Is level V neck dissection necessary in primary parotid cancer?

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.

Topography and probability diagram of cervical and intra-parotid lymph node metastasis in parotid gland cancer

In parotid gland cancer (PGC), cervical lymph node metastasis (LNM) and intra-parotid LNM are known as significant indicators of poor prognosis. However, the topography of LNM in the affected parotid gland and the lymphatic progression of PGC has never been explored in detail. This was a retrospective analysis of data from 423 patients with previously untreated primary PGC (2005 to 2020), excluding patients with squamous cell carcinoma, lymphoma or metastatic disease in the parotid gland. The pattern of LNM was analyzed by neck sub-level and parotid sub-site. Using the conditional probability of neck level involvement, a probability diagram was plotted on several thresholds to visualize the sequential progression of LNM in PGC. The pattern of LNM progression was found to be similar between low- and high-grade pathology, but the incidence differed significantly (8.0% vs. 45.4%). Intra-parotid LNs and level IIa LNs were the most common sites (57.3% and 61.0%) of LNM in PGC, followed by level III (31.7%), Ib (25.6%), IV (22.0%), IIb (20.7%) and Va (20.7%) LNM. In intra-parotid LNs, the incidence of LNM in the deep parotid LNs was relatively low (9.4%); most intra-parotid LNMs were observed in the superficial parotid (90.6%) and peri-tumoral (in contact with the tumor) (31.3%) LNs. LNM to levels Ia, Vb and contra-lateral LNM occurred only in the very late stage. Our results provide detailed information about LNM progression in PGC at the sub-level and can help clinicians decide the treatment extent, including surgery or radiation.

Systematic Review and Meta-Analysis on the Incidence of Level-Specific Cervical Nodal Metastasis in Primary Parotid Malignancies

OBJECTIVE

In primary parotid gland malignancies, the incidence of level-specific cervical lymph node metastasis in clinically node-positive necks remains unclear. This study aimed to determine the incidence of level-specific cervical node metastasis in clinically node-negative (cN0) and node-positive (cN+) patients who presented with primary parotid malignancies.

DATA SOURCES

Electronic databases (MEDLINE, EMBASE, PubMed, Cochrane).

REVIEW METHODS

Random-effects meta-analysis was used to calculate pooled estimate incidence of level-specific nodal metastasis for parotid malignancies with 95% confidence intervals (CIs). Subgroup analyses of cN0 and cN+ were performed.

RESULTS

Thirteen publications consisting of 818 patients were included. The overall incidence of cervical nodal involvement in all neck dissections was 47% (95% CI, 31%-63%). Among those who were cN+, the incidence of nodal positivity was 89% (95% CI, 75%-98%). Those who were cN0 had an incidence of 32% (95% CI, 14%-53%). In cN+ patients, the incidence of nodal metastasis was high at all levels (level I 33%, level II 73%, level III 48%, level IV 39%, and level V 37%). In cN0 patients, the incidence of nodal metastasis was highest at levels II (28%) and III (11%).

CONCLUSION

For primary parotid malignancies, the incidence of occult metastases was 32% compared to 89% in a clinically positive neck. It is recommended that individuals with a primary parotid malignancy requiring elective treatment of the neck have a selective neck dissection which involves levels II to III, with the inclusion of level IV based on clinical judgment. Those undergoing a therapeutic neck dissection should undergo a comprehensive neck dissection (levels I-V).

Indications and outcomes for elective dissection of level V in primary parotid cancer

BACKGROUND

The extent of cervical lymphadenectomy required for primary parotid cancer is not well-established.

METHODS

In this retrospective case-control study, 84 patients who underwent primary parotidectomy and neck dissection for primary parotid cancer between 2010 and 2019 were identified and analyzed.

RESULTS

Of the 84 patients, 37 underwent elective level V neck dissection. All six (16.0%) who had occult level V nodes had clinically evident, preoperative anterior cervical metastases, a statistically significant finding. No other clinical factors are correlated with posterior neck involvement. There was no significant difference in disease-free or overall survival for patients with occult level V disease relative to positive lymph nodes in other levels.

CONCLUSIONS

Patients with clinically evident anterolateral cervical lymphatic metastases from parotid cancer preoperatively have high rates of occult level V nodes. Level V neck dissection can be avoided in cN0 patients and offered no survival advantage.

