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

Current aspects of salivary gland tumors - a systematic review of the literature

Objectives: This study provides an up-to-date overview of the distribution of salivary gland tumors in relation to sex, land of treatment, localization of the tumor in the mouths, and benign/malignant disease of this type of tumor. We hypothesized that the distribution of patients with salivary gland tumors could vary according to country, gender, age and tumor specificity. In addition there is a comparison of the primary classification of salivary gland tumors from 1981 and the recent classification from 2005.

Materialsand methods: Data from the Medline database PubMed.gov and supplementary sources were used to conduct a systematic literature search. For this purpose, data from different studies were independently collected using a previously designed questionnaire.

Results: The first section analyzes the general features of the relevant salivary gland tumors from 141 studies involving a total of 25,826 patients across 30 different countries in terms of gender and the occurrence of benign/malignant salivary gland tumors. These data were summarized and presented.

Conclusion: This review offers an insight into the dramatic local differences with regard to salivary gland tumor occurrence as a stepping stone to further classify such data in order to derive effective therapy options, prognosis and widen the general understanding of the subject.

A nomogram to estimate the risk of developing distant metastases in parotid cancer

BACKGROUND

Parotid cancer (PC) is a heterogeneous group of malignant tumors whose management mainly focuses on locoregional control. However, distant metastases (DM) can represent the most common cause of treatment failure. We have defined the predictors and developed a model that can predict a single patient's risk to develop DM.

METHODS

We have analyzed our institutional database of 259 patients with PC and use it to develop a nomogram. C-index and calibration curves were used to assess performance of our model.

RESULTS

DM appeared in 18.9% of patients. Age, cT, pN, perineural invasion, and adenoid cystic carcinoma were significantly associated with distant failure.

CONCLUSIONS

We here present the first model to identify patients with PC at high risk of DM. Such tool can be of great value in managing these rare cancers in terms of a more precise prognosis and follow-up while waiting for better systemic therapies to come in the future.

Nomogram to predict the prognosis of parotid gland mucoepidermoid carcinoma: a population-based study of 1306 cases

Background

Mucoepidermoid carcinoma (MEC) is a common cancer in the oral salivary gland malignancy, which mainly occurs in the parotid gland. The aim of this study is to identify independent prognostic factors and establish a nomogram model for parotid gland mucoepidermoid carcinoma (P-MEC) patients using the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) database.

Method

Patients with P-MEC were selected from between 2004 and 2015. The overall survival (OS) and cancer-specific survival (CSS) rates were estimated using the Kaplan-Meier method with the log-rank test. Univariate and multivariate Cox proportional hazards regression analyses were performed to identify the independent prognostic factors.

Results

A total of 1,306 patients with P-MEC were enrolled. Age, grade, T stage, N stage, M stage, chemotherapy, and surgery type were independent prognostic factors for OS and CSS. A nomogram for OS was formulated based on these independent prognostic factors and validated using an internal bootstrap resampling approach, which showed that the nomogram exhibited a sufficient level of discrimination according to the C-index (0.877, 95% CI [0.855–0.898]).

Conclusion

Several prognostic factors for P-MEC were identified. The nomogram developed in this study accurately predicted the 5- and 10-year OS rates of American patients with P-MEC based on individual characteristics. Risk stratification using the survival nomogram can optimize individual therapies and follow-up.

Carboplatin and Docetaxel in Patients With Salivary Gland Carcinoma: A Retrospective Study

BACKGROUND/AIM

The aim of this study was to evaluate the efficacy and safety of carboplatin/docetaxel combination therapy in patients with locally advanced and/or recurrent/metastatic (LA/RM) salivary gland carcinoma (SGC).

MATERIALS AND METHODS

This was a retrospective analysis of 24 patients that included six patients with AR-positive salivary duct carcinoma (SDC) after progressive disease treated with combined androgen blockade (CAB). Carboplatin (AUC5) and docetaxel (70 mg/m²) were administered for six courses every three weeks.

RESULTS

The overall response rate was 42%, the median progression-free survival was 8.4 months, and the median overall survival was 26.4 months. Among the six patients with CAB-resistant SDC, two achieved a partial response and two long-term stable disease. Grade 3/4 neutropenia and anemia were observed in 20-30% of the patients; all adverse events were manageable.

