Diagnosis and Management of Malignant Salivary Gland Tumors of the Parotid Gland

Differential expression of epidermal growth factor receptor in various pathological types of salivary gland cancers

OBJECTIVE

While several studies reported epidermal growth factor receptor (EGFR) expression in salivary gland cancer (SGC), results varied due to a lack of unified definition of EGFR positivity. In this study, we assessed the EGFR expression level using both EGFR positive score and cumulative EGFR score in the patients with SGC.

METHODS

Between January 2010 and April 2021, 102 patients with SGC who underwent surgical resection were reviewed retrospectively by immunohistochemistry. The membrane staining intensity was scored as follows: no staining (0), weak staining (1+), intermediate staining (2+), and strong staining (3+). The cumulative EGFR score was determined on a continuous scale of 0-300 using the formula:1 × (1+: percentage of weakly stained cells) + 2 × (2+: percentage of moderately stained cells) + 3 × (3+: percentage of strongly stained cells).

RESULTS

EGFR expression in SGC varied widely even among the same as well as different histopathological types. The average EGFR positive scores were 46.0 %, 55.7 %, 51.6 %, 1.0 %, 26.8 %, 50 %, and 76.8 % for mucoepidermoid carcinoma (MEC), salivary duct carcinoma (SDC), adenoid cystic carcinoma (AdCC), acinic cell carcinoma (AcCC), adenocarcinoma NOS (ACNOS), carcinoma ex pleomorphic adenoma (CAexPA), and squamous cell carcinoma (SqCC), respectively. The average cumulative EGFR scores were 82, 91, 80, 1, 52, 93, and 185 for MEC, SDC, AdCC, AcCC, ACNOS, CAexPA, and SqCC, respectively.

CONCLUSIONS

EGFR positive scores and cumulative EGFR scores in SGCs varied among the various histological types, and even in the same histological type. These scores may predict the clinical outcome of SGC treated with EGFR-targeting therapies, such as head and neck photoimmunotherapy, and need to be evaluated in future studies.

Quality of Life Outcomes for Parotid Malignancies

BACKGROUND

This study describes patient-reported outcome measures (PROMs) and associated factors in patients who underwent surgery for malignant parotid tumors (MPT).

METHODS

This is a retrospective study of all surgically treated MPT patients in a multidisciplinary head and neck cancer (HNC) survivorship clinic (2017-2023). PROMs included University of Washington Quality of Life Questionnaire (UW-QOL), Eating Assessment Tool (EAT-10), Patient Health Questionnaire (PHQ-8), Generalized Anxiety Disorder (GAD-7), Neck Disability Index (NDI), and Insomnia Severity Index. Multivariable regression analysis was used to investigate clinical predictors associated with PROMs.

RESULTS

In 62 MPT patients, the prevalence of clinically relevant dysphagia symptoms (EAT-10), elevated symptoms of depression (PHQ-8), moderate/severe symptoms of anxiety (GAD-7), moderate/severe neck pain with activities of daily living (NDI), and moderate/severe symptoms of insomnia at last follow-up was 32.3%, 15.5%, 7.1%, 17.7%, and 7.2%, respectively. Nonparametric one-sided test revealed that patients treated with adjuvant CRT had significantly worse physical QOL, social-emotional QOL, and swallowing scores than patients treated with surgery alone (p = 0.01, p = 0.02, p = 0.03, respectively); that patients treated with surgery and adjuvant RT had significantly worse physical QOL and social-emotional QOL than patients treated with surgery alone (p < 0.01, p = 0.01, respectively) and that patients treated with surgery and adjuvant CRT had significantly worse swallowing and neck pain than patients treated with surgery and adjuvant RT (p = 0.03, p = 0.05, respectively).

CONCLUSIONS

In patients with surgically treated MPT, adjuvant CRT and RT were associated with worse PROMs.

LEVEL OF EVIDENCE

4 Laryngoscope, 2024.

Clinical Behavior of the Mucoepidermoid Carcinoma of the Larynx-A Scoping Review

OBJECTIVE

Mucoepidermoid carcinomas (MEC) of the larynx account for less than 1% of all laryngeal tumors. The unique features and clinical behavior of these rare entities remain unknown. To fill this knowledge gap, we performed a scoping review of every reported case of laryngeal MEC to study the clinical behavior and the treatment modalities in this rare entity.

REVIEW METHODS

We followed the guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR) statement.

DATA SOURCES

MedLine, Google Scholar, and Science Direct databases were searched to identify eligible studies.

RESULTS

We concluded with 25 studies and overall 66 cases. Our study revealed that the average age of cases was 55.7 years, and the range was from 12 to 81 years, with younger onset in females. Supraglottic (60%) is the most common subsite of laryngeal MEC s followed by glottis (27.3%). Supraglottic carcinomas frequently present with metastatic neck disease at the time of the initial diagnosis and require more extensive surgical approaches. Surgery with negative surgical margins seems to be the cornerstone in the treatment of MEC. Radiation therapy has not been tested widely as monotherapy but is considered a useful adjuvant modality.

CONCLUSION

This study suggests that negative surgical margins seem to be associated to higher disease control rate and that high-grade supraglottic cases likely benefit from addressing neck disease simultaneously.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:2578-2584, 2024.

The extracapsular dissection technique in the management of benign tumours of the parotid gland: our experience in 194 patients

OBJECTIVE

The indications for and approaches to extracapsular dissection for parotid gland benign tumours are debated in the literature. This study retrospectively evaluates a single site's short- and long-term results with a standardised extracapsular dissection approach to benign parotid tumours.

METHODS

A retrospective review of a single institution's records identified cases with extracapsular dissection as the primary surgery for non-recurrent benign parotid tumours. A total of 194 eligible patients were identified (124 women and 70 men, age 47.75 ± 15.62 years). Pre-, intra- and post-surgical data were reviewed for complications and recurrences.

RESULTS

Histology reported pleomorphic adenoma in 165 patients, Warthin's tumour in 28 patients and both in one patient. Mean follow up was 36 ± 16 months (range, 12-84 months). The incidences of complications following extracapsular dissection were temporary (n = 13) and permanent (n = 0) facial nerve dysfunction, Frey's syndrome (n = 1)) and recurrences (n = 5). These rates align with prior literature.

CONCLUSION

This case series shows how a standardised approach to extracapsular dissection for benign parotid tumours yields favourable results, supporting a progressive change of strategy towards reduced invasiveness.

Evaluation of Quantitative Dual-Energy Computed Tomography Parameters for Differentiation of Parotid Gland Tumors

RATIONALE AND OBJECTIVES

To assess the diagnostic performance of quantitative parameters from dual-energy CT (DECT) in differentiating parotid gland tumors (PGTs).

MATERIALS AND METHODS

101 patients with 108 pathologically proved PGTs were enrolled and classified into four groups: pleomorphic adenomas (PAs), warthin tumors (WTs), other benign tumors (OBTs), and malignant tumors (MTs). Conventional CT attenuation and DECT quantitative parameters, including iodine concentration (IC), normalized iodine concentration (NIC), effective atomic number (Zeff), electron density (Rho), double energy index (DEI), and the slope of the spectral Hounsfield unit curve (λHU), were obtained and compared between benign tumors (BTs) and MTs, and further compared among the four subgroups. Logistic regression analysis was used to assess the independent parameters and the receiver operating characteristic (ROC) curves were used to analyze the diagnostic performance.

