Management and outcome of patients with mucoepidermoid carcinoma of major salivary gland origin: a single institution's 30-year experience

Oncologic Safety of Close Margins in Patients With Low- to Intermediate-Grade Major Salivary Gland Carcinoma

Importance

Postoperative radiation therapy for close surgical margins in low- to intermediate-grade salivary carcinomas lacks multi-institutional supportive evidence.

Objective

To evaluate the oncologic outcomes for low- and intermediate-grade salivary carcinomas with close and positive margins.

Design, Setting, and Participants

The American Head and Neck Society Salivary Gland Section conducted a retrospective cohort study from 2010 to 2019 at 41 centers. Margins were classified as R0 (negative), R1 (microscopically positive), or R2 (macroscopically positive). R0 margins were subclassified into clear (>1 mm) or close (≤1 mm). Data analysis was performed from June to October 2023.

Main Outcomes and Measures

Main outcomes were risk factors for local recurrence.

Results

A total of 865 patients (median [IQR] age at surgery, 56 [43-66] years; 553 female individuals [64%] and 312 male individuals [36%]) were included. Of these, 801 (93%) had parotid carcinoma and 64 (7%) had submandibular gland carcinoma, and 748 (86%) had low-grade tumors and 117 (14%) had intermediate-grade tumors, with the following surgical margins: R0 in 673 (78%), R1 in 168 (19%), and R2 in 24 (3%). Close margins were found in 395 of 499 patients with R0 margins (79%), for whom margin distances were measured. A total of 305 patients (35%) underwent postoperative radiation therapy. Of all 865 patients, 35 (4%) had local recurrence with a median (IQR) follow-up of 35.3 (13.9-59.1) months. In patients with close margins as the sole risk factor for recurrence, the local recurrence rates were similar between those who underwent postoperative radiation therapy (0 of 46) or observation (4 of 165 [2%]). Patients with clear margins (n = 104) had no recurrences. The local recurrence rate in patients with R1 or R2 margins was better in those irradiated (2 of 128 [2%]) compared to observed (13 of 64 [20%]) (hazard ratio [HR], 0.05; 95% CI, 0.01-0.24). Multivariable analysis for local recurrence found the following independent factors: age at diagnosis (HR for a 10-year increase in age, 1.33; 95% CI, 1.06-1.67), R1 vs R0 (HR, 5.21; 95% CI, 2.58-10.54), lymphovascular invasion (HR, 4.47; 95% CI, 1.43-13.99), and postoperative radiation therapy (HR, 0.10; 95% CI, 0.04-0.29). The 3-year local recurrence-free survivals for the study population were 96% vs 97% in the close margin group.

Conclusions and Relevance

In this cohort study of patients with low- and intermediate-grade major salivary gland carcinoma, postoperative radiation therapy for positive margins was associated with decreased risk of local recurrence. In isolation from other risk factors for local recurrence, select patients with close surgical margins (≤1 mm) may safely be considered for observation.

Critical Appraisal of Histologic Grading for Mucoepidermoid Carcinoma of Salivary Gland: Is an Objective Prognostic 2-tiered Grading System Possible?

Multiple 3-tiered grading systems exist for mucoepidermoid carcinoma (MEC), leading to controversial results on the frequency and prognostic values of each grade. We aimed to identify prognostic histologic factors and to evaluate grading schemes in this retrospective study of 262 resected primary head and neck MECs. The rate of nodal metastasis was 8.4%. Large tumor size, tumor fibrosis, infiltrative border, lymphovascular invasion, perineural invasion, atypical mitosis, mitotic index (MI) ≥4/2 mm 2 (4/10 HPFs), necrosis, and pT4 stage were associated with increased risk of nodal metastasis. The 5-year recurrence-free survival (RFS) was 95%. Significant prognostic factors for RFS included infiltrative border, tumor-associated lymphoid stroma, architectural patterns (macrocystic, microcystic, and noncystic), anaplasia, atypical mitosis, MI, necrosis, lymphovascular invasion, margin, pT stage, and tumor size. Nuclear anaplasia, high mitotic rate, and ≥25% microcystic component were significant independent prognostic factors on multivariate survival analysis. There was no significant difference between low-grade (LG) and intermediate-grade (IG) MECs in terms of risk of nodal metastasis and outcomes using all 4 known grading systems. Rather, high-grade MEC was consistently associated with an increased risk of nodal metastasis at presentation and decreased RFS and distant metastasis-free survival (DMFS) compared with the LG/IG MECs. We therefore recommend simplifying MEC grading to a 2-tiered grading scheme using MI and/or tumor necrosis. Using a 2-tiered grading, high-grade histology independently predict RFS, and is associated with a 25% risk of nodal metastasis, a 5-year RFS of 76%, and a 5-year DMFS of 76%, whereas LG MEC has a nodal metastasis rate of 7.0%, 5-year RFS of 97% and 5-year DMFS of 99%.

Influence of Grading on Management and Outcome in Mucoepidermoid Carcinoma of the Parotid-A Multi-institutional Analysis

OBJECTIVE

To evaluate clinical outcome of low (G1), intermediate (G2), and high-(G3) grade mucoepidermoid carcinomas (MEC) of the parotid gland.

STUDY DESIGN

Retrospective chart review including 212 patients. Clinicopathological data was statistically analyzed regarding grading, overall survival (OS), disease-free survival (DFS) and disease-specific survival (DSS).

RESULTS

105 (49.5%) G1, 73 (34.5%) G2, and 34 (16%) G3 MEC were included and 56 (26.4%) patients presented with neck node metastases. The risk of occult nodal metastases was significantly associated with grading and increased from 9.2% in G1 to 26.7% and 27.8% in G2 and G3 tumors, respectively (p = 0.008). Elective periparotid and cervical lymph node dissection was performed in 170 (80.2%) and 70 (33%) patients, respectively. All patients with positive periparotid nodes when subjected to an additional neck dissection had associated cervical neck node involvement (p < 0.001). Grading was an independent significant prognostic factor for OS (HR 4.05; 95%CI: 1.15-14.35; p = 0.030) and DSS (HR 17.35; 95%CI: 1.10-273.53; p = 0.043). In a subgroup analysis, elective neck dissection (END) was also significantly associated with a better DFS (p = 0.041) in neck node-negative G1 MECs.

CONCLUSION

The risk of occult nodal metastasis in intermediate-grade MEC is as high as in high-grade MEC and that END in G1 tumors is associated with a prolonged DFS. Additionally, periparotid node involvement seems to be a predictor for positive neck node involvement. This study presents some preliminary data to consider END in clinically neck node negative patients with parotid MEC; however, larger series are needed.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:124-132, 2023.