CONCLUSION

Carboplatin/docetaxel combination therapy may be a chemotherapeutic option for patients with LA/RM SGC, and a valuable second-line chemotherapy for CAB-resistant, AR-positive SDC.

Sensitivity of Fine-Needle Aspiration and Imaging Modalities in the Diagnosis of Low-Grade Mucoepidermoid Carcinoma of the Parotid Gland

OBJECTIVE

To determine the diagnostic accuracy of fine-needle aspiration (FNA) and imaging modalities for low-grade mucoepidermoid carcinoma (MEC) of the parotid gland.

METHODS

Retrospective chart review of patients diagnosed with low-grade MEC of the parotid gland following surgical excision between January 2010 and June 2018. Imaging from patients with MEC were randomly mixed with imaging from patients with benign pathology and reviewed in a blinded fashion. Main outcome measure was sensitivity.

RESULTS

A total of 24 patients were confirmed to have had low-grade MEC on final pathology, with a total of 31 FNAs performed between them. Twelve of 31 FNAs were positive for low-grade MEC, with a sensitivity of 39%. A total of 27 imaging studies were reviewed, which included 16 patients with low-grade MEC and 11 patients with benign pathology. Of these 27 imaging studies, 10 were declared indeterminate. Of the remaining 17 imaging studies, 13 were reviewed as malignant (11 true positive and 2 false positive) and 4 as benign (4 true negative). Overall magnetic resonance imaging (MRI) sensitivity for low-grade MEC was 100% (9/9) with 95% CI (0.66-1.0) when considering indeterminate results as positive for malignancy.

CONCLUSION

This study reaffirms that for low-grade MEC, sensitivity of FNA is poor. MRI provides an important diagnostic tool in the evaluation of salivary gland neoplasms, due to its increased sensitivity for low-grade MEC when considering indeterminate results as positive. This provides confidence in the diagnosis of benign tumors and allows appropriate counseling of all options to the patient, including observation. Imaging and low threshold of excision should be considered despite an inflammatory or benign FNA.

Clinical behaviours and prognoses of high- and low-risk parotid malignancies based on histology

PURPOSE

To report 5-year survival in patients with primary parotid malignant tumours and assess the impact of various factors on survival or local control among diverse histologic groups.

METHODS

A total of 65 patients with primary parotid malignant tumours who had surgery between 2003 and 2014 were identified. Demographic characteristics including age, T stage, N stage and clinical or pathological performance were analysed. According to risk stratification (based on pathology), 65 primary parotid malignant tumours were divided into high-risk (23, 35.38%) and low-risk (35, 53.85%) groups. Overall survival (OS) and disease-free survival (DFS) were recorded by the Kaplan-Meier methods.

RESULTS

The 5-year overall survival rate for primary parotid malignant tumours was 70.9%. Patients older than 60 years with fixed mass, pain, facial-nerve palsy and high-grade N stage had adverse OS and DFS. Upon multivariable analysis, facial-nerve palsy (HR 24.59; 95% CI 2.338-178.446; P = 0.002) was the only independent predictive factor for OS. Patients with high-risk parotid malignant types were more likely to have tumour pain, facial-nerve palsy (Chi-square test: < 0.0001 and 0.02), lymphatic metastasis and local/regional recurrence (Chi-square test: 0.008 and 0.012).

CONCLUSIONS

Compared with low-risk parotid carcinoma, tumours with high-risk histological features tend to need aggressive surgical extirpation, neck dissection and postoperative radiotherapy.

The efficacy of neutron radiation therapy in treating salivary gland malignancies

OBJECTIVES

Radiation therapy is commonly used to treat head and neck malignancies. While there is abundant research regarding photon radiation therapy, literature on neutron radiotherapy (NRT) and oral complications is limited. This study aims to determine: (1) the 6-year and 10-year locoregional control and survival rates, (2) factors associated with locoregional control and survival and (3) the frequency of oral complications in patients undergoing NRT for salivary gland malignancies.

