Malignant tumours of the parotid gland: management of the neck (including the clinically negative neck) and a literature review

Survival Impact of Elective Neck Dissection and Adjuvant Radiation in N0 High-Grade Mucoepidermoid Carcinoma

OBJECTIVE

We aim to evaluate the role of elective neck dissection (END) and adjuvant radiation on survival in N0 high-grade mucoepidermoid carcinoma (MEC).

STUDY DESIGN

Retrospective cohort study.

SETTING

National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database.

METHODS

All patients diagnosed with high-grade MEC with node-negative disease (N0) from 2004 to 2018 were included. Demographic, clinicopathologic, treatment, and outcomes were analyzed. Kaplan-Meier survival curves were used to evaluate 5-year disease-specific survival (DSS) and 5-year overall survival (OS). Multivariate Cox regression analysis was used to control for confounders.

RESULTS

A total of 310 patients with high-grade MEC and N0 (clinical and pathologic) disease were identified. The parotid was the most common primary site (266, 86%). Of included patients, 133 (42.9%) were T3-T4 tumors and 212 (68%) received adjuvant radiation. END was performed on 223 (71.9%) of cases. END in T3-T4 high-grade MEC led to significant improvements in DSS (74.3% vs 34.0%, P < .01) and OS (55.2% vs 20.5%, P < .01) as compared to no END. Subanalysis shows that in patients who received neck dissections and were pathologic N0, adjuvant radiation had no impact on DSS (84.0% vs 72.1%, P = .45) and OS (52.1% vs 55.8%, P = .91). Benefits persisted when controlling for confounders using multivariate Cox proportional regression.

CONCLUSION

Patients with T3-T4 high-grade MEC who underwent END and found to be pathologically node-negative (pN0) had significantly improved 5-year DSS and 5-year OS than patients who were cN0 and did not undergo END. Importantly, although 68% of patients received adjuvant radiation, we show no benefit of this treatment modality on outcomes in pN0 high-grade MEC.

Tumor budding - a potential biomarker in low grade salivary gland carcinomas?

Background

Low-grade salivary gland carcinoma is regularly treated with surgical therapy of the salivary gland without elective neck dissection in T1/2 carcinomas, either alone or with adjuvant radiation therapy. However, occult metastasis and locoregional recurrence influence therapy and outcome. Tumor budding is an emerging prognostic pathological factor in many carcinomas, but has not yet been adequately considered in salivary gland carcinomas.

Methods

We conducted a retrospective single-center study of 64 patients diagnosed with low-grade carcinoma of the major salivary glands treated between 2003 and 2017. Pathological risk factors and TNM classification were thoroughly assessed for each case. All hematoxylin and eosin (HE)-stained histological specimens underwent careful examination, and tumor budding was identified following the guidelines set forth by the International Tumor Budding Consensus Conference in 2016.

Results

Tumor budding was not statistically significant concerning 5-year survival rate (5-YSR) (p=0.969) and mean overall survival (log-rank p=0.315). Whereas 5-year disease-free survival rate (5-YDFSR) was 87% in the low tumor budding group and 61.1% in the intermediate and high tumor budding group (p=0.021). Mean disease-free survival accounted for 100.2 months (CI: 88.6;111.9) in the low budding score group and 58.7 months (CI: 42.8;74.6) in the other group (log-rank p=0.032). Notably, pT1/2 showed significantly lower tumor buds than pT3/4 stages (2.43 tumor buds/0.785 mm2 vs. 4.19 tumor buds/0.785 mm2, p=0.034). Similar findings were noted comparing nodal-positive and nodal-negative patients, as well as patients with and without lymphovascular invasion and perineural invasion (each p<0.05).

Conclusions

Tumor budding might be used as an additional prognostic factor for recurrence in low-grade salivary gland carcinoma, seemingly associated with a higher nodal metastasis rate and advanced tumor stages and a worse 5-YDFSR. Consequently, the evaluation of tumor budding in resection specimens of low-grade salivary gland tumor may prove valuable in decision-making for neck dissection and follow-up strategy.

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.