Perineural Invasion as Worsening Criterion for Salivary Gland Mucoepidermoid Carcinoma

Mucoepidermoid carcinomas (MECs) are a form of salivary gland malignancy. They are classified according to histological grade and perineural invasion (PNI). In another cancer subtypes, positive-PNI suggests increased poor prognosis; however, the role of isolated positive-PNI salivary gland MEC can still be better investigated as a risk factor. This study investigated whether isolated PNI is independently associated with poor outcomes. Retrospective study, cohort case-series, single-center hospital from 2009 to 2019. Patient demographics, primary tumor, intervention, and survival data are included. Univariate, multivariate, and Kaplan-Meier survival curve analyses were used for comparison.The study group consisted of 32 patients (15 PNI-positive tumors, and 17 PNI-negative tumors), all admitted for surgery. Univariate analysis showed differences in grade (p = 0.038), positive margins (p = 0.034), soft tissue invasion (p < 0.001), pathological stage (p = 0.014), recurrence (p = 0.015), distant metastasis (p = 0.015) and MEC related death (p = 0.015). The risk in PNI-positive patients to develop soft tissue invasion and positive surgical margins was OR = 8.57 and OR = 4.88, respectively. Multivariate analysis found age differences (p = 0.038), with OR = 1.08. The Disease Specific Survival (DSS) was worst in the PNI-positive group (log-rank p-value = 0.0011), where the probability of dying occurred in the 12-24 months period (log-rank p-value = 0.002). PNI-positive salivary gland MEC is an independent prognostic factor, with poor DSS, increased locoregional recurrence, close correlation with a more aggressive pattern of the disease, and should be reviewed as a high grade histological criteria. Our findings may imply changes in the clinical approach with a more aggressive attitude in the overall treatment.

Presentation and outcomes of patients with clinically T1-2, N0 parotid mucoepidermoid carcinoma: The roles of elective neck dissection and adjuvant radiotherapy

Objectives

Examine the role of elective neck dissection (END) and adjuvant radiotherapy (RT) in early‐stage clinically N0 parotid mucoepidermoid carcinoma (MEC).

Methods

The study is a retrospective analysis of the National Cancer Database, 2004–2016. The study population included adult patients with MEC who underwent parotidectomy.

Results

A total of 1233 patients were included. Histopathology demonstrated well, moderately, and poorly differentiated MEC 47.12%, 39.98%, and 12.90% of the time, respectively. END was performed in 78.67% of patients, resulting in nodal upstaging in 4.43% and identification of extracapsular extension (ECE) in 0.72%. RT was utilized in 67.33% of patients with advanced pathological features. Neither END nor RT improved overall survival separately (p < 0.05) or combined (adjusted HR: 1.19, 95%CI: 0.52, 2.70, p = 0.68).

Conclusion

This study provides an epidemiological perspective regarding patients with clinically T1‐2, N0 MEC. There was no observed survival advantage with END and RT.

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

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

Prognostic Significance of Cancer Stem Cell Markers in Patients With Salivary Gland Carcinomas

OBJECTIVES

Cancer stem cells (CSCs) are a small group of cells resistant to therapy and play a major role in tumor progression, recurrence, and poor clinical outcomes of patients. This study aimed to evaluate the association of CSC markers with clinicopathologic features and survival in patients with salivary gland carcinomas (SGCs).

MATERIALS AND METHODS

The medical records of 48 patients affected by mucoepidermoid carcinoma (MEC) and 47 patients with adenoid cystic carcinoma (AdCC) were reviewed retrospectively. SOX2, CD133, and CD44 expression was appraised by immunohistochemistry and statistically analyzed to weigh the correlation between these markers and patients' clinicopathologic features and tumor outcomes.

RESULTS

In AdCC patients showing poor outcomes, a trend toward a high expression of CD133 and CD44 and low expression of SOX2 was observed, while in MEC patients experiencing the same outcomes, there was a trend toward a high expression of CD44 and low expression of CD133 and SOX2. Only the increase of MEC histopathologic grade was statistically significant with decreased SOX2 expression. Distant metastasis in AdCC patients, tumor grade, lymph node involvement, and local recurrence in MEC patients had significant correlations with patients' survival.

CONCLUSION

Besides the significant association between low SOX2 expression and higher grades of MEC, we found no statistically significant correlation between the studied CSC markers and patients' survival or clinicopathologic features. Therefore, a larger sample size with long-term follow-up is beneficial for thorough investigations toward the main role of CSCs in patients with SGCs.

miR-22 and miR-205 Drive Tumor Aggressiveness of Mucoepidermoid Carcinomas of Salivary Glands

Objectives

To integrate mRNA and miRNA expression profiles of mucoepidermoid carcinomas (MECs) and normal salivary gland (NSGs) tissue samples and identify potential drivers.

Material and Methods

Gene and miRNA expression arrays were performed in 35 MECs and six NSGs.

Results

We found 46 differentially expressed (DE) miRNAs and 3,162 DE mRNAs. Supervised hierarchical clustering analysis of the DE transcripts revealed two clusters in both miRNA and mRNA profiles, which distinguished MEC from NSG samples. The integrative miRNA-mRNA analysis revealed a network comprising 696 negatively correlated interactions (44 miRNAs and 444 mRNAs) involving cell signaling, cell cycle, and cancer-related pathways. Increased expression levels of miR-205-5p and miR-224-5p and decreased expression levels of miR-139-3p, miR-145-3p, miR-148a-3p, miR-186-5p, miR-338-3p, miR-363-3p, and miR-4324 were significantly related to worse overall survival in MEC patients. Two overexpressed miRNAs in MEC (miR-22 and miR-205) were selected for inhibition by the CRISPR-Cas9 method. Cell viability, migration, and invasion assays were performed using an intermediate grade MEC cell line. Knockout of miR-205 reduced cell viability and enhanced ZEB2 expression, while miR-22 knockout reduced cell migration and invasion and enhanced ESR1 expression. Our results indicate a distinct transcriptomic profile of MEC compared to NSG, and the integrative analysis highlighted miRNA-mRNA interactions involving cancer-related pathways, including PTEN and PI3K/AKT.

Conclusion

The in vitro functional studies revealed that miR-22 and miR-205 deficiencies reduced the viability, migration, and invasion of the MEC cells suggesting they are potential oncogenic drivers in MEC.

Overall and cause-specific survival for mucoepidermoid carcinoma of the major salivary glands: Analysis of 2210 patients

BACKGROUND

Mucoepidermoid carcinoma (MEC) is a rare malignancy of the head and neck; however, it accounts for a majority of the tumors of the salivary glands. This study used a national population-based registry to describe the pre-treatment and treatment-related prognostic factors that influence survival in patients with MEC of the major salivary glands. To our knowledge, this is the largest population-based study examining predictors of both overall and cause-specific survival of MEC of the major salivary glands.

AIM

To identify prognostic factors influencing overall survival (OS) and cause-specific survival (CSS) of patients with MEC of the major salivary glands.

METHODS

We used the Surveillance, Epidemiology and End-Results Database of the National Cancer Institute to investigate a variety of factors that could influence survival of patients diagnosed with mucoepidermoid carcinoma of the major salivary glands. A total of 2210 patients diagnosed with MEC of the major salivary glands during the years of 1975-2016 were studied. The primary endpoints were OS and CSS. Cox regression analysis was used to perform univariate and multivariate analyses of clinical variables such as age at diagnosis, diagnosis year, sex, race, tumor size, stage, grade, treatment with or without surgical excision, and adjuvant radiotherapy treatment.

