Occurrence of lymph node metastasis in early-stage parotid gland cancer

An end-to-end deep convolutional neural network-based dose engine for parotid gland cancer seed implant brachytherapy

BACKGROUND

Seed implant brachytherapy (SIBT) is a promising treatment modality for parotid gland cancers (PGCs). However, the current clinical standard dose calculation method based on the American Association of Physicists in Medicine (AAPM) Task Group 43 (TG-43) Report oversimplifies patient anatomy as a homogeneous water phantom medium, leading to significant dose calculation errors due to heterogeneity surrounding the parotid gland. Monte Carlo Simulation (MCS) can yield accurate dose distributions but the long computation time hinders its wide application in clinical practice.

PURPOSE

This paper aims to develop an end-to-end deep convolutional neural network-based dose engine (DCNN-DE) to achieve fast and accurate dose calculation for PGC SIBT.

METHODS

A DCNN model was trained using the patient's CT images and TG-43-based dose maps as inputs, with the corresponding MCS-based dose maps as the ground truth. The DCNN model was enhanced based on our previously proposed model by incorporating attention gates (AGs) and large kernel convolutions. Training and evaluation of the model were performed using a dataset comprising 188 PGC I-125 SIBT patient cases, and its transferability was tested on an additional 16 non-PGC head and neck cancers (HNCs) I-125 SIBT patient cases. Comparison studies were conducted to validate the superiority of the enhanced model over the original one and compare their overall performance.

RESULTS

On the PGC testing dataset, the DCNN-DE demonstrated the ability to generate accurate dose maps, with percentage absolute errors (PAEs) of 0.67% ± 0.47% for clinical target volume (CTV) D90 and 1.04% ± 1.33% for skin D0.1cc. The comparison studies revealed that incorporating AGs and large kernel convolutions resulted in 8.2% (p < 0.001) and 3.1% (p < 0.001) accuracy improvement, respectively, as measured by dose mean absolute error. On the non-PGC HNC dataset, the DCNN-DE exhibited good transferability, achieving a CTV D90 PAE of 1.88% ± 1.73%. The DCNN-DE can generate a dose map in less than 10 ms.

CONCLUSIONS

We have developed and validated an end-to-end DCNN-DE for PGC SIBT. The proposed DCNN-DE enables fast and accurate dose calculation, making it suitable for application in the plan optimization and evaluation process of PGC SIBT.

Radiotherapy for salivary gland cancer: REFCOR recommendations by the formal consensus method

OBJECTIVE

To determine the indications for radiotherapy in salivary gland cancer and to specify the modalities and target radiation volumes.

MATERIAL AND METHODS

The French Network of Rare Head and Neck Tumors (REFCOR) formed a steering group which drafted a narrative review of the literature published on Medline and proposed recommendations. The level of adherence to the recommendations was then assessed by a rating group, according to the formal consensus method.

RESULTS

Postoperatively, radiotherapy to the primary tumor site±to the lymph nodes is indicated if one or more of the following adverse histoprognostic factors are present (risk>10% of locoregional recurrence): T3-T4 category, lymph node invasion, extraglandular invasion, close or positive surgical margins, high tumor grade, perineural invasion, vascular emboli, and/or bone invasion. Intensity-modulated radiation therapy (IMRT) is the gold standard. For unresectable cancers or inoperable patients, carbon ion hadrontherapy may be considered.

CONCLUSION

Radiotherapy in salivary gland cancer is indicated in postoperative situations in case of adverse histoprognostic factors and for inoperable tumors.

Lymph node surgery for salivary gland cancer: REFCOR recommendations by the formal consensus method

OBJECTIVE

To determine the indications for neck dissection in the management of parotid, submandibular or minor salivary gland cancers depending on the clinical situation: i.e., clinical lymph node involvement (cN+) or not (cN0); low or high risk of occult nodal metastasis; diagnosis of malignancy before, during or after surgery.

MATERIAL AND METHODS

The French Network of Rare Head and Neck Tumors (REFCOR) formed a steering group which drafted a narrative review of the literature published on Medline and proposed recommendations. The level of adherence to the recommendations was then assessed by a rating group according to the formal consensus method.

RESULTS

In cN+ salivary gland cancer, ipsilateral neck dissection is recommended. In cN0 salivary gland cancer, ipsilateral neck dissection is recommended, except for tumors at low risk of occult nodal metastasis. If definitive pathology reveals a high risk of occult nodal involvement, additional neck treatment is recommended: ipsilateral neck dissection or elective nodal irradiation.

CONCLUSION

The rate of occult lymph node involvement, and therefore the indication for elective neck dissection, depends primarily on the pathologic grade of the salivary gland cancer.

Recurrence after primary salivary gland carcinoma: Frequency, survival, and risk factors

BACKGROUND

Primary salivary gland carcinomas (SGC) are rare neoplasms that present therapeutic challenges especially in recurrent tumors. The aim of this study was to investigate the incidence and distribution of tumor recurrence, associated risk factors, and survival.

METHODS

This analysis includes data from 318 patients treated for SGC between 1992 and 2020. Survival analysis was performed using the Kaplan-Meier method. Univariate and multivariate analyses were used to identify risk factors associated with recurrence.

RESULTS

21.7% of the patients developed recurrent disease after a mean of 38.2 months. In multivariate analysis, positive-resection margins, vascular invasion, and tumor localization in the submandibular gland and small salivary glands were independent factors for recurrence. The 5-year overall survival was 67%, the 5-year disease-free survival was 54%.

CONCLUSION

Tumor recurrence in SGC occurred in one out of five patients. In highly aggressive entities and patients with risk factors, treatment intensification should be considered.

