Management of salivary gland tumors

A Case of Undetermined Adenoid Cystic Carcinoma With Airway Stenosis Treated With Palliative X-Ray Radiotherapy Leading to Significant Improvement in Patient’s General Condition

Primary adenoid cystic carcinoma (ACC) of the upper anterior mediastinum is rarely encountered in clinical practice, and no standard treatment has been established. We performed palliative radiotherapy to improve airway narrowing in a patient with primary ACC of the mediastinum who presented with respiratory distress as their main complaint. As a result of radiotherapy, the ACC was reduced in size, the narrowed airway was opened due to compression by the ACC, and the patient's general condition improved. We present the results of this case with a review of the relevant literature.

Adenoid cystic carcinoma of Bartholin's gland, a case report with genomic data and literature review

Adenoid cystic carcinoma of the Bartholin's gland (ACCBG) is a rare, slowly but aggressive malignancy. We reported the case of a 31-year-old woman who was treated by local excision and then hemi-vulvectomy, with positive margins and perineural invasion. Radiation therapy (RT) was then performed delivering 45Gy in 25 fractions in bilateral inguinal lymph nodes and 64.8Gy in 36 fractions on the vulvar area. After 30 months, there was no local relapse (LR) but the patient presented a histologically documented lung recurrence. Genomic profiling of the tumor showed a MYB-NFIB fusion transcript and a somatic mutation of PLCG1. A treatment by Lenvatinib was started. We conducted a literature review of 100 published cases. Patients were mainly treated by radical vulvectomy (30%), hemi-vulvectomy (17%), wide or local excision (21% and 24%, respectively) or other. Forty-four percent of patients received postoperative RT, more frequently in case of positive margin (71.9% versus 29.5%). RT may reduce the risk of LR regardless of margin status, with 15.4% vs. 41.9% of LR with or without RT, respectively, in patients with negative margins, and 13% vs. 33.3% of LR with or without RT, respectively, in patients with positive margins. The risk of relapse of any type was 40.9% in patients who received adjuvant RT vs. 48.2% in patients who did not. Median time to relapse was 24 months (range 6-156 months). The most frequent metastatic sites were lung (76.7%) and bone (26.7%). Optimal treatment for ACCBG is still not clearly defined but pooling the data from published case report help us better understand this rare disease and help in the therapeutic decision.

Patterns of Lymph Node Metastasis in Parotid Cancer and Implications for Extent of Neck Dissection

OBJECTIVE

The role and extent of neck dissection in primary parotid cancer are controversial. Herein, we characterize patterns of lymph node metastasis in parotid cancer.

STUDY DESIGN

Retrospective analysis.

SETTING

National Cancer Database.

METHODS

Patients with the 6 most common histologic subtypes of parotid cancer were selected. Primary outcomes were the distribution of positive lymph nodes by level and overall survival assessed by Cox analysis. Secondary outcomes included predictors of extended lymph node involvement (≥3 lymph nodes or Level IV/V involvement), via logistic regression.

RESULTS

Six thousand nine hundred seventy-seven patients with acinic cell carcinoma, adenocarcinoma, adenoid cystic carcinoma, carcinoma ex pleomorphic adenoma (CExPA), mucoepidermoid carcinoma, and salivary duct carcinoma (SDC) were included. Among cN0 patients, 8.2% of low-grade tumor patients had occult nodal metastasis versus 30.9% in high-grade tumor patients. Elective neck dissection was not associated with an overall survival benefit (adjusted hazard ratio: 1.10; 0.94-1.30, p = .238). Among cN+ tumors, CExPA (odds ratio [OR]: 1.88, 1.05-3.39, p = .034) and high-grade pathology (OR: 3.03, 1.87-4.93, p < .001) were predictive of having ≥3 pathologic nodes. CExPA (OR: 2.13, 1.22-3.72, p = .008), adenocarcinoma (OR: 1.60, 1.11-2.31, p = .013), SDC (OR: 1.92, 1.17-3.14, p < .01), and high-grade pathology (OR: 3.61, 2.19-5.97, p < .001) were predictive of Level IV/V neck involvement.