RESULTS

A total of 2210 patients diagnosed with MEC of the major salivary glands met inclusion criteria. In this study, 95% of patients underwent surgical excision and 41% received adjuvant radiation therapy. Median OS time for Grade I, II, and III/IV was 401 mo (± 48.25, 95%CI), 340 mo (± 33.68, 95%CI) and 55 mo (± 11.05, 95%CI), respectively. Univariate analysis revealed that lack of surgical excision was associated with decreased OS [hazard ratio (HR) 4.26, P < 0.0001] and that patients with localized disease had improved OS compared to both regional and distant disease (HR 3.07 and 6.96, respectively, P < 0.0001). Additionally, univariate analysis demonstrated that male sex, age over 50 at diagnosis, Grade III tumors, and increasing tumor size were associated with worsened OS (P < 0.0006). Univariate analysis of CSS similarly revealed that lack of surgical excision and Grade III carcinoma conferred decreased CSS (HR 4.37 and 5.44, respectively, P < 0.0001). Multivariate analysis confirmed that increasing age, in 10-year age bands, advanced tumor stage, increasing tumor size, Grade III carcinoma, male sex, and lack of surgical excision were associated with a statistically significant decrease in OS and CSS (P < 0.04). Of note, multivariate analysis revealed that the use of adjuvant radiation therapy was not associated with improved OS or CSS.

CONCLUSION

Multivariate analysis demonstrated increasing age, advanced tumor stage, increasing tumor size, Grade III carcinoma, male sex, and lack of surgical excision were associated with decreased OS and CSS (P < 0.04).

Rare entities in head-and-neck cancer: salvage re-irradiation with carbon ions

Background

The objective of this investigation is to evaluate the outcomes and toxicity of carbon-ion re-irradiation (CIR) in patients with rare head and neck cancers (HNC). There is a paucity of data regarding treatment approaches in this patient cohort, which we aim to address in this work.

Methods

Thirty-two (n = 32) consecutive patients with uncommon HNC treated between 2010 and 2017 were retrospectively analyzed in terms of clinical outcomes, patterns of failure, and toxicity.

Results

Mucoepidermoid carcinoma (MEC) was the most common histology (22%). Patients received a median cumulative dose equivalent in 2 Gy fractions (EQD₂) after CIR of 128.6 Gy (range, 105.8–146.5 Gy). The local and distant control rates 1 year after CIR were 66 and 72%. No serious acute or late toxicity (≥ grade 3) after CIR was observed.

Conclusions

CIR may represent an effective and safe treatment alternative to palliative systemic therapies in these rare indications.

Baicalin-induced Cytotoxicity and Apoptosis in Multidrug-resistant MC3/5FU Mucoepidermoid Carcinoma Cell Line

Background:

Multidrug Resistance (MDR) is a serious hindrance to cancer chemotherapy and profoundly influences the clinical findings. Many Traditional Chinese Medicines (TCM) have been tested with the aim of developing effective resistance modulators or anticancer drugs to overcome the MDR of human cancers.

Methods:

The anticancer effect of baicalin on multidrug-resistant MC3/5FU (5-fluorouracil) cells was investigated by MTT test and xenografts in nude mice. Cell apoptosis was studied by transmission electron microscopy, Hoechst-33342 staining, DNA fragmentation detection, and flow cytometry. RT-PCR and Rhodamine 123 efflux assay was also used to detect its effect on ABC drug transporter proteins, ABCB1 (P-glycoprotein, P-gp) and ABCC1 (multidrug resistance protein 1, MRP1).

Results:

The results indicate that there was no significant effect of baicalin on ABC transporters expression or efflux function, although it induced potent growth inhibition in MC3/5FU cells. Flow cytometry, Hoechst 33342 staining and transmission electron microscope revealed that baicalin caused MC3/5FU cell death through the induction of apoptosis. It is demonstrated that baicalininduced apoptosis could be mediated by up-regulation of Bax and caspase-3 protein levels and downregulation of Bcl-2 protein levels. In addition, daily intraperitoneal injection of baicalin (100 and 200 mg/kg) for 2 weeks significantly inhibited the growth of MC3/5FU cells xenografts in nude mice.

Conclusion:

Our results suggest that baicalin possesses considerable cytotoxic activity in multidrug resistance MC3/5FU cells in vitro and in vivo.

Intermediate-grade carcinoma of the parotid and the impact of adjuvant radiation

PURPOSE

To determine the influence of adjuvant radiotherapy on survival in surgically-managed early stage intermediate-grade mucoepidermoid and acinic cell carcinoma of the parotid.

MATERIALS AND METHODS

The National Cancer Database was reviewed between 2004 and 2015 to identify patients with intermediate-grade, early T-stage, node-negative parotid carcinoma who underwent parotidectomy ± radiotherapy.

RESULTS

There were 744 patients identified of which 81% had mucoepidermoid carcinoma and 19% had acinic cell carcinoma. Positive surgical margins were identified in 21% and adjuvant radiotherapy was administered in 38% of cases. Of the 159 patients with positive margins, 113 (71%) received adjuvant radiotherapy. Of the 585 patients with negative margins, 173 (30%) underwent adjuvant radiotherapy. In multivariable analysis, age (over 52 years: HR 5.19, 95%CI 2.33-11.57), insurance status (private insurance: HR 0.24 95%CI 0.13-0.43), and extent of parotidectomy (total parotidectomy: HR 2.02 95%CI 1.23-3.31) were significantly associated with overall survival, while adjuvant radiotherapy was not a significant predictive factor (HR 0.81, 95%CI 0.49-1.36). In patients with positive margin resections, however, adjuvant radiation was an independent predictor of improved survival when adjusted for age, insurance status, and extent of parotidectomy (HR 0.34, 95%CI 0.13-0.88). Conversely, in patients with negative margin resections, adjuvant radiation did not influence survival outcomes when adjusted for these covariates (HR 1.02, 95%CI 0.53-1.93).

CONCLUSIONS AND RELEVANCE

In patients with early stage intermediate-grade parotid carcinoma, adjuvant radiotherapy significantly and independently improves survival in those with post-operative positive margins. Adjuvant therapy, however, does not appear to improve survival outcomes in those with negative margin resections.

Efficacy of combined surgery and 125 I seed brachytherapy for treatment of primary mucoepidermoid carcinoma of the parotid gland

BACKGROUND

This study aimed to determine the effectiveness and safety of surgery combined with postoperative ¹²⁵ I seed brachytherapy for treatment of primary mucoepidermoid carcinoma (MEC) of the parotid gland.

METHODS

Retrospective analysis of data of patients with MEC (n = 108) treated with surgery plus postoperative ¹²⁵ I seed brachytherapy between 2004 and 2016. Overall survival (OS), disease-free survival (DFS), local control rate (LCR), distant metastasis, and radiation-associated toxicities were analyzed, and factors affecting outcomes were evaluated.

RESULTS

The 5- and 10-year OS were 98.8% and 95.8%, respectively. The DFS and LCR at 5 and 10 years were all 91.4%. Age ≥ 60 years (hazard ratio [HR] = 6.86, 95% confidence interval [CI]: 1.54-30.55) and T4 disease (HR = 7.15, 95% CI: 1.40-36.52) were poor prognostic factors. Acute radiation-associated toxicities were minor.

