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

Surgical treatment of the neck in patients with salivary gland carcinoma

BACKGROUND

Elective neck dissection (END) in patients with salivary gland carcinoma is controversial and there are no universally accepted guidelines.

METHODS

Patients were identified from the Danish Head and Neck Cancer Group. Between 2006 and 2015, 259 patients with primary salivary gland carcinoma were treated with END. Variables potentially associated with regional metastases were analyzed using logistic regression. Neck recurrence-free survival was calculated using the Kaplan-Meier method.

RESULTS

Occult metastases were found in 36 of the patients treated with END (14%) and were particularly frequent among patients with T3/T4 tumors and high-grade histology tumors. In multivariate analyses, high-grade histology and vascular invasion were associated with occult metastases.

CONCLUSION

We recommend END of levels II and III for patients with high-grade or unknown histological grade tumors, and for T3/T4 tumors. Levels I, II, and III should be included in END in patients with submandibular, sublingual, or minor salivary gland carcinomas.

Adenoid cystic carcinoma: a review of clinical features, treatment targets and advances in improving the immune response to monoclonal antibody therapy

The natural history of adenoid cystic carcinoma (ACC) is relentless, defined by treatment failure heralded by locoregional recurrence and distant metastatic disease. In this review, we present an update of clinical features, molecular classification, current targeted therapies, immune landscapes and novel treatment targets with their respective clinical trials. The presented results are defined by a lack of overall response rate and limited progression free survival, with restriction to stable disease. In addition, ACC is resistant to immune checkpoint inhibition due to low tumour immunogenicity and lack of PD-L1 expression. Here we present a new prospective research paradigm for ACC, including the potential to target prostate specific membrane antigen (PSMA) and the potential for manipulation of target receptors in the clinic. The presentation of this review aims to promote future research to improve response rates and outcomes for therapeutics undergoing clinical trial in ACC.

Elective neck dissection in primary parotid carcinomas: A systematic review and meta-analysis

BACKGROUND

To estimate the rate of occult cervical lymph node metastases in cN0 patients affected by primary parotid carcinomas and to scrutinize the evidence on the indication and extent of elective neck dissection in these neoplasms.

METHODS

Medline, Embase, Web of Science, Cochrane Library and Scopus were searched until August 31, 2020, to identify studies reporting the use of elective neck dissection in the management of malignant parotid tumours. The PRISMA checklist was used. A single arm meta-analysis was then made to determine the pooled rate of occult lymph node metastases. Risk of bias of the included studies was assessed through the ROBINS-E tool.

RESULTS

The initial search returned 20 541 articles, of which twelve met the inclusion criteria and were included in the meta-analysis. They comprised 1310 patients with parotid carcinoma, of whom 542 cN0 underwent elective neck dissection, which led to the diagnosis of lymph node metastasis (pN+/cN0) in 113 cases. Meta-analysis of the results of elective neck dissection showed an overall rate of occult metastases of 0.22 (99% CI: 0.14-0.30). Locally advanced or high-grade tumours were the commonest indications for elective neck dissection in the included studies. The most dissected lymph node levels were I-II-III, and level II was the commonest site of occult nodal metastases.

CONCLUSIONS

An occult metastasis rate of 0.22 (99% CI: 0.14-0.30) represents a not negligible percentage value, which should encourage further research to outline the most appropriate elective neck management in cN0 patients with parotid carcinomas.

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Elective neck dissection in patients with salivary gland carcinoma: A systematic review and meta-analysis

OBJECTIVE

Elective neck dissection in patients with salivary gland carcinoma and clinically negative lymph nodes is controversial. Reported proportion of occult nodal metastases vary with histological subtype, tumour classification and preoperative diagnostic methods. This is a systematic review and meta-analysis on the role of END in salivary gland carcinoma.