Salivary gland tumors: an audit from a tertiary care centre in Northern India

Salivary gland tumors are relatively rare and can exhibit various clinical behaviors. The study aims to understand the natural history, pathology, diagnostic workup, and treatment strategies for these tumors to improve patient outcomes. The audit included patients with salivary gland tumors detected through radiology or cytology. Patients underwent surgery, with some receiving adjuvant treatment. Demographic information, treatment interventions, and survival outcomes were analyzed using SPSS software. A total 89 as malignant salivart gland tumours were audited Malignant tumors were predominantly found in the parotid gland, with fewer cases in the minor salivary gland and submandibular gland.The median age of presentation was 47 years, and the majority of patients were male. The study examined various pathological and clinical factors, including tumor stage, nodal status, and the presence of facial palsy. Surgical procedures and histological types of tumors were documented. Adverse histological features like positive margins, lymph node positivity, lympho-vascular invasion, extracapsular spread, and perineural invasion were noted. POSTOP RT was administered to high-risk patients. Most malignant salivary gland tumors were found in the parotid gland, while minor salivary gland tumors were underrepresented in the audit. Surgical practices were diverse. Radiotherapy protocols were relatively standardized. The study found that certain histological features, such as lymph node positivity, margin positivity, lympho-vascular invasion, perineural invasion, and extracapsular spread, were associated with adverse effects on DFS and OS. The findings suggest that specific histological features, including LVI and ECE have emerged as independent prognostic factors for DFS and OS.

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.

Intraparotid node metastasis affects the long-term survival of patients with resectable recurrent parotid gland carcinoma

PURPOSE

The recurrence rate of parotid gland cancer is high, but research on the prognosis of recurrent parotid gland cancer (RPC) is relatively limited. We aim to determine the potential prognosis factors of RPC.

STUDY DESIGN

Retrospective cohort analysis.

SETTING

Tertiary cancer center.

METHODS

We conducted a retrospective review from 2012 to 2021 on RPC patients treated at the China National Cancer Center (CNCC). To analyze the impact of various variables on overall survival (OS) after recurrence, a univariate and multivariate Cox proportional hazard model was employed.

RESULTS

A total of 50/218 (23.0%) patients diagnosed with RPC and underwent surgery. The 5-year OS of all RPC patients in this cohort was 61.9%. 5 of 50 patients (10%) exhibited intraparotid node (IPN) metastasis. By univariate and multivariate analyses, we found that IPN metastasis was one of the prognostic factors of OS (p = 0.039) in RPC patients. The presence of IPN metastasis was also related to poor survival in individuals with negative cervical lymph nodes (CN0) (p = 0.011). In terms of the influence of surgical margins on prognosis, our findings revealed that RPC patients with negative margins exhibited a higher survival result than those with positive margins (p = 0.002).

CONCLUSION

According to this study, IPN metastasis indicate a high incidence of mortality in recurrent parotid cancer patients. Particularly, in CN0 patients, the presence of IPN metastasis was associated with poor survival in CN0 patients.

Rapid multi-task diagnosis of oral cancer leveraging fiber-optic Raman spectroscopy and deep learning algorithms

Introduction

Oral cancer, a predominant malignancy in developing nations, represents a global health challenge with a five-year survival rate below 50%. Nonetheless, substantial reductions in both its incidence and mortality rates can be achieved through early detection and appropriate treatment. Crucial to these treatment plans and prognosis predictions is the identification of the pathological type of oral cancer.

Methods

Toward this end, fiber-optic Raman spectroscopy emerges as an effective tool. This study combines Raman spectroscopy technology with deep learning algorithms to develop a portable intelligent prototype for oral case analysis. We propose, for the first time, a multi-task network (MTN) Raman spectroscopy classification model that utilizes a shared backbone network to simultaneously achieve different clinical staging and histological grading diagnoses.

Results

The developed model demonstrated accuracy rates of 94.88%, 94.57%, and 94.34% for tumor staging, lymph node staging, and histological grading, respectively. Its sensitivity, specificity, and accuracy compare closely with the gold standard: routine histopathological examination.

Discussion

Thus, this prototype proposed in this study has great potential for rapid, non-invasive, and label-free pathological diagnosis of oral cancer.

Distribution of sentinel nodes from parotid tumors-A feasibility study

BACKGROUND

Optimum management of the N0 neck is unresolved in parotid salivary gland cancer. Sentinel node biopsy (SNB) can reliably detect microscopic lymph node metastasis and its´ clinical use is increasing for head and neck tumors. The object of this study was to establish whether the technique is applicable to detect distribution of sentinel nodes for parotid tumors.

MATERIALS AND METHODS

Prosepective observational study in 30 patients with benign or low-grade T1-T2N0 malignant tumors in the parotid gland planned for surgical treatment. Distribution of SN was detected with a preoperative ultrasound-guided peritumoral injection with a technetium-99 (Tc-99 m) laballed tracer followed by a SPECT-CT and intraoperative measurement in the neck and parotidal tissue. In patients with cytologically suspected malignant tumor or highly unclerar cytology, SNB was also performed.

RESULTS

Sentinel nodes (SNs) were detected in 26/30 cases. Out of these, 7 presented with only one SN, whereas multiple sentinel nodes where detected in 19 cases. No SNs were found in neck level 1. SN was detected in level 5 independent of tumor location within the parotid gland. An intraparotidal distribution of SNs was more frequent in larger tumors.

CONCLUSIONS

The use of SN-technique in the planning of surgical treatment of parotid tumors seems feasible. It may be of clinical value for patients with parotid cancer to enable a more accurate staging and to detect occult metastasis in the SNs within the parotid as well as in the neck, enabaling the possibility to surgically remove all positive SNs at primary surgery and with reduced surgical morbidity.