CONCLUSION

Surgery plus ¹²⁵ I seed brachytherapy appears to be an effective treatment for parotid gland MEC, capable of providing satisfactory outcomes with few complications.

Mucoepidermoid Carcinoma of the Parotid: Very Close Margins and Adjuvant Radiotherapy

BACKGROUND/AIMS

The importance of adjuvant radiotherapy in patients with close margin resections for mucoepidermoid carcinoma of the parotid gland remains unclear.

METHODS

Patients who underwent parotidectomy for mucoepidermoid carcinoma with or without adjuvant radiotherapy at a single academic tertiary care center from 2000 to 2014 were identified. Included patients had negative but close (≤2 mm) surgical margins without other high-risk histopathological factors including advanced T-stage, positive nodal disease, lymphovascular or perineural invasion, or high-grade histology.

RESULTS

Nineteen patients were identified, of whom 15 (79%) were observed postoperatively, while 4 (21%) underwent adjuvant radiotherapy. There were no significant differences in extent of parotidectomy, elective neck dissection, T staging, or tumor size between patients who were observed and those undergoing adjuvant radiation. There were no locoregional or distant recurrences in any patients at a mean follow up 74.3 months. Patients undergoing adjuvant radiation, however, had significantly more intermediate-grade as compared to low-grade histology (75% vs. 13%, difference 62%, 95% CI 4% to 100%).

CONCLUSIONS

Patients with negative but close (≤2 mm) surgical margins without other high-risk histopathological factors have excellent long-term locoregional control with surgery alone. The effects of adjuvant radiotherapy for those who have intermediate-grade disease remain uncertain.

Postoperative radiotherapy for mucoepidermoid carcinoma of the major salivary glands: long-term results of a single-institution experience

Purpose

This study aimed to evaluate the long-term survival outcomes and prognostic factors that affect the clinical outcomes of patients who underwent surgery and postoperative radiotherapy for major salivary gland mucoepidermoid carcinoma (MEC).

Materials and Methods

We retrospectively reviewed the clinical data of 44 patients who underwent surgery followed by radiotherapy for primary MEC of the major salivary glands between 1991 and 2014. The median follow-up period was 9.8 years (range, 0.8 to 23.8 years).

Results

The overall outcomes at 5 and 10 years were 81.5% and 78.0% for overall survival (OS), 86.2% and 83.4% for disease-free survival, 90.6% and 87.6% for locoregional recurrence-free survival, and both 90.5% for distant metastasis-free survival (DMFS). Histologic grade was the only independent predictor of OS (low vs. intermediate vs. high; hazard ratio = 3.699; p = 0.041) in multivariate analysis. A poorer survival was observed among patients with high-grade tumors compared with those with non-high-grade tumors (5-year OS, 37.5% vs. 91.7%, p < 0.001; 5-year DMFS, 46.9% vs. 100%, p < 0.001).

Conclusion

Surgery and postoperative radiotherapy resulted in excellent survival outcomes for patients with major salivary gland MEC. However, high-grade tumors contributed to poor DMFS and OS. Additional aggressive strategies for improving survival outcomes should be developed for high-grade MEC.

A rare case of endobronchial mucoepidermoid carcinoma of the lung presenting as non-resolving pneumonia

Background

Mucoepidermoid carcinoma (MEC) is the most common malignant salivary gland tumor, and MECs of the lung are rare, accounting for 0.1–0.2% of malignant lung tumors. Pulmonary MECs are commonly found in the segmental or lobar bronchi, rarely presenting as endobronchial lesions.

Case presentation

Here we describe the case of a 21-year-old female with no comorbid conditions who presented at the emergency room with a cough, yellow phlegm, pleuritic chest pain, and a subjective fever. These symptoms had been present for approximately one week prior to the patient's arrival at the hospital. A chest X-ray revealed right lower lobe alveolar infiltrate and computed tomography of the chest showed dense consolidation of the right lower lobe with ovoid intraluminal density in the right main stem bronchus. Upon fiber optic bronchoscopy, an endobronchial lesion was found in the right main stem sparing the right upper lobe uptake. Endobronchial biopsy results was consistent with MEC of the lung. The patient underwent a bilobectomy with complete resection of the tumor.

Conclusion

Endobronchial MEC is a rare type of salivary gland tumor. Patients with low-grade MECs have a good prognosis, whereas those with high-grade MECs, which are aggressive and associated with metastatic disease, have a poor prognosis. However, early identification and surgical resection can result in a good prognosis.

Identifying Candidate Biomarkers for Pleomorphic Adenoma: A Case-Control Study

Pleomorphic adenoma (PA) is the most common benign salivary gland tumor. Kallikrein-related peptidases have been identified as biomarkers in many human tumors and may influence tumor behavior. We investigated KLK1-15 messenger ribonucleic acid and proteins in PA specimens to determine a KLK expression profile for this tumor. Fresh frozen PA tissue specimens (n = 26) and matched controls were subjected to quantitative real-time reverse transcription polymerase chain reaction to detect KLK1-15 mRNA. Expression of KLK1, KLK12, KLK13, and KLK8 proteins were then evaluated via immunostaining techniques. Statistical analyses were performed with the level of significance set at P < .05. We observed downregulation of KLK1, KLK12, and KLK13 mRNA expression, and immunostaining studies revealed downregulation of the corresponding proteins. Histologic evidence of capsular perforation was associated with increased KLK1 protein expression. Tumor size was not associated with capsular invasion and/or perforation. This study is the first to detail a KLK expression profile for PA at both the transcriptional level and the protein level. Future work is required to develop clinical applications of these findings.

Bilateral Synchronous Mucoepidermoid Carcinoma of the Parotid Gland

Mucoepidermoid carcinoma is the most common malignant tumor of the parotid; however, its synchronous occurrence in both of the parotid glands is extremely rare. Herein, we presented a case of 53-year-old man with bilateral synchronous mucoepidermoid carcinoma of the parotid gland treated with surgery.

The patient mainly complained of a painless mass in the left parotid gland. A mass located in the right parotid gland was incidentally detected by imaging. Based on cytopathology, left total parotidectomy was performed while preserving the facial nerve with ipsilateral neck dissection, and 5 weeks later, right superficial parotidectomy was performed. At the 3-year follow-up, there was no recurrence in the parotid regions and the neck.

A detailed examination for parotid masses is suggested for identifying possible occult synchronous tumors in the contralateral side or in other salivary glands. A close follow-up is also recommended for the risk of future occurrence of metachronous tumors.

Mucoepidermoid carcinoma of the parotid gland: A National Cancer Database study

OBJECTIVE

To describe the demographics, tumor characteristics, and prognostic features of mucoepidermoid carcinoma of the parotid gland.

MATERIALS AND METHODS

A retrospective study of the National Cancer Database was reviewed for all mucoepidermoid carcinomas of the parotid gland between 2004 and 2012). Patient demographics and tumor characteristics were abstracted and analyzed. Univariate and multivariate Cox multivariate regression models were used to identify predictors of survival.