MATERIALS AND METHODS

This is a retrospective cohort study. The sample was composed of patients with salivary gland malignancies treated with NRT between 1997 and 2010. Data were extracted from patient charts, telephone surveys, and social security records. Multivariate competing risk and Cox regression models were used to assess predictors of locoregional control and survival.

RESULTS

The sample was composed of 545 subjects with a mean age of 54.2 years (±16). The predominant tumor and location were adenoid cystic carcinoma (47%) and the parotid (56%). Multivariate analysis indicated that positive surgical margins, biopsied/inoperable malignancies, neck involvement, and lymphovascular invasion were prognostic risk factors associated with decreased survival. The 6- and 10-year locoregional control rates were 84% and 79%. The 6- and 10-year survival rates were 72% and 62%. Osteoradionecrosis developed in 3.4% of subjects.

CONCLUSIONS

The 6- and 10-year locoregional control and survival rates compare favorably to rates reported for conventional photon radiation. Osteoradionecrosis rates were comparable to that of photon radiation treatment (2-7%). Given the potential benefits of NRT, healthcare professionals should be educated regarding its indications and oral complications.

Phase II Trial of Trastuzumab and Docetaxel in Patients With Human Epidermal Growth Factor Receptor 2-Positive Salivary Duct Carcinoma

PURPOSE

Clinical evidence demonstrating the effectiveness of systemic therapy for advanced salivary duct carcinoma (SDC) is lacking because of the disease's rarity. We assessed the efficacy and toxicity of trastuzumab plus docetaxel in patients with locally advanced and/or recurrent or metastatic human epidermal growth factor receptor 2-positive SDC.

PATIENTS AND METHODS

This was a single-center, single-arm, open-label, phase II study in Japan. The patients received trastuzumab at a loading dose of 8 mg/kg, followed by 6 mg/kg every 3 weeks. Docetaxel 70 mg/m² was administrated every 3 weeks. The primary end point was the overall response rate; the secondary end points included the clinical benefit rate, progression-free survival, overall survival, and toxicity. This study is registered with the University Hospital Medical Information Network Clinical Trials Registry (Identification No. UMIN000009437).

RESULTS

Fifty-seven eligible patients with SDC were enrolled. The overall response rate was 70.2% (95% CI, 56.6% to 81.6%), and the clinical benefit rate was 84.2% (95% CI, 72.1% to 92.5%). Median progression-free and overall survival times were 8.9 months (95% CI, 7.8 to 9.9 months) and 39.7 months (95% CI, not reached), respectively. The most frequent adverse event was anemia (52 patients [91%]), followed by a decreased WBC count (51 patients [89%]) and neutropenia (50 patients [88%]). The most frequently observed grade 4 adverse event was a decreased neutrophil count (34 patients [60%]). Grade 3 febrile neutropenia was reported in eight patients (14%). No grade 2 or greater adverse events of heart failure or left ventricular ejection fraction decline to less than 50% occurred.

CONCLUSION

Our data show encouraging efficacy of trastuzumab plus docetaxel therapy in patients with human epidermal growth factor receptor 2-positive SDC, with a manageable toxicity profile.

Review of the Major and Minor Salivary Glands, Part 2: Neoplasms and Tumor-like Lesions

The salivary glands are small structures in the head and neck, but can give rise to a wide variety of benign and malignant pathology. When this occurs, patients may present with palpable swelling, although it is quite common that they are asymptomatic and a salivary gland mass was discovered as an incidental finding on imaging performed for another reason. It is, therefore, critical that radiologists pay careful attention to the salivary glands and have working knowledge of the key differentiating features of the most common neoplastic and nonneoplastic etiologies of salivary gland masses. The purpose of this review is to provide a succinct image-rich article illustrating the various causes of salivary gland masses via an extensive review of the primary literature. In Part 2, we discuss neoplasms and tumor-like lesions of the salivary glands with a key emphasis on specific imaging features of the most common pathologic entities.

Comprehensive approach to reestablishing form and function after radical parotidectomy

INTRODUCTION

The reconstructive goals following radical parotidectomy include restoration of symmetry, reanimation of the face, and reestablishment of oral competence. We present our experience utilizing the anterolateral thigh (ALT) free flap, orthodromic temporalis tendon transfer (OTTT), and facial nerve cable grafting to reestablish form and function.