[Surgery for parotid gland cancer-controversial and proven aspects]

BACKGROUND

Due to the rarity of primary parotid malignancies, there are currently only limited clinical study data on the optimal surgical therapy. Parotid malignancies encompass a broad spectrum of more than 20 different histological subtypes with varying biology, which thus represents a challenge for even experienced pathologists and head and neck surgeons with proven expertise in salivary gland surgery.

OBJECTIVE

The aim of this review article is to provide an overview of the current literature on surgical therapy of the primary tumor and the cN0 neck as well as treatment of the facial nerve, and to shed light on the various controversial aspects of this topic.

RESULTS

In salivary gland oncology there is a trend towards safe (R0) but more conservative surgery. Currently, less-invasive surgical approaches could potentially be applied in a small subgroup with carefully selected caudally located and R0-resected "low-grade tumors" in stages T1-T2 and cN0 in relatively young patients with high compliance and more in the context of structured clinical studies. Elective neck dissection in the case of cN0 status should be carried out if risk factors for occult cervical lymph node metastasis (T3-T4a, "high-grade subtypes," advanced age, lymphangitic carcinomatosis) are present. In cases of small "low-grade parotid carcinomas," narrow resection margins or even microscopic tumor residues on the facial nerve can potentially be adequately compensated with adjuvant radiation therapy. However, due to the lack of solid data, the significance of the actual effect of the radiation in this situation should be viewed with great caution.

Is elective neck dissection necessary for patients with cT3-4N0 parotid gland cancer?

OBJECTIVE

Management of the cervical lymph nodes in patients with cT3-4N0 parotid gland cancer (PGC) has been controversial. This study investigated the need for elective neck dissection (END) in patients with cT3-4N0 PGC.

METHODS

We retrospectively examined cervical lymph node metastasis, overall survival (OS), and disease-free survival (DFS) rates in 40 patients with cT3-4N0 PGC according to whether or not END was performed.

RESULTS

Cervical lymph node metastasis occurred in 27.5% of patients and level II was the most common area. Recurrence could be treated by salvage neck dissection. There was no significant difference in OS (P=0.581) or DFS (P=0.728) between the group that underwent END and the group that did not.

CONCLUSION

END at level II is worth performing because of the occult lymph node metastasis rate. The area of neck dissection should be limited because there is no evidence that END improves the prognosis of cT3-4N0 PGC.

Extent and Indications for Elective and Therapeutic Neck Dissection for Salivary Carcinoma

Although salivary gland malignancies account for only a small percentage of all head and neck cancers, the incidence is increasing. Furthermore, there is a wide variety of histologic subtypes which must be taken into account in the context of their location. Each is associated with a different rate of regional metastasis and overall survival. This article examines the incidence of salivary gland malignancies and provides evidence for the indications for and extent of elective or therapeutic neck dissection based on location, pathologic type, and histopathologic characteristics.

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.

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.

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.

Rate of Occult Neck Nodal Metastasis in Parotid Cancer: A Meta-Analysis

BACKGROUND

The risk for occult neck nodal metastasis in carcinoma of the parotid gland is inconclusive. Therefore, addressing a negative neck prophylactically and the extent to do so remain controversial. This systematic review aimed to determine the rate of occult nodal metastasis for each neck level, and consequently, to elucidate the proper extent of elective neck dissection (END).

METHODS

A meta-analysis of all studies that included patients with a diagnosis of parotid malignancies who underwent an END was performed. The risk for occult nodal metastasis was calculated for each neck level separately.

RESULTS

The search strategy identified 124 papers from January 1980 to December 2019 in the various databases. Nine retrospective studies (n =548) met the inclusion criteria. The risk for occult neck nodal metastasis ranged from 0.0 to 9.43% with a random-effect model of 2.2% for level 1 (n =459), from 3.4 to 28.38% with a random-effect model of 16.51% for level 2 (n =548), from 0.0 to 21.63% with a random-effect model of 4.23% for level 3 (n =518), from 0.0 to 17.02% with a fixed-effect model of 0.39% for level 4 (n =310), and from 0.0 to 11.63% with a fixed-effect model of 1.7% for level 5 (n =417).

CONCLUSION

The rate of occult neck nodal metastasis in parotid malignancies is low, with neck level 2 the most commonly involved. The results of this meta-analysis prevented the authors from substantiating the appropriate extent of an END in parotid cancer.

Does neck dissection affect post-operative outcomes in parotidectomy? A national study

OBJECTIVE

To characterize post-operative complications in parotidectomy with neck dissection.