RESULTS

A total of 4431 patients met inclusion criteria. Average age at diagnosis was 57 years (median 62, SD 19), with no overall sex preference (52% female), and majority white (78%). The 1-year overall survival was 92.9% (95% CI [92.1-93.6]) and 5-year overall survival was 75.2% (95% CI [73.8-76.7%]). Median overall survival was not reached at 5 years. Factors associated with decreased survival were increasing age, comorbidities, high tumor grade, advanced pathologic group stage, and positive surgical margins. Female sex was the only factor associated with improved survival. Controlling for either histopathologic grade or pathologic stage to determine how patient demographics and tumor characteristics affected overall survival yielded similar results. Of note, intermediate grade tumors, although not independently associated with worse survival, when seen in conjunction with tumors ≥T2 and/or ≥N2, a negative impact on overall survival was seen.

CONCLUSION

Although mucoepidermoid carcinoma of the parotid gland is the most common parotid gland malignancy, it is still a rare tumor with a lack of large population-based studies. Advanced stage and high-grade tumors are significant predictors of decreased survival. Females have improved survival compared to males.

Human Kallikrein 14 (Klk14) Expression in Salivary Gland Tumors

Objective

To analyze the expression of human kallikrein 14 (KLK14) in salivary gland tumors.

Methods

A standard immunoperoxidase staining technique was used to assess the expression profile of KLK14 in normal salivary glands and tumors including pleomorphic adenoma (PA; n=17), adenoid cystic carcinoma (ACC; n=13) and mucoepidermoid carcinoma (MEC; n=9). Tumor stage, grade, patient age and gender, and site of occurrence were recorded. These clinical parameters were correlated with KLK14 levels in malignant tumors. The expression profiles for KLK3, 5, 6, 8 and 13 were also retrieved.

Results

Normal salivary glands, PA, ACC and MEC showed strong expression of KLK14 in ductal and non-ductal cells. Both PA and ACC showed higher KLK14 levels than normal glands and MEC tissues. There were no statistically significant associations between levels of KLK14 and clinical parameters.

Conclusions

The differences in the levels of KLK14 suggest that KLKs may aid in the differential diagnosis of salivary gland tumors. The coexpression of KLKs suggests their possible involvement in an enzymatic pathway activated in salivary gland. KLK14 may be a promising new biomarker in salivary gland tumors.

Mucoepidermoid Carcinoma: A 23-Year Experience with Emphasis on Low-Grade Tumors with Close/Positive Margins

Objective Describe outcomes for mucoepidermoid carcinoma by histologic grade and evaluate outcomes for patients with low-grade tumors with close/positive margins after initial surgical resection. Study Design Cohort study. Setting Kaiser Permanente Southern California Medical Group from 1993 to 2016. Subjects and Methods Retrospective review of 154 patients with major and minor salivary gland mucoepidermoid carcinoma of the head and neck. Disease-specific and recurrence-free survival were stratified by tumor grade. Subgroup analysis of recurrence-free survival in patients with low-grade disease with close or positive margins was also performed. Results Five-year recurrence-free and disease-specific survival were excellent for both low- and intermediate-grade tumors, while there was there was a high rate of recurrence and mortality among patients with high-grade tumors. Patients with low-grade tumors with close or positive margins who were observed had no difference in recurrence-free survival compared to those who underwent revision surgery and/or adjuvant radiotherapy. Conclusions High-grade mucoepidermoid carcinoma has poor outcomes despite aggressive treatment. Among patients with low-grade tumors with close or positive margins on initial resection, additional treatment had no impact on survival or recurrence. Observation may be a reasonable alternative to additional treatment in this select group of patients.

Comparison of histological grading methods in mucoepidermoid carcinoma of minor salivary glands

CONTEXT

Mucoepidermoid carcinoma (MEC) is the most common salivary gland malignancy and its grading is greatly consequential in the management and prognosis of patients with the disease.

AIMS

To compare histologic grading systems in MEC of minor salivary glands.

SETTINGS AND DESIGN

Two qualitative (modified Healy and Memorial Sloan-Kettering Cancer Center [MSKCC] methods) and two quantitative (Armed Forces Institute of Pathology [AFIP] and Brandwein methods) were evaluated.

SUBJECTS AND METHODS

Diagnostics slides of 19 patients including one recurrent case were evaluated using the four grading systems.

STATISTICAL ANALYSIS USED

Percentages and proportions were used.

RESULTS

Agreement across all grading system was found to be very low (32%) while there was a better agreement between AFIP and MSKCC methods (84%) between modified Healy and Brandwein (58%). The method that gave the poorest agreement with all the others was the Brandwein grading. In general, the AFIP and MSKCC methods tended to grade the tumors lower while the Brandwein and modified Healy methods seemed to grade them higher.

CONCLUSIONS

Most MEC of minor salivary glands appear to be low-grade tumors. It is conceivable that some grading methods (Brandwein and modified Healy) may lead to an unnecessary escalation of management methods in these tumors. The MSKCC method may have emphasized some parameters which may not have much importance in minor salivary gland MEC. The AFIP method appears to be the most appropriate to use for the grading of minor salivary gland MEC. Further studies are required to confirm or disprove this finding.

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

Malignant parotid tumors are heterogeneous and diverse. Accurate diagnosis requires a pathologist familiar with the various histologic subtypes, immunohistochemistry stains, and common translocations. Clinical course varies according to tumor subtype, ranging from indolent, slow-growing adenoid cystic carcinoma to rapidly progressive, possibly fatal, salivary ductal carcinoma. Histologic grade is important in prognosis and therapy. Surgery remains the mainstay of treatment when negative margins can be achieved. Radiation improves locoregional control of tumors with high-risk features. Chemotherapy for parotid tumors can be disappointing. Studies of new targeted therapies have not offered significant benefits.

Colonic metastasis in mucoepidermoid carcinoma of the parotid: a rare occurrence

We present a case of intermediate-grade mucoepidermoid carcinoma of the parotid with late local recurrence and colonic metastasis. A 69-year-old man who had undergone right total conservative parotidectomy followed by adjuvant radiotherapy for intermediate-grade mucoepidermoid carcinoma 10 years prior, presented with a recurrent swelling in the postoperative site and cardiac failure. On evaluation, he was found to have severe anaemia with positive stool occult blood. Colonoscopic evaluation revealed a globular submucosal bulge with erosion 40 cm from the anal verge, the biopsy of which was consistent with mucoepidermoid carcinoma. The presentation, diagnostic details and management of this rare case are discussed.

Disorders and tumors of the salivary glands in children

Salivary gland neoplasms are rare in children. In infants most tumors are benign hemangiomas, with some notable exceptions, such as sialoblastomas. An asymptomatic swelling in the periauricular region is the most common presenting complaint in older children. Approximately 50% of these lesions are malignant, which dictates a thorough diagnostic evaluation by a head and neck surgeon. Surgical excision is the primary treatment modality. Prognosis is primarily determined by histopathologic findings. This review discusses neoplastic lesions of the salivary glands in children, and malignant epithelial tumors in particular.

