Cancers of the Major Salivary Gland

Saliva metabolomics: concepts and applications in oral disorders

OBJECTIVES

The purpose of this review was to present the basic concepts of metabolomics methodology and the use of saliva for diagnostic, prognostic, and predictive strategies.

MATERIAL AND METHODS

This review followed the focus in: "saliva metabolomics" and "oral diseases". The authors searched studies on PubMed database. The inclusion criteria were original studies and reviews that assessed metabolomics techniques. A descriptive analysis was performed considering the study design, approach system, clinical steps, and tools for the determination of profile or biomarkers metabolites, and the advantages and disadvantages.

RESULTS

Metabolomic analyses use a combination of analytical instrumentation and informatic tools to provide information on metabolite characteristics. In this review we described different technologies applied and the advantages and limitations of each technique. Furthermore, in the literature search, we retrieved 25 studies that investigated saliva metabolites in oral diseases: 8 studies used targeted analysis and 17 untargeted metabolomics approaches. Most studies included patients with periodontal diseases, oral squamous cell carcinoma, and Sjögren Syndrome. The most frequently reported metabolites were glycine, leucine, phenylalanine, dipeptides, linoleic acid, arachidonic acid, tyrosine, choline, taurine, lactate, valine, and proline.

CONCLUSIONS

Metabolomics analysis has emerged as a powerful tool for tumor diagnosis and to enhance tumor classification, including salivary gland tumors (SGTs). It also holds promise for developing personalized treatment plans and defining more precise prognostic categories.

CLINICAL RELEVANCE

Metabolomics is the most functional and comprehensive technique for monitoring and understanding gene functions and identifying the biochemical state of an organism in response to genetic and environmental changes.

Unique Cohorts of Salivary Gland Cancer Cells as an in-vitro Model of Circulating Tumor Cells

Introduction

The characterization of circulating tumor cells (CTC) and circulating tumor microemboli (CTM) has emerged as both a challenge to the standard view of metastasis, and as a valuable means for understanding genotypic and phenotypic variability shown even within the same cancer type. However, in the case of salivary gland neoplasms, limited data are available for the role that CTCs and CTMs play in metastasis and secondary tumor formation.ru.AQ1 In response to this, we propose that similarities between in vitro clusters of cultured salivary gland cancer cells may act as a surrogate model for in vivo CTCs and CTMs isolated from patients.

Materials and Methods

Using techniques in immunofluorescence, immunoblotting, and 2-dimensional migration, we isolated and characterized a group of cohort cells from a commercially available cell line (HTB-41). Results: Here, cells exhibited a hybrid phenotype with simultaneous expression of both epithelial and mesenchymal markers (E-cadherin, vimentin, and α-SMA). Cohort cells also exhibited increased migration in comparison to parental cells.

Conclusion

Data suggest that these isolated cell clusters may fucntion as a potential in vitro model of CTCs and CTMs.

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

OBJECTIVE

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

STUDY DESIGN

Retrospective cohort study.

SETTING

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

METHODS

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

RESULTS

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

CONCLUSION

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

Assessing Morphological Diversity of Acinic Cell Carcinoma of Salivary Glands at a Tertiary Care Hospital in Pakistan

INTRODUCTION

Acinic cell carcinoma (AciCC) is a rare clinical entity and a salivary gland malignancy. It is associated with wide histological variations in the cytomorphological patterns.

METHODS

Sixty cases diagnosed as AciCC from 2002 to 2023 were assessed for diverse cytomorphological patterns.

RESULTS

The mean age of patients at the time of diagnosis was 44.35±16.8 years ranging from 15 to 81 years. Females comprised 58.3% for a F: M ratio of 1.4:1. Fifty three cases (88.3%) occurred in the parotid gland, two cases in the nasal region (3.3%), and one case each in the soft plate and upper lip (1.7%). The location of the remaining three cases was not specified. The most common presenting complaint was a well-defined facial swelling associated with pain. The average tumor size was 3.8±1.9 cm. The most predominant architectural pattern was solid (83.3%) followed by microcystic (60%), then follicular (41.7%), papillary cystic (14.3%), and tubulocystic (28.6%), and AciCC with de-differentiation/high-grade transformation was reported in three cases (5%). In 83.3% of the cases (50 out of 60), we noticed a mixture of two or more growth patterns. Other degenerative changes included prominent lymphoid stroma, hemorrhage, and cystic change.

CONCLUSION

Awareness and recognition of diverse cytomorphological patterns of AciCC, especially in institutions of a developing country where there is limited availability of highly specific and sensitive immunohistochemical stains or molecular diagnostics, are crucial and essential.

Elective nodal dissection for cN0 intermediate-grade parotid mucoepidermoid carcinoma: A NCDB study

PURPOSE

To determine the occult nodal disease rate and whether elective regional lymph node dissection (RLND) confers any 10-year overall survival (OS) in cN0 intermediate-grade mucoepidermoid carcinoma (MEC) of the parotid gland.

MATERIALS & METHODS

The National Cancer Database was reviewed from 2004 to 2016 on adults with cT1-4aN0M0 intermediate-grade parotid MEC undergoing resection with/without RLND. Comparisons between patients with and without RLND were made. Occult nodal rate and 10-year overall survival (OS) were determined.

RESULTS

Out of 898 included patients with cN0 intermediate grade parotid MEC undergoing elective RLND, the occult nodal rate was 7.6%. This was significantly different from low-grade (3.9%) and high-grade (25.7%) cN0 disease. When stratified by pT-classification, marginal differences were identified between low-grade and intermediate-grade tumors, whereas high-grade tumors demonstrated increased occult nodal disease with low T-stage (pT1-pT2, 20.4% vs. 5.1%) and high T-stage (pT3-pT4a, 32.1% vs. 17.6%). Patients undergoing elective RLND were more often treated at an academic facility (53.8% vs. 41.2%), had higher pT3-pT4 tumors (19.2% vs. 10.4%), and more frequently underwent total/radical parotidectomy (46.0% vs. 29.9%) with adjuvant radiation therapy (53.8% vs. 41.0%) Cox-proportional hazard modeling did not identify RLND, regardless if stratified by nodal yield or pT-classification, nor nodal positivity as significant predictors of 10-year OS.

CONCLUSIONS

The occult nodal disease in intermediate-grade parotid MEC is low and similar to low-grade. Elective RLND may have a limited impact on OS, though its effect on locoregional control remains unknown.

