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

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.

Elective Neck Dissection in cT1-4 N0M0 Head and Neck Basaloid Carcinoma

OBJECTIVE

To investigate the survival benefit of elective neck dissection (END) over neck observation in surgically resected cT1-4 N0M0 head and neck basaloid carcinoma (HNBC).

STUDY DESIGN

Retrospective cohort study.

SETTING

The 2006 to 2017 hospital-based National Cancer Database.

METHODS

Patients with surgically resected cT1-4 N0M0 HNBC were selected. Linear, binary logistic, Kaplan-Meier, and Cox proportional hazards regression models were implemented.

RESULTS

Of 857 patients satisfying inclusion criteria, the majority were male (77.0%) and white (88.1%) with disease of the oral cavity (21.5%) or oropharynx (42.9%) classified as high grade (76.9%) and cT1-2 (72.9%). 389 (45.4%) patients underwent END. END utilization between 2006 and 2017 increased for cT1-2 disease (33.3% vs 56.9%, R2 = .699) but remained relatively constant for cT3-4 disease (66.7% vs 57.9%, R2 = .062). One-hundred and fifteen (29.6%) ENDs detected occult nodal metastases (ONMs). The 5-year overall survival (OS) of patients undergoing neck observation and END was 65.6% and 66.8%, respectively (P = .652). END was not associated with improved OS in survival analyses stratified by patient demographics, clinicopathologic features, and adjuvant therapy. Compared with surgery alone, adjuvant radiotherapy (adjusted hazard ratio: 0.74, 95% confidence interval [CI]: 0.57-0.97, P = .031) was associated with improved OS. END (hazard ratio [HR]: 0.96, 95% CI: 0.71-1.28, P = .770) and ONM (HR: 1.12, 95% CI: 0.78-1.61, P = .551) were not associated with OS.

CONCLUSION

END is performed in nearly half of patients with HNBC but is not associated with improved OS, even after stratifying survival analyses by patient demographics, clinicopathologic features, and adjuvant therapy. The rate of ONM approaching 30%, however, justifies inclusion of END in the surgical management of HNBC.

Pathological nodal status as a main predictive factor of survival and treatment outcomes of submandibular salivary gland cancers: A 25-year single center experience

INTRODUCTION

Aim of this study was to explore the survival predictive factors and treatment outcomes in a cohort of SGC patients treated at a single center over a period of 25 years.

MATERIALS AND METHODS

Patients who had received primary treatment for SGC were enroled. Outcomes evaluated were: overall survival (OS), disease specific survival (DSS), recurrence free survival (RFS), locoregional recurrence free survival (LRFS) and distant metastasis free survival (DFS).

RESULTS

A total of 40 patients with SGC were enroled in the study. The most common tumor was the adenoid cystic carcinoma (60% of cases). Cumulative OS for 5-and 10-year follow up period was 81% and 60%, respectively. Thirteen patients (32.5%) developed distant metastases during follow-up. Nodal status, high-grade histology, tumor stage and adjuvant radiation-therapy (RT) were significant variables on multivariate analysis for survival and treatment outcomes.

CONCLUSIONS

Submandibular gland carcinomas represent rare and heterogenous tumor group regarding histological appearance and locoregional and distant metastatic potential. Tumor histological grade, AJCC tumor stage and nodal status were the strongest predictive factors for survival and treatment outcomes. RT improved OS and locoregional treatment outcome, but not DFS. Elective neck dissection (END) could be beneficial for selected cases of SGC. Superselective neck dissection of levels I-IIa may be the level of dissection for END. Distant metastases were the main cause of death and treatment failure. Prognostic factors for poor DMFS were AJCC stage III and IV, high tumor grade and nodal status.

Elective Neck Dissection for cT1-4 N0M0 Head and Neck Verrucous Carcinoma

OBJECTIVE

To investigate the survival benefit of elective neck dissection (END) over neck observation in cT1-4 N0M0 head and neck verrucous carcinoma (HNVC).

STUDY DESIGN

Retrospective cohort study.

SETTING

The 2006 to 2017 National Cancer Database.

METHODS

Patients with surgically resected cT1-4 N0M0 HNVC were selected. Linear, binary logistic, Kaplan-Meier, and Cox proportional hazards regression models were utilized.