METHODS

A search in PubMed, Embase and Cochrane was performed. Original articles in English with data on tumour characteristics, clinical and pathological N-classification, and neck dissection were included. Reporting Items for Systematic Reviews and Meta-analyses were followed. Random effect modelling was performed to pool the data. Meta-analysis of proportions was performed for occult metastases overall, for T3/T4 versus T1/T2 tumours and for tumours with high-grade versus low-grade histology. Heterogeneity across studies was assessed with I-squared statistics.

RESULTS

We included 22 articles in the qualitative synthesis and meta-analysis. The pooled proportion of occult metastases was 21%. In patients with T3/T4 tumour, the pooled proportion of occult metastases was 36%, and in patients with high-grade histology, it was 34%. Most studies concluded that END should be performed in patients with advanced T-classification and high-grade histology tumours. Nine studies assessed occult metastases per level.

CONCLUSION

The overall occult metastases proportion does not require END in all patients with salivary gland carcinoma. We recommend END in patients with high-grade or unknown histology or T3/T4 tumours. END should involve level II and III, and level I should be included in tumours in the submandibular gland, sublingual gland and minor oral salivary glands.

[Cervical lymph node metastasis in adenoid cystic carcinoma of the salivary glands: A clinicopathologic study]

OBJECTIVE

To investigate the incidence and clinicopathologic features of cervical lymph node metastasis in salivary gland adenoid cystic carcinoma (AdCC).

METHODS

Retrospective analysis was made in 798 AdCC patients who underwent tumor resection during January, 2001 to January, 2019 in Peking University School and Hospital of Stomatology, especially the clincopathologic characteristics of 82 cases with lymph node metastasis.

RESULTS

In the study, 82 of the 798 patients were identified with cervical lymph node metastasis, which was confirmed by histopathological examination. The palate, the region of sublingual gland and mouth floor, and the parotid were the frequently involved primary sites for AdCCs. The general incidence rate of lymph node metastasis was approximately 10%. The submandibular gland, the region of sublingual gland and mouth floor, and the mobile tongue were the most frequent sites of lymph node metastasis with the incidence rates of 20.8%, 16.1%, and 15.1%, respectively; while lymph node metastasis was uncommon in the tumors which were the origin from the palate and parotid, with incidence rates of 6.1% and 3.4%, respectively. Most AdCC cases (70.7%) showed the classic "tunnel-style" metastatic pattern of occurrence, and the level I and II regions were the most frequently involved areas. The 5-year and 10-year overall survival rates of the patients with lymph node metastasis were 77.4% and 20.6% respectively, while the 5-year and 10-year overall survival rates of the patients with no lymph node metastasis were 83.5% and 57.6%, respectively. The univariate analysis demonstrated that statistically significant differences in the overall survival for the presence of lymph node metastasis (P<0.001). In the meantime, the 5-year disease-free survival rate of the patients with lymph node metastasis also showed statistically significant differences to that of the AdCC patients with no lymph node metastasis. In addition, the primary site and histological grade were significantly associated with lymph node metastasis, and the high-grade solid growth pattern was identified as a strong predictor for the occurrence of lymph node metastasis.

CONCLUSION

Cervical lymph node metastasis has a high tendency of occurrence in submandibular gland and tongue-mouth floor complex, and the high-grade solid growth pattern could be taken as a strong predictor for the occurrence of lymph node metastasis, which correlates to poor prognosis of AdCC patients. A selective neck dissection should be considered as a management in such patients.

Should a neck dissection be performed on patients with cN0 adenoid cystic carcinoma? A REFCOR propensity score matching study

BACKGROUND

Patterns of nodal involvement in adenoid cystic carcinoma (ACC) of the head and neck have not been sufficiently assessed to guide a decision of prophylactic neck dissection (ND). The objective of this study is to analyse the influence of ND on event-free survival (EFS) for patients with cN0 ACC.