CONCLUSIONS

In parotid malignancy, nodal metastasis distribution is dependent on histology and grade. High-grade tumors and certain histologies (SDC and adenocarcinoma) had a higher incidence of occult nodes. Comprehensive neck dissection should also be considered for node-positive high-grade tumors, SDC, and adenocarcinoma.

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

Purpose

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

Methods

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

Results

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

Conclusions

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

Central mucoepidermoid carcinoma of the mandible deriving from odontogenic cyst: A case report and review of the literature

Mucoepidermoid Carcinoma (MEC) it can origin from a mandibular odontogenic cyst. We report the case of a 63‐year‐old man with MEC of the right retromolar trigonum of the mandibula. We performed a wide mandibular excision and immediate reconstruction with a fibula bone free flap.

Treatment of mandibular mucoepidermoid carcinoma central type can be carried out safely and aesthetical valid through a wide segmental mandibular excision with an immediate reconstruction with fibula bone‐free flap and a postoperative RT.

Clinical features in salivary gland lymphoepithelial carcinoma in 10 patients: Case series and literature review

Objective

Lymphoepithelial carcinoma (LEC) accounts for 0.4% of malignant tumors of the salivary gland and 0.8% of parotid gland malignancies. Over the past 50 years, less than 300 cases have been reported in the literature. The purpose of this study was to investigate the characteristics of salivary gland LEC.

Methods

We retrospectively reviewed the medical records and analyzed clinical data obtained from 10 patients seen at our hospital between 2005 and 2020 with salivary gland LEC.

Results

All patients presented with a self‐palpable, non‐tender, hard swelling, or lump near the jaw or infra‐auricular region. Most cases (n = 8) were of solitary tumors, and enhancing patterns on computed tomography mainly were homogenous (n = 8). Interestingly, eight patients tested positive for the Epstein–Barr encoding region in in situ hybridization. Still, only three patients had detectable circulating Epstein–Barr virus (EBV) DNA, and one patient had detectable EBV IgA. All patients underwent complete tumor resection, followed by radiotherapy, and six also underwent chemotherapy. Nine patients became disease‐free within 5 years, and one died due to disease 4 years after surgery.

Conclusion

Although rare and considered to be a high‐risk malignancy, LECs have favorable treatment outcomes. Circulating EBV DNA is still not considered a marker for preoperative assessment or postoperative treatment response. The role of EBV DNA requires further investigation.

Level of Evidence: 4

Proteasome inhibition by bortezomib parallels a reduction in head and neck cancer cells growth, and an increase in tumor-infiltrating immune cells

Head and neck cancer (HNC) has frequently an aggressive course for the development of resistance to standard chemotherapy. Thus, the use of innovative therapeutic drugs is being assessed. Bortezomib is a proteasome inhibitor with anticancer effects. In vitro antitumoral activity of Bortezomib was investigated employing human tongue (SCC-15, CAL-27), pharynx (FaDu), salivary gland (A-253) cancer cell lines and a murine cell line (SALTO-5) originated from a salivary gland adenocarcinoma arising in BALB-neuT male mice transgenic for the oncogene neu. Bortezomib inhibited cell proliferation, triggered apoptosis, modulated the expression and activation of pro-survival signaling transduction pathways proteins activated by ErbB receptors and inhibited proteasome activity in vitro. Intraperitoneal administration of Bortezomib delayed tumor growth of SALTO-5 cells transplanted in BALB-neuT mice, protracted mice survival and adjusted tumor microenvironment by increasing tumor-infiltrating immune cells (CD4⁺ and CD8⁺ T cells, B lymphocytes, macrophages, and Natural Killer cells) and by decreasing vessels density. In addition, Bortezomib modified the expression of proteasome structural subunits in transplanted SALTO-5 cells. Our findings further support the use of Bortezomib for the treatment of HNC and reveal its ineffectiveness in counteracting the activation of deregulated specific signaling pathways in HNC cell lines when resistance to proteasome inhibition is developed.