RESULTS

Attenuation, Zeff, DEI, IC, NIC, and λHU in the arterial phase (AP) and venous phase (VP) were higher in MTs than in BTs (p < 0.001-0.047). λHU in VP and Zeff in AP were independent predictors with an area under the curve (AUC) of 0.84 after the combination. Furthermore, attenuation, Zeff, DEI, IC, NIC, and λHU in the AP and VP of MTs were higher than those of PAs (p < 0.001-0.047). Zeff and NIC in AP and λHU in VP were independent predictors with an AUC of 0.93 after the combination. Attenuation and Rho in the precontrast phase; attenuation, Rho, Zeff, DEI, IC, NIC, and λHU in AP; and the Rho in the VP of PAs were lower than those of WTs (p < 0.001-0.03). Rho in the precontrast phase and attenuation in AP were independent predictors with an AUC of 0.89 after the combination. MTs demonstrated higher Zeff, DEI, IC, NIC, and λHU in VP and lower Rho in the precontrast phase compared with WTs (p < 0.001-0.04); but no independent predictors were found.

CONCLUSION

DECT quantitative parameters can help to differentiate PGTs.

Persistent bleeding following biopsy of an epidermoid cyst within the parotid gland

Epidermoid cysts are benign lesions most commonly found in the skin but which can arise in many other locations including, very rarely the salivary glands. This rarity often leaves them off standard differential lists and can create a diagnostic dilemma. A patient with an incidentally detected parotid mass on MRI underwent core biopsy, which was unfortunately complicated by formation of a pseudoaneurysm and persistent arterial bleeding requiring coil embolisation. The histology showed only keratinous material and, in retrospect, the signal characteristics of the mass were entirely typical of an epidermoid cyst. Recognition of this common, benign entity in a very rare location can obviate the need for invasive tests and potential complications and direct management to more appropriate imaging follow-up.

Brain metastases in patients with salivary duct carcinoma: A retrospective study

BACKGROUND

Salivary duct carcinoma (SDC) is a high-grade adenocarcinoma with a 5-year survival rate of 40%. Although drug therapy has improved patients' prognosis, the impact of brain metastasis (BM) remains poorly understood. We aimed to retrospectively examine the incidence of BM in patients with SDC (n = 464) and develop a tool to estimate their prognoses.

METHODS

We retrospectively examined 464 patients with SDC enrolled in a multicenter study. We investigated the incidence of BM, overall survival (OS) rates, and factors affecting prognosis in patients with BM. We also developed an SDC-graded prognostic assessment (GPA) score for disease prognostication.

RESULTS

Sixty-five (14%) patients had BM. The median OS (mOS) was 13.1 months. On univariate and multivariate analyses, factors such as Eastern Cooperative Oncology Group Performance Status >1, human epidermal growth factor receptor 2-negative status, and locoregional uncontrolled disease were associated with poor OS. SDC-GPA scores according to the prognostic factors were 0, 1, 2, and 3 points, and mOS estimates were 50.5, 16.1, 3.9, and 1.2 months, respectively (p < 0.001).

CONCLUSION

The SDC-GPA score emerged as a useful prognostication tool for patients with BM.

Prognostic effects of previous cancer history on patients with major salivary gland cancer

OBJECTIVES

To explore the prognostic effects of previous cancer history on patients with major salivary gland cancer (SGC).

SUBJECTS AND METHODS

SGC patients with (sec-SGC) and without (one-SGC) a previous cancer from the SEER database were identified. Cox proportional hazards regression (CoxPH) models were used to compare the prognosis between sec-SGC and one-SGC patients. Subgroup analyses for sec-SGC patients by gender, previous cancer types, previous cancer histology, and cancer diagnosis interval (CDI) were performed. Two CoxPH models were constructed to distinguish sec-SGC patients with different prognostic risks.

RESULTS

9098 SGC patients were enrolled. Overall, sec-SGC patients (adjusted HR [aHR] = 1.26, p < 0.001), especially those with a CDI ≤ 5 years (aHR = 1.47, p < 0.001), had worse overall survival (OS) than one-SGC patients. In subgroup analysis, only sec-SGC patients with a previous head and neck cancer who were female (aHR = 2.38, p = 0.005), with a CDI ≤ 5 years (aHR = 1.65, p = 0.007) or with a previous squamous cell carcinoma (aHR = 6.52, p < 0.001) had worse OS. Our models successfully differentiated all sec-SGC patients into high-, intermediate- and low-risk groups with different prognosis.

CONCLUSIONS

Sec-SGC patients with different previous cancer types, gender, CDI and previous cancer histology had varied prognosis. The models we constructed could help differentiate the prognosis of sec-SGC patients with different risks.

Evaluation of the efficacy of adjuvant radiotherapy versus chemoradiotherapy in patients with salivary gland tumors

AIMS

The aim of this study was to compare the efficacy of adjuvant radiotherapy (RT) versus adjuvant chemoradiotherapy (CRT) in patients with salivary gland tumors (SGTs).

MATERIALS AND METHODS

Data from patients who underwent adjuvant RT for a diagnosis of SG cancer at Ankara Atatürk Education and Research Hospital, Ankara Numune Education and Research Hospital and Ankara Bilkent City Hospital between September 01, 2009 and September 01, 2022 were analysed retrospectively. We evaluated the efficacy of RT alone versus CRT in these patients in terms of acute response, treatment tolerance, overall survival (OS), and disease-free survival (DFS).

RESULTS

Fifty-five patients who underwent RT between September 14, 2009 and August 04, 2022 at Ankara Atatürk Education and Research Hospital, Ankara Numune Education and Research Hospital and Ankara Bilkent City Hospital were included in this study. Eight patients who did not meet the study criteria were excluded; thus, the analysis was performed for 47 patients. The median follow-up period was 60 months (range: 6-160 months). The median patient age was 53 years (range: 18-86 years). Thirty-nine patients (83%) had parotid tumors and eight patients (17%) had submandibular cancer. The time from surgery to RT was 48 days (range: 20-126 days). Intensity-modulated radiotherapy was administered to all patients and the median RT dose was 66 Gy (range: 52-70 Gy). Concomitant chemotherapy (CCT) (40 mg/m2 of cisplatin weekly) was administered to 13 patients (27.7%). Acute adverse events were observed in 17 patients (36.2%). Interruption of RT was noted for only six patients (12.8%), and this proportion did not differ significantly between the CRT and RT-only arms (P = 0.538). Acute side effects were observed in 17 patients (36.2%), and there were no significant relationships between acute side effects and the administration of CCT (P = 0.112). Recurrence was observed in 10 patients (21.3%). All recurrences were locoregional and no distant metastases were observed during the follow-up period. The median DFS of the patients was 48 months (range: 4-160 months), 1-year DFS was 86%, 2-year DFS was 83.5%, and 5-year DFS was 77.9%. There was no statistically significant difference in DFS between the adjuvant CRT and RT-alone arms (P = 0.114). At the date of last follow-up, 14 patients (29.8%) had died. The median OS of the patients was 58.5 months (range: 6-160 months), 1-year OS was 91.4%, 2-year OS was 86.8%, and 5-year OS was 78%. There was no statistically significant difference in OS between the adjuvant CRT and RT-only arms (P = 0.453).

CONCLUSION

Stage was identified as the most important prognostic factor for DFS and OS. No significant differences in OS, DFS, or acute side effects were observed between the CRT and RT-only arms. Additional studies are needed to identify the subgroup of SGT patients for which CRT is most warranted.

A Radiomics-Based Machine Learning Perspective on the Parotid Gland as a Potential Surrogate Marker for HPV in Oropharyngeal Cancer

BACKGROUND

In treatment of oropharyngeal squamous cell carcinoma (OPSCC), human papillomavirus status (HPV) plays a crucial role. The HPV-positive subtype tends to affect younger patients and is associated with a more favorable prognosis. HPV-associated lesions have been described in the parotid gland, which is included in routine imaging for OPSCC. This work aims to explore the ability of an ML system to classify HPV status based on imaging of the parotid gland, which is routinely depicted on staging imaging.