RESULTS

Of 1015 patients satisfying inclusion criteria, 223 (22.0%) underwent END. The majority of patients were male (55.4%) and white (91.0%) with disease of the oral cavity (67.6%) classified as low grade (90.0%) and cT1-2 (81.8%). The minority of ENDs (4.0%) detected occult nodal metastases. The rate of END increased from 2006 to 2017 for both cT1-2 (16.3% vs 22.0%, p = .126, R2  = 0.405) and cT3-4 (41.7% vs 70.0%, p = .424, R2  = 0.232) disease but these trends were not statistically significant. Independent predictors of undergoing END included treatment at an academic facility (adjusted odds ratio [aOR]: 1.75, 95% confidence interval [CI]: 1.19-2.55), cT3-4 disease (aOR: 3.31, 95% CI: 2.16-5.07), and tumor diameter (aOR: 1.09, 95% CI: 1.01-1.19) (p < 0.05). The 5-year overall survival (OS) of patients treated with and without END was 71.3% and 70.6%, respectively (p = .661). END did not significantly reduce the 5-year hazard of death (adjusted hazard ratio: 1.25, 95% CI: 0.91-1.71, p = .172). END did not significantly improve 5-year OS in univariate and multivariate analyses stratified by several patient, facility, tumor, and treatment characteristics.

CONCLUSION

END does not confer an appreciable survival benefit in HNVC, even after stratifying univariate and multivariate analyses by several patient, facility, tumor, and treatment characteristics.

LEVEL OF EVIDENCE

Level 4.

Utility of Elective Neck Dissection in Clinically Node-Negative Parotid Malignancy

OBJECTIVE

We sought to investigate the utility of elective neck dissection (END) in clinically node-negative parotid malignancy through the evaluation of factors that are associated with receiving END and survival analysis of patients who received END.

STUDY DESIGN

Retrospective cohort database study.

SETTING

The National Cancer Database (NCDB).

METHODS

The NCDB was used to extract patients with clinically node-negative parotid malignancy. END was defined as having 5 or more lymph nodes examined pathologically, as previously defined in the literature. Univariate and multivariate analyses were used to compare predictors of receiving END, rates of occult metastasis, and survival.

RESULTS

Of the 9405 included patients, 3396 (36.1%) underwent an END. END was most frequently performed for squamous cell carcinoma (SCC) and salivary duct histology. All other histologies were significantly less likely to undergo END compared to SCC (p < .05). Salivary ductal carcinoma and adenocarcinoma had the greatest rates of occult node disease (39.8% and 30.0%, respectively), followed by SCC (29.8%). Kaplan-Meier survival analysis showed a statistically significant increase in 5-year overall survival in patients who received END with poorly differentiated mucoepidermoid (56.2% vs 48.5%, p = .004) along with moderately and poorly differentiated SCC (43.2% vs 34.9%, p = .002; 48.9% vs 36.2%, p < .001, respectively).

CONCLUSION

Histological classification is a benchmark for determining which patients should receive an END. We demonstrated an increase in overall survival in patients who undergo END with poorly differentiated tumors of mucoepidermoid and SCC histology. As such, histology should be considered along with clinical T-stage and rate of occult nodal metastasis to determine eligibility for END.

Sinonasal mucosal melanoma: Is there a need for elective neck irradiation?

BACKGROUND AND PURPOSE

Sinonasal mucosal melanoma (SNMM) is a rare malignant neoplasm. The regional failure pattern and effectiveness of elective neck irradiation (ENI) were not well defined. Here, we would assess the value of ENI for clinical node negative (cN0) SNMM patients.

MATERIALS AND METHODS

A total of 107 SNMM patients treated at our institution over a period of 30 years was retrospectively analyzed.

RESULTS

Five patients had lymph node metastases at diagnosis. Among the 102 cN0 patients analyzed, 37 patients had received ENI, and 65 patients had not. ENI significantly reduced the regional recurrence rate from 23.1% (15/65) to 2.7% (1/37). Ipsilateral levels Ib and II were the most common locations of regional relapse. Multivariate analysis also showed that ENI was the only independent favorable predictor for the achievement of regional control (HR: 9.120; 95% CI: 1.204-69.109; P = 0.032).

CONCLUSION

This is the largest cohort of SNMM patients from a single institution analyzed for the assessment of the value of ENI on regional control and survival. ENI significantly reduced the regional relapse rate in our study. Ipsilateral levels Ib and II might be considerable when deliver elective neck irradiation, more evidence is needed in the future.

[Frozen section biopsy for tumors of the submandibular triangle]

BACKGROUND

Diagnosis and treatment of submandibular lesions is challenging. Carcinomas, which frequently occur, should be surgically removed with sufficient safety margins, while simultaneously protecting functional structures. In particular, the preservation of neuronal structures with simultaneous tumor control suggests that single-stage concepts are appropriate, although they are not yet established. The aim of this study was to evaluate intraoperative frozen section biopsy as a possible basis for a one-stage surgical concept to thus prevent functional alterations by reoperation.