Nomograms-based prediction of overall and cancer-specific survivals for patients diagnosed with major salivary gland carcinoma

Background

Major salivary glands carcinoma (MSGC) is a relatively rare cancer with diverse histological types and biological behavior. The treatment planning and prognosis prediction are challenging for clinicians. The aim of the current study was to establish a reliable and effective nomogram to predict the overall survival (OS) and cancer-specific survival (CSS) for MSGC patients.

Methods

Patients pathologically diagnosed with MSGC were recruited from Surveillance, Epidemiology, and End Results (SEER) database and randomly divided into training and validation groups (7:3 ratio). Univariate, multivariate Cox proportional hazard models, and least absolute shrinkage and selection operator (LASSO) regression were adopted for the selection of risk factors. Nomograms were developed using R software. The model performance was evaluated by drawing receiver operating characteristic (ROC), overtime C-index curves, and calibration curves. Harrell C-index, areas under the curves (AUC), and Brier score were also calculated. The decision curve analysis (DCA) was conducted to measure the net clinical benefit.

Results

A total of 11,362 patients were identified and divided into training (n=7,953) and validation (n=3,409) dataset. Sex, age, race, marital status, site, differentiation grade, American Joint Committee on Cancer (AJCC) stage, T/N/M stage, tumor size, surgery, and histological type were incorporated into the Cox hazard model for OS prediction after variable selection, while all predictors, except for marital status and site, were selected for CSS prediction. For 5-year prediction, the AUC of the nomogram for OS and CSS was 83.5 and 82.7 in the training and validation dataset, respectively. The C-index was 0.787 for OS and 0.798 for CSS in the validation group. The Brier score was 0.0153 and 0.0130 for OS and CSS, respectively. The calibration curves showed that the nomogram had well prediction accuracy. From the perspective of DCA, a nomogram was superior to the AJCC stage and TNM stage in net benefit. In general, the performance of the nomogram was consistently better compared to the AJCC stage and TNM stage across all settings.

Conclusions

The performance of the novel nomogram for predicting OS and CSS of MSGC patients was further verified, revealing that it could be used as a valuable tool in assisting clinical decision-making.

Application of Diffusion Kurtosis Imaging and Dynamic Contrast-Enhanced Magnetic Resonance Imaging in Differentiating Benign and Malignant Head and Neck Lesions

BACKGROUND

Preoperative differentiation of head and neck lesions is important for treatment plan selection.

PURPOSE

To evaluate the diagnostic value of diffusion kurtosis imaging (DKI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in differentiating benign from malignant head and neck lesions and subgroups, including lymphoma subgroup (LS), Warthin's tumor subgroup (WS), malignant tumor subgroup (excluding lymphoma) (MTS), and benign tumor subgroup (excluding Warthin's tumor) (BTS).

STUDY TYPE

Retrospective.

POPULATION

Seventy-four patients with 79 head and neck lesions (44 benign, 35 malignant), divided into four subgroups: LS (14), WS (12), MTS (21), and BTS (32).

FIELD STRENGTH/SEQUENCES

A 3.0 T, single-shot echo-planar sequence with 5 b-values for DKI and enhanced T1 high-resolution isotropic volume excitation (eTHRIVE) sequence for DCE-MRI.

ASSESSMENT

The mean diffusivity (MD) and mean kurtosis (MK) derived from DKI and the time-signal intensity curve (TIC), peak time (T_peak ), and washout ratio (WR) based on DCE-MRI were measured. The diagnostic efficiencies of DKI and DCE-MRI, alone and in combination, were calculated and compared. The parameters mentioned above were compared between the four subgroups.

STATISTICAL TEST

Mann-Whitney U test, chi-square test, receiver operating characteristic curve, Delong test, one-way analysis of variance test, and Kruskal-Wallis H test. A P value < 0.05 was considered statistically significant.