Deep-Learning-Based Automatic Segmentation of Parotid Gland on Computed Tomography Images

This study aims to develop an algorithm for the automatic segmentation of the parotid gland on CT images of the head and neck using U-Net architecture and to evaluate the model's performance. In this retrospective study, a total of 30 anonymized CT volumes of the head and neck were sliced into 931 axial images of the parotid glands. Ground truth labeling was performed with the CranioCatch Annotation Tool (CranioCatch, Eskisehir, Turkey) by two oral and maxillofacial radiologists. The images were resized to 512 × 512 and split into training (80%), validation (10%), and testing (10%) subgroups. A deep convolutional neural network model was developed using U-net architecture. The automatic segmentation performance was evaluated in terms of the F1-score, precision, sensitivity, and the Area Under Curve (AUC) statistics. The threshold for a successful segmentation was determined by the intersection of over 50% of the pixels with the ground truth. The F1-score, precision, and sensitivity of the AI model in segmenting the parotid glands in the axial CT slices were found to be 1. The AUC value was 0.96. This study has shown that it is possible to use AI models based on deep learning to automatically segment the parotid gland on axial CT images.

Number of positive lymph nodes combined with the logarithmic ratio of positive lymph nodes predicts long-term survival for patients with node-positive parotid gland carcinoma after surgery: a SEER population-based study

PURPOSE

To evaluate the prognostic value of the number of positive lymph nodes (NPLN), the ratio of positive lymph nodes (pLNR), and the logarithmic ratio of positive lymph nodes (LODDS) in patients with parotid gland carcinoma. On this basis, establishing and validating an optimal nomogram.

METHODS

A total of 895 patients with T1-4N1-3M0 parotid gland carcinoma were included in our study from the Surveillance, Epidemiology, and End Results (SEER) database. Patients' data were randomly assigned to the training cohort and the validation cohort by a ratio of 7:3. Univariate and multivariate COX regression analysis were used to explore the relationship between the study factors and the prognosis of parotid gland carcinoma, including overall survival (OS) and cause-specific survival (CSS). The Akaike Information Criterion (AIC) was used to evaluate model fit. Harrell's concordance index (C-index), integrated discrimination improvement (IDI), and net reclassification index (NRI) were used to evaluate the predictive ability of these models. The decision curve analysis was used to evaluate the clinical benefit of the nomograms compared with the TNM stage.

RESULTS

NPLN, pLNR, and LODDS are independent risk factors for the prognostic of PGC. According to the AIC, C index, IDI, and NRI, the models combined with NPLN and LODDS were the best. The decision curves suggested that our nomograms had good predictive abilities for the prognosis of parotid gland carcinoma.

CONCLUSION

The two nomograms which contained NPLN and LODDS had the potential to predict OS and CSS in patients with parotid gland carcinoma.

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).

Role of Intra-Parotid Lymph Node Metastasis in Primary Parotid Carcinoma

The parotid gland contains intra-glandular lymph nodes, the distribution of which is crucial for understanding the pathogenesis of intra-parotid lymph node metastases of parotid carcinoma and other head and neck carcinomas. Positive intra-parotid lymph node metastasis predicts the risk of positive cervical nodal metastasis. It is important to establish whether prophylactic neck dissection, including intra-parotid lymph nodes, contributes to treatment outcomes. The presence or absence of intra-parotid lymph nodes or metastasis-positive lymph nodes warrants further study. A preoperative diagnosis by imaging and fine-needle aspiration cytology of intra-parotid lymph nodes is difficult. Although intraoperative frozen section biopsy is performed during surgery, it is challenging to identify intra-parotid lymph nodes. The number of lymph nodes was the largest (47%) in the lower half of the superficial lobe, with 35% of nodes being concentrated in the inferior part of the cervicofacial branch, i.e., the lower pole of the parotid gland. Therefore, superficial parotidectomy and lower pole lobectomy need to be performed in cases in which a malignant tumor localizes to the superficial lobe or a lower pole. When intra-parotid lymph node metastases are detected during surgery, selective neck dissection (at least levels II and III) needs to be simultaneously performed.

Salivary gland cancer: ESMO-European Reference Network on Rare Adult Solid Cancers (EURACAN) Clinical Practice Guideline for diagnosis, treatment and follow-up

•This ESMO–EURACAN Clinical Practice Guideline provides key recommendations for managing salivary gland cancer. •The guideline covers clinical and pathological diagnosis, staging and risk assessment, treatment and follow-up. •Treatment algorithms for parotid, submandibular, sublingual and minor salivary gland cancer are provided. •The author group encompasses a multidisciplinary group of experts from different institutions and countries in Europe. •Recommendations are based on available scientific data and the authors’ collective expert opinion.

[Radiation therapy of malignant salivary gland tumors]

Due to their rarity, histologic heterogeneity, and localization, treatment of malignant salivary gland tumors requires an interdisciplinary approach. First-line treatment includes complete tumor resection. Postoperative radiation therapy is advised in patients with risk factors, i.e., incomplete tumor resection, high-grade tumors, or perineural invasion. Definitive radiation therapy is only advised for inoperable tumors because of significantly lower local control and survival rates when compared to combined surgery and radiation therapy. In radiation oncology, modern techniques such as intensity-modulated radiation therapy (IMRT) or particle therapy with heavy ions (i.e., C12) have led to improved outcomes in the treatment of head and neck tumors, especially of adenoid cystic carcinomas. Given the biological and physical benefits of particles, particle therapy, particularly carbon ion radiation, is a promising therapeutic approach for salivary gland tumors that will be further investigated in prospective clinical studies.

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.

Prediction of Long-Term Survival Outcome by Lymph Node Ratio in Patients of Parotid Gland Cancer: A Retrospective study

Background

Lymph node ratio (LNR) has been reported to reliably predict cancer-specific survival (CSS) in parotid gland cancer (PGC). Our study was designed to validate the significance of LNR in patients with PGC.