LEVEL OF EVIDENCE

III.

Diagnostic Utility of Expression Pattern of S100/Mammaglobin/SOX10/DOG 1 Immunohistochemistry in Differentiation of Secretory and Acinic Cell Carcinoma: A Systematic Review and Meta-Analysis

Secretory carcinoma (SC) is a relatively new disease entity, separate from acinic cell carcinoma (AciCC), which frequently displays ETV6-NTRK3 gene fusion. However, the differences between SC and AciCC remain ambiguous. Genetic diversity makes its diagnosis complicated. In this regard combined expression of immunohistochemistry markers S100/Mammaglobin/SOX10 and DOG1 is need of the hour as alternative methodology. The current systematic review was to investigate the diagnostic utility of combined immunohistochemical expression of S100/Mammaglobin/SOX10/DOG1 in distinction of SC from AciCC histologically. An electronic search of databases was carried out using MEDLINE by PubMed, Google scholar, Scopus and Web of science. Articles inclusive of SC and AciCC were assessed with S100/Mammaglobin/SOX10/DOG1 immunohistochemistry and their predominant expression pattern, predictive values, sensitivity and specificity were gathered. Fourteen eligible articles were analysed, which revealed predominant immunostaining pattern of S100 + /Mammaglobin + /SOX10 + /DOG1- by nearly all ETV6::NTRK3 fusion prevalent SCs alongside with other gene fusions like RET, MET and MAML3 with 98.4% sensitivity as well as 86.1% specificity. The evidence supports that S100/Mammaglobin/SOX10/DOG1 combined immunostaining can serve as a reliable diagnostic method to differentiate secretory from acinic cell carcinoma.

Cocaine use and head and neck cancer risk: A pooled analysis in the International Head and Neck Cancer Epidemiology Consortium

BACKGROUND

Cocaine is an illegal recreational drug used worldwide, yet little is known about whether cocaine inhalation (smoking/snorting) increases the risk of head and neck cancer (HNC).

METHODS

The analyses were conducted by pooling data from three case-control studies with 1639 cases and 2506 controls from the International Head and Neck Cancer Epidemiology Consortium. Epidemiologic data, including cocaine use histories, were obtained in face-to-face interviews. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated using hierarchical logistic regression models.

RESULTS

Controlling for cumulative tobacco and alcohol use, we observed a weak positive association between cocaine use and HNC (ORever vs. never  = 1.35, 95% CI: 0.96, 1.90). In stratified analysis, while we did not detect associations among never tobacco or alcohol users due to the limited sample size, the association with cocaine use was observed among tobacco users and alcohol drinkers. ORs for ever and high cumulative use (>18 times) versus never use were 1.40 (95% CI: 0.98, 2.00) and 1.66 (95% CI: 1.03, 2.69) among tobacco users, and 1.34 (95% CI: 0.93, 1.92) and 1.59 (95% CI: 1.00, 2.51) among alcohol drinkers, respectively.

CONCLUSION

In this pooled analysis, we observed a weak positive association between cocaine inhalation and HNC risk. Our findings provide preliminary evidence of the potential carcinogenic effect of cocaine on HNC. Because of study limitations, including limited number of cocaine users, confounding, and heterogeneity across studies, future investigations will require larger studies with more detailed information on cocaine use history.

Pathological nodal status as a main predictive factor of survival and treatment outcomes of submandibular salivary gland cancers: A 25-year single center experience

INTRODUCTION

Aim of this study was to explore the survival predictive factors and treatment outcomes in a cohort of SGC patients treated at a single center over a period of 25 years.

MATERIALS AND METHODS

Patients who had received primary treatment for SGC were enroled. Outcomes evaluated were: overall survival (OS), disease specific survival (DSS), recurrence free survival (RFS), locoregional recurrence free survival (LRFS) and distant metastasis free survival (DFS).

RESULTS

A total of 40 patients with SGC were enroled in the study. The most common tumor was the adenoid cystic carcinoma (60% of cases). Cumulative OS for 5-and 10-year follow up period was 81% and 60%, respectively. Thirteen patients (32.5%) developed distant metastases during follow-up. Nodal status, high-grade histology, tumor stage and adjuvant radiation-therapy (RT) were significant variables on multivariate analysis for survival and treatment outcomes.

CONCLUSIONS

Submandibular gland carcinomas represent rare and heterogenous tumor group regarding histological appearance and locoregional and distant metastatic potential. Tumor histological grade, AJCC tumor stage and nodal status were the strongest predictive factors for survival and treatment outcomes. RT improved OS and locoregional treatment outcome, but not DFS. Elective neck dissection (END) could be beneficial for selected cases of SGC. Superselective neck dissection of levels I-IIa may be the level of dissection for END. Distant metastases were the main cause of death and treatment failure. Prognostic factors for poor DMFS were AJCC stage III and IV, high tumor grade and nodal status.

Liquid Biopsy in Head and Neck Cancer: Its Present State and Future Role in Africa

The rising mortality and morbidity rate of head and neck cancer (HNC) in Africa has been attributed to factors such as the poor state of health infrastructures, genetics, and late presentation resulting in the delayed diagnosis of these tumors. If well harnessed, emerging molecular and omics diagnostic technologies such as liquid biopsy can potentially play a major role in optimizing the management of HNC in Africa. However, to successfully apply liquid biopsy technology in the management of HNC in Africa, factors such as genetic, socioeconomic, environmental, and cultural acceptability of the technology must be given due consideration. This review outlines the role of circulating molecules such as tumor cells, tumor DNA, tumor RNA, proteins, and exosomes, in liquid biopsy technology for the management of HNC with a focus on studies conducted in Africa. The present state and the potential opportunities for the future use of liquid biopsy technology in the effective management of HNC in resource-limited settings such as Africa is further discussed.

Incurable advanced salivary gland tumours: a retrospective analysis and peek into the perplexing clinical and molecular intricacies from a tertiary care centre in India

Background

Salivary gland tumours are rare cancers with variable course and prognosis. There is a paucity of data, especially for the advanced stages.

Materials and methods

This is a retrospective analysis carried out in our institute. All patients seeking treatment for incurable advanced salivary gland tumours from October 2018 to September 2022 were included. Relevant clinical data were collected and appropriate statistical analysis was applied.