METHODS

Using a radiomics approach, we investigate the ability of five contemporary machine learning (ML) models to distinguish between HPV-positive and HPV-negative OPSCC based on non-contrast computed tomography (CT) data of tumor volume (TM), locoregional lymph node metastasis (LNM), and the parotid gland (Parotid). After exclusion of cases affected by streak artefacts, 53 patients (training set: 39; evaluation set: 14) were retrospectively evaluated. Classification performances were tested for significance against random optimistic results.

RESULTS

The best results are AUC 0.71 by XGBoost (XGB) for TM, AUC 0.82 by multi-layer perceptron (MLP) for LNM, AUC 0.76 by random forest (RF) for Parotid, and AUC 0.86 by XGB for a combination of all three regions of interest (ROIs).

CONCLUSIONS

The results suggest involvement of the parotid gland in HPV infections of the oropharyngeal region. While the role of HPV in parotid lesions is under active discussion, the migration of the virus from the oral cavity to the parotid gland seems plausible. The imaging of the parotid gland offers the benefit of fewer streak artifacts due to teeth and dental implants and the potential to screen for HPV in cases of an absent or unlocatable tumor. Future investigation can be directed to validation of the results in independent datasets and to the potential of improvement of current classification models by addition of information based on the parotid gland.

Prognostic factors for sublingual gland carcinoma: a population-based Surveillance, Epidemiology and End Results database study

OBJECTIVE

To identify the clinical features and prognostic factors for sublingual gland carcinoma.

METHODS

This was a case-control study. Patients with surgically treated sublingual gland carcinoma were retrospectively included in the Surveillance, Epidemiology and End Results database and divided into adenoid cystic carcinoma (ACC) and non-ACC groups. Primary outcome variables were disease-specific survival (DSS) and overall survival (OS). Prognostic factors for each group were analyzed using Cox models.

RESULTS

We included 251 patients (115 men and 136 women). Compared with the non-ACC group, the ACC group had a larger average tumor size and received more adjuvant radiotherapy. In patients with ACC, the pathologic grade had an independent impact on DSS and OS, and patients who were undergoing adjuvant chemotherapy had worse DSS than those who were not receiving chemotherapy. In the non-ACC group, pathologic grade IV, lymph node metastasis, and adjuvant chemotherapy were associated with poor DSS and OS, and tumor extension predicted worsening DSS.

CONCLUSIONS

In sublingual gland carcinoma, the pathologic grade and adjuvant chemotherapy were the most important prognostic factors, whereas lymph node metastasis had a negative impact in non-ACC patients but not in ACC patients.

Deep learning-assisted diagnosis of parotid gland tumors by using contrast-enhanced CT imaging

OBJECTIVES

Imaging interpretation of the benignancy or malignancy of parotid gland tumors (PGTs) is a critical consideration prior to surgery in view of therapeutic and prognostic values of such discrimination. This study investigates the application of a deep learning-based method for preoperative stratification of PGTs.

MATERIALS AND METHODS

Using the 3D DenseNet-121 architecture and a dataset consisting of 117 volumetric arterial-phase contrast-enhanced CT scans, we developed a binary classifier for PGT distinction and tested it. We compared the discriminative performance of the model on the test set to that of 12 junior and 12 senior head and neck clinicians. Besides, potential clinical utility of the model was evaluated by measuring changes in unassisted and model-assisted performance of junior clinicians.

RESULTS

The model finally reached the sensitivity, specificity, PPV, NPV, F1-score of 0.955 (95% CI 0.751-0.998), 0.667 (95% CI 0.241-0.940), 0.913 (95% CI 0.705-0.985), 0.800 (95% CI 0.299-0.989) and 0.933, respectively, comparable to that of practicing clinicians. Furthermore, there were statistically significant increases in junior clinicians' specificity, PPV, NPV and F1-score in differentiating benign from malignant PGTs when unassisted and model-assisted performance of junior clinicians were compared.

CONCLUSION

Our results provide evidence that deep learning-based method may offer assistance for PGT's binary distinction.

Radiomics Analysis in Characterization of Salivary Gland Tumors on MRI: A Systematic Review

Radiomics analysis can potentially characterize salivary gland tumors (SGTs) on magnetic resonance imaging (MRI). The procedures for radiomics analysis were various, and no consistent performances were reported. This review evaluated the methodologies and performances of studies using radiomics analysis to characterize SGTs on MRI. We systematically reviewed studies published until July 2023, which employed radiomics analysis to characterize SGTs on MRI. In total, 14 of 98 studies were eligible. Each study examined 23-334 benign and 8-56 malignant SGTs. Least absolute shrinkage and selection operator (LASSO) was the most common feature selection method (in eight studies). Eleven studies confirmed the stability of selected features using cross-validation or bootstrap. Nine classifiers were used to build models that achieved area under the curves (AUCs) of 0.74 to 1.00 for characterizing benign and malignant SGTs and 0.80 to 0.96 for characterizing pleomorphic adenomas and Warthin's tumors. Performances were validated using cross-validation, internal, and external datasets in four, six, and two studies, respectively. No single feature consistently appeared in the final models across the studies. No standardized procedure was used for radiomics analysis in characterizing SGTs on MRIs, and various models were proposed. The need for a standard procedure for radiomics analysis is emphasized.

Diagnosis and Management of Parotid Gland Cancer with Focus on the Role of Preoperative Fine-Needle Aspiration Cytology: A 10-Year-Long Retrospective Study with 5-Year Follow-Up

Introduction

Salivary gland cancers represent a rare heterogeneous group of neoplasms with complex clinicopathological characteristics and distinct biological behaviour. The appropriate diagnosis and management of parotid gland cancer are challenging and should be based on the clinical, imaging, cytological, and histological features. The present study analysed the use of preoperative fine-needle aspiration cytology (FNAC) and intraoperative frozen section (FS) to guide the appropriate surgical and postoperative treatment of parotid gland cancers.

Materials and Methods

We selected 48 patients with primary malignancy of the parotid gland surgically treated between 1 January 2008 and 30 June 2017 at the Maxillo-Facial Surgery Division, University Hospital of Parma, Italy. The patients had postoperative histological diagnosis of malignant parotid cancer and were followed up for longer than 5 years.

Results

The 48 patients included in this study had a mean age of 56.7 years. The most frequent type of parotid gland cancer was carcinoma ex pleomorphic adenoma (22.9%), followed by mucoepidermoid carcinoma (16.7%) and acinic cell carcinoma (14.6%). All 48 patients underwent preoperative FNAC: 29 (60.4%) and 19 (39.6%) were suggestive of malignant and benign lesions, respectively. In 31 patients, intraoperative FS was performed.

Discussion

Compared to previous studies, the present study showed significantly lower diagnostic sensitivity of FNAC for parotid gland cancers. The preoperative diagnostic accuracy for suspected malignant cases may be improved by repeat analysis of the cytological specimen by experts, preoperative core needle biopsy, and/or intraoperative FS analysis of the suspected mass.

Extracapsular Dissection of Deep Lobe Parotid Mass Aided by Retromandibular Vein on Imaging: A Case Report

This report investigates the use of the retromandibular vein on imaging as a diagnostic tool for planning deep lobe parotid tumors. A unique aspect of this case is the performance of extracapsular dissection on a deep lobe parotid lesion, which is rare. Preoperative imaging showed a superficially displaced retromandibular vein, indicating a deeply seated tumor, which aided surgical planning. Under general anesthesia, extracapsular dissection was performed while protecting the facial nerve branches. The patient's postoperative course was uneventful, and the facial nerve was intact with no weakness.