MATERIAL AND METHODS

From 2010 to 2016, 17 patients underwent radical parotidectomy followed by immediate reconstruction. An ALT was harvested to accommodate the volume and skin defect. Additional fascia lata and motor nerve to vastus lateralis (MNVL) were obtained. Anastomosis of the ALT to recipient vessels was performed, most commonly using the facial artery and internal jugular vein. OTTT was performed by securing the medial tendon of the temporalis to orbicularis oris through a nasolabial incision. Fascia lata was tunneled through the lower lip, then secured laterally to the temporalis tendon. The MNVL was cable grafted from either the proximal facial nerve or masseteric nerve to the distal facial nerve branches. ALT fascia was suspended to the superficial muscular aponeurotic system.

RESULTS

Average follow up was 19 months. Only one patient failed to achieve symmetry attributed to dehiscence of OTTT. All patients achieved oral competence and dynamic smile with OTTT activation. Facial nerve recovery was seen in 8 patients. 5 reached a House Brackman Score of 3. Two donor site seromas and two wound infections occurred.

CONCLUSION

Simultaneous ALT, OTTT, and facial nerve cable grafting provides early reestablishment of facial symmetry, facial reanimation, and oral competence with minimal morbidity.

Salivary gland carcinoma: Prediction of cancer death risk based on apparent diffusion coefficient histogram profiles

We evaluated apparent diffusion coefficient (ADC) histogram parameters for predicting the outcomes of patients with salivary gland carcinoma. Diffusion-weighted MR imaging was performed in 20 patients with salivary gland carcinoma, and ADCs were determined using b-values of 500 and 1000 s/mm². ADC histogram parameters (mean, median, percentage tumor area with distinctive ADC values [pADC], skewness, and kurtosis) were analyzed. The patients were followed for 5–136 months after primary surgery. The ADC histogram parameters and T (pT), N(pN), and M categories of the primary tumors were assessed for the prognostic importance using Cox proportional hazards models, logistic regression analysis, and receiver operating characteristic (ROC) analysis. Cohen’s d was determined for evaluating the importance of differences in the parameters between two patient groups with different outcomes. Six patients died of cancer (DOC) within 3 years after the primary surgery. Cox proportional hazards models indicated that ADC mean (95% CI = 0.494–0.977, p = 0.034), ADC median (95% CI = 0.511–0.997, p = 0.048), pADC with extremely low (<0.6 mm²/s) ADC (95% CI = 1.013–1.082, p = 0.007), kurtosis (95% CI = 1.166–7.420, p = 0.023), and pN classification (95% CI = 1.196–4.836, p = 0.012) were important factors of cancer death risk. ROC analyses indicated that the pADC <0.6 ×10⁻³ mm²/s was the best prognostic predictor (p <0.001; AUC = 0.929) among the ADC and TNM classification parameters that were significant in a univariate logistic regression analysis. Cohen’s d values between the DOC and survived patients for the ADC mean, ADC median, pADC with extremely low ADC, and kurtosis were 1.06, 1.04, 2.12, and 1.13, respectively. These results suggest that ADC histogram analysis may be helpful for predicting the outcomes of patients with salivary gland carcinoma.

Parotid gland adenocarcinoma in a cow: case report

ABSTRACT A 9-year-old Girolando dairy cow, weighing 400kg, with a history of increased volume in the right parotid region, which extended to the submandibular region, was assisted. Fine needle aspiration cytology was performed, and the cytological findings were consistent with malignant neoplasm of epithelial origin (carcinoma). Because of the unfavorable prognosis, the animal was euthanized and submitted to an anatomopathological examination. Samples of the increased parotid and affected lymph nodes were collected for histopathological evaluation. The microscopic changes were accentuated features of anaplasia, moderate cell proliferation, atypical mitotic figures, and necrosis. Stroma ranged from delicate to scirrhous, and the tumor boundaries were not distinct. These findings substantiated the preliminary histomorphological diagnosis of undifferentiated carcinoma with metastasis in lymph nodes. Immunohistochemical tests were performed with anti-CK Pan (clone AE1AE3), anti-CK HMW (clone 34βE12), anti-CK19 (clone RCK108), anti-vimentin (clone V9), anti-S100 (polyclonal), and anti-androgen (polyclonal) antibodies. The immunophenotype favored the diagnosis of salivary gland adenocarcinoma. Despite the rareness in cattle, salivary gland adenocarcinoma should be considered in the differential diagnosis of diseases that occur with increased volume in the head, lymphadenopathy, drooling, dysphagia, and progressive weight loss.