Results

30 patients were included in the analysis. The parotid gland was the most common site of origin (73%). Adenoid cystic carcinoma (ACC) and salivary duct carcinoma (SDC) were equally (37%) the most common pathological subtypes. The majority of patients were males (73%) and lungs (57%) were the most common site of metastases. On molecular analysis, SDC had high rates of androgen receptor (AR) (90%) and human epidermal growth factor receptor 2 (HER2) (55%) positivity. Mucoepidermoid carcinoma (MEC) had AR and HER2 positivity rates of 17% and 20%, respectively, while for ACC it was even lower. A variety of treatment regimens including hormonal therapy, anti-HER2 targeted therapy and chemotherapy were used in first-line treatment. With an overall response rate (ORR) of 10/21 (48%), only 9/21 (43%) went on to receive second-line treatment with an ORR of 4/9 (44%). The progression-free survival (PFS) with first-line treatment (PFS1) was a median of 5 months. The median PFS1 was worst for MEC. The median overall survival (OS) was 10 months. Median OS for ACC, SDC and MEC were 11, 10 and 7 months, respectively. At 24 months, ACC had much higher survival (50%) than others (10%) indicating a proportion of ACC with an indolent course.

Conclusion

Our analysis highlights the variable disease biology of advanced salivary gland tumours and throws light on the various possible treatment targets and strategies. Molecular profiling and advancement in targeted therapies are expected to increase survival in this group of rare cancers.

Chaotic transformation of parotid acinic cell carcinoma to metastatic dedifferentiated high-grade pathology - A rare case with clinical and emotional challenge

INTRODUCTION AND IMPORTANCE

Acinic cell carcinoma (AciCC) is a rare entity in which high-grade transformation (HGT), formerly dedifferentiation, is uncommon. This case report presents a rare case of AciCC, with rapid transformation to metastatic high-grade dedifferentiated pathology after initial curative treatment.

CASE PRESENTATION

A 58-year-old woman presented in the medical oncology clinic with a progressive swelling on the right side of her face. Magnetic resonance imaging revealed a 5 × 5 cm lobulated parotid gland lesion, and fine needle aspiration biopsy was consistent with carcinoma. After informed consent, a Modified-Blair incision was given as a standard approach to the right preauricular area under general anaesthesia, and a right superficial parotidectomy with the removal of the tumor and selective lymph node dissection was performed. Histopathology of the resected mass was reported as parotid AciCC. She was given adjuvant radiation therapy. A repeat PET CT scan ten weeks after the completion of her adjuvant radiation treatment showed local disease recurrence as well as multiple pulmonary deposits. A repeat biopsy was reported as DOG-1 positive dedifferentiated (high-grade) acinic cell carcinoma, and she was offered platinum-based palliative systemic chemotherapy.

CLINICAL DISCUSSION

Parotid acinic cell carcinomas with high-grade transformation are rare. This case highlights its critical diagnostic markers, curative and palliative management and long-term follow-up.

CONCLUSION

The transformation of parotid AciCC to high-grade, dedifferentiated pathology is unusual and belligerent. Hence, these tumors need intense treatment with a multimodality approach. Close follow-ups with history and physical examination, along with periodic imaging, should be considered for these patients.

Development of machine learning models to predict lymph node metastases in major salivary gland cancers

INTRODUCTION

Indications for elective treatment of the neck in patients with major salivary gland cancers are still debated. Our purpose was to develop a machine learning (ML) model able to generate a predictive algorithm to identify lymph node metastases (LNM) in patients with major salivary gland cancer (SGC).

METHODS

A Retrospective study was performed with data obtained from the Surveillance, Epidemiology, and End Results (SEER) program. Patients diagnosed with a major SGC between 1988 and 2019 were included. Two 2-class supervised ML decision models (random forest, RF; extreme gradient boosting, XGB) were used to predict the presence of LNM, implementing thirteen demographics and clinical variables collected from the SEER database. A permutation feature importance (PFI) score was computed using the testing dataset to identify the most important variables used in model prediction.

RESULTS

A total of 10 350 patients (males: 52%; mean age: 59.9 ± 17.2 years) were included in the study. The RF and the XGB prediction models showed an overall accuracy of 0.68. Both models showed a high specificity (RF: 0.90; XGB: 0.83) and low sensitivity (RF: 0.27; XGB: 0.38) in identifying LNM. According, a high negative predictive value (RF: 0.70; XGB: 0.72) and a low positive predictive value (RF: 0.58; XGB: 0.56) were measured. T classification and tumor size were the most important features in the construction of the prediction algorithms.

CONCLUSIONS

Classification performance of the ML algorithms showed high specificity and negative predictive value that allow to preoperatively identify patients with a lower risk of LNM.

LAY SUMMARY

Based on data from the Surveillance, Epidemiology, and End Results (SEER) program, our study showed that machine learning algorithms owns a high specificity and negative predictive value, allowing to preoperatively identify patients with a lower risk of lymph node metastasis.

LEVEL OF EVIDENCE: 3

Tumor-infiltrating lymphocytes and tumor-associated macrophages as potential predictors of lymph node metastases in major salivary gland cancers

Purpose

The purpose of this study is to define if tumor-infiltrating lymphocytes (TILs) and tumor-associated macrophages (TAMs) could represent potential predictors of lymph node metastases (LNM) in salivary gland cancers (SGC).

Methods

A selected number of immunohistochemical markers related to TILs (CD3, CD4, CD68, and FOXP3) and TAMs (CD68 and CD163) were investigated on major salivary gland cancers. TIL and TAM densities were measured on digital images using the open-source QuPath both in the tumor interior (TI) and invasive margin (IM). Correlation with pathologic N classification and follow-up clinical data was investigated.

Results

A total of 25 consecutive patients (men: 11; median age: 62.0) were included. Densities of CD3+ IM (OR = 7.7, 95% CI 1.2-51.2), CD8+ TI (OR = 7.7, 95% CI 1.2-51.2), CD8+ IM (OR = 7.7, 95% CI 1.2-51.2), FOXP3+ TI (OR = 24.0, 95% CI 2.2-255.9), CD68+ TI (OR = 7.7, 95% CI 1.2-51.2), and CD163+ IM (OR = 7.7, 95% CI 1.2 - 51.2), and the Immunoscore CD8/CD3 (OR = 1.9, 95% CI 1.1-3.4) were significantly associated with LNM (p < 0.05). CD3+ TI density was significantly associated with tumor recurrence and death (HR = 5.8, 95% CI 1.5-22.6; p < 0.05).

Conclusion

A high density of specific TIL and TAM subpopulations might be correlated with a higher probability of LNM in SGC.