Current trends in the treatment of recurrent adenocystic cancer of the salivary glands: case report

Salivary gland carcinomas is a rare family of neoplasms with different histological characteristics and biological behavior. Treatment regimens have remained virtually unchanged for decades, leaving the leading role for surgical treatment and radiation therapy. However, a special place in the salivary gland carcinomas group is occupied by adenoid cystic carcinoma, which is quite often characterized by a recurrent and / or metastatic course with the use of chemotherapy as the main option in treatment. It is worth noting the fact that the results of standard chemotherapy regimens show unsatisfactory results, respectively, with recurrent or metastatic adenoid cystic carcinoma, treatment options are minimal. Accordingly, there is a need to study new therapeutic methods for the treatment of this disease. In this situation, high hopes were placed on targeted therapy, in particular, the family of epidermal growth factor receptors, c-Kit are the most frequently studied molecular targets. Due to the rare occurrence of adenoid cystic carcinoma, the number of cases of using targeted therapy for analysis is relatively small, so each clinical observation is of particular value. The following is a clinical case of treatment of recurrent adenoid cystic carcinoma using a personalized treatment approach.

Aim. To describe the clinical observation of the use of targeted drugs in recurrent or metastatic adenocystic cancer of the salivary glands.

Molecular Targets in Salivary Gland Cancers: A Comprehensive Genomic Analysis of 118 Mucoepidermoid Carcinoma Tumors

INTRODUCTION

Salivary gland carcinomas (SGC) are histologically diverse cancers and next-generation sequencing (NGS) to identify key molecular targets is an important aspect in the management of advanced cases.

METHODS

DNA was extracted from paraffin embedded tissues of advanced SGC and comprehensive genomic profiling (CGP) was carried out to evaluate for base substitutions, short insertions, deletions, copy number changes, gene fusions and rearrangements. Tumor mutation burden (TMB) was calculated on approximately 1.25 Mb. Some 324 genes in the FoundationOne CDX panel were analyzed.

RESULTS

Mucoepidermoid carcinoma (MECa) mutations were assessed. CDKN2A and CDKN2B GA were common in mucoepidermoid carcinoma (MECa) (52.5 and 30.5%). PIK3CA was also common in MECa (16.9%). ERBB2 amplification/short variants (amp/SV) were found in MECa (5.9/0%). HRAS GA was common in MECa (14.4%) as well. Other targets, including BAP1, PTEN, and KRAS, were noted but had a low incidence. In terms of immunotherapy (IO)-predictive markers, TMB > 10 was more common in MECa (16.9%). PDL1 high was also seen in MECa (4.20%).

CONCLUSION

SGC are rare tumors with no FDA-approved treatment options. This large dataset reveals many opportunities for IO and targeted therapy contributing to the continuously increased precision in the selection of treatment for these patients.

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.

Prognostic Factors of Pretreatment Magnetic Resonance Imaging for Predicting Clinical Outcome in Patients With Parotid Gland Cancer

PURPOSE

This study aimed to assess the utility of pretreatment magnetic resonance imaging (MRI) in predicting the clinical outcomes of patients with parotid gland cancer.

METHODS

A total of 43 patients with histopathologically confirmed primary parotid gland cancer, who underwent pretreatment MRI, were enrolled in this study. All images were retrospectively reviewed, and MRI features were evaluated as possible prognostic factors influencing the progression-free survival (PFS) using the Kaplan-Meier method and Cox proportional hazards regression model. Cox regression analysis was used to estimate the hazard ratios (HRs) with 95% confidence interval (95% CI) values.

RESULTS

Kaplan-Meier survival analysis showed that old age (>73 years, P < 0.01), large maximum tumor diameter (>33 mm, P < 0.01), low apparent diffusion coefficient value (≤1.29 ×10-3 mm2/s, P < 0.01), ill-defined margin (P < 0.01), skin invasion (P < 0.01), regional nodal metastasis (P < 0.01), heterogeneous enhancement (P < 0.05), and high signal intensity ratio on gadolinium-enhanced fat-suppressed T1-weighted images (>2.017, P < 0.05) were significant predictors of worse PFS. Cox proportional hazards regression analysis revealed that regional nodal metastasis (HR, 32.02; 95% CI, 6.42-159.84; P < 0.01) and maximum tumor diameter (HR, 1.04; 95% CI, 1.01-1.08; P < 0.05) were independent predictors of PFS.

CONCLUSION

Pretreatment MRI parameters could be prognostic factors of patients with parotid gland cancer. In particular, the maximum tumor diameter and regional nodal metastasis, which were closely associated with T and N classifications, were important prognostic factors in predicting the PFS.

Clinical value of adjuvant therapy on the prognosis of ductal carcinoma of the major salivary gland: a large-scale cohort study

PURPOSE

To explore the clinical characteristics, prognostic factors, and value of adjuvant therapy for major salivary duct carcinoma (SDC).

METHODS

Data of SDC patients who received surgery was obtained from Surveillance, Epidemiology, and End Results (SEER) database (2004-2016). Kaplan-Meier and Cox regression analyses were performed to assess prognostic factors. Propensity score matching (PSM) was done to evaluate the clinical value of adjuvant therapy.

RESULTS

A total of 287 patients were enrolled. The 5-year overall survival (OS) and disease-specific survival (DSS) rates were 53.8% and 70.8%, respectively. In the univariate analysis, tumor size, T, N, TNM staging, SEER combined staging, number of regional lymph nodes examined, and number of positive lymph nodes were associated with OS and DSS. Age and primary surgical methods were also related to OS. Among patients with negative lymph nodes, patients with tumor size > 4 cm had significantly worse prognosis (P = 0.009). Multivariate analysis showed that age > 75 years, T3-4, and positive lymph nodes were independent risk factors for SDC. After PSM, the prognostic factors were age, tumor site, and T and N stage. Postoperative radiotherapy could improve OS in patients with tumor size > 4 cm (P = 0.049).

CONCLUSIONS

Advanced age, submandibular gland lesions, T3-4 stage, and lymph node involvement were independent prognostic factors for SDC. In patients with tumors > 4 cm, adjuvant radiotherapy improved the OS of SDC patients.

High-grade mucoepidermoid carcinoma of the salivary gland in a bull

Salivary gland neoplasia is uncommon in veterinary species and has rarely been reported in cattle. Adenocarcinoma, squamous cell carcinoma, and pleomorphic carcinoma have been described in the parotid gland of dairy cows. Here we describe a case of high-grade mucoepidermoid carcinoma in a bull. The bull had a chronic history of caudal mandibular soft tissue swelling. Postmortem examination revealed a 30 × 30-cm mass with a caseonecrotic center, hemorrhage and necrosis of the ipsilateral cervical musculature, osteolysis of the right paracondylar process of the skull and right horn base, pulmonary nodules, and enlarged tracheobronchial lymph nodes. Histology of the mass, lungs, and lymph nodes revealed an invasive neoplasm composed of epithelial cells arranged in nests and ductular structures supported by a spindle cell stroma, with frequent central necrosis. Immunohistochemistry revealed that epithelial cells were diffusely positive for pancytokeratin and p63 with multifocal vimentin positivity; stromal cells were diffusely positive for vimentin and α-SMA. A salivary gland mucoepidermoid carcinoma was diagnosed based on these findings. Although rare, salivary gland neoplasia should be considered a differential diagnosis for mandibular masses in cattle.

Survival Outcome of Salivary Gland Carcinoma: A 50-Year Retrospective Study With Long-Term Follow-up

PURPOSE

Salivary gland carcinomas (SGCs) can be classified into more than 20 subtypes with various clinical behaviors. The present study aimed to analyze the clinical and pathological features of SGCs and evaluate their long-term prognosis.