RESULTS

The combination of TIC and parameters of DKI and DCE-MRI for differentiating benign and malignant lesions with 94.94% accuracy is superior to DKI or DCE-MRI alone with approximately 75% accuracy. MD, MK, T_peak , and WR showed significant differences among the four subgroups. The accuracy of MD and MK was 91.14% and 92.41% for differentiating BTS from the other three subgroups. WR achieved 100% accuracy for discriminating WS from LS or MTS. MD and MK both differentiated LS from MTS with 97.14% accuracy.

DATA CONCLUSION

A combination of DKI and DCE-MRI can effectively differentiate head and neck lesions with good accuracy.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 2.

Competing-risks nomograms for predicting cause-specific mortality in parotid-gland carcinoma: A population-based analysis

INTRODUCTION

Parotid-gland carcinoma (PGC) is a relatively rare tumor that comprises a group of heterogeneous histologic subtypes. We used the Surveillance, Epidemiology, and End Results (SEER) program database to apply a competing-risks analysis to PGC patients, and then established and validated predictive nomograms for PGC.

METHODS

Specific screening criteria were applied to identify PGC patients and extract their clinical and other characteristics from the SEER database. We used the cumulative incidence function to estimate the cumulative incidence rates of PGC-specific death (GCD) and other cause-specific death (OCD), and tested for differences between groups using Gray's test. We then identified independent prognostic factors by applying the Fine-Gray proportional subdistribution hazard approach, and constructed predictive nomograms based on the results. Calibration curves and the concordance index (C-index) were employed to validate the nomograms.

RESULTS

We finally identified 4,075 eligible PGC patients who had been added to the SEER database from 2004 to 2015. Their 1-, 3-, and 5-year cumulative incidence rates of GCD were 10.1%, 21.6%, and 25.7%, respectively, while those of OCD were 2.9%, 6.6%, and 9.0%. Age, race, World Health Organization histologic risk classification, differentiation grade, American Joint Committee on Cancer (AJCC) T stage, AJCC N stage, AJCC M stage, and RS (radiotherapy and surgery status) were independent predictors of GCD, while those of OCD were age, sex, marital status, AJCC T stage, AJCC M stage, and RS. These factors were integrated for constructing predictive nomograms. The results for calibration curves and the C-index suggested that the nomograms were well calibrated and had good discrimination ability.

CONCLUSION

We have used the SEER database to establish-to the best of our knowledge-the first competing-risks nomograms for predicting the 1-, 3-, and 5-year cause-specific mortality in PGC. The nomograms showed relatively good performance and can be used in clinical practice to assist clinicians in individualized treatment decision-making.

DNA methyltransferase expression is associated with cell proliferation in salivary mucoepidermoid carcinoma

OBJECTIVES

The present study investigated the correlation between the expression of DNA methyltransferase (DNMT)1, DNMT3A, and DNMT3B and the proliferation of mucoepidermoid carcinomas (MECs) using the molecular markers Ki-67 and cyclin D1. This study also demonstrates the effects of 5-aza-2-deoxycytidine (5AC) on the MEC tumor cell lines in relation to DNMT1 and DNMT3A expression, and cell-cycle arrest.

MATERIALS AND METHODS

The immunohistochemistry of DNMT1, DNMT3A, DNMT3B, Ki-67, and cyclin D1 was analyzed in 40 samples of MEC and 15 samples of healthy minor salivary glands. The effects of 5AC on DNMT1 and DNMT3B expression in MEC cell lines were analyzed by Western blot, and the effects of 5AC on the cell cycle were analyzed using flow cytometry.

RESULTS

The expression of DNMT1 and DNMT3B was more intense in MECs than in healthy salivary glands. A strong correlation was found between the expression of the DNMTs and the proliferation markers. This correlation was validated In Vitro, where treatment with 5AC reduced the expression of the DNMTs and the percentage of cells at the G2/M phase of the cell cycle.

CONCLUSION

The expression of DNMT1, DNMT3A, DNMT3B is correlated significantly with the expression of Ki-67 and cyclin D1. The treatment with 5AC reduces DNMT expression and decreases the percentage of cells at the G2/M phase of the cell cycle, while increasing the cells at the G0/G1 phase.