METHODS

Patients age ≥ 18 receiving a parotidectomy or parotidectomy with neck dissection between 2005 and 2017 were eligible for inclusion. Patients with unknown demographic variables were excluded. Univariate and multivariable logistic regression analyses were performed.

RESULTS

A total of 13,609 parotidectomy patients were analyzed, 11,243 (82.6%) without neck dissection and 2366 (17.4%) with neck dissection. Both length of surgery (mean minutes ± standard deviation [SD] = 335.9 ± 189.2 vs. 152.9 ± 99.0, p < 0.001) and length of hospital stay (mean days ± SD = 3.90 ± 4.76 vs. 1.04 ± 2.14, p < 0.001) were greater with dissection. 13.9% of parotidectomies with neck dissection and 3.5% without dissection (p < 0.001) had at least one complication, which remained significant after multivariable adjustment (Odds Ratio[OR] = 1.565 (95%CI = 1.279-1.914), p < 0.001). The increase in post-operative complications was predominately driven by an increased transfusion rate (7.4% vs. 0.5%, p < 0.001). Multivariable analysis also demonstrated no significant difference in rates of returning to the operating room (OR = 1.122 (95%CI 0.843-1.493), p > 0.05) or rates of readmission (OR = 1.007 (95%CI 0.740-1.369), p > 0.05). Parotidectomy with neck dissection was more likely to be inpatient (OR = 4.411 (95%CI 3.887-5.004), p < 0.001) and to be ASA class 3 (OR = 1.367 (95%CI 1.194-1.564), p < 0.001).

CONCLUSIONS

Nationwide data demonstrates that parotidectomy with neck dissection is associated with increased rates of post-operative complications; however, neck dissection did not significantly impact readmission or reoperation rates. These findings indicate that neck dissection is a relatively safe addition to parotidectomy and provide novel evidence in the management of parotid malignancies.

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.

Controversies in the Workup and Surgical Management of Parotid Neoplasms

OBJECTIVE

Parotid neoplasms are a rare heterogeneous group of tumors with varied clinical presentation and behavior. Here we provide an evidence-based review of the contemporary approach to evaluation and surgical management of parotid tumors.

DATA SOURCE

PubMed and Web of Science Databases.

REVIEW METHODS

Searches of the PubMed and Web of Science databases were performed on subjects related to the diagnosis and surgical management of parotid neoplasms. Particular emphasis was placed on the following areas: evaluation of parotid tumors, including imaging workup and the utility of fine-needle aspiration; extent of surgery of the primary lesion, including the extent of parotidectomy as well as oncologic management of the facial nerve; the extent of surgery of involved and at-risk cervical lymphatics; and parotid bed reconstruction. Articles published from 2014 to the present were prioritized, supplementing with information from prior studies in areas where data are lacking.

CONCLUSION

A summary of the literature in these areas is outlined to provide an evidence-based approach to evaluation and management of parotid neoplasms.

IMPLICATIONS FOR PRACTICE

While data are available to help guide many aspects of workup and management of parotid neoplasms, further research is needed to refine protocols for this heterogeneous group of diseases.

An evidence-based analysis of the management of N0 neck in patients with cancer of the parotid gland

Introduction: Management of clinically negative neck (cN0) in patients with parotid gland cancer is controversial. Treatment options can include observation, elective neck dissection or elective radiotherapy. Areas covered: We addressed the treatment options for cN0 patients with parotid gland cancer. A literature review was undertaken to determine the optimal management of this group of patients. Expert opinion: Patients with parotid carcinoma and clinically negative neck have various options for their management. The analysis of tumor stage, histology and grade is essential to better define patients at risk for occult lymph node metastasis. These patients can be managed by surgery, radiotherapy or their combination, depending on the presence of risk factors, the moment at which such risk factors are detected, patient-related clinical conditions, medical provider expertise and institutional facilities.

AHNS series: Do you know your guidelines? Diagnosis and management of salivary gland tumors

This article is the next installment of the series "Do you know your guidelines" presented by the Education Committee of the American Head and Neck Society. Guidelines for the workup and management of tumors of the major and minor salivary glands are reviewed.

Development of a novel salivary gland cancer lymph node staging system

BACKGROUND

Current lymph node (LN) staging for salivary gland cancer (SGC) is extrapolated from mucosal head and neck squamous cell carcinoma. However, given its unique biology and clinical behavior, it is possible that a SGC-specific LN staging system would be more accurate.