Recurrent acinic cell carcinoma of the parotid gland with lateral skull base invasion: Case report and discussion of the literature

Medical records of a 76-year-old woman with a recurrent acinic cell carcinoma of the left parotid gland with lateral skull base invasion were reviewed. She underwent subtotal petrosectomy followed by radiation therapy. After surgery, she remained disease-free for more than 16 months.

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.

Lymph node ratio-based prognostic model for risk stratification and individualized adjuvant therapy for postoperative major salivary duct carcinoma

BACKGROUND

To investigate the value of lymph node ratio (LNR) for postoperative major salivary duct carcinoma (MSDC) and to establish a model for prognosis assessment and treatment optimization.

METHODS

Data of MSDC were retrieved in public database, and prognostic factors were identified by univariate and multivariate analyses. A nomogram and risk stratification system were constructed.

RESULTS

Four hundred and eleven eligible patients were included (training cohort vs. validation cohort: 287: 124). LNR ≥0.09 was associated with worse overall survival (OS). Age at diagnosis, sex, T stage, and LNR were identified as prognostic factors and integrated into nomogram. Low-risk patients were found to have better OS than high-risk patients. Furthermore, postoperative radiotherapy (PORT) significantly improved OS in the high-risk subgroup, but chemotherapy did not confer a long-term survival benefit.

CONCLUSIONS

A nomogram model integrating LNR could better assess postoperative prognosis and risk stratification in MSDC, and identify patients who might benefit from PORT to avoid overtreatment.

Major and minor salivary gland cancers: A multicenter retrospective study

BACKGROUND

Most of the studies on salivary gland cancers are limited for various reasons such as being single-center, small number of patients, including only major or minor SGCs, or only including epidemiological data.

METHODS

A total of 37 medical oncology clinics from different regions of Turkey participated in this retrospective-multicenter study. The analyzed data included clinical and demographical features, primary treatment, metastasis localizations, and treatments and includes certain pathologic features.

RESULTS

The study included data from a total of 443 SGCs. 56.7% was in major salivary glands and 43.3% was in minor salivary glands. Distant metastasis in the major SGCs was statistically significantly more common than in the minor SGCs, locoregional recurrence was statistically significantly more common in the minor SGCs than in the major SGCs (p = 0.003).

CONCLUSIONS

Epidemiological information, metastasis and recurrence patterns, treatment modalities, and survival analysis of the patients over 20 years of follow-up are presented.

A molecular guide to systemic therapy in salivary gland carcinoma

Salivary gland carcinomas (SGC) are a rare and variable group of head and neck cancers with historically poor response to cytotoxic chemotherapy and immunotherapy in the recurrent, advanced, and metastatic settings. In the last decade, a number of targetable molecular alterations have been identified in SGCs including HER2 upregulation, androgen receptor overexpression, Notch receptor activation, NTRK gene fusions, and RET alterations which have dramatically improved treatment outcomes in this disease. Here, we review the landscape of precision therapy in SGC including current options for systemic management, ongoing clinical trials, and promising future directions.

Predictive factors for survival and treatment outcomes of patients with minor salivary gland malignancies: a retrospective study

INTRODUCTION

Aim of this study was to explore the incidence, pathology, clinical behaviour and evaluate factors predictive on survival and treatment outcomes in a cohort of patients with minor salivary gland (MiSG) malignancies treated at a single center over a period of 25 years.

MATERIALS AND METHODS

Patients who had received primary treatment for MiSG malignancy during 25 years observation period were identified. Outcomes that were evaluated were overall survival (OS), disease specific survival (DSS), recurrence free survival (RFS), locoregional recurrence free survival (LRFS) and distant metastasis free survival (DFS).

RESULTS

A total of 88 patients with MSG malignancies were included in the study. The most common location for MiSG malignancies was the oral cavity (65 tumors; 77%). Cumulative OS for 5 and 10 year follow up period was 82% and 62% respectively. Cumulative DSS for 5 and 10 year follow up period was 85% and 73% respectively. Twenty one (23%) patients developed distant metastases during follow-up. High-grade pathology and tumor stage were significant variables on multivariate analysis for all survival and treatment outcomes.

CONCLUSIONS

Minor salivary gland malignancies are minor only by name. Tumor histological grade, AJCC tumor stage and pT stage were the strongest predictive factors for survival and treatment outcomes. The elective neck dissection could be considered therapeutic approach for selected cases of high grade MiSG malignancies. Distant metastases were the main cause of death and treatment failure.

Pathology Mimicking Orofacial Pain

A case of a 64-year-old woman is reported, who developed new-onset pain over a preexisting area of right mandibular fullness. Clinical examination, MRI, and fine-needle aspiration cytology confirmed the diagnosis of a benign parotid gland tumor-pleomorphic adenoma, which was treated by total parotidectomy with complete removal of the tumor. When evaluating a patient with orofacial pain, oral health care providers should be cognizant of all potential differential diagnoses, especially in the setting of red flags such as persistent or enlarging facial swelling/fullness.

Prognostic impact of MUC1 and potential regulatory miR-145 and miR-21 expression in salivary mucoepidermoid carcinoma

BACKGROUND

Salivary gland mucoepidermoid carcinoma (MEC) poses a considerable risk of locoregional and distant metastasis after conventional treatments. There is an evident need for specifying prognostic biomarkers to identify patients who are in need of more intensive and prolonged follow-ups. This study aimed to assess the mucin 1 (MUC1) expression level and its potential regulatory microRNAs in salivary gland MEC and their prognostic potentials.

MATERIALS AND METHODS

The expression of MUC1 in salivary gland MEC tissues was assessed in 47 samples using immunohistochemistry. Related microRNA (miR-145 and miR-21) were evaluated using quantitative Reverse Transcription PCR. The associations between MUC1 and microRNAs expressions and clinicopathological parameters were investigated.

RESULTS

MUC1 expression levels positively correlated with histologic grade (p < 0.001), clinical stage (p = 0.04), risk of nodal metastasis (p = 0.02), as well as the likelihood of opting for radical treatment (p = 0.01). Increased expression of miR-21 (p < 0.001) and decreased expression of miR-145 (p < 0.001) were observed in MECs compared to normal salivary gland tissue. MiR-145 negatively (p = 0.01) and miR-21 positively (p = 0.01) correlated with MUC1 overexpression. Based on the univariate cox proportional hazard model, histologic grade and MUC1 expression level were significantly associated with disease-free, cancer-specific, and overall survival. However, the multivariable cox proportional hazard model indicated tumor grade as the only prognostic factor associated with disease-free survival.