Diagnostic performance of inflammatory biomarkers and cytological analysis in salivary gland tumors

BACKGROUND

This study aimed to evaluate the diagnostic performance of serum inflammatory biomarkers in salivary gland tumors with dubious results following cytological analysis.

METHODS

A retrospective analysis of 239 cases following surgery between January 2011 and June 2022 was performed. Receiver Operating Characteristic curves were drawn and areas under the curves were computed to evaluate the diagnostic performance of the inflammatory biomarkers (SII, SIRI, PLR, and NLR). Optimal cut-offs for each marker were determined by maximizing the Youden index.

RESULTS

Analysis showed that among the major biomarkers examined, SIRI performed an AUC of 0.77. The best SIRI cut-off was 0.94 with an accuracy of 79.9%. The accuracy, sensitivity, and specificity of cytological analysis were 77.8%, 59.6%, and 90.7% respectively. By combining SIRI with cytological analysis we demonstrated an increase in sensitivity to 82.8%.

CONCLUSIONS

Inflammatory biomarkers could be evaluated to support the diagnosis and treatment of salivary gland tumors in difficult cases.

Postoperative Radiation Therapy Refusal in Major Salivary Gland Cancers

OBJECTIVE

Major salivary gland cancers (MSGCs) are often treated with primary surgery followed by adjuvant therapy for high-risk pathology. Patients with these cancers may opt out of recommended postoperative radiation therapy (PORT) for many reasons and consequently may suffer worse outcomes.

STUDY DESIGN

Retrospective cohort study.

SETTING

National Cancer Database.

METHODS

Patients diagnosed with MSGC from 2004 to 2016 were identified, and overall survival and risk factors for refusal of recommended PORT were analyzed based on demographic, socioeconomic, and clinical factors. Multivariable logistic regression and a Cox model were used to conduct the analysis.

RESULTS

211 out of 4704 qualifying patients (4.5%) refused recommended PORT. Multivariable analysis demonstrated increased PORT refusal for age >74 years (odds ratio OR 4.34, confidence interval [CI] [2.43-7.85]), Asian race (OR 2.25, CI [1.10-4.23]), and certain facility types (comprehensive cancer center, OR 2.39, CI [1.08-6.34]; academic research program, OR 3.29, CI [1.49-8.74]; and integrated network cancer program, OR 2.75, CI [1.14-7.7]). N2 stage was associated with decreased PORT refusal (OR 0.67, CI [0.45-0.98]). The 5-year overall survival for patients who received and refused PORT were significantly different at 65.8% and 53.8%, respectively (p < .001). When controlling for several factors, PORT refusal was independently associated with significantly lower overall survival (HR 1.54, CI [1.21-1.98]).

CONCLUSION

Patient refusal of recommended PORT in MSGC is rare, associated with various disease and socioeconomic factors, and may decrease overall survival. Our findings can assist clinicians in counseling patients and identifying those who may be more likely to opt out of recommended PORT.

Characteristics, Surgical Management, and Outcomes of Parotid Gland Masses in the Pediatric Age Group: A Single Tertiary Institute Experience

Context

Parotid gland lesions in children requiring surgical management are not common. Neoplastic lesions of the parotid glands are also less common. Parotid tumors in children have different characteristics from those that occur in adults. When they occur in the pediatric age group, malignancy has to be ruled out.

Subjects and Methods

This is a retrospective study of children who presented to our institute, a tertiary care referral hospital for children <12 years, with parotid swellings during the 5-year period between April 2018 and March 2023. The children who underwent surgical management for parotid lesions, in the form of parotidectomy, were included in the study. Children who were treated by nonoperative management were excluded from the study.

Results

Twelve children were included. Of the 12 children, three (25.0%) children had malignancy, four (33.33%) children had benign tumors, three (25.0%) children had vascular malformations, and the remaining two (16.67%) children had inflammatory etiology. All children underwent superficial/total parotidectomy, depending on the involvement of superficial and/or deep lobe. Of the three malignant parotid tumors, two were of mucoepidermoid carcinoma and one was myoepithelial carcinoma. One of the children with mucoepidermoid carcinoma had recurrence.