METHODS

Patients from the National Cancer Data Base with nonmetastatic SGC of the head and neck who were diagnosed from 2004 through 2013 and underwent surgical resection and neck dissection removing at least 10 LNs were included. Multivariable models were constructed to assess the association between survival and LN factors, including number of metastatic LNs, extranodal extension, LN size, and lower LN involvement.

RESULTS

Overall, 4520 patients met the inclusion criteria. An increasing number of metastatic LNs was found to be strongly associated with worse survival without plateau. The risk of death increased more rapidly up to 4 LNs (hazard ratio, 1.34; 95% confidence interval, 1.27-1.41 [P < .001]), and was more gradual for additional LNs >4 (hazard ratio, 1.02; 95% confidence interval, 1.01-1.03 [P < .001]). LN size, extranodal extension, and lower LN involvement appeared to have no impact on survival when accounting for the number of metastatic LNs. Recursive partitioning analysis was used to create a novel SGC LN staging system in which N0 indicates 0 positive LNs, N1 indicates 1 to 2 positive LNs, N2 indicates 3 to 21 positive LNs, and N3 indicates ≥ 22 positive LNs. This system exhibited greater concordance than the current American Joint Committee on Cancer (eighth edition) system.

CONCLUSIONS

Quantitative LN burden is an important determinant of survival in patients with SGC. Use of this variable may improve SGC staging. Cancer 2018. © 2018 American Cancer Society.

Contemporary Management of Benign and Malignant Parotid Tumors

To report the standard of care, interesting new findings and controversies about the treatment of parotid tumors. Relevant and actual studies were searched in PubMed and reviewed for diagnostics, treatment and outcome of both benign and malignant tumors. Prospective trials are lacking due to rarity of the disease and high variety of tumor subtypes. The establishment of reliable non-invasive diagnostics tools for the differentiation between benign and malignant tumors is desirable. Prospective studies clarifying the association between different surgical techniques for benign parotid tumors and morbidity are needed. The role of adjuvant or definitive radiotherapy in securing loco-regional control and improving survival in malignant disease is established. Prospective clinical trials addressing the role of chemotherapy/molecular targeted therapy for parotid cancer are needed. An international consensus on the classification of parotid surgery techniques would facilitate the comparison of different trials. Such efforts should lead into a clinical guideline.

Multidisciplinary Management of Salivary Gland Cancers

BACKGROUND

Salivary carcinomas are a rare group of biologically diverse neoplasms affecting the head and neck. The wide array of different histological entities and clinical presentations has historically limited attempts to establish well-defined treatment algorithms. In general, low-risk lesions can be managed with a single treatment modality, whereas advanced lesions require a more complex, multidisciplinary approach.

METHODS

The relevant literature was reviewed, focusing on diagnostic and treatment algorithms for salivary malignancies.

RESULTS

Salivary carcinomas with high-risk features require an aggressive treatment approach with complete surgical resection, neck dissection to appropriate cervical lymph-node basins, and postoperative radiotherapy.

CONCLUSIONS

The heterogeneity of salivary neoplasms represents a unique clinical challenge. Despite the multidisciplinary management paradigm detailed in this review, outcomes for advanced disease are unsatisfactory. Future progress will likely require the addition of novel systemic therapeutic strategies.

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.

Clinicopathologic factors associated with recurrence in low- and high-grade parotid cancers

BACKGROUND

The purpose of this study was to determine clinicopathological correlates of outcome among patients with parotid gland cancer.

METHODS

The medical records of 126 patients treated by surgery for localized parotid cancer were retrospectively reviewed to identify the clinicopathologic correlates of recurrence-free survival (RFS) according to histologic grade.

RESULTS

Multivariate analysis revealed that age and lymphovascular invasion were significant factors for recurrence in patients with low-grade cancer (p = .049 and p = .019, respectively), whereas perineural invasion was the only significant factor in patients with high-grade cancer (p = .001). The most frequent recurrence site tends to be different according to histologic grade: local recurrence at low-grade cancer (8.3%) and distant at high-grade cancer (13.6%). The duration of RFS was significantly longer in low-grade cancer than high-grade cancer in regional and distant recurrence (p = .044 and p = .016, respectively).

CONCLUSION

Consideration of different factors may be required for individual low-grade and high-grade parotid cancers when predicting the risk of recurrence. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1788-E1793, 2016.