METHODS

A total of 114 consecutive patients with neoplastic lesions in whom the type of lesion could not be determined after ENT examination and imaging were included in the study. Patients with a known history of carcinoma or evidence of an acute inflammatory or carcinogenic primary lesion in the ENT examination and/or imaging were excluded. An intraoperative frozen section biopsy was performed to determine the presence of a carcinoma. Patient-related data and the reliability of the frozen section result were recorded comparatively.

RESULTS

Intraoperative frozen section biopsy was performed in a total of 114 patients. Carcinomas were diagnosed with a sensitivity of 87% and a specificity of 100%. There would thus not have been unnecessary radical surgery in a one-stage approach. In 26 of 30 patients with carcinoma, a second operation could have been avoided.

CONCLUSION

Intraoperative frozen section biopsy is potentially an important method to histologically confirm carcinomas and avoid two-stage procedures. The absence of false-positive findings would have prevented an unnecessary radical procedure in 100% of patients.

Adenoid cystic carcinoma of the head and neck: Patterns of recurrence and implications for intensity-modulated radiotherapy

BACKGROUND

We seek to inform radiotherapy (RT) delivery for adenoid cystic carcinoma of the head and neck (ACC) by evaluating RT techniques and recurrence patterns.

METHODS

We identified patients with ACC treated with curative-intent RT from 2005 to 2021. Imaging was reviewed to determine local recurrence (LR).

RESULTS

Ninety-one patients were included. The 5-year LR risk was 12.2% (6.6-22.7). One patient each experienced a marginal and out-of-field recurrence. Patients receiving >60 Gy postoperatively had a 5-year LR risk of 0% compared to 10.7% (4.2-27.2) with ≤60 Gy. Those receiving 70 and <70 Gy definitively had a 5-year LR risk of 15.2% (2.5-91.6) and 33.3% (6.7-100.0), respectively. No patients had regional nodal failure.

CONCLUSIONS

Modern, conformal RT for ACC results in low rates of LR. Doses >60 and 70 Gy may improve control in the postoperative and definitive settings, respectively. Elective nodal treatment can be omitted in well-selected patients.

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.

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.

Adenoid cystic carcinoma of the sublingual gland developing lung metastasis 20 years after primary treatment: A case report and literature review

RATIONALE

Adenoid cystic carcinoma (ACC) is a rare malignant tumor that primarily occurs in the salivary glands. Distant metastases can develop despite favorable local control. Moreover, distant metastasis of ACC can occur after a long time interval without local recurrence. We report the first case of ACC of the sublingual gland that developed lung metastasis 20 years after primary treatment.

PATIENT CONCERNS

A 52-year-old man was referred to our department with a 1-year history of painful swelling on the right oral floor.

DIAGNOSIS

An incisional biopsy was performed, and histopathological examination revealed malignancy.

INTERVENTIONS

Surgical excision of the right oral floor and right supra-omohyoid neck dissection with postoperative chemoradiation therapy were performed, and ACC of the sublingual gland was diagnosed. Left pulmonary metastasis was detected 20 years after the primary treatment. Metastasectomy was performed; however, subsequently, skin and bone metastases developed.

OUTCOMES

After receiving palliative care, the patient died of multiple organ failure.

LESSONS

As late distant metastasis of salivary ACC can develop, patients who undergo primary treatment need a long-term, strict follow-up plan even if locoregional control is favorable.

Omitting elective neck irradiation in clinically N0 sinonasal adenoid cystic carcinoma: A propensity score-matched analysis

OBJECTIVE

To explore the effects of elective neck irradiation (ENI) in clinically node-negative (cN0) sinonasal adenoid cystic carcinoma (SNACC).

MATERIALS AND METHODS

Between January 2000 and December 2016, 60 patients with cN0 sinonasal adenoid cystic carcinoma receiving surgery combined with radiotherapy were analyzed retrospectively, there were 39 received ENI (ENI group) and 21 with no ENI (non-ENI group). Propensity score matching (PSM) was performed to balance clinical factors and match patients. Kaplan-Meier method and Cox proportional hazard model were used to evaluate the impact of ENI on regional relapse risk and survival outcomes.