CONCLUSION

Our results support the tumor suppressor role of miR-145 and the oncogenic role of miR-21 in salivary gland MEC. Also, MUC1 and miR-145 overexpression, as well as miR-21 suppression, show promising association with histologic tumor grade and clinical stage.

MicroRNAs’ Crucial Role in Salivary Gland Cancers’ Onset and Prognosis

Simple Summary

Salivary gland cancers are incredibly heterogeneous, both in the physical onset and in the aggressiveness. Setting up a novel diagnostic and prognostic detection method based on the noninvasive microRNAs’ profiling might represent a goal for the clinical management of those particular malignancies, saving precious time for the patients.

Abstract

Salivary gland cancer (SGC) is an uncommon and heterogeneous disease that accounts for around 8.5% of all head and neck cancers. MicroRNAs (miRNAs) consist of a class of highly conserved, short, single-stranded segments (18–25 nucleotides) of noncoding RNA that represent key gene-transcription regulators in physiological and pathological human conditions. However, their role in SGC development and progression is not completely clear. This review aims to compile and summarize the recent findings on the topic, focusing on the prognostic and diagnostic value of the major modulated and validated microRNAs in SGC. Their differential expression could possibly aid the clinician in delivering an early diagnosis, therapeutic strategy and precision medicine.

Transoral robotic surgery for parapharyngeal carcinoma ex-pleomorphic adenoma: A case report

BACKGROUND

Carcinoma ex-pleomorphic adenoma (Ca ex-PA) comprises 0.5% of head and neck neoplasms. Transoral robotic surgery (TORS) is an approach being used to treat a variety of benign and malignant head and neck neoplasms. Recently, this technique has gained popularity as an alternative for parapharyngeal space (PPS) tumor resection. To our knowledge, this is the first case of Ca ex-PA managed successfully by TORS of the PPS.

CASE

Fifty-nine-year-old male with incidental mass in PPS, initial diagnosis of pleomorphic adenoma, who underwent transoral robotic resection. The histopathology diagnosis with minimally invasive Ca ex-PA findings and malignant component of high-grade epithelial/myoepithelial carcinoma and salivary duct carcinoma. Patient discharged on the fifth post-operative day without complications.

CONCLUSION

Based on our findings, TORS may be a safe procedure to remove selected Ca ex-PA from the PPS; however, further research is needed.

Systemic therapy for salivary gland malignancy: current status and future perspectives

Salivary gland malignancies are rare neoplasms that have a broad histological spectrum and a variety of biologic behaviors. Salivary gland malignancies are known as chemo-resistant tumors, which render optimal treatment challenging. This review summarizes the role of systemic therapy for salivary gland malignancies. To date, the advantage of adding concurrent chemotherapy has remained undefined for both postoperative and inoperable locally advanced salivary gland malignancy patients undergoing radiotherapy. For recurrent/metastatic disease, local and/or systemic treatment options should be discussed in a multidisciplinary setting with consideration to both patient needs and tumor factors. For symptomatic patients or those who may compromise organ function, palliative systemic therapy can be a reasonable option based on the results of phase II studies. Platinum combination regimens as first-line therapy have been widely accepted. Personalized therapies have become established options, particularly for androgen receptor-positive, HER2-positive and NTRK fusion-positive salivary gland malignancies (i.e. androgen receptor and HER2 in salivary duct carcinoma and NTRK3 in secretory carcinoma). For patients with adenoid cystic carcinoma, multi-targeted tyrosine kinase inhibitors have also been developed. Anti-PD1 checkpoint inhibitors have shown limited activity to date. Investigation of active systemic treatments for salivary gland malignancy remains a significant unmet need. Future directions might include a more comprehensive genomic screening approach (usually next-generation sequencing-based) and combination strategies using immune checkpoint inhibitors. These are rare malignancies that require ongoing effort in the conduct of high-quality clinical trials.

Surgical Navigation, Augmented Reality, and 3D Printing for Hard Palate Adenoid Cystic Carcinoma En-Bloc Resection: Case Report and Literature Review

Adenoid Cystic Carcinoma is a rare and aggressive tumor representing less than 1% of head and neck cancers. This malignancy often arises from the minor salivary glands, being the palate its most common location. Surgical en-bloc resection with clear margins is the primary treatment. However, this location presents a limited line of sight and a high risk of injuries, making the surgical procedure challenging. In this context, technologies such as intraoperative navigation can become an effective tool, reducing morbidity and improving the safety and accuracy of the procedure. Although their use is extended in fields such as neurosurgery, their application in maxillofacial surgery has not been widely evidenced. One reason is the need to rigidly fixate a navigation reference to the patient, which often entails an invasive setup. In this work, we studied three alternative and less invasive setups using optical tracking, 3D printing and augmented reality. We evaluated their precision in a patient-specific phantom, obtaining errors below 1 mm. The optimum setup was finally applied in a clinical case, where the navigation software was used to guide the tumor resection. Points were collected along the surgical margins after resection and compared with the real ones identified in the postoperative CT. Distances of less than 2 mm were obtained in 90% of the samples. Moreover, the navigation provided confidence to the surgeons, who could then undertake a less invasive and more conservative approach. The postoperative CT scans showed adequate resection margins and confirmed that the patient is free of disease after two years of follow-up.

Therapeutic Targeting of FGFR Signaling in Head and Neck Cancer

ABSTRACT

Squamous cell carcinoma of the head and neck (HNSCC) is the sixth most prevalent cancer worldwide, with an annual incidence of 600,000 new cases. Despite advances in surgery, chemotherapy, and radiotherapy, the overall survival for HNSCC patients has not been significantly improved over the past several decades. Fibroblast growth factor (FGF)/fibroblast growth factor receptor (FGFR) genomic alterations are frequently detected in HNSCC, including amplification, activating mutation, and chromosomal rearrangement. Among them, FGFR1 amplification, FGF amplifications, and FGFR3 mutations are the most prevalent. In addition, FGF/FGFR expression has also been observed in most HNSCCs. However, the prognostic value of FGF/FGFR aberrations remains unclear, especially for gene amplification and overexpression. Nonetheless, FGF/FGFR has been a promising target for HNSCC treatment, and recent preclinical studies demonstrate the potential of the combination treatment regimens involving FGFR inhibitors on HNSCC. Therefore, there are a number of FGFR inhibitors currently in clinical trials for the treatment of head and neck cancers.