Convallaria keiskei as a novel therapeutic alternative for salivary gland cancer treatment by targeting myeloid cell leukemia-1

BACKGROUND

Various chemotherapeutic agents have been used largely for the treatment of salivary gland cancer. However, results are disappointing, and these agents can cause some serious side effects. Therefore, recent studies have focused on the possible roles of natural products to overcome these limitations.

METHODS

Salivary gland cancer cells treated with or without Convallaria keiskei (MECK) for 24 hours. Apoptotic changes were evaluated by live/dead assay, immunoblotting, and expression levels of caspase-3 and B-cell lymphoma-2 family member.

RESULTS

MECK significantly inhibited salivary gland cancer growth. At the molecular level, MECK dramatically reduced myeloid cell leukemia-1 (Mcl-1) in a translation-dependent manner and thereby induced apoptosis through Bax/Bid. Furthermore, we found that Mcl-1 could be a potential therapeutic target of MECK-induced apoptosis and its stability is regulated by extracellular signal-regulated kinases 1/2 (ERK1/2) signaling

CONCLUSION

MECK can be used as a safe and efficient therapeutic alternative for the treatment of salivary gland cancer. © 2015 Wiley Periodicals, Inc. Head Neck 38: E761-E770, 2016.

Postoperative radiation therapy for parotid mucoepidermoid carcinoma

Salivary gland cancers are rare and represent approximately 5% of all head and neck cancers and only 0.3% of all malignancies. The majority (75%) of salivary gland tumors occur in the parotid gland, and while benign lesions are more common, mucoepidermoid carcinoma (MEC) makes up 40–50% of malignant parotid gland tumors. No randomized controlled trials exist regarding the role of adjuvant radiation for patients who undergo surgical resection of low-grade MECs. Herein, we report two cases of successful postoperative radiation therapy in low-grade, pT2N0 MEC of the parotid gland. The role of adjuvant radiation therapy for patients with MEC of the parotid gland is based on data from institution reviews and lacks data from randomized controlled trials. Per our review of the literature, the pathological findings of positive surgical margins and/or perineural invasion in two patients with low-grade MEC of the parotid gland warranted adjuvant radiation for improved local control after partial parotidectomy. Both patients tolerated postoperative radiation therapy with only mild side effects and, at last follow-up, five years after completion of therapy, had no clinical or radiographic evidence of either local recurrence or distant metastasis.

Salivary gland carcinomas in children and adolescents: the Italian TREP project experience

BACKGROUND

Salivary gland carcinomas are extremely rare in pediatric age. We report the clinical features of a series of children/adolescents with salivary gland carcinomas prospectively registered in the Italian TREP (Rare Tumors in Pediatric Age) project.

PROCEDURES

Diagnostic/therapeutic guidelines were developed and shared among Italian pediatric oncology/surgical centers.

RESULTS

Seventeen patients were registered between 2000 and 2012, representing 19% of the cases expected to be seen based on epidemiological data. Tumors arose mainly in the parotid gland (14 cases). In most cases they were low-grade tumors (14 cases), often with a favorable clinical presentation, and low-stage disease. All patients underwent surgical resection, achieving histologically free margins in 9/17 cases. Thirteen of the 14 patients with parotid gland tumors had parotidectomy (10 total, 3 superficial), while one had a tumorectomy. Postoperative facial nerve lesions were reported in two cases. Adjuvant radiotherapy was given to 6 patients. The overall prognosis was good: only one patient with a huge high-grade tumor experienced disease progression and died of the disease. The other 16 patients were alive in first continuous remission 1-8 years after diagnosis. In 4/17 cases, the salivary gland carcinoma was a second tumor occurring 6-9 years after another primary cancer.

CONCLUSIONS

This is the first reported prospective national cooperative series of pediatric salivary gland carcinoma patients. Compliance with the TREP recommendations was high. These tumors are rarely managed by pediatric oncologists/surgeons. A broader international cooperation and better networking with otolaryngologists and head-neck surgeons expert on adult salivary gland carcinomas would be advisable.

Carcinoma of the salivary glands: guidelines and case report of sustained remission with docetaxel

WHAT IS KNOWN AND OBJECTIVE

Salivary glands tumours are rare neoplasms for which there are few clinical trials. The most common malignant parotid tumour is the mucoepidermoid carcinoma. High-grade mucoepidermoid carcinomas are highly aggressive tumours. The initial therapy of localized disease is known, but when there is a recurrence, several options are possible and chemotherapy is generally reserved for palliative treatment. We comment on published guidelines and report a case of sustained remission with docetaxel.

CASE SUMMARY

Our case concerns a 64-year-old woman with a high-grade mucoepidermoid carcinoma of the parotid gland with local recurrence treated with docetaxel 50 mg/m² every 15 days. After the sixth cycle, a complete remission was observed on CT-scan. The tolerability was excellent. After 2 years of docetaxel, the patient was still in complete remission.

WHAT IS NEW AND CONCLUSION

Docetaxel is an active drug for the treatment of mucoepidermoid carcinoma of salivary glands. A prospective study should confirm these data.

Prognostic features in mucoepidermoid carcinoma of major salivary glands with emphasis on tumour histologic grading

AIMS

To compare the different grading systems of mucoepidermoid carcinoma (MEC) and identify the most reliable and objective histopathologic features predictive of outcome.

METHODS AND RESULTS

Seventy-two cases diagnosed as MEC were subjected to a meticulous histopathologic re-review. 20 of 72 (28%) cases were originally misdiagnosed as MEC including 16 as high grade (HG). Among the 52 confirmed MEC, median follow up (FU) was 59 months. Mitosis (≥4/10 High Power Fields), necrosis, pleomorphism, focal keratinization, desmoplasia, and lymph node metastasis were associated with adverse disease specific survival (DSS) and recurrence free survival (RFS) (P < 0.002). In all grading systems, low and intermediate grade had similar DSS and RFS but much better outcome than HG (P < 0.007). All patients with tumour harboring low mitotic rate and no necrosis did not recur except for one patient with a positive margin. All cases with high mitotic rate and necrosis died or recurred.

CONCLUSIONS

The majority of previously diagnosed HG MEC cases are misclassified. There is no difference in outcome between low and intermediate grade in all grading schemes. Consideration should be given to stratify MEC based on relatively objective criteria such as mitosis and necrosis.

Robot-assisted removal of a posterior pharyngeal wall mucoepidermoid carcinoma

This report presents a rare case of a mucoepidermoid carcinoma of the posterior pharyngeal wall of the hypopharynx. Excision of the lesion was performed by transoral robotic surgery (TORS). The rarity of hypopharyngeal mucoepidermoid carcinoma and the technical advantages of TORS are presented and discussed in this study.

Inhibition of specificity protein 1 by dibenzylideneacetone, a curcumin analogue, induces apoptosis in mucoepidermoid carcinomas and tumor xenografts through Bim and truncated Bid

OBJECTIVES

Dibenzylideneacetone (DBA), a curcumin analogue that has anti-cancer activity in a variety of tumor cells. In this study, we investigated the apoptotic effects of DBA and its molecular mechanism in human mucoepidermoid carcinoma (MEC) cell lines and tumor xenografts.