Fine Needle Aspiration Cytology for Neck Masses in Childhood. An Illustrative Approach

The primary indication of fine-needle aspiration cytology of the head and neck region is a thyroid nodule or a mass located in the cervical area or the head. Although a thyroid nodule may raise the suspicion of malignancy, less than one in 20 cases results in a carcinoma. In addition, the list of differential diagnoses is quite different according to the age of the patient. A number of benign lesions, such as branchial cysts, sialadenosis, and sialoadenitis are often seen in childhood and youth. The malignant lesions that are on the top of the list of a pediatric mass of the head and neck (H&N) region include rhabdomyosarcoma, neuroblastoma, and papillary carcinoma of the thyroid gland. This critical review of the diagnostic features of a pediatric mass of the H&N region is accompanied by panels of several cytology features that may be of help to the cytopathologist and clinician.

A prospective phase II study of combined androgen blockade in patients with androgen receptor-positive metastatic or locally advanced unresectable salivary gland carcinoma

Background

There is no standard first-line chemotherapy for recurrent/metastatic (RM) or unresectable locally advanced (LA) salivary gland carcinoma (SGC).

Patients and methods

We conducted a single institution, open-label, single arm, phase II trial of combined androgen blockade (CAB) for androgen receptor (AR)-positive SGC. Leuprorelin acetate was administered subcutaneously at a dose of 3.75 mg every 4 weeks. Bicalutamide was administered orally at a daily dose of 80 mg. Patients were treated until progressive disease or unacceptable toxicities.

Results

Thirty-six eligible patients were enrolled. Thirty-three patients had RM disease and three patients had LA disease. The pathological diagnoses were salivary duct carcinoma (34 patients, 94%) and adenocarcinoma, NOS (two patients, 6%). The best overall response rate was 41.7% [n = 15, 95% confidence interval (CI), 25.5%-59.2%], the clinical benefit rate was 75.0% (n = 27, 95% CI, 57.8%-87.9%). The median progression-free survival was 8.8 months (95% CI, 6.3-12.3 months) and the median overall survival was 30.5 months (95% CI, 16.8 months to not reached). Additional analyses between treatment outcomes and clinicopathological factors or biomarkers including AR positivity, human epidermal growth factor receptor 2 status, and its complex downstream signaling pathway gene mutations showed no statistically significant differences. Elevated grade 3 liver transaminases and increased serum creatinine were reported in two patients, respectively. Discontinuation of leuprorelin acetate or bicalutamide due to adverse event occurred in one patient.

Conclusion

This study suggests that CAB has equivalent efficacy and less toxicity for patients with AR-positive RM or unresectable LA SGC compared with conventional chemotherapy, which warrants further study.

Clinical Trial Registration

UMIN-CTR (http://www.umin.ac.jp/ctr/index-j.htm), identification number: UMIN000005703.

Validation of nomograms for overall survival, cancer-specific survival, and recurrence in carcinoma of the major salivary glands

BACKGROUND

The purpose of this study was to investigate the performance of the Memorial Sloan Kettering Cancer Center salivary carcinoma nomograms predicting overall survival, cancer-specific survival, and recurrence with an external validation dataset.

METHODS

The validation dataset comprised 123 patients treated between 2010 and 2015 at our institution. They were evaluated by assessing discrimination (concordance index [C-index]) and calibration (plotting predicted vs actual probabilities for quintiles).

RESULTS

The validation cohort (n = 123) showed some differences to the original cohort (n = 301). The validation cohort had less high-grade cancers (P = .006), less lymphovascular invasion (LVI; P < .001) and shorter follow-up of 19 months versus 45.6 months. Validation showed a C-index of 0.833 (95% confidence interval [CI] 0.758-0.908), 0.807 (95% CI 0.717-0.898), and 0.844 (95% CI 0.768-0.920) for overall survival, cancer-specific survival, and recurrence, respectively.