Methods

Patients diagnosed with stage I–IV PGC were enrolled from Surveillance Epidemiology and End Results database (SEER, N = 3529), which is the training group, and Sun Yat-sen University Cancer Center database (SYSUCC, N = 99), the validation group. We used X-tile software to choose the optimal cutoff value of LNR; then, univariable and multivariable analyses were performed, assessing the association between LNR and CSS.

Results

The optimal cutoff value of LNR was 0.32 by X-tile based on 3529 patients from SEER. Cox proportional hazard regression analysis revealed better CSS for patients with LNR ≤ 0.32 (adjusted hazard ratio [HR] 1.612, 95% confidence interval [95% CI] 1.286–2.019; p < 0.001) compared with patients with LNR > 0.32 in SEER. In the SYSUCC cohort, patients with LNR ≤ 0.32 also had better CSS over patients with LNR > 0.32 (p < 0.001). In N2 and N3 stage groups, patients with LNR ≤ 0.32 had superior CSS outcomes over those with the LNR > 0.32 group, but this benefit was absent in the N1 stage group.

Conclusions

In conclusion, the lymph node ratio turned out to be an independent prognostic factor for cancer-specific survival of PGC in this study. This valuable information could help clinicians to evaluate the prognosis of PGC and suggest that adequate lymph node dissection is necessary.

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.

Occult nodal metastasis in major salivary gland malignancy: An update from the National Cancer Database

OBJECTIVES

Malignant salivary gland tumors are rare neoplasms that are vastly heterogenous in their histological patterns and clinical behaviors. As a consequence, studies have lacked the robust sample sizes needed to define treatment strategies. In this study, we used the National Cancer Database to identify the incidence of occult nodal metastasis and effect on overall survival for the most common malignant salivary gland subtypes. A retrospective review of patients in the National Cancer Database with primary site malignancies of major salivary glands between 2004 and 2016 was performed. Subjects included in the study underwent surgical treatment with and without adjuvant radiation and had complete information on TNM pathological stage.

MATERIALS AND METHODS

8,689 patients with primary malignant salivary gland cancer were analyzed. The sample was stratified by histologic subtype. Univariate analysis of lymph node metastasis of the whole cohort showed a higher risk of death (p < 0.001), when compared to those without. Also when comparing occult vs evident metastasis, the risk of death was higher for the latter (p < 0.001).

RESULTS AND CONCLUSION

Occult cervical lymph node metastasis ranged from 14.9% to 35.8% in malignant salivary gland cancers, depending on histological subtype. Occult nodal metastasis was a poor prognostic factor with significantly worse overall survival.

The role of total parotidectomy in high-grade parotid malignancy: A multisurgeon retrospective review

PURPOSE

Determine rates of intra-parotid and neck nodal metastasis, identify risk factors for recurrence, and report outcomes in patients with primary high-grade parotid malignancy who undergo total parotidectomy and neck dissection.

MATERIALS & METHODS

Retrospective review of patients undergoing total parotidectomy and neck dissection for high-grade parotid malignancy between 2005 and 2015. The presence and number of parotid lymph nodes, superficial and deep, as well as cervical lymph nodes involved with metastatic disease were assessed. Risk factors associated with metastatic spread to the parotid deep lobe were identified and recurrence rates reported.

RESULTS

75 patients with median follow-up time of 47 months. 35 patients (46.7%) had parotid lymph node metastasis. Seven patients (9.3%) had deep lobe nodal metastasis without metastasis to the superficial lobe nodes. Nine patients (12%) had positive intra-parotid nodes without positive cervical nodes. Cervical nodal disease was identified in 49.3% patients (37/75). Local, parotid-bed recurrence rate was 5.3% (4/75). Regional lymph node recurrence rate was also 5.3% (4/75). Rate of distant metastasis was 30.6% (23/75). The overall disease free survival rate for all patients at 2 and 5 years were 71% and 60% respectively.

CONCLUSION

Parotid lymph node metastasis occurred at a similar rate to cervical lymph node metastasis (46.7% and 49.3%, respectively). Deep lobe parotid nodal metastasis occurred in nearly a quarter of patients and can occur without superficial parotid nodal metastasis. Rate of recurrence in the parotid bed, which may represent local or regional recurrence, was similar to regional cervical lymph node recurrence. Total parotidectomy and neck dissection should be considered high-grade parotid malignancy regardless of clinical nodal status.

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.

Prognostic indicators in clinically node-negative malignant primary salivary tumours of the parotid: A multicentre experience

OBJECTIVES

Nodal metastasis is an important prognosticator in primary parotid cancers. The management of the clinically node-negative neck is an area lacking consensus. This study investigates the occult nodal metastasis rate, and prognostic indicators in primary parotid cancers.

MATERIALS AND METHODS

We performed a multicentre retrospective case note review of patients diagnosed and treated surgically with curative intent between 1997 and 2020. Demographic, clinic-pathological and follow-up data was recorded.

RESULTS

After exclusions, 334 patients were included for analysis, with a median follow-up of 48 months. The overall rate of occult lymph node metastasis amongst patients undergoing elective neck dissection was 22.4%, with older age, high-grade and more advanced primary tumours being associated with higher rates. On multivariable analysis, age ≥ 60 years (HR = 2.69, p = 0.004), high-grade tumours (HR = 2.70, p = 0.005) and advanced primary tumours (pT3-4, HR = 2.06, p = 0.038) were associated with worse overall survival. Occult nodal metastasis on final pathology was associated with a close-to-significant reduction in regional recurrence free survival (HR = 3.18, p = 0.076).