MATERIAL AND METHODS

The apoptotic effects and related molecular mechanisms of DBA on MEC cell lines were evaluated using cell viability assay, DAPI staining, Western blot analysis, reverse transcriptase-polymerase chain reaction (RT-PCR) and Dual-luciferase Reporter Assay. The anti-tumor activity using in vivo were determined by Nude mouse xenograft assay and histopathological examination.

RESULTS

DBA decreased cell viability and induced apoptosis in MEC cells. These events were accompanied by inhibition of specificity protein 1 (Sp1). DBA did not induce major changes in Sp1 mRNA and promoter activity. Furthermore, inhibition of protein synthesis by cycloheximide demonstrated that DBA decreased Sp1 protein stability, but DBA did not attenuate phosphorylation of eIF4E. DBA also increased Bim and truncated Bid (t-Bid) via Sp1. Finally, DBA exhibited significant anti-tumor activity in athymic nude mice xenografts bearing MC-3 cells by regulating Sp1, Bim and t-Bid without any systemic toxicity.

CONCLUSION

These results elucidate a crucial apoptotic mechanism of DBA and suggest that DBA may be a potent anticancer drug candidate for MEC.

Mucoepidermoid carcinoma of the larynx with transglottic involvement in a child: a case report

Mucoepidermoid carcinoma (MEC) of the larynx is one of the rarest tumors in the pediatric age group. Our review of the English-language literature found only 1 previously reported case of a laryngeal MEC in a child. We present what to the best of our knowledge is the first case of a pediatric MEC of the larynx with transglottic involvement. Our patient was a 12-year-old girl who presented with long-standing hoarseness and recent dysphagia, breathing difficulty, and pain radiating to the left ear. Investigation revealed the presence of an endophytic mass in the larynx. Histopathologic examination of biopsy tissue identified the mass as a low-grade MEC. The patient was scheduled to undergo a total laryngectomy 1 week later, but she did not report for surgery. Three weeks later, she presented to the emergency department in a semiconscious state and in respiratory distress. Despite all resuscitative measures, she died.

Histologic grade as prognostic indicator for mucoepidermoid carcinoma: a population-level analysis of 2400 patients

BACKGROUND

Mucoepidermoid carcinoma (MEC) is an uncommon malignancy. To the best of our knowledge, this is the largest study investigating disease-specific survival (DSS) of parotid MEC and the first population-level study of the distribution of nodal metastases.

METHODS

Patients with MEC of the parotid gland were identified in the Surveillance, Epidemiology, and End Results (SEER) database (1988-2009).

RESULTS

We identified 2400 patients with MEC: 522 low grade, 1137 intermediate grade, and 741 high grade. Five-year DSS rates for low-grade, intermediate-grade, and high-grade MEC were 98.8%, 97.4%, and 67.0%, respectively (p < .001). Negative prognostic factors included high grade, increasing patient age, and tumor size, extraparenchymal extension, nodal metastases, and distant metastases. High-grade MEC was more likely to have lymph node metastases in levels I to III (34.0%) than low-grade (3.3%) and intermediate-grade MEC (8.1%; p < .001).

CONCLUSION

Grade influences the prognosis and distribution of nodal metastases. Results indicate that management guidelines should vary based on grade.

Genomic profiles and CRTC1-MAML2 fusion distinguish different subtypes of mucoepidermoid carcinoma

Mucoepidermoid carcinoma is the most common salivary gland malignancy, and includes a spectrum of lesions ranging from non-aggressive low-grade tumors to aggressive high-grade tumors. To further characterize this heterogeneous group of tumors we have performed a comprehensive analysis of copy number alterations and CRTC1-MAML2 fusion status in a series of 28 mucoepidermoid carcinomas. The CRTC1-MAML2 fusion was detected by RT-PCR or fluorescence in situ hybridization in 18 of 28 mucoepidermoid carcinomas (64%). All 15 low-grade tumors were fusion-positive whereas only 3 of 13 high-grade tumors were fusion-positive. High-resolution array-based comparative genomic hybridization revealed that fusion-positive tumors had significantly fewer copy number alterations/tumor compared with fusion-negative tumors (1.5 vs 9.5; P=0.002). Twelve of 18 fusion-positive tumors had normal genomic profiles whereas only 1 out of 10 fusion-negative tumors lacked copy number alterations. The profiles of fusion-positive and fusion-negative tumors were very similar to those of low- and high-grade tumors. Thus, low-grade mucoepidermoid carcinomas had significantly fewer copy number alterations/tumor compared with high-grade mucoepidermoid carcinomas (0.7 vs 8.6; P<0.0001). The most frequent copy number alterations detected were losses of 18q12.2-qter (including the tumor suppressor genes DCC, SMAD4, and GALR1), 9p21.3 (including the tumor suppressor genes CDKN2A/B), 6q22.1-q23.1, and 8pter-p12.1, and gains of 8q24.3 (including the oncogene MAFA), 11q12.3-q13.2, 3q26.1-q28, 19p13.2-p13.11, and 8q11.1-q12.2 (including the oncogenes LYN, MOS, and PLAG1). On the basis of these results we propose that mucoepidermoid carcinoma may be subdivided in (i) low-grade, fusion-positive mucoepidermoid carcinomas with no or few genomic imbalances and favorable prognosis, (ii) high-grade, fusion-positive mucoepidermoid carcinomas with multiple genomic imbalances and unfavorable prognosis, and (iii) a heterogeneous group of high-grade, fusion-negative adenocarcinomas with multiple genomic imbalances and unfavorable outcome. Taken together, our studies indicate that molecular genetic analysis can be a useful adjunct to histologic scoring of mucoepidermoid carcinoma and may lead to development of new clinical guidelines for management of these patients.

Kallikrein-related peptidase 10 expression in salivary gland tissues and tumours

OBJECTIVES

Kallikrein-related peptidase 10 (KLK10) has been implicated in the development of several types of cancer. The purpose of this study was to analyze the expression of KLK10 in 3 types of salivary gland tumour and normal salivary glands.

MATERIALS AND METHODS

A standard immunoperoxidase staining technique was used to assess the immunoexpression profile of KLK10 in normal salivary glands and 3 types of salivary gland tumour: pleomorphic adenoma, adenoid cystic carcinoma and mucoepidermoid carcinoma.

RESULTS

Pleomorphic adenomas showed significantly lower KLK10 levels than control tissues. Neither of the malignant tumours (adenoid cystic carcinoma and mucoepidermoid carcinoma) showed a significant alteration in the immunoreactive scores of KLK10 in comparison with the normal salivary gland tissues. KLK10 immunoreactive scores were comparable in adenoid cystic carcinoma and mucoepidermoid carcinoma. Pleomorphic adenoma had significantly lower levels of KLK10 than mucoepidermoid carcinoma.

CONCLUSIONS

The finding of lower KLK10 levels in pleomorphic adenoma suggests aberrant expression in a tumour that develops primarily from myoepithelial cells. A kallikrein cascade may play a role in the development and/or outcome of some salivary gland tumours.

Paediatric salivary gland cancer in Finland

OBJECTIVES

Worldwide, only 5% of all salivary gland tumours are reported in children and 35-50% of these are malignant. According to the Finnish Cancer Registry, 15 children were diagnosed with salivary gland cancer (SGC) during 1990-2009 in Finland. There are no previous studies available on the histopathology, treatment, and survival of patients with these rare malignancies in Finland.