PATIENTS AND METHODS

A multicentre prospective study was conducted between 2009 and 2018. Patients presenting cN0 non-metastatic ACC on any site, and who received surgery on the tumour, were included. EFS was the main judgement criterion. A comparative survival analysis between the groups that received a ND versus those that did not was performed, using a propensity score. Analyses were carried out using the R software.

RESULTS

Between 2009 and 2018, 322 patients with cN0 ACC were included, out of which 58% were female. The average age was 53 years. Tumours were in minor salivary glands in 58% of cases, and 52% had T3/T4 stages. ND was performed on 46% of patients. Out of them, seven had histological lymph node invasion, out of which six had tumour infiltration in the mucosa of oral cavity. After propensity score, the median EFS for N0 patients with ND was 72 months (95% Confidence Interval (CI) [48-81]), compared to 73 months (95% CI [52-85]) for patients without ND (HR = 1.33; 95% CI [0.82-2.16]; p = 0.2).

CONCLUSION

ND of cN0 patients does not provide any benefit on EFS, which suggests that its application on such patients is not necessary.

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.

LAPTM4B-35 expression is associated with pathological grades and clinical stages in salivary adenoid cystic carcinoma

Salivary adenoid cystic carcinoma is one of the most common malignancies of the head and neck. The lysosome-associated protein transmembrane-4β gene (LAPTM4B) is a novel oncogene that has been found overexpressed in a number of clinically aggressive cancers. This study aimed to investigate the expression of the LAPTM4B-35 protein in normal salivary gland and salivary adenoid cystic carcinoma, a relatively indolent malignancy, and explore its clinicopathological significance in this malignancy. By immunohistochemical analysis, LAPTM4B-35 expression was evaluated in 106 cancer tissues, their adjacent non-cancerous tissues and five normal salivary glands. The correlation of LAPTM4B-35 expression with clinicopathological parameters was assessed using Chi-square or Fisher's exact test. The level of LAPTM4B-35 expression varied among different cell types of normal salivary glands. It was expressed at a fairly low level in serous and mucous acini, at low level in intercalated duct and excretory duct cells and moderately in secretory/striated ducts. In 50% of high grade tumor tissues tested, LAPTM4B-35 was markedly overexpressed. LAPTM4B-35 levels were significantly associated with histological grade and clinical stage. LAPTM4B-35 plays an important role in salivary adenoid cystic carcinoma and may serve as a diagnostic marker and a target for individualized therapy.

High levels of ANXA2 are characteristic of malignant salivary gland tumors

OBJECTIVE

Malignant salivary gland tumors (MSGTs) present different phenotypic characteristics and various clinical outcomes, which proved to be a diagnostic challenge. Considering the heterogeneity of MSGT, this study aims to identify molecule related to the nature of MSGT.

METHODS

For screening, proteomic analysis comparing MSGT with pleomorphic adenoma (PA) and salivary gland was performed. The MSGT-associated protein which presented in the higher number in the Gene Expression Omnibus (GEO) database was selected. To validate the data, immunohistochemistry (IHC) was performed in 14 patients with PA, 22 patients with MSGT, and 14 controls.

RESULTS

16 proteins were associated with MSGT. ANXA2 was the primary protein, according to GEO database analyses. ANXA2 was most expressed in the cell membrane. However, some ANXA2 staining was also observed in the cytoplasm and nucleus. ANXA2 was highly expressed in MSGT in comparison with control. Also, ANXA2 has a higher expression in adenocarcinoma not otherwise specified (ANOS) and myoepithelial carcinoma (MC) in comparison with PA.

CONCLUSION

In conclusion, this study demonstrated that MSGT presented higher levels of ANXA2 in comparison with normal salivary glands. Also, ANXA2 might be interesting as a molecular marker of ANOS and MS.

Impact of lymph node sampling on survival in cN0 major salivary gland adenoid cystic carcinoma

BACKGROUND

The role of elective neck dissection in the management of major salivary gland adenoid cystic carcinoma is unclear.