Conclusions

Facial nerve-sparing parotidectomy is the treatment for neoplastic and inflammatory lesions. Initially, lymphovascular tumors were treated aggressively with parotidectomy. Neck node dissection should be performed only in children with fine-needle aspiration cytology-confirmed nodal metastases during primary surgery. Adjuvant treatment may be required in selected cases.

Support Tools in the Differential Diagnosis of Salivary Gland Tumors through Inflammatory Biomarkers and Radiomics Metrics: A Preliminary Study

BACKGROUND

The purpose of this study was to investigate how the systemic inflammation response index (SIRI), systemic immune-inflammation index (SII), neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR), and radiomic metrics (quantitative descriptors of image content) extracted from MRI sequences by machine learning increase the efficacy of proper presurgical differentiation between benign and malignant salivary gland tumors.

METHODS

A retrospective study of 117 patients with salivary gland tumors was conducted between January 2015 and November 2022. Univariate analyses with nonparametric tests and multivariate analyses with machine learning approaches were used.

RESULTS

Inflammatory biomarkers showed statistically significant differences (p < 0.05) in the Kruskal-Wallis test based on median values in discriminating Warthin tumors from pleomorphic adenoma and malignancies. The accuracy of NLR, PLR, SII, and SIRI was 0.88, 0.74, 0.76, and 0.83, respectively. Analysis of radiomic metrics to discriminate Warthin tumors from pleomorphic adenoma and malignancies showed statistically significant differences (p < 0.05) in nine radiomic features. The best multivariate analysis result was obtained from an SVM model with 86% accuracy, 68% sensitivity, and 91% specificity for six features.

CONCLUSIONS

Inflammatory biomarkers and radiomic features can comparably support a pre-surgical differential diagnosis.

Parotid gland masses: outcomes in the pediatric age group

BACKGROUND

Childhood parotid neoplasms appear to have different characteristics from adults. This point, in addition to the rarity of these tumors, reflects the challenges faced in diagnosing and treating parotid neoplasms in children.

PATIENTS AND METHODS

This retrospective study included all children who presented to the Children's Cancer Hospital Egypt (CCHE, 57357) with parotid masses from January 2008 to December 2020.

RESULTS

Twenty-one patients were included. Malignant neoplasms were found in 12 (57.1%) of which mucoepidermoid carcinoma was the most common. Benign neoplasms were found in 6 (28.6%) all of them were pleomorphic adenoma, and non-neoplastic lesions were found in 3 (14.3%). Superficial, deep, or total parotidectomy was performed according to the involved lobes. The facial nerve was sacrificed in three cases because of frank invasion by the tumor. Neck dissection was considered in clinically positive lymph nodes and/or T3/4 masses. Complications occurred in 7 (33.3%) all were of the malignant cases. Adjuvant radiotherapy was restricted to high-risk cases (7 cases). Recurrence occurred in two cases, and one patient died of distant metastasis. Fine needle aspiration cytology (FNAC) showed 88.9% sensitivity and 100% specificity for diagnosing malignant neoplasms. The correlation of radiological and pathological staging was fair (66.74% for overall staging).

CONCLUSIONS

Parotidectomy is the backbone treatment for benign and malignant pediatric parotid tumors. Neck nodal dissection should be considered after preoperative FNAC of suspicious nodes. Adjuvant radiotherapy is considered only in high-risk tumors. Preoperative FNAC of parotid masses and clinically suspicious lymph nodes is highly recommended.

Caudatin Inhibits the Proliferation, Invasion, and Glycolysis of Osteosarcoma Cells via the Wnt/β- Catenin Pathway

Background

Caudatin is a steroidal glycoside with reported anticancer activity in a variety of studies. Nevertheless, the role and mechanisms of caudatin in osteosarcoma (OS) remain unclear. In this study, we explored the potential anticancer effects of caudatin in OS cells and investigated the underlying mechanisms.

Methods

Both the CCK8 proliferation assay and flow cytometry were employed to evaluate cell proliferation and apoptosis. A transwell assay was applied to determine cell invasion ability. Besides, glycolytic capacity was examined by measuring glucose consumption, lactic acid production, as well as ATP production. A western blot was utilized to assess the protein levels of β-catenin, CyclinD 1, C-myc, HK2 (Hexokinase 2), LDHA (lactate dehydrogenase), as well as epithelial-mesenchymal transition (EMT)-related markers. The inhibitory effect of caudatin on tumor growth was investigated using a xenograft tumorigenesis model.