Elective neck dissection in salivary gland malignancies: Systematic review and meta-analysis

We defined the occult nodal metastasis (ONM) rate of clinical node-negative salivary gland malignancies and examined the role of elective neck dissection (END). Meta-analysis querying four databases, from inception of databases to March 25th, 2020. Fifty-one studies with 11 698 patients were included. ONM rates were 64% for salivary ductal carcinoma (SDC), 51% for undifferentiated carcinoma, 34% for carcinoma ex-pleomorphic adenoma (CXPA), 32% for adenocarcinoma not otherwise specified (ANOS), 31% for lymphoepithelial carcinoma (LE), 20% for mucoepidermoid carcinoma, 17% for acinic cell carcinoma, and 17% for adenoid cystic carcinoma. T3/T4 tumors had a 2.3 times increased risk of ONM than T1/T2 tumors. High-grade tumors had a 3.8 times increased risk of ONM than low/intermediate-grade tumors. ONM rates were exceedingly high for T3/T4, high-grade, and undifferentiated, SDC, ANOS, CXPA, and LE tumors, indicating the potential role of END.

An Overview on the Histogenesis and Morphogenesis of Salivary Gland Neoplasms and Evolving Diagnostic Approaches

Simple Summary

Diagnosing salivary gland neoplasms (SGN) remain a challenge, given their underlying biological nature and overlapping features. Evolving techniques in molecular pathology have uncovered genetic mutations resulting in these tumors. This review delves into the molecular etiopatho-genesis of SGN, highlighting advanced diagnostic protocols that may facilitate the identification and therapy of a variety of SGN.

Abstract

Salivary gland neoplasms (SGN) remain a diagnostic dilemma due to their heterogenic complex behavior. Their diverse histomorphological appearance is attributed to the underlying cellular mechanisms and differentiation into various histopathological subtypes with overlapping fea-tures. Diagnostic tools such as fine needle aspiration biopsy, computerized tomography, magnetic resonance imaging, and positron emission tomography help evaluate the structure and assess the staging of SGN. Advances in molecular pathology have uncovered genetic patterns and oncogenes by immunohistochemistry, fluorescent in situ hybridization, and next–generation sequencing, that may potentially contribute to innovating diagnostic approaches in identifying various SGN. Surgical resection is the principal treatment for most SGN. Other modalities such as radiotherapy, chemotherapy, targeted therapy (agents like tyrosine kinase inhibitors, monoclonal antibodies, and proteasome inhibitors), and potential hormone therapy may be applied, depending on the clinical behaviors, histopathologic grading, tumor stage and location, and the extent of tissue invasion. This review delves into the molecular pathways of salivary gland tumorigenesis, highlighting recent diagnostic protocols that may facilitate the identification and management of SGN.

Parotid incidentalomas: a systematic review

OBJECTIVE

Parotid incidentalomas on fluorodeoxyglucose positron emission tomography/computed tomography imaging are rare. A systematic review was performed to assess their aetiology and association with scanning indication, and to develop an evidence-based algorithm for their management.

METHODS

A literature search was performed on 25 August 2020 using the keywords 'incidentaloma', 'incidental finding', 'parotid', 'parotid gland', 'salivary gland' and 'head and neck'. Articles were reviewed by two authors before their inclusion.

RESULTS

Forty articles were included, totalling 558 incidentalomas. The mean incidence was 0.74 per cent. Lung cancer was the most common imaging indication. The most common aetiologies were cystadenolymphoma, pleomorphic salivary adenoma and metastases. Only cystadenolymphoma (p = 0.015) and pleomorphic salivary adenoma (p = 0.011) were significantly associated with a primary malignancy (lung). The most common further investigations were aspiration cytology, ultrasound imaging and core biopsy, usually prior to parotidectomy.

CONCLUSION

If appropriate, parotid incidentalomas should be followed up with flexible endoscopy, skin examinations, and head and neck examinations. Ultrasound-guided core biopsy provides higher accuracy, avoiding repeat sampling and excision biopsy.

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

Objective

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

Results

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

Conclusion

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

HER2 Positivity in Histological Subtypes of Salivary Gland Carcinoma: A Systematic Review and Meta-Analysis

Background

HER2 aberrations in salivary gland carcinomas (SGC) as well as benefit of HER2 directed therapy have been reported in small studies. However, reliable estimates of the prevalence of HER2 positivity in SGC and its various histological subtypes are lacking.

Objective

To assess the prevalence of HER2 positivity in histological subtypes of salivary gland carcinomas (SGC).

Methods

Studies were identified by a systematic review of the literature. Data on in situ hybridization (ISH) and immunohistochemistry (IHC) were extracted to derive pooled prevalence estimates calculated by a random effects model. Characteristics of the studies were extracted for subgroup analysis.

Results

Fifty studies including 3372 patients were identified, providing data on sixteen histological subtypes. Based on the meta-analysis, the estimated prevalence of HER2 positivity were 43% (95% CI: 36% – 51%) in salivary duct carcinoma (SDC), 39% (95% CI: 32% – 45%) in carcinoma ex pleomorphic adenoma (CEP), 17% (95% CI: 7.5% – 33%) in squamous cell carcinoma (SCC), 13% (95% CI: 7.6% – 21%) in adenocarcinoma NOS (ADC), 6.7% (95% CI: 0.17%-32%) in poorly differentiated carcinoma, 5.5% (95% CI: 2.9% – 9.6%) in mucoepidermoid carcinoma, 4.3% (95% CI: 1.4% – 13%) in myoepithelial carcinoma, 1.8% (95% CI: 0.04%-9.6%) in epithelial-myoepithelial carcinoma, 0.45% (95% CI: 0.0097% – 18%) in acinic cell carcinoma and 0.15% (0.037% – 5.4%) in adenoid cystic carcinoma. Estimates for five additional subtypes were assessed.

Conclusion

Prevalence of HER 2 positivity in SGC varies greatly based on histological subtype, with SDC, CEP, SCC, and ADC displaying the highest rates.