CONCLUSION

This large series confirms the significant occult lymph node metastasis rate in primary parotid cancer, and demonstrates the importance of primary histology, tumour grade and stage in predicting survival outcome. This data supports the use of elective neck dissection in patients with high-risk tumours.

Is Revision Surgery Necessary for Patients With High Risk of Recurrence After Parotidectomy? A Multicenter Retrospective Study

OBJECTIVES

Close margin is a frequent situation after parotidectomy. The need for systematic prophylactic revision surgery is a question that arises regularly for malignant tumors, as it exposes to a high risk of facial palsy, while oncological benefits are unclear.

STUDY DESIGN

retrospective study.

SETTING

Multicentric.

SUBJECTS AND METHODS

We included all patients operated for systematic revision surgery in case of close margins after parotidectomy for a malignant tumor and analyzed the rate of tumor residue and its risk factors.

RESULTS

A tumor residue was identified in 43.5% of 23 cases, but none in case of initial complete excision with supra-millimetric margins. Invaded lymph nodes were identified in 6 cases, but none in case of low-grade tumors.

CONCLUSIONS

Systematic revision seems mandatory in case of infra-millimetric margins and high-grade tumors or positive lymph node; further studies are needed to confirm whether it can be spared for T1-T2/N0 low-grade tumors, with close margins but complete initial excision.

The Clinical Characteristics and CT Findings of Parotid and Submandibular Gland Tumours

Objective

To investigate the clinical characteristics and CT findings of parotid and submandibular gland tumours. Materials and methods. From May 2017 to April 2020, all patients with clinically proven parotid and submandibular gland enlargement and palpable masses underwent CT examinations. All patients were confirmed by pathology after surgery. The clinical characteristics and CT features were observed and evaluated. The mean density values before and after enhancement were measured and analyzed. The chi-square test, one-way ANOVA, and Student's t-test were used.

Results

Ninety-four patients with a total of 94 unilateral tumours in the parotid and submandibular glands were enrolled, including 38 pleomorphic adenomas (PAs), 27 Warthin's tumours (WTs), and 29 malignant tumours (MTs). The majority of the PAs (28/38) and MTs (23/29) were located in the parotid gland; the others were located in the submandibular gland. All the WTs were in the parotid gland. The most common benign tumours of the parotid gland were PAs (28/38, 73.7%) and WTs (27/27, 100%), and the most common MTs were mucoepidermoid carcinoma, acinic cell carcinoma, and squamous cell carcinoma (4/29, 13.8%). The most common benign and malignant tumours in the submandibular gland were PAs (10/38, 26.3%) and ductal adenocarcinomas (3/4, 75%). The majority of PA patients (28/38) were female, compared with WT (2/27) (P < 0.001) and malignant tumour patients (10/29) (P < 0.01). A significant difference was also found between WTs and MTs in female patients (P < 0.05). The mean age of PA patients was 43.4 ± 12.1 years, which was lower than that of WTs (62.1 ± 11.7) and MTs (58 ± 14.18) (P < 0.001, P < 0.001, and P=0.244, respectively). On CT imaging, the mean diameter of the PAs and WTs was significantly smaller than that of the MTs (P=0.001 and P < 0.001), and no difference was observed between the PAs and WTs (P=0.275). In the parotid gland, the superficial lobe was more frequently involved than the deep lobe (PAs, 22 : 6; WTs, 17 : 10; and MTs, 15 : 8). The majority of PAs and WTs demonstrated round shapes (25/38, 19/27) and were well defined (30/38, 24/27); by contrast, most MTs were lobulated, irregular shapes (24/29), and ill defined (25/29). On plain CT, the PAs were usually homogeneous, while MTs were frequently heterogeneous, with more necrosis, larger cystic areas, and more haemorrhage or calcification. The mean CT values of PAs, WTs, and MTs were 39.2 ± 3.9 HU, 39.1 ± 3.0 HU, and 37.6 ± 3.1 HU (P > 0.05), respectively. On contrast CT, the WTs were significantly enhanced compared with MTs and PAs, with mean CT values of 53.5 ± 4.0 HU, 84.4 ± 6.0 HU, and 65.2 ± 3.8 HU, respectively (all P < 0.001). The mean CT value changes for PAs, WTs, and MTs (∆) were 14.4 ± 3.0 HU, 45.3 ± 4.5 HU, and 27.7 ± 2.5 HU, respectively. Significant differences were observed between ∆_PAs and ∆_WTs, ∆_PAs and ∆_MTs, and ∆_WTs and ∆_MTs (all P < 0.001).

Conclusion

Parotid and submandibular gland tumours have some typical clinical characteristics and CT findings, and plain and early contrast-phase CT combined with clinical parameters may be helpful for diagnosis.

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.

The potential of somatostatin receptor 2 as a novel therapeutic target in salivary gland malignant tumors

BACKGROUND

Treatment regimens for patients with metastatic or recurrent post-radiation, locoregional, unresectable salivary cancer are limited. An inverse correlation between somatostatin receptor 2 (SSTR2) and the proliferating marker Ki-67 in neuroendocrine tumors has enabled a treatment plan for metastatic disease, utilizing peptide receptor radionuclide therapy. Interestingly, healthy salivary glands express high levels of SSTR2. In this study, the presence of SSTR2, its correlation with Ki-67 in glandular salivary carcinomas and the clinical applicability thereof was determined.

METHODS

In the retrospective part of this study, 76 adequate tumor tissue specimens obtained from patients diagnosed with primary or metastatic salivary carcinomas between 1988 and 2016, were collected for tissue array and histologically classified. Immunohistochemistry was performed to determine the presence, relative expression and potential correlation of SSTR2 and Ki-67. The clinical significance of SSTR2 expression was determined by prospectively assessing ⁶⁸Ga-DOTATATE uptake using PET-CT imaging, in patients diagnosed with metastatic salivary gland malignant tumors between 2015 and 2016.