METHODS

Data were retrospectively extracted from the National Cancer Center Database. The study cohort included 1504 patients with adenoid cystic carcinoma of major salivary glands with clinical N0 necks who were treated with surgery between 2004 and 2014. The cohort was divided into four groups based on number of lymph nodes (LNs) examined on pathology: 0, 1-8, 9-17, and ≥18 LNs.

RESULTS

The rate of occult nodal metastasis was 9.0%. Number of LNs removed was not associated with survival (Reference, 0 LNs; HR = 0.98, 95% CI 0.73-1.32 for 1-8 LNs; HR = 1.22, 95% CI 0.80-1.88 for 9-17 LNs; HR = 0.94, 95% CI 0.61-1.46 for ≥18 LNs) after adjusting for important covariates.

CONCLUSIONS

LN sampling is not associated with survival in cN0 major salivary gland ACC.

An update on head and neck cancer: new entities and their histopathology, molecular background, treatment, and outcome

The head and neck region harbor numerous specialized tissues of all lineages giving rise to a plethora of different malignancies. In recent years, new types and subtypes of cancer has been described here due to the recognition of their histological and molecular characteristics. Some have been formally accepted in the most recent classifications from the World Health Organization (WHO) and American Joint Committee on Cancer (AJCC) as distinct diseases due to characteristics in clinical presentation, outcome, and treatment. In particular, this applies to malignancies of the salivary gland, sinonasal tract, and oropharynx. In this overview, we present the most recent developments in the classification, histopathological characteristics, and molecular features of head and neck cancer. The clinical and radiological characteristics, outcome, and treatment options including perspectives for targeted therapies, are discussed.

Disparities in Postoperative Therapy for Salivary Gland Adenoid Cystic Carcinomas

OBJECTIVES

The patterns of care for salivary gland adenoid cystic carcinomas (ACC) are unknown. We sought to assess predictors of receiving postoperative radiation and/or chemotherapy for patients with nonmetastatic, definitively resected ACC, as well as report unexpected nodal disease.

METHODS

The National Cancer Data Base was queried for definitively resected nonmetastatic ACC from 2004 to 2014. Logistic regression, Kaplan-Meier, and Cox proportional-hazard models were utilized. Propensity-score matched analysis was employed to reduce confounding variables.

RESULTS

A total of 3,136 patients met entry criteria: 2,252 (71.8%) received postoperative radiation, with 223 (7.4%) also receiving concurrent chemotherapy. Median follow-up was 4.87 years. In clinically lymph node negative (cN0) patients, 7.4% had pathologically positive lymph nodes (pN) + after elective neck dissection. Patients who lived closer to their treatment facility and had positive margins were more likely to receive postoperative radiation. Black patients and uninsured patients were less likely to receive radiation. Older age, male sex, advancing stage, and positive surgical margins were associated with worse overall survival (OS). With limited follow-up, receipt of radiation or chemotherapy was not associated with OS.

CONCLUSION

Postoperative radiation was frequently given for resected ACC, with a minority receiving chemotherapy. Black patients and uninsured patients were less likely to receive radiation. Postoperative radiation and/or chemotherapy had no association with OS but were given in greater frequency in more advanced disease, and our series is limited by short follow-up. The disparity findings for this rare disease need to be addressed in future studies.

LEVEL OF EVIDENCE

2c Laryngoscope, 129:377-386, 2019.

The role of elective neck dissection in patients with adenoid cystic carcinoma of the head and neck

OBJECTIVE

To investigate the frequency and outcomes of elective neck dissection (END) for adenoid cystic carcinoma (ACC) of the head and neck.

METHODS

The National Cancer Database was queried for a cohort study of patients with ACC of the major salivary glands, nasal cavity/nasopharynx, hard/soft palate, tongue, floor of mouth, larynx, and oral cavity who underwent primary surgical resection from 2004 to 2014. Multivariable logistic regression was used to identify predictors of END and occult nodal metastasis. Overall survival (OS) was estimated using the Kaplan-Meier method and modeled with Cox proportional hazards regression.