Differential diagnosis and treatment of salivary secretory carcinoma and acinic cell carcinoma

Secretory carcinoma (SC) and acinic cell carcinoma (AciCC) are two rare tumors originating in the salivary gland of the head and neck. Before the World Health Organization (WHO) classified SC as a new entity in 2017, the majority of SC cases were incorrectly diagnosed as AciCC. Indeed, they are similar in biological behaviors, clinical manifestations and histomorphological features. Especially, SC and zymogen granule-poor AciCC are difficult to differentiate, which brings a tough challenge in clinical diagnosis. This article provides an updated understanding of the differential diagnosis in SC and AciCC from two main perspectives: histopathology and molecular genetics. The targeted therapies for both tumors are also mentioned. It aims to give some hints in clinical diagnosis and treatment, in hopes that patients with adequate diagnosis could obtain the opportunityformore effective treatment.

LMW cyclin E and its novel catalytic partner CDK5 are therapeutic targets and prognostic biomarkers in salivary gland cancers

Salivary gland cancers (SGCs) are rare yet aggressive malignancies with significant histological heterogeneity, which has made prediction of prognosis and development of targeted therapies challenging. In majority of patients, local recurrence and/or distant metastasis are common and systemic treatments have minimal impact on survival. Therefore, identification of novel targets for treatment that can also be used as predictors of recurrence for multiple histological subtypes of SGCs is an area of unmet need. In this study, we developed a novel transgenic mouse model of SGC, efficiently recapitulating the major histological subtype (adenocarcinomas of the parotid gland) of human SGC. CDK2 knock out (KO) mice crossed with MMTV-low molecular weight forms of cyclin E (LMW-E) mice generated the transgenic mouse models of SGC, which arise in the parotid region of the salivary gland, similar to the common site of origin seen in human SGCs. To identify the CDK2 independent catalytic partner(s) of LMW-E, we used LMW-E expressing cell lines in mass spectrometric analysis and subsequent biochemical validation in pull down assays. These studies revealed that in the absence of CDK2, LMW-E preferentially binds to CDK5. Molecular targeting of CDK5, using siRNA, resulted in inhibition of cell proliferation of human SGCs overexpressing LMW-E. We also provide clinical evidence of significant association of LMW-E/CDK5 co-expression and decreased recurrence free survival in human SGC. Immunohistochemical analysis of LMW-E and CDK5 in 424 patients representing each of the four major histological subtypes of human salivary cancers (Aci, AdCC, MEC, and SDC) revealed that LMW-E and CDK5 are concordantly (positive/positive or negative/negative) expressed in 70% of these patients. The co-expression of LMW-E/CDK5 (both positive) robustly predicts the likelihood of recurrence, regardless of the histological classification of these tumors. Collectively, our results suggest that CDK5 is a novel and targetable biomarker for the treatment of patients with SGC presenting with LMW-E overexpressing tumors.

Deep Lobe Parotid Tumors: A Systematic Review and Meta-analysis

OBJECTIVE

We performed a systematic review and meta-analysis of deep lobe parotid tumors to evaluate their unique characteristics.

DATA SOURCES

PubMed/Medline, Embase, Web of Sciences, and Cochrane Library databases were queried for relevant literature.

REVIEW METHODS

Studies were individually assessed by 2 independent reviewers. Risk of bias was assessed with the Cochrane bias tool, GRADE criteria, and MINORS criteria. Results were reported according to the PRISMA guidelines. Statistical analysis was performed by comparing rates of malignancy between deep and superficial lobe tumors.

RESULTS

In total, 8 studies including 379 deep lobe parotid tumors met inclusion criteria. Mean age at diagnosis was 44.9 years. Computed tomography scan was the most common imaging modality. Preoperative diagnostic fine-needle aspiration was utilized in 39.4% of patients and demonstrated high sensitivity for malignant disease. The most common approach was subtotal parotidectomy with facial nerve preservation (58.9%). The rate of malignancy was 26.6%, which was significantly higher than that of the superficial lobe tumors in this study (risk ratio, 1.25; 95% CI, 1.01-1.56). The rate of temporary postoperative facial nerve weakness between deep and superficial lobe tumors was 32.5% and 11.7%, respectively.

CONCLUSION

Deep lobe parotid tumors had a 26.6% rate of malignancy. On meta-analysis, deep lobe tumors appeared to have higher rates of malignancy than superficial lobe tumors. Surgical excision of deep lobe tumors showed increased rates of temporary facial nerve paresis as compared with superficial lobe tumors. Computed tomography scan was the most common imaging modality. There were limited data regarding the utility of fine-needle aspiration.

Intensity Modulated Radiotherapy with Carbon Ion Radiotherapy Boost for Acinic Cell Carcinoma of the Salivary Glands

Simple Summary

Acinic cell carcinoma is a rare disease treated usually by surgery. The role of radiotherapy is controversially discussed. In this retrospective analysis based on 15 patients undergoing postoperative or definitive radiotherapy (intensity-modulated radiotherapy, IMRT) with carbon ion radiotherapy boost leads to excellent results after R1-resection, and is a promising treatment modality in inoperable patients. G1-2 xerostomia, dysgeusia, and trismus were the main reported morbidity symptoms after radiotherapy. Confirmation of the results with larger patient cohorts is needed.

Abstract

Aim: to report clinical outcome in patients with acinic cell carcinoma of the salivary glands treated with intensity-modulated radiotherapy (IMRT) and carbon ion radiotherapy (CIRT) boost. Materials and Methods: all patients with acinic cell carcinoma of the salivary glands treated at the Heidelberg Ion-Beam Therapy Center were considered for this retrospective analysis. All patients received a CIRT boost with 18–24 Gy radiobiologic effectiveness (RBE)-weighted dose in 3 Gy RBE-weighted dose per fraction followed by IMRT, with 50–54 Gy in 2 Gy per fraction. Disease outcome was evaluated for local (LR), nodal (NR), distant recurrence (DR), and disease-free (DFS) and overall survival (OS). Morbidity was scored based on Common Terminology Criteria for Adverse Events (CTCAE) version 5. Descriptive statistics and the Kaplan-Meier method were used for analysis. Results: fifteen patients were available for analysis. Median follow-up after radiotherapy was 43 months. Six patients were treated for primary disease and nine for recurrent disease. Eight patients were treated with radiotherapy for macroscopic disease. Disease recurrence was observed in four patients: 1 LR, 2 NR, and 2 DR; 5-year local control, DFS, and OS were 80%, 52%, and 80%, respectively. No radiotherapy-related G3-5 morbidity was observed. Conclusion: In acinic cell carcinoma, IMRT with carbon ion radiotherapy boost leads to excellent results after R1-resection and is a promising treatment modality for definitive treatment in inoperable patients.