METHODS

A retrospective cohort study was performed. This study investigated cases of histologically confirmed SGC at the authors' institution from January 1963 to December 2014. Data on sex, age, site, histopathological diagnosis, tumor-node-metastasis classification, postoperative radiotherapy and/or chemotherapy, local and regional recurrence, and distant metastasis (DM) were collected as covariates. The overall survival (OS) rate was analyzed as the outcome. Kaplan-Meier survival analysis and Cox multivariate analysis were used for survival analysis. The cohort was divided into 2 groups-before and after 1989. The clinicopathological characteristics of the 2 groups were compared using the χ² test.

RESULTS

The cohort included 1,637 patients who met the admission criteria and had a male-to-female ratio of 0.9:1. The median age was 47 years (range, 8 months to 86 years). The median follow-up time was 54 months (range, 1-432 months). The majority of the tumors occurred in the parotid gland (35.3%), followed by the palate gland (25.2%). Adenoid cystic carcinoma was the most common tumor type (34.3%), and mucoepidermoid carcinoma (29%) was the second most common type. In the 1,637 patients, the neck lymph node metastasis rate was 8.7% at the first surgery, and the overall DM rate was 14.1%. The 5-, 10-, and 15-year OS rates of the 1,637 cases were 93.1%, 87.2%, and 79.3%, respectively. Comparative analysis before and after 1989 showed statistically significant differences in sex, site, histologic subtype, T classification, local and regional recurrence rate, and radiotherapy (P < .05), while no significant differences were found in age, N classification, M staging, DM, or chemotherapy.

CONCLUSIONS

The OS rates of SGC have improved significantly over the past 30 years. This is attributable to an increase in the proportion of patients diagnosed at the early stage and receiving radiotherapy, as this has led to a reduction in the local and regional recurrence rate and, consequently, an improvement in the survival rates.

The Diagnostic Value of Fine Needle Aspiration Biopsy in Parotid Tumors

The aim of this study was to investigate the diagnostic accuracy rates of the patients who underwent an operation for parotid mass, by comparing their fine needle aspiration biopsy (FNAB) cytology results with the final pathology. A total of 136 patient files of those who applied to Otorhinolaryngology clinic due to parotid mass and underwent parotidectomy procedure between 2010 and 2020 at a tertiary center were scanned retrospectively. Database on patient age, gender, preoperative FNAB results, and final surgical histopathology results was created. The mean age of the patients was 48.26 ± 17.37 Superficial parotidectomy was performed to 108 (79.4%) and total parotidectomy to 28 (20.6%) of the patients. The sensitivity of FNAB was found as 85.2%, specificity as 96.2%, positive predictive value as 85.2%, negative predictive value as 96.2% and accuracy as 94.0%. It is found that FNAB has the high specificity and high negative predictive value with high diagnostic accuracy on detecting preoperative malignancy in parotid gland. We think that FNAB is a significant, necessary and safe method in the diagnosis of parotid lesions in preoperative sense.

Assessment of a limited-access parotidectomy technique's complications and scar characteristics - A cohort study

OBJECTIVE

Parotidectomy is the treatment of choice for benign tumors of the parotid gland, with the modified Blair incision most commonly utilized. This retrospective analysis aimed to determine the incidence of complications and assess the relationship between the mass and scar characteristics, in patients who had undergone parotidectomy.

MATERIALS AND METHODS

The scar characteristics of patients who had undergone parotidectomy for benign neoplasms at our medical center between 2013 and 2019 were evaluated.

RESULTS

Overall, 49 patients met the inclusion criteria, of whom 33 agreed to participate in the study. The mean patient age was 52.8 years; 57.5% were males. No correlation was identified between the parotid mass size or location and scar type or length. The most common complications in this study were similar to those reported in the literature.

CONCLUSION

The results of this study suggest that the smaller, tailored modified Blair incision for parotidectomy does not increase complication rates. Future studies with larger cohorts should be conducted to further assess the potential benefits of tailored incision size during modified Blair parotidectomies.

The Therapeutic Landscape of Salivary Gland Malignancies-Where Are We Now?

Salivary gland malignancies (SGMs) account for less than 5% of new diagnoses in head and neck tumors. If feasible, surgery is the preferred treatment modality. Nevertheless, some malignancies have a tendency of recurrence, with possible distant metastasis. Alternative treatment strategies, such as primary radiation or chemotherapeutics, often present low response rates. As a result, there is an unmet need for novel therapeutic approaches. Nowadays, target-based therapies (e.g., small inhibitors and immunotherapy) are used by the medical oncologist for possible treatment of advanced SGMs. Based on recent published trials, some novel treatments may provide additional disease control for some patients. However, sample sizes are small, the general findings are unsatisfactory, and a lot of uncertainties remain to be elucidated. Nevertheless, research shows that patients do not benefit from blind administration of systemic treatments and therefore a more personalized approach is highly needed. The aim of this review paper is to summarize the most recent advances in the biological understanding and molecular pathways of salivary gland cancers, the association of these pathways with the current treatments used and their implications for more personalized targeted-based therapies.

An attention base U-net for parotid tumor autosegmentation

A parotid neoplasm is an uncommon condition that only accounts for less than 3% of all head and neck cancers, and they make up less than 0.3% of all new cancers diagnosed annually. Due to their nonspecific imaging features and heterogeneous nature, accurate preoperative diagnosis remains a challenge. Automatic parotid tumor segmentation may help physicians evaluate these tumors. Two hundred eighty-five patients diagnosed with benign or malignant parotid tumors were enrolled in this study. Parotid and tumor tissues were segmented by 3 radiologists on T1-weighted (T1w), T2-weighted (T2w) and T1-weighted contrast-enhanced (T1wC) MR images. These images were randomly divided into two datasets, including a training dataset (90%) and an validation dataset (10%). A 10-fold cross-validation was performed to assess the performance. An attention base U-net for parotid tumor autosegmentation was created on the MRI T1w, T2 and T1wC images. The results were evaluated in a separate dataset, and the mean Dice similarity coefficient (DICE) for both parotids was 0.88. The mean DICE for left and right tumors was 0.85 and 0.86, respectively. These results indicate that the performance of this model corresponds with the radiologist's manual segmentation. In conclusion, an attention base U-net for parotid tumor autosegmentation may assist physicians to evaluate parotid gland tumors.

The efficacy of PD-1 inhibitors in patients with salivary gland carcinoma: A retrospective observational study

Objective

Immune checkpoint inhibitors (ICIs) have been considered as novel therapeutic approaches for various cancers. ICIs were reportedly efficacious against rare cancers, including salivary gland carcinoma (SGC). We aimed to analyze the efficacy and safety of ICIs in patients with SGC.

Methods

We retrospectively analyzed the oncologic outcomes and immune-related adverse events (irAEs) in patients with SGC treated with at least one cycle of nivolumab or pembrolizumab.

Results

Among 12 patients, there were two with a complete response (CR), two with a partial response, five with stable diseases, and three with progressive diseases. The overall response rate was 33.3%. A CR was achieved in patients with poorly differentiated carcinoma (carcinoma ex pleomorphic adenoma) and salivary duct carcinoma. The progression-free survival ranged between 1 and 18 months (median, 4 months), while the overall survival ranged between 2 and 25 months (median, 13.5 months). An irAE was observed in only one patient who developed grade 3 erythema multiforme, and this patient's condition improved with withdrawal of pembrolizumab alone.

Conclusion

Programmed death-1 blockade was an effective therapy for patients with SGC, including aggressive histologic types.