RESULTS

Among 2,807 patients with ACC treated surgically, 636 (22.7%) underwent END. Patients with ACC of the salivary glands and tongue most frequently underwent END; patients with hard/soft palate (odds ratio [OR] 0.06, P < 0.001) and nasal cavity/nasopharynx (OR 0.05, P < 0.001) ACC rarely underwent END compared to patients with major salivary gland cancer. Increasing tumor (T) stage (T4 vs. T1, OR 3.02, P < 0.001) was associated with END. Patients with advanced T3 to T4 ACC of the major salivary glands demonstrated extended OS associated with END (5-year OS 78.1% vs. 70.4%, P = 0.041) on Kaplan-Meier analysis and with END with adjuvant radiation therapy (hazard ratio 0.55, P = 0.027) using Cox proportional hazards regression. Elective neck dissection for T4 ACC of the salivary glands (21.3%) and tongue (25.5%) most consistently revealed occult nodal metastasis.

CONCLUSION

Elective neck dissection for ACC of the major salivary glands or tongue is most likely to reveal occult nodal metastasis. Elective neck dissection is associated with extended OS for advanced-stage ACC of the major salivary glands.

LEVEL OF EVIDENCE

NA Laryngoscope, 129:2094-2104, 2019.

Prognostic factors and survival in adenoid cystic carcinoma of the sinonasal cavity

BACKGROUND

Optimal treatment and prognostic factors affecting long-term survival in patients with sinonasal adenoid cystic carcinoma (ACC) have yet to be clearly defined.

METHODS

We conducted a retrospective review of patients treated with curative intent from 1980-2015 at MD Anderson Cancer Center.

RESULTS

One hundred sixty patients met inclusion criteria, including 8 who were treated with radiotherapy alone. Median follow-up time was 55 months. The 5-year overall survival (OS) and disease-free survival (DFS) rates were 67.0% and 49.0%, respectively. The 10-year OS and DFS rates were 44.8% and 25.4%, respectively. Factors that portended for poor survival on multivariate analysis were recurrent disease, any solid type histology, epicenter in the sinus cavity, the presence of facial symptoms, or the original disease not treated with surgery. There was no association between surgical margin status or nodal status and survival.

CONCLUSION

In this large cohort of patients with sinonasal ACC with extended follow-up, long-term survival is better than reported in prior literature. Future research should target patients with adverse risk factors.

Regulation of β-Catenin Phosphorylation by PR55β in Adenoid Cystic Carcinoma

BACKGROUND/AIM

Adenoid cystic carcinoma (AdCC) is a rare cancer of the salivary gland with high risk of recurrence and metastasis. Wnt signalling is critical for determining tumor grade in AdCC, as it regulates invasion and migration. β-catenin dephosphorylation plays an important role in the Wnt pathway, but its underlying molecular mechanism remains unclear.

MATERIALS AND METHODS

Because the regulatory subunits of protein phosphatase 2A (PP2A) drive Wnt signalling via target molecules, including β-catenin, we used qRT-PCR and immunoblot analysis to investigate the expression of these subunits in an AdCC cell line (ACCS) and a more aggressive subline (ACCS-M).

RESULTS

PR55β was highly expressed in ACCS-M, suggesting its functional importance. In addition, PR55β expression was associated with tumor grade, with ACCS-M exhibiting higher PR55β levels. More importantly, knockdown of PR55β in ACCS-M cells significantly reduced invasiveness and metastatic ability. Furthermore, dephosphorylation and total levels of β-catenin were dependent on PR55β in ACCS-M. Finally, we confirmed a correlation between PR55β staining intensity and histopathological type in human AdCC tissues.

CONCLUSION

Our study provides new insight into the interaction between PR55β and β-catenin and suggests that PR55β may be a target for the clinical treatment of AdCC.