A 10-year review of primary major salivary gland cancers

Primary salivary gland cancers comprise a heterogeneous group of histological entities and represent less than 5% of head and neck malignancies. Surgical resection is the main treatment, and adjuvant radiotherapy is performed in selected cases. Chemotherapy is an option in metastatic or recurrent disease, with poor evidence. We aimed to review a 10-year experience of a cancer centre on major salivary gland cancers, focusing on clinical, pathological, treatment and patients' outcomes data. A total of 93 patients were identified, median age at diagnosis was 64 years (IQR, 23), and 51.6% were male. The parotid gland was the site of origin in 76.3% of cases. The most frequent histological type was salivary duct carcinoma (21.5%). All patients were submitted to surgery and adjuvant radiotherapy was performed in 74.2%. From 26 patients diagnosed with metastatic disease, 9 were treated with systemic therapy. At 8 years, disease-free survival was 54.6% and overall survival was 48.4%. Male sex, salivary duct carcinoma, stage pT3-4, stage pN2-3, high histologic grade, lymphovascular invasion and perineural invasion were negative prognostic indicators for disease-free survival and overall survival. Extracapsular spread was a negative prognostic indicator for overall survival. In the multivariable analysis, histological type-salivary duct carcinoma-kept significant negative impact in disease-free survival and high histologic grade in overall survival. The most frequent histological type was salivary duct carcinoma, which is estimated to represent only 9% of salivary tumours. Patients with salivary duct carcinoma relapsed more than other histological types. High histologic grade was a negative prognostic indicator for overall survival.

Usefulness of immunohistochemistry to distinguish between secretory carcinoma and acinic cell carcinoma in the salivary gland

Secretory carcinoma (SC) of the salivary gland is a relatively newly described disease, separate from acinic cell carcinoma (ACC), which frequently displays ETV6-NTRK3 gene fusion. However, the differences between SC and ACC remain unclear. Here, histological reevaluation of 12 formerly diagnosed ACC cases was performed, which yielded a new diagnosis of SC in four cases due to a lack of obvious acinar-like cells. Immunohistochemically, phosphorylated signal transducer and activator of transcription 5 (p-STAT5) was expressed in SC but not in ACC, whereas discovered on GIST-1 (DOG1) was expressed in ACC but not in SC. Molecular analysis was possible in three SC cases, of which two showed the ETV6-NTRK3 fusion transcript on reverse-transcription polymerase chain reaction, as well as breaks in the ETV6 gene on fluorescence in situ hybridization. However, the remaining SC cases did not show this fusion transcript. Recently, several reports have suggested that SC might not be adequately diagnosed if the focus is placed solely on the ETV6-NTRK3 fusion gene due to genetic diversity. In this regard, immunohistochemistry of p-STAT5 and DOG1 is expected to be a useful alternative diagnostic tool to discriminate SC from ACC.

Acinic cell carcinoma of the parotid gland: from pathogenesis to management: a literature review

PURPOSE

Acinic cell carcinoma (ACCs) is uncommon malignant epithelial neoplasm of the salivary glands; the most common presentation is a well-defined painless solid mass. Diagnosis of ACCs is frequently complicated, due to its similarity with benign tumors.

METHODS

A review of the literature available on ACCs was carried out. Studies were sourced from PubMed with searching of relevant headings and sub-headings and cross-referencing.

RESULTS

There are no clear characteristics of ACCs found on CT, MRI and ultrasound imaging. The management of the ACC, a rare malignancy of the parotid gland, is often difficult and controversial. Radical surgery is the best treatment option. The role of radiotherapy remains controversial: the precise indications and oncologic effects of adjuvant radiotherapy in ACC of the parotid gland are not well known. There is insufficient literature regarding the chemotherapy for metastatic ACC.

CONCLUSION

Knowledge about ACC, a rare malignancy of parotid gland, has changed over the past few decades. More clinical randomized works would be needed, both to assess the real effectiveness of radio and chemotherapy and to have an unanimous consensus about their indications.

The current markers of cancer stem cell in oral cancers

Head and neck cancer (HNC) constitute 5% of all reported cancers. Among all, the oral cavity cancer is the most frequent type of HNC which accounts for over half of HNC cases. Mouth cancer ranks the sixth leading cause of cancer-related mortality. Generally, conventional chemotherapy has shown success at decreasing relapse and metastasis rates and improves the overall prognosis. Recently, target therapy and targeted drug delivery systems have been introduced as promising treatments. The elimination of efficiency of current therapeutic strategies due to the spared cancer stem cells that cause chemotherapy resistance, relapse and metastasis. Inefficiency methodologies in the elimination of all cancer cells in the body are a major problem that remained to be resolved before to confront the new cancer therapies. Many studies imply to cancer stem cell markers as important agents for targeted anti-cancer as well as improving chemotherapy efficiencies. The potentials of targeted cancer therapy led us to search for novel markers in the mouth cancer stem cells especially in rare cancers. The aimed of this research was, first a comprehensive critical review of the previous studies on the markers of cancer stem cells in oral cancers including oral squamous cell carcinoma, salivary gland cancers, and to highlight the most common cancer stem cell markers which have potential to be exploited as indicators for the preneoplastic lesion malignancy, oral cancer progression, and/or treatment prognosis.

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.

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.

Effect of simvastatin and microRNA-21 inhibitor on metastasis and progression of human salivary adenoid cystic carcinoma

Salivary adenoid cystic carcinoma (SACC) is a common malignancy of the salivary glands. Epithelial-mesenchymal transition (EMT) and P53 signaling pathway are associated with SACC metastasis and progression. Although simvastatin (SIM) is effective against the growth of many cancer types, its side effects limit its use. microRNA-21 (miR-21) is highly expressed in a variety of tumors and has a role in promoting tumor development. Therefore, the aim of the present study was to evaluate the effect of SIM in combination with miR-21 inhibitor (miR-21i) against lung metastatic SACC cells (SACC-LM). Our results showed that miR-21i was effective in reducing the resistance of SACC-LM to SIM, resulting in SACC-LM acquisition of epithelial traits, cell migration and invasion reduction, growth inhibition and induction of apoptosis. The expression of proteins associated to metastasis and tumor progression were regulated by the combined use of SIM and miR-21i. Thus, our findings demonstrated that such combination was effective in inhibiting SACC-LM progression, suggesting that multi-target therapy against SACC might represent a potentially successful approach in clinical treatment.