RESULTS

The median follow-up time for our cohort was 82.0 months (12.4-190.7 months). Four patients (6.7%) developed neck nodal relapses, with a median time to progression of 38.8 months. Among them, two patients in ENI group but failed out-field. After PSM, 21 patients were matched in each group. The 7-year regional relapse-free survival (RRFS), distant metastasis free survival (DMFS), progression-free survival (PFS), and overall survival (OS) between ENI group and non-ENI group were 85.4% vs 73.3% (p = 0.845), 65.2% vs 65.6% (p = 0.548), 68.3% vs 66.2% (p = 0.425), and 87.3% vs 84.0% (p = 0.953). Multivariate Cox analysis showed ENI was not an independent prognostic factor associated with RRFS, DMFS, PFS and OS.

CONCLUSION

Our findings firstly demonstrated the omission of elective neck irradiation in the management of cN0 sinonasal adenoid cystic carcinoma might be safe without compromising disease control and should be further investigated.

Elective neck dissection in salivary gland malignancies: Systematic review and meta-analysis

We defined the occult nodal metastasis (ONM) rate of clinical node-negative salivary gland malignancies and examined the role of elective neck dissection (END). Meta-analysis querying four databases, from inception of databases to March 25th, 2020. Fifty-one studies with 11 698 patients were included. ONM rates were 64% for salivary ductal carcinoma (SDC), 51% for undifferentiated carcinoma, 34% for carcinoma ex-pleomorphic adenoma (CXPA), 32% for adenocarcinoma not otherwise specified (ANOS), 31% for lymphoepithelial carcinoma (LE), 20% for mucoepidermoid carcinoma, 17% for acinic cell carcinoma, and 17% for adenoid cystic carcinoma. T3/T4 tumors had a 2.3 times increased risk of ONM than T1/T2 tumors. High-grade tumors had a 3.8 times increased risk of ONM than low/intermediate-grade tumors. ONM rates were exceedingly high for T3/T4, high-grade, and undifferentiated, SDC, ANOS, CXPA, and LE tumors, indicating the potential role of END.

Rare Diseases of the Orbit

This article provides an overview of rare orbital diseases. Congenital malformations, inflammatory diseases, benign and malignant neoplasias are described. Although it represents a relatively small area of the body the orbit contains multiple different tissues. Therefore, a great variety of diseases can be found within the orbital space. That is the reason, why both the completeness and the level of detail in the description of particular diseases must be somewhat limited. Nevertheless, clinical manifestations, important aspects of diagnosis, treatment strategies, and, when specific data are available, the prognosis are described. The authors tried to highlight the most characteristic aspects of the different diseases to describe their relevant aspects in spite of the brevity of the subsections.

Management of Salivary Gland Malignancy: ASCO Guideline

PURPOSE

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

METHODS

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

RESULTS

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

RECOMMENDATIONS

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

The Role of Elective Neck Treatment in the Management of Sinonasal Carcinomas: A Systematic Review of the Literature and a Meta-Analysis

The impact of elective neck treatment (ENT), whether by irradiation or dissection, on the prognosis of patients with cN0 sinonasal carcinomas (SNCs) remains an understudied issue. METHODS: A systematic review and meta-analysis of the literature were performed according to PRISMA guidelines in order to assess regional nodal relapse rate after ENT compared to observation in cN0 SNCs patients. Twenty-six articles for a total of 1178 clinically N0 patients were analyzed. Globally, the 5-year overall survival was 52%; 34.6% of patients underwent ENT and 140 regional recurrences were registered (5.9% in the ENT cohort and 15% in the observation group). ENT appears to confer a lower risk of regional recurrence compared to observation alone, with a cumulative OR of 0.38 (95% CI 0.25-0.58). Our meta-analysis supports the efficacy of ENT for reducing the risk of regional recurrence, but its overall impact on survival remains uncertain.

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.

Prognostic value of elective neck dissection in adenoid cystic carcinoma of head and neck: a meta-analysis. A call for randomized trials and international consensus

Adenoid cystic carcinoma of head and neck (AdCCHN) is an uncommon salivary gland cancer characterized for infrequent neck metastases, and high rate of local and distant recurrence. The aim of this meta-analysis was to analyse the significance of elective neck dissection (END) in terms of overall survival (OS) in patients with AdCCHN. A systematic literature search and meta-analysis was performed. Endpoint assessed by this meta-analysis included 5-year OS (death from any cause). Statistical heterogeneity was assessed using the Cochrane Q test and I² statistic. A pooled odds ratio (OR) was reported with 95% confidence interval (CI). There were 1934 patients in the END arm and 3083 in the observation group. The pooled OR, calculated for END vs. observation, was 0.94. Patients receiving END had similar risk for death compared to observation cohort (P=0.76). No significant difference in final outcome after patient stratification based on T stage was identified (OR for T1/T2 1.27, P=0.39; OR for T3/T4 0.95, P=0.90). Observation for cN0 neck is a reasonable option in AdCCHN. These findings suggest the need for prospective trials on indications and extent of END in AdCCHN.