RESULTS

Sixty-three primary cancer tumors and 14 metastatic tumors were tested. All tumor subtypes were found to express SSTR2 to some extent. The highest expression was seen in Mucoepidermoid carcinoma (MEC) tissues where the majority of specimens (86.4%) expressed SSTR2. A relatively strong immunohistochemical staining score for SSTR2 was observed in MEC, adenoid cystic carcinoma and polymorphous adenocarcinoma. Interestingly, an inverse correlation between SSTR2 and Ki-67 expressions was observed (44%) in MEC tissue. Uptake of ⁶⁸Ga-DOTATATE was visualized using PET-CT imaging in 40% of patients, across metastatic MEC and ACC. All observations were found to be statistically significant.

CONCLUSION

This study confirms the expression of SSTR2 in glandular salivary carcinomas and an inverse correlation in expression levels between SSTR2 and Ki-67. This lays a foundation for novel treatment options in salivary metastatic cancers where SSTR2 may be a potential novel therapeutic target.

The impact of nodal status in major salivary gland carcinoma: A multicenter experience and proposal of a novel N-classification

OBJECTIVES

Despite differences in oncological behavior, the 8th edition of AJCC TNM staging currently proposes the same N-classification for major salivary glands (MSG) carcinoma and squamous cell carcinoma of the upper aerodigestive tract. The present study aims to investigate a more reliable definition of N-categories for MSG carcinoma.

MATERIALS AND METHODS

A retrospective multicenter study was performed, including 307 patients treated for primary MSG carcinoma from 1995 to 2019. Outcome measures included overall survival (OS), disease specific survival, and local, regional, and distant recurrence. Survival analysis was performed using log-rank test and Cox proportional-hazards model. Overall number (ON) and largest diameter (LD) of nodal metastases, including intra-parotid metastases, were considered to develop three novel proposals of N-classification; their performance were compared with the current TNM staging using Akaike information criterion (AIC), Bayesian information criterion (BIC), and Nagelkerke pseudo-R2.

RESULTS

Intra-parotid nodes, ON and LD of nodal metastases emerged as major prognosticators for OS, while extra-nodal extension did not impact on any survival. The current N-classification did not show a satisfactory OS stratification. Three novel N-classifications were developed according to number of metastatic nodes (0 vs 1-3 vs ≥ 4) and/or their maximum diameter (<20 mm vs ≥ 20 mm). They all showed better accuracy in OS stratification, and achieved better AIC, BIC and Nagelkerke pseudo-R2 indices when compared to current N-classification.

CONCLUSION

All the proposed N-classifications improved OS stratification and could help in defining a specific N-classification for MSG carcinoma. Their validation and assessment in an external cohort is needed.

A Parsimonious Prognostic Model and Heat Map for Predicting Survival Following Adjuvant Radiotherapy in Parotid Gland Carcinoma With Lymph Node Metastasis

OBJECTIVES

To construct a simplified prognostic risk model to predict overall survival after adjuvant radiotherapy for parotid gland carcinoma patients with stage T1-4aN1-3M0.

MATERIALS AND METHODS

We evaluated 879 patients who were pathological diagnosed as stage T1-4aN1-3M0 parotid gland cancer. Those eligible patients treated with parotidectomy and neck lymph node dissection between 2004 and 2015 in the Surveillance Epidemiology and End Results database. All cases received adjuvant radiotherapy. Independent prognostic factors included in the original model were identified by Cox regression analysis. The primary endpoint was overall survival. The model's prediction power was evaluated by the concordance index. The entire cohort was categorized into new low- and high-risk groups using X-tile software according to the results of prognostic model. Kaplan-Meier method was used to depict the survival curves. And the statistical significance was determined by log-rank test. Besides, a heat map was visually described the association between the survival time and 2 most significant prognostic factors.

RESULTS

In the univariable and multivariate analyses, 4 independent factors for overall survival were age, tumor size, pTNM stage, and the number of positive lymph nodes, which were all selected in the parsimonious prognostic model. The concordance indices of the prognostic model and pTNM stage were 0.652 and 0.565, respectively. Patients in the low-risk group had better overall survival over patients in the high-risk group [unadjusted hazard ratio =  2.578, 95% confidence interval 2.095-3.172, P  < 0.001]. The results of the heat map revealed that patients with smaller tumor size and fewer positive lymph nodes had much longer survival time.

CONCLUSIONS

This parsimonious prognostic model could estimate the long-term survival after adjuvant radiotherapy for parotid gland carcinoma with stage T1-4aN1-3N0M0. The tools may be valuable to guide multidisciplinary team in making treatment decisions.

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.

Prognostic role of intraparotid lymph node metastasis in primary parotid cancer: Systematic review

BACKGROUND

The prognostic importance of intraparotid lymph node metastasis (P+) in patients with primary parotid gland carcinoma is unclear.

METHODS

Nineteen retrospective and noncomparative cohort studies, published between 1992 and 2020, met the inclusion criteria and included 2202 patients for this systematic review.

RESULTS

The pooled prevalence of the P in adult patients in the unselected studies was 24.10% (95% confidence interval = 17.95-30.25). The number of P+ lymph nodes per patient was counted in only three studies and ranged from 1 to 11. The 5-year recurrence-free survival rate based on Kaplan-Meier analysis varied from 83% to 88% in P- patients compared to 36% to 54% in P+ patients. The average hazard ratio for tumor recurrence in patients with P+ compared to P- was 2.67 ± 0.58.

CONCLUSIONS

P+ is an independent negative prognostic factor in primary parotid gland cancer and should be included into the treatment planning.