Parotid Gland Tumors: A Multicenter Analysis of 1020 Cases. Increasing Incidence of Warthin's Tumor

We assessed the frequency of the parotid gland tumor entities and correlated sex and age in different tumor types. Retrospective data were obtained from three major otorhinolaryngology clinics in Karlsruhe and Pforzheim, Germany within a 10-year period. In total, 1020 cases of parotidectomy for benign and malignant lesions were identified. We found 864 (84.7%) and 156 (15.3%) patients with benign and malignant tumors of the parotid gland, respectively. The most common benign parotid tumor was Warthin's tumor, followed by pleomorphic adenoma. The most common primary malignant tumor types were acinic cell carcinoma and mucoepidermoid carcinoma. Secondary malignant tumors of the parotid gland included lymphoma and metastatic, cutaneous squamous cell carcinoma. The frequency of Warthin's tumors was higher than that of pleomorphic adenomas. A large proportion of the malignant parotid tumors represent metastases from squamous cell carcinoma of the skin of the head and neck.

Diagnostic performance of elastosonography in the differential diagnosis of benign and malignant salivary gland tumors: A meta-analysis

Purpose

The clinical practice of elastosonography for the detection of salivary gland tumors is still a controversial issue. The objective of this meta-analysis was to evaluate the effect of elastosonography for the diagnosis of salivary gland tumors and to compare the diagnostic value of elastosonography and conventional ultrasound in the diagnosis of salivary gland tumors.

Methods

A comprehensive literature search through PubMed, EMBASE, and Cochrane Library was carried out from inception to November 2021. Two researchers independently extracted the data from the enrolled papers using a standard data extraction form. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the curve (AUC) were calculated to evaluate the diagnostic performance of elastosonography. The Quality Assessment of Diagnostic Accuracy Studies—2 (QUADAS-2) tool was utilized to evaluate the quality of each included study. Meta-DiSc version 1.4, Review Manager 5.3, and StataSE 15 were used.

Results

Sixteen studies with a total of 1105 patients with 1146 lesions were included in this meta-analysis. The pooled sensitivity, specificity, PLR, NLR, and DOR of elastosonography for the differentiation between benign and malignant salivary gland tumors were 0.73 (95%CI, 0.66–0.78), 0.64 (95%CI, 0.61–0.67), 2.83 (95%CI, 1.97–4.07), 0.45 (95%CI, 0.32–0.62), and 9.86 (95%CI, 4.49–21.62), respectively, with an AUC of 0.82. Four studies provided data regarding the conventional ultrasound for the differentiation between benign and malignant salivary gland tumors. The pooled sensitivity, specificity, and DOR were 0.62 (95%CI, 0.50–0.73), 0.93 (95%CI, 0.90–0.96), and 25.07 (95%CI, 4.28–146.65), respectively. The meta-regression and subgroup analyses found that assessment methods were associated with significant heterogeneity, and quantitative or semiquantitative elastosonography performed better than the qualitative one.

Conclusions

Elastosonography showed a limited value for diagnosing malignant salivary gland tumors; it could be considered as a supplementary diagnostic technology to conventional ultrasound, and quantitative or semiquantitative elastosonography was superior to the qualitative one.

Prognostic role of PD-L1 expression in patients with salivary gland carcinoma: A systematic review and meta-analysis

Background

Although programmed cell death-ligand 1 (PD-L1) has been recognized as a potential marker in several cancers, the relationship between PD-L1 expression and survival in patients with salivary gland carcinoma (SGC) has remained unclear. We aimed to evaluate the association of PD-L1 expression with clinicopathological features and prognosis in SGC patients.

Methods

The databases Ovid Medline, PubMed, Scopus, and EMBASE were searched for relevant studies that detected PD-L1 expression in SGC. The meta-analysis was performed according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA), and the reporting recommendations for tumor marker prognostic studies (REMARK) was used to assess the quality of research eligible for this meta-analysis. Included studies were assessed using the Quality in Prognosis Studies (QUIPS) tool. Odds ratios (ORs) with 95% confidence interval (CI) were calculated to estimate the correlation between PD-L1 expression and clinicopathological features. Hazard ratios (HRs) with 95% CI were applied to assess the association between PD-L1 expression and survival outcomes of patients.

Results

A total of ten studies (including 952 patients with SGC) were evaluated. The meta-analysis showed that positive PD-L1 expression in SGC was significantly associated with male patients, older age, Tumor stage, lymph node metastasis, high pathological grade, and non-adenoid cystic carcinoma subtype. The pooled data demonstrated that high PD-L1 expression was associated with poor overall survival and disease-free survival. There was no significant correlation between PD-L1 expression and progression-free survival or disease-specific survival of SGC patients.

Conclusion

According to the meta-analysis, positive PD-L1 expression may play an important role as an effective marker of poor prognosis in patients with SGC. However, large-scale, prospective investigations are still needed to confirm the findings. The assessment of PD-L1 expression may aid in the personalized management of SGC.

Differentiation of Benign From Malignant Parotid Gland Tumors Using Conventional MRI Based on Radiomics Nomogram

Objectives

We aimed to develop and validate radiomic nomograms to allow preoperative differentiation between benign- and malignant parotid gland tumors (BPGT and MPGT, respectively), as well as between pleomorphic adenomas (PAs) and Warthin tumors (WTs).

Materials and Methods

This retrospective study enrolled 183 parotid gland tumors (68 PAs, 62 WTs, and 53 MPGTs) and divided them into training (n = 128) and testing (n = 55) cohorts. In total, 2553 radiomics features were extracted from fat-saturated T2-weighted images, apparent diffusion coefficient maps, and contrast-enhanced T1-weighted images to construct single-, double-, and multi-sequence combined radiomics models, respectively. The radiomics score (Rad-score) was calculated using the best radiomics model and clinical features to develop the radiomics nomogram. The receiver operating characteristic curve and area under the curve (AUC) were used to assess these models, and their performances were compared using DeLong’s test. Calibration curves and decision curve analysis were used to assess the clinical usefulness of these models.

Results

The multi-sequence combined radiomics model exhibited better differentiation performance (BPGT vs. MPGT, AUC=0.863; PA vs. MPGT, AUC=0.929; WT vs. MPGT, AUC=0.825; PA vs. WT, AUC=0.927) than the single- and double sequence radiomics models. The nomogram based on the multi-sequence combined radiomics model and clinical features attained an improved classification performance (BPGT vs. MPGT, AUC=0.907; PA vs. MPGT, AUC=0.961; WT vs. MPGT, AUC=0.879; PA vs. WT, AUC=0.967).

Conclusions

Radiomics nomogram yielded excellent diagnostic performance in differentiating BPGT from MPGT, PA from MPGT, and PA from WT.

ACTH-secreting parotid acinic cell carcinoma unusually reported as a paraneoplastic syndrome

Paraneoplastic syndromes, induced by an immunological cross-reaction or hormone/peptide secretion, are an atypical presentation of tumors. Some tumors, such as small cell lung cancer and bronchial carcinoid, can be adrenocorticotropic hormone (ACTH) secreting tumors. Less commonly, parotid acinic cell carcinoma can be ACTH-secreting tumor leading to Cushing’s syndrome. Few literature cases have described ACTH related paraneoplastic syndrome of parotid adenocarcinoma. Because of the rarity of the condition, little is known about the management and prognosis of this phenomenon. In this report, we highlighted the case of a 59-year-old male with a past medical history of parotid adenocarcinoma treated with surgery, chemotherapy, and radiation therapy presented with clinical and biochemical signs of hyperaldosteronism. Abdominal ultra-sound, computed tomography, and magnetic resonance imaging showed hepatic mass. Liver biopsy with immunohistochemistry confirmed the presence of parotid adenocarcinoma secreting ACTH. He is on paclitaxel and carboplatin medication with good clinical response.

Machine learning-based radiomics for histological classification of parotid tumors using morphological MRI: a comparative study

OBJECTIVES

To evaluate the effectiveness of machine learning models based on morphological magnetic resonance imaging (MRI) radiomics in the classification of parotid tumors.