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.

Management of salivary gland carcinomas - a review

Salivary gland carcinomas are a heterogeneous group of tumors with many histological subtypes which occur in both major and minor salivary glands. However, they have a relatively low of incidence. Their rarity limits study size and the ability to perform phase III trials. Therefore, to date, the entire management is usually varied. Certain published studies have paid more attention to the systemic therapy in the management of metastatic or locally recurrent salivary gland cancer, while little effort has been made to study the entire management for this lesions. Although results of treatment for patients with salivary gland carcinoma have improved in recent years, the treatment of salivary gland cancers is still not standardized. And some patients who haven’t received optimal treatment strategies had a reduced survival. In this review, the topics covered include surgery and radiotherapy, selective neck dissection, chemotherapy, and targeted therapy, which aimed to summarize the optimal management approaches and to develop recommendations for managing this lesions. For these rare cancers, there is also a need for a determined, coordinated effort to conduct high-quality clinical trials.

Adenoid cystic carcinoma evaluation and management: progress with optimism!

PURPOSE OF REVIEW

Adenoid cystic carcinoma (ACC) when diagnosed presents several diagnostic and treatment challenges. The standard treatment of surgery and postoperative radiotherapy has remained the standard of care for the past 3 decades. The purpose of this review is to update what's been reported and what's new since the last review in 2004.

RECENT FINDINGS

As accurate a histological diagnosis and staging of disease should be achieved prior to commencing any treatment. Patients' prognosis, in the long term, is determined by the finding of any solid tumour component in the examined excised specimen. The continued treatment of patients with ACC by surgery and postoperative radiotherapy has not changed in the long-term tumour-free outcome of patients. The majority of patients die because of loco-regional failure and/or distant metastases. Optimism is being generated by the findings at the molecular and genetic level of ACC giving hope that nonsurgical treatment can be complemented by novel treatments that will improve patients' disease cure and improved long-term survival.

SUMMARY

The histological grading determined by optical methods has not advanced our selection of treatment and new recent research findings on molecular and genetic factors give new hopes to changing the ACC classification, determining differing treatments and thus influencing an improved and prolonged tumour-free survival for more patients.

Predictors of Outcome in Adenoid Cystic Carcinoma of Salivary Glands: A Clinicopathologic Study With Correlation Between MYB Fusion and Protein Expression

Adenoid cystic carcinoma (ACC) is the second most common salivary gland malignancy and it has a high rate of recurrences and a poor long-term prognosis. Our aim was to assess the prognostic factors in ACC and study MYB-NFIB fusion and MYB protein expression in a large retrospective cohort of 135 patients with a median follow-up of 6.3 years. The 5- and 10-year local recurrence-free survival (RFS) rate of 94% and 78%, 5- and 10-year distant metastasis survival rate of 77% and 58%, and 5- and 10-year RFS of 66% and 44%. The following features were identified as adverse prognostic factors of RFS on univariate analysis: large tumor size, solid growth pattern, increased mitoses, positive margin, American Joint Committee on Cancer clinical staging, high-grade transformation, vascular invasion, nuclear atypia, open chromatin, prominent nucleoli, and tumor necrosis. However, on multivariate analysis, only increased mitoses (≥5/10 high-power fields), any solid growth pattern, and advanced American Joint Committee on Cancer TNM staging were independent adverse predictors for RFS. MYB immunoexpression and MYB-NFIB translocation were common findings in ACC, occurring in 72% and 59% of the tested ACCs, respectively. The sensitivity and specificity of MYB immunohistochemistry in detecting MYB-NFIB fusion was relatively low at 78% sensitivity and 50% specificity. The high prevalence of alterations leading to high expression of the MYB transcription factor family suggests that targeted approaches developed to suppress the expression of these oncogenic transcription factors and/or the transcriptional activity of these proteins would be a rational therapeutic approach to investigate in ACC.