Results

Caudatin restrained cellular glycolysis, suppressed cell proliferation and invasion by reducing HK2 and LDHA expression and regulating the Wnt/β-Catenin signaling pathway. Caudatin treatment caused the upregulation of E-cadherin and suppressed N-cadherin expression. Further, caudatin treatment impaired cell viability, invasion ability, and intracellular glycolysis level but induced apoptosis. The administration of BML 284 reversed the inhibitory effects of caudatin. Moreover, caudatin suppressed the tumorigenesis of OS cells in the xenograft model of nude mice.

Conclusions

Our study revealed the anticancer effects of caudatin, including proliferation inhibition, cell invasion suppression, and glycolysis impairment. These effects seem to be executed through targeting the Wnt/β-Catenin signaling pathway. These data indicate that caudatin may be formulated as a potential therapeutic for osteosarcoma.

Apparent Diffusion Coefficient (ADC) Histogram Analysis in Parotid Gland Tumors: Evaluating a Novel Approach for Differentiation between Benign and Malignant Parotid Lesions Based on Full Histogram Distributions

The aim of this study was to assess the diagnostic value of ADC distribution curves for differentiation between benign and malignant parotid gland tumors and to compare with mean ADC values. 73 patients with parotid gland tumors underwent head-and-neck MRI on a 1.5 Tesla scanner prior to surgery and histograms of ADC values were extracted. Histopathological results served as a reference standard for further analysis. ADC histograms were evaluated by comparing their similarity to a reference distribution using Chi2-test-statistics. The assumed reference distribution for benign and malignant parotid gland lesions was calculated after pooling the entire ADC data. In addition, mean ADC values were determined. For both methods, we calculated and compared the sensitivity and specificity between benign and malignant parotid gland tumors and three subgroups (pleomorphic adenoma, Warthin tumor, and malignant lesions), respectively. Moreover, we performed cross-validation (CV) techniques to estimate the predictive performance between ADC distributions and mean values. Histopathological results revealed 30 pleomorphic adenomas, 22 Warthin tumors, and 21 malignant tumors. ADC histogram distribution yielded a better specificity for detection of benign parotid gland lesions (ADChistogram: 75.0% vs. ADCmean: 71.2%), but mean ADC values provided a higher sensitivity (ADCmean: 71.4% vs. ADChistogram: 61.9%). The discrepancies are most pronounced in the differentiation between malignant and Warthin tumors (sensitivity ADCmean: 76.2% vs. ADChistogram: 61.9%; specificity ADChistogram: 81.8% vs. ADCmean: 68.2%). Using CV techniques, ADC distribution revealed consistently better accuracy to differentiate benign from malignant lesions (“leave-one-out CV” accuracy ADChistogram: 71.2% vs. ADCmean: 67.1%). ADC histogram analysis using full distribution curves is a promising new approach for differentiation between primary benign and malignant parotid gland tumors, especially with respect to the advantage in predictive performance based on CV techniques.

Trans-Oral Robotic Surgery: 14 Cases of Pleomorphic Adenoma of the Parapharyngeal Space

PURPOSE

The aim of this study has been to describe our experience with pleomorphic adenomas of the parapharyngeal space (PPS) treated with trans-oral robotic surgery (TORS). Tumors arising from the PPS comprise less than 0.5% of all head and neck tumors. Salivary gland tumors account for 40% to 50% of PPS lesions with pleomorphic adenomas representing the most common salivary tumors (80%-90%). Parapharyngeal space tumors cause nonspecific symptoms and may be difficult to diagnose.

METHODS

In our study a preoperative diagnosis was conducted by fine needle aspiration biopsy and magnetic resonance imaging and the results were used to plan the correct surgical approach.

RESULTS

In all cases we were able to employ TORS, a minimally invasive procedure that allows us to operate in narrow and anatomically complex spaces that we can only reach thanks to the use of well-articulated hand pieces.

CONCLUSIONS

This report indicates that TORS is a safe surgical procedure for the excision of benign tumors of the PPS in selected cases.