METHODS

In total, 298 patients with parotid tumors were randomly assigned to a training and test set at a ratio of 7:3. Radiomics features were extracted from the morphological MRI images and screened using the Select K Best and LASSO algorithm. Three-step machine learning models with XGBoost, SVM, and DT algorithms were developed to classify the parotid neoplasms into four subtypes. The ROC curve was used to measure the performance in each step. Diagnostic confusion matrices of these models were calculated for the test cohort and compared with those of the radiologists.

RESULTS

Six, twelve, and eight optimal features were selected in each step of the three-step process, respectively. XGBoost produced the highest area under the curve (AUC) for all three steps in the training cohort (0.857, 0.882, and 0.908, respectively), and for the first step in the test cohort (0.826), but produced slightly lower AUCs than SVM in the latter two steps in the test cohort (0.817 vs. 0.833, and 0.789 vs. 0.821, respectively). The total accuracies of XGBoost and SVM in the confusion matrices (70.8% and 59.6%) outperformed those of DT and the radiologist (46.1% and 49.2%).

CONCLUSION

This study demonstrated that machine learning models based on morphological MRI radiomics might be an assistive tool for parotid tumor classification, especially for preliminary screening in absence of more advanced scanning sequences, such as DWI.

KEY POINTS

• Machine learning algorithms combined with morphological MRI radiomics could be useful in the preliminary classification of parotid tumors. • XGBoost algorithm performed better than SVM and DT in subtype differentiation of parotid tumors, while DT seemed to have a poor validation performance. • Using morphological MRI only, the XGBoost and SVM algorithms outperformed radiologists in the four-type classification task for parotid tumors, thus making these models a useful assistant diagnostic tool in clinical practice.

CT-based radiomics analysis of different machine learning models for differentiating benign and malignant parotid tumors

OBJECTIVES

This study aimed to explore and validate the value of different radiomics models for differentiating benign and malignant parotid tumors preoperatively.

METHODS

This study enrolled 388 patients with pathologically confirmed parotid tumors (training cohort: n = 272; test cohort: n = 116). Radiomics features were extracted from CT images of the non-enhanced, arterial, and venous phases. After dimensionality reduction and selection, radiomics models were constructed by logistic regression (LR), support vector machine (SVM), and random forest (RF). The best radiomic model was selected by using ROC curve analysis. Univariate and multivariable logistic regression was applied to analyze clinical-radiological characteristics and identify variables for developing a clinical model. A combined model was constructed by incorporating radiomics and clinical features. Model performances were assessed by ROC curve analysis, and decision curve analysis (DCA) was used to estimate the models' clinical values.

RESULTS

In total, 2874 radiomic features were extracted from CT images. Ten radiomics features were deemed valuable by dimensionality reduction and selection. Among radiomics models, the SVM model showed greater predictive efficiency and robustness, with AUCs of 0.844 in the training cohort; and 0.840 in the test cohort. Ultimate clinical features constructed a clinical model. The discriminatory capability of the combined model was the best (AUC, training cohort: 0.904; test cohort: 0.854). Combined model DCA revealed optimal clinical efficacy.

CONCLUSIONS

The combined model incorporating radiomics and clinical features exhibited excellent ability to distinguish benign and malignant parotid tumors, which may provide a noninvasive and efficient method for clinical decision making.

KEY POINTS

The current study is the first to compare the value of different radiomics models (LR, SVM, and RF) for preoperative differentiation of benign and malignant parotid tumors. A CT-based combined model, integrating clinical-radiological and radiomics features, is conducive to distinguishing benign and malignant parotid tumors, thereby improving diagnostic performance and aiding treatment.

Establishment of prognostic nomogram for high-grade parotid gland mucoepidermoid carcinoma based on the SEER database

Purpose: We aim to investigate the clinical factors that affect the prognosis of overall survival (OS) for patients with high-grade parotid gland mucoepidermoid carcinoma (high-grade pMEC) and construct a nomogram for prognosis prediction. Subjects and method: Totally, 519 patients diagnosed as high-grade pMEC from the surveillance, epidemiology, and end results (SEER) database between 2004 and 2015 were reviewed. Independent prognostic factors for OS were identified by univariate and multivariate Cox regression analyses. Nomogram was generated to predict the individual's 3- and 5- year OS rates by using R software. Prediction ability was evaluated using the area under the receiver operating characteristic (ROC) curve (AUC) and model calibration was evaluated through calibration plots. Decision curve analysis (DCA) was used to assess the clinical usefulness and net benefit. Results: The results of univariate analysis demonstrated that age, AJCC stage, T stage, N stage, M stage, extraparenchymal lesions, regional lymph nodes status, lymph node dissection status, radiotherapy, chemotherapy, and surgery were significantly correlated with the OS (P < 0.05). Multivariate Cox regression analyses showed that older age at diagnosis, advanced AJCC stage, and positive regional lymph nodes were independent risk factors for OS. In addition, the present study revealed that radiotherapy and surgery were independent protective factors for OS (P < 0.05). The nomograms showed accurate prognostic ability that individually predict 3-years and 5-years overall survival (OS) rates based on age, AJCC stage, regional lymph nodes status, radiotherapy, and surgery. The area under the receiver operating characteristic (ROC) curve (AUC) of the nomogram used to predict the 3-year and 5-year overall survival rate were 0.779 and 0.793, indicating that the model had a good predictive power for the overall survival in high-grade pMEC patient. Conclusions: Using the SEER database, we performed univariate and multivariate analyses to determine independent prognostic factors in high-grade pMEC patients. Subsequently, we constructed and validated a prognostic nomogram to predict 3-and 5-year OS rates based on the SEER database and can assist clinicians to intuitively evaluate prognosis of high-grade pMEC patients.

Establishment and Validation of Prognostic Nomograms for Patients With Parotid Gland Adenocarcinoma Not Otherwise Specified: A SEER Analysis From 2004 to 2016

Background: Parotid gland adenocarcinoma not otherwise specified (PANOS) is a rare malignant tumor with limited data on its characteristics and prognosis. This research is aimed at characterizing PANOS and developing prognostic prediction models for patients with PANOS. Methods: Cases from 2004-2016 were selected from the Surveillance, Epidemiology, and End Results (SEER) Program database. Univariate and multivariate Cox regression were applied to ascertain the factors associated with survival. Competing risk analysis and Gray's tests were employed to analyze cancer-specific death. Propensity score matching (1:1) was conducted to reduce the influence of confounding variables. Results: A total of 446 patients with a median age of 66 years were selected, of which 307 were diagnosed with stage III/IV PANOS. The 5-year overall survival (OS) rate of all patients was 51.8%, and the median survival time was 66 months. Surgical treatment clearly improved survival time (p < 0.001). In the subgroup analysis, radiotherapy showed survival benefits in patients with stage III/IV disease (p < 0.001). Multivariate Cox regression analyses showed that age, T classification, N classification, M classification and surgery were independent prognostic indicators for OS; T classification, N classification, M classification and surgery were independent risk factors for cancer-specific survival (CSS). In addition, age was independently associated with other cause-specific death. Based on the results of multivariate analysis, two nomograms were developed and verified by the concordance index (C-index) (0.747 and 0.780 for OS and CSS) and the area under the time-dependent receiver operating characteristic (ROC) curve (0.756, 0.764, and 0.819 regarding for nomograms predicting 3-, 5-, and 10- year OS, respectively and 0.794, 0.789, and 0.806 for CSS, respectively). Conclusions: Our study clearly presents the clinicopathological features and survival analysis of patients with PANOS. In addition, our constructed nomogram prediction models may assist physicians in evaluating the individualized prognosis and deciding on treatment for patients.