Risk of Nodal Metastasis in Major Salivary Gland Adenoid Cystic Carcinoma

Objective

To determine the risk of nodal metastasis, examine risk factors for nodal metastasis, and evaluate the impact of nodal metastasis on survival in patients with major salivary gland adenoid cystic carcinoma.

Study Design

Retrospective cohort study from a large population- based cancer database.

Methods

Data were extracted from the SEER 18 database (Surveillance, Epidemiology, and End Results) of the National Cancer Institute. The study cohort included 720 patients diagnosed with major salivary gland adenoid cystic carcinoma between 1988 and 2013.

Results

The overall rate of lymph node metastasis was 17%. T3 disease (odds ratio, 4.74) and T4 disease (odds ratio, 9.24) were associated with increased risk of nodal metastasis. Age, sex, and site were not associated with nodal metastasis. Nodal metastasis was associated with worse overall survival (hazard ratio, 2.56) and disease-specific survival (hazard ratio, 3.27), after adjusting for T stage, presence of distant metastasis, site, surgical resection, radiotherapy, neck dissection, age, sex, race, marital status, and year of diagnosis.

Conclusion

Major salivary gland adenoid cystic carcinoma carries significant risk of nodal metastasis. Advanced T stage is associated with increased risk of nodal metastasis. Nodal metastasis is associated with worse survival.

Cervical lymph node metastasis in adenoid cystic carcinoma of the major salivary glands

Objective:

To verify the prevalence of cervical lymph node metastasis in adenoid cystic carcinoma of major salivary glands, and to establish recommendations for elective neck treatment.

Methods:

A search was conducted of the US National Library of Medicine database. Appropriate articles were selected from the abstracts, and the original publications were obtained to extract data.

Results:

Among 483 cases of major salivary gland adenoid cystic carcinoma, a total of 90 (18.6 per cent) had cervical metastasis. The prevalence of positive nodes from adenoid cystic carcinoma was 14.5 per cent for parotid gland, 22.5 per cent for submandibular gland and 24.7 per cent for sublingual gland. Cervical lymph node metastasis occurred more frequently in patients with primary tumour stage T3–4 adenoid cystic carcinoma, and was usually located in levels II and III in the neck.

Conclusion:

Adenoid cystic carcinoma of the major salivary glands is associated with a significant prevalence of cervical node metastasis, and elective neck treatment is indicated for T3 and T4 primary tumours, as well as tumours with other histological risk factors.

Population-based trends in outcomes in adenoid cystic carcinoma of the oral cavity

PURPOSE

Adenoid cystic carcinoma (ACC) is a rare malignant epithelial neoplasm of secretory glands of the upper aerodigestive tract. It accounts for 3-5% of head and neck malignancies and most commonly arises from the minor salivary glands of the oral cavity. The clinical behavior of ACC from specific anatomic subsites, including the oral cavity, is not well described in the literature. We aim to elucidate patient demographics, clinicopathologic features, incidence, and survival trends for oral cavity ACC (OCACC).

METHODS

Retrospective population-based analysis of OCACC in the SEER database between 1973 and 2012.

RESULTS

1066 OCACC patients were identified, of which 57.7% were female (P<0.0001). Incidence was 0.049 per 100,000. Whites were most commonly affected (81.1%). The hard palate was the most commonly involved subsite (44.1%). Nodal involvement was seen in 8.4% of cases and distant metastasis was present in 6.2% of cases at the time of presentation. Disease-specific survival (DSS) rates at 1, 5, 10, 15, and 20years were 97.4%, 83.9%, 69.9%, 57.6%, and 46.2%, respectively. Females had a higher 5-year DSS (87.8%) than males (78.4%, P=0.0004). Cases treated with surgery had a favorable prognosis regardless of whether they received radiotherapy (P<0.0001). Nodal involvement reduced 5-year DSS by 51.6% (P<0.0001), while distant metastasis reduced 5-year DSS by 46.4% (P<0.0001).