CONCLUSION

The 3 salivary gland nomograms performed well using a contemporary validation dataset, despite limitations related to sample size, follow-up, and differences in clinical and pathology characteristics between the original and validation cohorts.

Current State of Knowledge on Salivary Gland Cancers

Salivary gland cancers (SGCs), categorized as head and neck cancers (HNCs), constitute about 6% of head and neck cancer diagnoses based on estimate by American Head and Neck Society. Salivary gland tumors originate from different glandular cell types and are thus morphologically diverse. These tumors arise from any of the three major and various minor salivary glands. The incidence of SGCs has slowly increased during the last four decades. The etiology of SGCs is mostly unknown; however, specific gene mutations are associated with certain types of salivary tumors. Treatment options include surgical resection, radiation therapy (RT), chemotherapy, and multimodality therapy. HNC patients treated with RT often develop xerostomia and salivary hypofunction due to damaged salivary glands. In this review, we discuss etiology of SGCs, present findings on the role of autophagy in salivary tumorigenesis, review adverse effects of radiation treatment, and examine remedies for restoration of salivary function.

Prognostic and histogenetic roles of gene alteration and the expression of key potentially actionable targets in salivary duct carcinomas

The molecular characteristics of therapeutically-relevant targets and their clinicopathological implications in salivary duct carcinomas (SDCs) are poorly understood. We investigated the gene alterations and the immunoexpression of crucial oncogenic molecules in 151 SDCs. The mutation rates that were identified, in order of frequency, were as follows: TP53, 68%; PIK3CA, 18%; H-RAS, 16%; BRAF, 4%; and AKT1, 1.5%. PIK3CA/H-RAS/BRAF mutations were more common in de novo SDC than in SDC ex-pleomorphic adenoma. Furthermore, these mutations were mutually exclusive for HER2 overexpression/amplification. TP53 mutations were frequently detected in cases with the aberrant p53 expression, and TP53 missense and truncating mutations were associated with p53-extreme positivity and negativity, respectively. DISH analysis revealed no cases of EGFR amplification. The rates of PI3K, p-Akt, and p-mTOR positivity were 34%, 22%, and 66%, respectively; PTEN loss was observed in 47% of the cases. These expressions were correlated according to the signaling axis. Cases with PI3K negativity and PTEN loss appeared to show a lower expression of androgen receptor. In the multivariate analysis, patients with SDC harboring TP53 truncating mutations showed shorter progression-free survival. Conversely, p-Akt positivity was associated with a favorable outcome. This study might provide information that leads to advances in personized therapy for SDC.

Tumor Differentiation as a Prognostic Factor for Major Salivary Gland Malignancies

Objective The effect of tumor differentiation on prognosis of major salivary gland malignancies is controversial. The aim of this study was to determine the effect of tumor differentiation on prognosis by stage in patients with major salivary gland malignancies and to analyze which patient factors are associated with tumor differentiation. Study Design and Setting Cross-sectional analysis of Surveillance, Epidemiology, and End Results (SEER) database. Subjects and Methods In total, 9810 patients who had a major salivary gland malignancy from 2004 to 2012 were identified using the SEER database. Patients with no staging information or no information on histologic differentiation were excluded. A total of 5366 patients were included in the study. For analysis, patients were categorized by American Joint Committee on Cancer (AJCC) stage and subdivided by tumor differentiation. Multivariate analysis was used to analyze the impact of tumor differentiation on survival, tumor location (parotid, submandibular, sublingual), and sex within each AJCC stage of disease. Results Data analysis demonstrated a significant difference in histologic differentiation by stage, with P < .0001. Within stages II, III, and IV, tumor differentiation was significantly associated with a decrease in survival. There was no significant difference in tumor differentiation between the parotid and submandibular gland. Conclusion For patients with stage II, III, and IV disease, tumor differentiation was an independent predictor of survival. This information can be useful when discussing prognosis and can potentially influence management of disease.