Critical Quality and Readability Analysis of Online Patient Education Materials on Parotidectomy: A Cross-Sectional Study

PURPOSE

Complications related to parotidectomy can cause significant morbidity, and thus, the decision to pursue this surgery needs to be well-informed. Given that information available online plays a critical role in patient education, this study aimed to evaluate the readability and quality of online patient education materials (PEMs) regarding parotidectomy.

METHODS

A Google search was performed using the term "parotidectomy" and the first 10 pages of the search were analyzed. Quality and reliability of the online information was assessed using the DISCERN instrument. Flesch-Kincaid Grade Level (FKGL) and Flesch-Reading Ease Score (FRE) were used to evaluate readability.

RESULTS

Thirty-five PEMs met the inclusion criteria. The average FRE score was 59.3 and 16 (46%) of the online PEMs had FRE scores below 60 indicating that they were fairly difficult to very difficult to read. The average grade level of the PEMs was above the eighth grade when evaluated with the FKGL. The average DISCERN score was 41.7, which is indicative of fair quality. There were no significant differences between PEMs originating from medical institutions and PEMs originating from other sources in terms of quality or readability.

CONCLUSION

Online PEMs on parotidectomy may not be comprehensible to the average individual. This study highlights the need for the development of more appropriate PEMs to inform patients about parotidectomy.

CRISPR/Cas gene-editing technology and its advances in dentistry

A recent discovery of revolutionary Clustered regularly interspaced palindromic repeats (CRISPR) is a gene-editing tool that provides a type of adaptive immunity in prokaryotic organisms, which is currently used as a revolutionizing tool in biomedical research. It has a mechanism of correcting genome errors, turning on/off genes in cells and organisms. Most importantly playing a crucial function in bacterial defence by identifying and destroying Deoxyribonucleic acid (DNA) segments during bacteriophage invasions since the CRISPR-associated protein 9 (Cas9) enzyme recognizes and cleaves invasive DNA sequences complementary to CRISPR. Therefore, researchers employ this biological device to manipulate the genes to develop new therapies to combat systemic diseases. Currently, the most significant advance at the laboratory level is the generation of cell and animal models, functional genomic screens, live images of the cell genome, and defective DNA repairs to find the cure for genetic disorders. Even though this technology has enormous biomedical applications in various sectors, this review will summarize CRISPR/Cas emphasizing both the therapeutic and diagnostic mechanisms developed in the field of dentistry and the promising attempts to transfer this technology to clinical application. Finally, future developments are also described, which proposes to use CRISPR/Cas systems for prospective clinical dentistry applications.

Prognostic factors in acinic cell carcinoma of the head and neck: The Amsterdam experience

INTRODUCTION

The aim was to analyse prognosticators in acinic cell carcinoma (AciCC) in two head and neck referral centers in Amsterdam, the Netherlands.

MATERIALS AND METHODS

Eighty- nine cases of AciCC treated between 1979 and 2016 were retrospectively reviewed. Five, - 10 -and 20- year estimates of survival were executed as well as univariate analysis of prognosticators.

RESULTS

The majority of AciCC were T1-T2; 89%. Two percent had nodal disease (2%). The most affected organ was the parotid gland (84%) with a female preponderance (67%). Mean age was 52 years with most cases diagnosed in the fourth to sixth decade. The majority of patients received adjuvant radiotherapy. Elective neck dissection (END) in the N0 neck showed no metastases. High grade transformation (HGT) was found in 21% of cases. Median follow up was 101.9 months. Median time to recurrence was 26 months. Nine patients developed distant metastases (DM) of whom 6 had HGT-AciCC. Median survival with DM was 7 months. Five,- ten -and twenty- year estimates were 84%, 81% and 81% for recurrence free survival respectively. Negative clinical features were advanced stage disease and tumour size > 2.6 cm. Negative histological features were a high mitotic rate, HGT, close and involved surgical margins and necrosis.

CONCLUSION

AciCC- HGT excluded- of the head and neck has an excellent prognosis and shows acceptable long term results. END can be considered as part of the standard treatment due to the relative high incidence of HGT- AciCC and low accuracy of cytology.

PCP4/PEP19 and HER2 Are Novel Prognostic Markers in Mucoepidermoid Carcinoma of the Salivary Gland

Simple Summary

Mucoepidermoid carcinoma (MEC) is the most common malignancy of all salivary neoplasms, and no effective treatment strategy for MEC has been established other than resection. In this study, we showed that Purkinje cell protein (PCP) 4/peptide (PEP) 19 and human epidermal growth factor receptor 2 (HER2) are predicted to play important roles in the pathogenesis and progression of MEC. The detection of PCP4/PEP19 and HER2 may be useful for providing more effective treatments against MEC.

Abstract

Mucoepidermoid carcinoma (MEC) is one of the most common malignant salivary gland carcinomas, but no effective treatment strategy has been established other than surgical resection. Purkinje cell protein (PCP) 4/peptide (PEP) 19 is a calmodulin-binding antiapoptotic peptide that is expressed and inhibits apoptosis in human breast cancer cells. Human epidermal growth factor receptor 2 (HER2) is an epidermal growth factor that has been implicated in the pathogenesis of many carcinomas, particularly breast and gastric carcinomas. In the present study, we performed immunohistochemical analyses of samples from 73 patients who underwent surgical resection for MEC of the salivary gland using antibodies against PCP4/PEP19 and HER2. PCP4/PEP19 expression was related to better prognosis, while HER2 expression was associated with worse prognosis. Patients that were PCP4/PEP19-positive and HER2-negative showed similar outcomes to PCP4/PEP19 and HER2 alone. Therefore, PCP4/PEP19 and HER2 are predicted to play important roles in the pathogenesis and progression of MEC.

Partial parotid sialoadenectomy in a horse with parotid ductal carcinoma: Surgical description and case report

OBJECTIVES

To describe the surgical findings, histopathological features, and long-term outcome for a horse with parotid salivary carcinoma.

STUDY DESIGN

Case report ANIMALS: Twelve year old American Quarter Horse gelding.

METHODS

The gelding was presented for a 10 × 10 cm swelling below the base of the right ear. Ultrasonographic examination revealed a mass involving the right parotid salivary gland. Incisional biopsy was consistent with parotid carcinoma. The tumor was marginally excised. The lateral wall of the guttural pouch was excised with the mass and was reconstructed with a porcine small intestinal submucosal (SIS) sheet. Cisplatin beads were implanted in the wound bed prior to closure. Firocoxib (0.1 mg/kg orally, daily, every 24 h) treatment was initiated.

RESULTS

Postoperative complications included right-sided facial nerve paralysis, difficulty with deglutition of fibrous feeds, and surgical site dehiscence. Wound healing was achieved by second intention. Partial improvement in nerve function was observed within the first 6 months. At 12 months postparotidectomy, no sign of tumor reoccurrence or metastatic disease was present, and the gelding returned to work.

CONCLUSION

Partial parotid sialoadenectomy was performed with a favorable long-term outcome. Regional anatomic knowledge is crucial.

Posttreatment Magnetic Resonance Imaging Surveillance of Head and Neck Cancers

Treatment strategies and recommended surveillance imaging differ for head and neck cancers depending on subsite and neoplasm type, and pose confusion for referring physicians and interpreting radiologists. The superior soft tissue resolution offered by magnetic resonance imaging is most useful in the surveillance of cancers with high propensities for intraorbital, intracranial, or perineural disease spread, which most commonly include those arising from the sinonasal cavities, nasopharynx, orbits, salivary glands, and the skin. This article discusses recommended surveillance protocoling and reviews treatment approaches, common posttreatment changes, and pearls for identifying disease recurrence in a subsite-based approach.