CONCLUSIONS

OCACC is a rare malignancy with females and whites being more commonly affected. At presentation, regional and distant metastases are uncommon. Poor prognostic indicators include male gender, nonsurgical therapy, nodal involvement, and distant metastasis.

Cervical Lymph Node Metastasis in Adenoid Cystic Carcinoma of the Larynx: A Collective International Review

Adenoid cystic carcinoma (AdCC) of the head and neck is a well-recognized pathologic entity that rarely occurs in the larynx. Although the 5-year locoregional control rates are high, distant metastasis has a tendency to appear more than 5 years post treatment. Because AdCC of the larynx is uncommon, it is difficult to standardize a treatment protocol. One of the controversial points is the decision whether or not to perform an elective neck dissection on these patients. Because there is contradictory information about this issue, we have critically reviewed the literature from 1912 to 2015 on all reported cases of AdCC of the larynx in order to clarify this issue. During the most recent period of our review (1991-2015) with a more exact diagnosis of the tumor histology, 142 cases were observed of AdCC of the larynx, of which 91 patients had data pertaining to lymph node status. Eleven of the 91 patients (12.1%) had nodal metastasis and, based on this low proportion of patients, routine elective neck dissection is therefore not recommended.

Cervical lymph node metastasis in adenoid cystic carcinoma of oral cavity and oropharynx: A collective international review

The purpose of this study was to suggest general guidelines in the management of the N0 neck of oral cavity and oropharyngeal adenoid cystic carcinoma (AdCC) in order to improve the survival of these patients and/or reduce the risk of neck recurrences. The incidence of cervical node metastasis at diagnosis of head and neck AdCC is variable, and ranges between 3% and 16%. Metastasis to the cervical lymph nodes of intraoral and oropharyngeal AdCC varies from 2% to 43%, with the lower rates pertaining to palatal AdCC and the higher rates to base of the tongue. Neck node recurrence may happen after treatment in 0-14% of AdCC, is highly dependent on the extent of the treatment and is very rare in patients who have been treated with therapeutic or elective neck dissections, or elective neck irradiation. Lymph node involvement with or without extracapsular extension in AdCC has been shown in most reports to be independently associated with decreased overall and cause-specific survival, probably because lymph node involvement is a risk factor for subsequent distant metastasis. The overall rate of occult neck metastasis in patients with head and neck AdCC ranges from 15% to 44%, but occult neck metastasis from oral cavity and/or oropharynx seems to occur more frequently than from other locations, such as the sinonasal tract and major salivary glands. Nevertheless, the benefit of elective neck dissection (END) in AdCC is not comparable to that of squamous cell carcinoma, because the main cause of failure is not related to neck or local recurrence, but rather, to distant failure. Therefore, END should be considered in patients with a cN0 neck with AdCC in some high risk oral and oropharyngeal locations when postoperative RT is not planned, or the rare AdCC-high grade transformation.

Ongoing challenges in the treatment of adenoid cystic carcinoma of the head and neck

BACKGROUND

Adenoid cystic carcinoma is a malignant tumour of major and minor salivary glands. Distant metastasis and poor survival are persistent in the literature, with recent publications aimed at understanding molecular pathogenesis and development of pharmaceutical therapeutic options.

AIM

Provide an update of recent studies in the management of adenoid cystic carcinoma of the head and neck.

METHODS

Literature search using Medline, Scopus, Google Scholar, the Cochrane Database of Systematic Reviews and the Cochrane central register of controlled trials for articles on adenoid cystic carcinoma from January 2005 to January 2015.

CONCLUSION

Adenoid cystic carcinoma is characterized by a slow growing mass, with distant metastasis independent of local or regional control. Primary tumour resection remains the preferred option with radiotherapy having an adjuvant role. Recent advances have been made with novel targeted therapies however, limited to clinical trials and advanced disease.