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.

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.

Elective neck dissection in adenoid cystic carcinoma of head and neck: yes or no? A systematic review

PURPOSE

Adenoid cystic carcinoma of head and neck (AdCCHN) is salivary gland malignancy known for its slow progression accompanied with perineural invasion, rare lymphatic spread to the neck, high rate of local recurrence and delayed onset of distant metastases. While local recurrence and distant metastases are most common patterns of relapse and cause of death in AdCCHN, it has been debated whether lymph node involvement affects the course of the disease. The aim of this systematic review was to address this important issue and to recommend guidelines on clinically node-negative neck management in patients with AdCCHN.

METHODS

A systematic review of the published literature on cases of elective neck dissection (END) among patients with AdCCHN was performed.

RESULTS

This analysis included a total of 5767 AdCCHN patients with 2450 ENDs, ranging from 10 to 1190. Elective lymphadenectomy was employed in 42.5% of patients with AdCCHN (range 9.2-100%). The overall rate of occult neck metastases in patients with AdCCHN was reported to range between 0 and 43.7%, the average being 13.9%.

CONCLUSIONS

If performed, END should be limited to levels I-III of the ipsilateral neck since occult metastases are exclusively located within these neck regions. Although END is associated with a prolonged regional recurrence-free period, it influence on final outcome or survival is still controversial. This review strongly supports conduction of prospective trials on indications, prognostic significance and extent of END in AdCCHN.

The role of elective neck dissection in high-grade parotid malignancy: A hospital-based cohort study

OBJECTIVES/HYPOTHESIS

The role of elective neck dissection (END) in patients with clinically N0 (cN0), high-grade parotid carcinoma is unclear. The objective of this study was to assess the association between END and survival in patients with cN0, high-grade parotid carcinoma.

STUDY DESIGN

Retrospective, multicenter cohort study.

METHODS

A review of hospital-based cases from the National Cancer Data Base was performed. Participants included patients diagnosed with cN0, high-grade parotid cancer between January 1, 2004 and December 31, 2013. The primary exposure was receipt of neck dissection. Secondary exposures included receipt of adjuvant radiation and/or chemotherapy. Univariate and multivariate survival analyses were performed. Unadjusted and adjusted survival estimates were determined.

RESULTS

Overall, 1,547 patients were included, with a median follow-up time of 48 months. END did not have a statistically significant effect on 3-year survival (3-year: 69.9%, 95% confidence interval [CI]: 67.2 to 72.6). Survival at 3-years among those not receiving END was 66.1% (95% CI: 62.7 to 69.5). Parotidectomy and adjuvant radiotherapy had the strongest effect on mortality. There was no difference in 3-year survival among patients who underwent parotidectomy and adjuvant radiation stratified by receipt of END nor did END have a statistically significant effect on survival in mucoepidermoid carcinoma, adenocarcinoma, high-risk histology, high T stage, or academic center treatment subgroups.

CONCLUSIONS

END did not have a statistically significant effect on survival among cN0 patients with high-grade parotid cancer when taking into account receipt of adjuvant therapy and confounding. The role of END on survival and locoregional control remains to be further elucidated in prospective studies.

LEVEL OF EVIDENCE

4 Laryngoscope, 130:1487-1495, 2020.

Current thinking in the management of adenoid cystic carcinoma of the head and neck

Adenoid cystic carcinoma (ACC) is an aggressive, rare, malignant tumour that accounts for about 1% of all head and neck neoplasms and 10% of all salivary gland tumours. It is characterised by frequent local recurrences and distant metastases. Growth is slow but relentless, and progression poses a challenge to head and neck clinicians. Many small retrospective studies have described its clinical management, but the lack of multicentre, randomised, controlled trials has resulted in inconsistencies in management globally. We have focused on three key management-related controversies: the role of elective neck dissection (END) for the N0 neck; the role of adjuvant treatment or radiotherapy; and finally, the follow-up protocol, particularly cross-sectional surveillance imaging of the full body or chest computed tomography (CT) alone, and options for treatment if metastases are found. The paucity of published studies may reflect the inconsistencies that exist in the management of ACC of the head and neck in the UK. The collaboration of head and neck centres would, we think, help to correct the imbalance in these three domains of care.