[Results of surgical and radiotherapeutic treatment of adenoid cystic carcinoma of the salivary glands]

Surgical treatment in patients with rare adenoid cystic carcinoma (ACC) of the salivary glands is considered to be the state of the art. With respect to an additional radiotherapy there are different approaches regarding the type of radiotherapy and timing. In this study the overall survival and recurrence-free survival in 52 individuals with salivary gland ACC who were treated at the University Hospital in Essen and received irradiation with fast neutrons and photons (mixed beam technique) either A) immediately following surgical treatment or B) only after the appearance of local recurrence were compared. Group A (n = 28, first diagnosis, FD September 1991-September 2009) received adjuvant radiotherapy immediately postoperative, group B (n = 24, FD June 1979-November 2001) underwent primarily surgical tumor resection according to the treatment regimen at that time and were irradiated only on the appearance of a local recurrence. In comparison to group B, patients in group A showed a lower recurrence rate and a significantly longer local relapse-free survival. Group B, however, showed a significantly higher overall survival. The frequency of distant metastasis occurred equally in both groups but the onset of distant metastasis was significantly earlier in group A. In general, overall survival was negatively influenced by distant metastasis. The local recurrence rate was very high after primary surgical treatment only. The immediate adjuvant high-linear energy transfer (LET) radiotherapy reduced the local recurrence rates. Irradiation after the appearance of a recurrence had a positive influence on overall survival. Overall, definitive high-LET radiotherapy in the mixed beam technique enabled high local control rates both primarily postoperative and also locoregional recurrences.

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.

Development of sentinel lymph node biopsy technique in patients with salivary gland cancer using the IDEAL framework

BACKGROUND

Salivary cancer is rare and comprises a variety of histological subtypes and clinical behaviors. There is no agreed method of estimating the risk of occult metastasis or managing the clinically N0 neck.Sentinel node biopsy (SNB) may offer a solution but previous studies have not produced a reliable imaging protocol. This study uses novel technology and trial methodology to develop a reliable SNB technique, with primary aim to identify peri-and intraglandular sentinel nodes.

METHODS

IDEAL framework was used to undertake SNB in clinically node negative salivary gland cancer. Patients with cT1-2 N0 salivary cancer were eligible. Lymphoscintigraphy was undertaken using Tc-99 m labelled nanocoll. Injection technique as well as adjunctive use of freehand SPECT (fhSPECT), near-infrared (NIR) fluorescence imaging, and navigation-guided surgery were used and optimisied during the study protocol.

RESULTS

10 patients were recruited. Initial protocol of peritumoural injection of Tc99 m nanocoll showed poor image resolution. Subsequent adjustment to single intratumoural injection allowed identification of intraglandular sentinel nodes. Fh/SPECT and NIR fluorescence imaging found intraglandular lymph nodes otherwise not recognizable to the naked eye. In two cases occult lymph node metastasis were identified.

CONCLUSION

This study has shown the IDEAL framework is vital in allowing iterative changes in surgical protocol in the light of experience. This study has produced a reliable method for detection of sentinel nodes, in particular the ability to identify intra- and periglandular nodes with diagnosis of occult metastatic deposits and no false negative results. Our protocol can be readily transferred in to larger scale studies.

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.

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.

Nodal Metastases in Acinic Cell Carcinoma of the Parotid Gland

The objective of this study was to evaluate the clinical outcome of patients with acinic cell carcinomas of the parotid gland after elective neck dissection (END). A retrospective chart review was performed including 66 patients with acinic cell carcinoma of the parotid gland. Clinical parameters were retrieved and statistically analyzed regarding disease-free survival (DFS) and disease-specific survival (DSS). An END was done in 27 (40.9%) patients, and occult metastases were detected in 4 (14.8%) patients of whom three were low-grade carcinoma. Positive neck nodes were associated with significantly worse DSS (p = 0.05). Intermediate and high-grade carcinoma (HR 8.62; 95% confidence interval (CI): 1.69-44.01; p = 0.010), perineural invasion (HR 19.6; 95%CI: 0.01-0.37; p = 0.003) and lymphovascular invasion (HR 10.2; 95%CI: 0.02-0.59; p = 0.011) were worse prognostic factors for DFS. An END should be considered in patients with acinic cell carcinoma of the parotid gland due to (i) a notable rate of occult neck metastases in low-grade tumors and (ii) the worse DSS of patients with positive neck nodes.

Cancers of the Major Salivary Gland

Salivary gland malignancies are rare tumors that comprise multiple histologic entities with diverse clinical behavior. Mucoepidermoid carcinoma is the most frequent primary salivary malignancy, followed by adenoid cystic and acinic cell carcinoma. Although most salivary malignancies are asymptomatic, presentation with a rapidly enlarging mass may be accompanied by pain, functional neurologic deficits, soft-tissue invasion, or nodal enlargement. Assessment of clinical behavior and physical exam greatly contributes to diagnostic workup. Preoperative imaging, to include ultrasound, computed tomography, or magnetic resonance imaging, may assist with surgical planning. Limitations of preoperative fine-needle aspiration cytology mean that, in some cases, definitive histologic diagnosis may not be established until therapeutic surgery is undertaken. Treatment strategies rely on oncologic resection of the primary site with negative margins as well as adjuvant radiotherapy in patients with high-risk features, such as high-grade histology, advanced T class, or perineural invasion. Regional lymphadenectomy is recommended for involved nodal basins. Patients with clinically node-negative disease at high risk for occult nodal metastases may be considered for elective lymphadenectomy or radiotherapy. Use of chemotherapy in the adjuvant setting, in combination with radiotherapy, remains controversial. The rate of objective response to palliative chemotherapy in recurrent or metastatic salivary gland malignancy remains low. In studies that include a significant proportion of adenoid cystic carcinomas, whether disease stability represents an indolent disease process or the true effect of a therapeutic drug may be difficult to discern. Recognition of genetic alterations and protein expression unique to salivary malignancies presents exciting new opportunities for molecularly targeted therapy, although the response to molecularly targeted therapy in studies has been modest thus far.