METHODS

Retrospective patient and tumour data covering the past 20 years were retrieved from the five University Hospitals in Finland. Ten paediatric SGC patients with a median age of 14 years (range, 9-19 years) and with available adequate patient data were included. The series comprised four boys and six girls. Follow-up time varied from five months to 14 years.

RESULTS

Two patients had a history of a previous malignancy. The majority of cases had a parotid gland cancer (7/10), and mucoepidermoid carcinoma was the most common histological subtype (5/10). All patients presented with Stage I-II disease and were treated surgically with curative intent. One patient with a Stage I mucoepidermoid carcinoma of the parotid gland received postoperative radiotherapy. No recurrences were encountered and all patients were free of disease at the last follow up.

CONCLUSIONS

The individual treatment design for paediatric SGC should follow consistent treatment strategies. All patients in the present study had low-grade tumours with a favourable prognosis. Since paediatric SGC is infrequent worldwide, the diagnostics, treatment, and follow up should be centralized in multidisciplinary Head and Neck Centres.

Unicystic Mucoepidermoid Carcinoma Presenting as a Salivary Duct Cyst

A cystic swelling in the parotid gland should lead to a differential diagnosis that includes benign cystic lesion of the gland, benign tumors that are frequently associated with cystic degeneration or entirely cystic de novo, or even a malignant neoplasm. The case presented is that of a cystic parotid swelling of 2 years’ duration in a 52-year-old female patient. The clinical differentials in the present case were reviewed and were entirely different from the final histological diagnosis of low-grade mucoepidermoid carcinoma. The uniqueness of this case is the very rare unicystic presentation of the lesion. The authors also discuss why the clinical and radiological investigations were not suggestive of the final diagnosis.

Common Malignant Salivary Gland Epithelial Tumors

Malignant salivary gland epithelial tumors are histologically diverse with at least 24 recognized distinct entities. In general, malignant tumors account for 15% to 30% of parotid tumors, 40% to 45% of submandibular tumors, 70% to 90% of sublingual tumors, and 50% of minor salivary tumors. Common malignancies include mucoepidermoid carcinoma, adenoid cystic carcinoma, acinic cell carcinoma, salivary duct carcinoma, carcinoma ex pleomorphic adenoma, polymorphous lowgrade adenocarcinoma, and myoepithelial carcinoma. Each tumor type has its own unique histologic variants and prognostic pathologic features, and only mucoepidermoid carcinomas have a formalized grading system. The molecular pathogenesis of certain tumors, such as mucoepidermoid carcinoma and adenoid cystic carcinoma, has recently begun to be elucidated.

P27/SKP-2 histochemical profile is relevant to malignant salivary gland tumors (MST) histogenesis and tumor grade

Malignant salivary gland tumors (MST) represent over more than 24 distinct morphological subtypes. Most high grade tumors arise from the excretory duct portion of the salivary gland apparatus; the remainder from the intercalated duct portion. Altered p27/skp-2 expression has been associated with tumor aggressiveness and histologic differentiation. In our study, we analyzed p27/skp-2 expression proteins on series of malignant salivary gland tumors in order to assess their value as a histogenetic marker, which is relevant to tumor grade. 61 MST cases were segregated by proposed histogenesis and immunohistochemistry was performed using antibodies directed against p27 and skp-2. MST of proposed intercalated duct origin (n=27) showed strong p27 expression (n=25/27; 93%) in the vast majority of cases and all cases weakly expressed skp-2. MST of proposed excretory duct origin (n=32) showed strong p27 expression (n=18/32; 56%) and moderately strong/strong skp-2 expression (n=18/32; 56%), respectively, in over half the cases. MST of intercalated duct origin showed evident p27/skp-2 inverse correlation. Differences in p27/skp-2 expression among the MST subtypes correlated with histogenesis and tumor grade, which reinforces the notion that tumor behavior is relevant to the portion of the salivary gland unit from which they arise. MST of proposed intercalated duct origin strongly expressed p27, and not skp-2, unlike MST of proposed excretory duct origin. The immunohistochemical profile of high grade mucoepidermoid carcinoma was distinct from its low/intermediate grade counterparts, suggesting a separate identity. These results may influence future decision making when formulating workable MST categorization schemes. Further studies on a larger series of MST are warranted in order to support the value of our findings.

Histologic grading and prognostic biomarkers in salivary gland carcinomas

Both the variety and rarity of salivary gland carcinomas pose challenge for using histologic grade and biomarkers to predict outcome. Mucoepidermoid carcinoma is the histologic subtype for which grading is most prognostically and therapeutically relevant. This tumor is graded using standard schemes in a 3-tier manner with the intermediate-grade category shows the most variability between grading systems and thus the most controversy in management. The t(11;19)(q21; p13) MECT1-MAML2 translocation may be an objective marker that can help to further stratify difficult cases. Adenoid cystic carcinomas are graded based on pattern with solid areas correlating with a worse prognosis. Occasionally, adenoid cystic carcinomas may undergo transformation to highly aggressive pleomorphic high-grade carcinomas with frequent nodal metastases. Comparative genomic hybridization has revealed several chromosomal regions (such as 1p32-p36, 6q23-q27) of prognostic interest in adenoid cystic carcinoma. Carcinoma ex-pleomorphic adenoma is actually a category of tumors rather than a single tumor type with both aggressive and indolent versions. These tumors should be further qualified as to type/grade of carcinoma and extent, as intracapsular and minimally invasive tumors behave favorably. Acinic cell carcinomas, although generally considered low grade, can recur, metastasize, or even prove lethal in a significant number of cases suggesting amenability to a grading scheme to separate these biologic groups. Although aggressive histologic parameters (anaplasia, necrosis, and mitoses) are predictive of poor outcome, a standard grading scheme does not yet exists. Acinic cell carcinomas can also undergo high-grade transformation.

Expression pattern of claudins 1 and 3-an auxiliary tool in predicting behavior of mucoepidermoid carcinoma of salivary gland origin

Claudins (CLDNs) are a family of membrane proteins important for permeability of tight junctions. They have also been implicated in carcinogenesis and tumor progression. We analyzed patterns of distribution and intensity of expression of CLDNs 1, 3, 4, and 7 in mucoepidermoid carcinoma (MEC) of salivary gland in 39 patients. Correlations between the expression of CLDNs, tumor grade, and survival were explored. In immunohistochemical analysis, high expression of CLDN 1 was seen in low-grade MEC, and it appeared to be a suitable auxiliary marker of good prognosis. It classified MEC similarly to histological grading in 89.7% of cases (p = 0.001). High CLDN 3 expression was seen in intermediate- and high-grade MEC, while it was low in low-grade MEC. CLDN 3 intensity correctly categorized tumors into grades in 71.8% of cases (p = 0.017). However, in multivariate analysis CLDN 1 and CLDN 3 did not achieve significance over tumor grade in predicting patient behavior. We conclude that analysis of staining intensities of CLDN 1 and 3 is useful as an auxiliary diagnostic and prognostic tool in patients with salivary gland MEC.