Sentinel lymph node biopsy in cN0 neck management of parotid cancer

Our goals was to evaluate how sentinel lymph node biopsy (SLNB) benefit neck management in patients with parotid cancer. Patients diagnosed with cN0 parotid cancer by preoperative fine needle puncture were prospectively enrolled. The neck status was evaluated by SLNB. If node metastasis was proved by SLNB, a neck dissection of level I-V a was performed, or a wait-and-see policy was conducted for the patient. All related information was extracted and analyzed. Positive SLNB result occurred in 33 (16.7%) patients, and level II metastasis was noted in 100% of the patients. Isolated level III metastasis was noted in 3 (9.1%) patients. During our follow-up with mean time of 49.5 months, 20 patients developed regional recurrence, in which 6 patients had neck dissection as part of their initial management. All the recurrent neck disease was successfully salvaged. Therefore, SLNB was a reliable procedure for neck management in parotid cancer.

[Delineation of the primary tumour clinical target volumes and neck node levels selection of parotid cancers]

Salivary glands tumours are uncommon tumours showing a large diversity of histological types. This article presents a synthesis of patterns and paths of invasion of parotid glands tumours in order to propose an approach of the delineation of primary tumour clinical target volumes and of the selection of lymph nodes target volumes. This article does not discuss treatment indications but defines clinical target volumes to treat if radiotherapy is indicated. Postoperative situation being the most frequent, the delineation of primary tumour clinical target volume is based on an anatomical approach.

Role of intraparotid node metastasis in mucoepidermoid carcinoma of the parotid gland

BACKGROUND

Prognostic factors for parotid mucoepidermoid carcinoma (MEC) usually include disease grade, tumor stage, node stage, perineural invasion, and lymphovascular invasion. But the role of intraparotid nodes (IPNs) remains unclear, therefore, the study aimed to analyze the significance of IPNs in predicting recurrence in parotid MEC.

METHODS

One hundred and ninety patients were included for analysis finally. Data regarding demography, pathological characteristics, IPN metastasis, TNM stage, follow up was collected and evaluated. The recurrence-free survival (RFS) was the main study endpoint.

RESULTS

A total of 47 (24.7%) patients had IPN metastasis, and the IPN metastasis was significantly related to tumor stage, pathologic N stage, lymph-vascular invasion, perineural invasion, and disease grade. Recurrence occurred in 34 (17.9%) patients. For patients without IPN metastasis, the 10-year RFS rate was 88%, for patients with IPN metastasis, the 10-year RFS rate was 54%, the difference was significant (p < 0.001). Further Cox model analysis confirmed the independence of IPN metastasis in predicting the prognosis.

CONCLUSION

The IPN metastasis is relatively common in parotid MEC, it is significantly related to tumor stage and disease grade, IPN metastasis means worse recurrence-free survival.

Role of the pretreatment neutrophil-to-lymphocyte ratio in the survival of primary parotid cancer patients

BACKGROUND

To analyze the value of the pretreatment neutrophil-to-lymphocyte ratio (NLR) in the survival of patients with parotid cancer.

METHODS

In total, 249 patients were enrolled. Information including age, sex, pretreatment NLR, and pathologic variables such as, tumor stage, intraparotid node (IPN) metastasis, and follow-up findings was extracted and analyzed.

RESULTS

IPN metastasis was noted in 45 (18.1%) patients, and the mean NLR was 2.48, with a range from 1.5 to 6.1. The NLR was significantly associated with tumor stage, disease stage, and disease grade. A total of 73 patients died of the disease, and the 10 -year disease-specific survival (DSS) rate was 62%. In patients with an NLR<2.48, the 10 -year DSS rate was 68%; in patients with an NLR≥2.48, the 10 -year DSS rate was 58%, and the difference was significant (P=0.006). Cox model analysis showed that the NLR was an independent prognostic factor for DSS.

CONCLUSION

The long-term survival of primary parotid cancer patients is relatively favorable, and the pretreatment NLR is significantly associated with prognosis.

Oncologic outcome of parotid mucoepidermoid carcinoma in pediatric patients

Background

The goal of this study was to investigate the long-term oncologic outcome of parotid mucoepidermoid carcinoma (MEC) in pediatric patients.

Patients and methods

Patients <19 years old who were diagnosed with MEC from January 1990 to December 2017 were retrospectively enrolled in this study. The main analyzed indexes included intraparotid node (IPN) metastasis, neutrophil-tolymphocyte ratio (NLR), loco-regional control (LRC), and disease-specific survival (DSS) rates.

Results

A total of 73 patients were enrolled. IPN metastasis occurred in 13 (17.8%) patients; the mean value of the NLR was 2.48 (range: 1.3–6.1). Loco-regional recurrence occurred in 12 patients, and 7 patients died of the disease. The 10-year LRC and DSS rates were 83% and 88%, respectively. IPN metastasis remained significantly related to recurrence in both univariate and Cox model analyses; a high NLR was significantly associated with recurrence in the univariate analysis but not in the Cox model. IPN metastasis remained significantly related to disease-related death in both the univariate and Cox model analyses; a high NLR was not associated with the DSS in univariate analysis.

Conclusion

The long-term survival rate was relatively favorable in pediatric MEC. IPN metastasis was an independent risk factor for loco-regional recurrence and DSS. The role of the NLR in predicting survival in parotid cancer requires more research.

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.