Clinical Outcome of Minor Salivary Gland Cancers in the Oral Cavity: A Comparative Analysis With Squamous Cell Carcinomas of the Oral Cavity

Purpose: Salivary gland cancer (SGC) in the oral cavity is not common and has been less studied in comparison with oral squamous cell carcinoma (SCC). This study aimed to identify the clinical characteristics and outcomes of SGC in the oral cavity compared with oral SCC.

Methods: The medical charts of the patients with SGC (N = 68) arising from minor salivary glands and SCC (N = 750) in the oral cavity between 1995 and 2017 were reviewed retrospectively. The clinical and pathological factors and treatment outcomes were compared to identify clinical differences between oral SGC and SCC in total cases and in tumor size and subsite (propensity score)-matched pairs (N = 68 in each group). In addition, pattern of local invasion was pathologically assessed in a subset of SGC and SCC tumors.

Results: Patients with SGC in the oral cavity showed >90% survival at 5 years. Most common pathologies of SGC were mucoepidermoid carcinoma (39.7%) and adenoid cystic carcinoma (35.3%), where high-grade tumors (including adenoid cystic carcinomas having solid components, grade 2 or 3) represented only 36.8%. Compared with oral SCC, surgery for SGC had narrow surgical safety margin. However, local control was very successful in SGC even with <5 mm or positive resection margin through surgery plus adjuvant radiation treatments or surgery alone for small low-grade tumors. Pathologic analysis revealed that the frequency of oral SGC with infiltrative tumor border was significantly lower than that of oral SCC (46.4 vs. 87.2%, P < 0.001).

Conclusions: SGC in the oral cavity represents relatively good prognosis and has a locally less aggressive pathology compared with oral SCC. Adjuvant radiation can be very effective to control minimal residual disease in oral SGC. Our study proposed that a different treatment strategy for oral SGC would be reasonable in comparison with oral SCC.

IGF2/IGF1R Signaling as a Therapeutic Target in MYB-Positive Adenoid Cystic Carcinomas and Other Fusion Gene-Driven Tumors

Chromosome rearrangements resulting in pathogenetically important gene fusions are a common feature of many cancers. They are often potent oncogenic drivers and have key functions in central cellular processes and pathways and encode transcription factors, transcriptional co-regulators, growth factor receptors, tyrosine kinases, and chromatin modifiers. In addition to being useful diagnostic biomarkers, they are also targets for development of new molecularly targeted therapies. Studies in recent decades have shown that several oncogenic gene fusions interact with the insulin-like growth factor (IGF) signaling pathway. For example, the MYB-NFIB fusion in adenoid cystic carcinoma is regulated by IGF1R through an autocrine loop, and IGF1R is a downstream target of the EWSR1-WT1 and PAX3-FKHR fusions in desmoplastic small round cell tumors and alveolar rhabdomyosarcoma, respectively. Here, we will discuss the mechanisms behind the interactions between oncogenic gene fusions and the IGF signaling pathway. We will also discuss the role of therapeutic inhibition of IGF1R in fusion gene driven malignancies.

Non-primary salivary malignancies: A 22-year retrospective study

PURPOSE

Most salivary gland malignancies are primary tumors, but in our medical center one of six is non-primary. The relative scarcity of such reports justifies studying them.

SUBJECTS & METHODS

We studied patients' demographic and clinical parameters, salivary tumors/metastasis, diagnosis and treatment, and survival rates.

RESULTS

Of all our salivary malignancy patients over the last 22 years, 15% (18/119) had non-primary malignant tumors, all located in the parotid glands. Of these, nine had skin cancer (SCC), 3 malignant solid tumors and 6 hematological systemic malignancies. Four had concomitant second malignancy. Mean age was 70.2 ± 13.8 years, 66.7% of the patients were males, 27.8% were smokers, none reported alcohol use. The most prevalent diagnostic tools used were CT (16 patients), FNA (13) and PET-CT (12). Eleven of 18 patients died from the disease despite receiving therapy: 6 SCC patients, 2 CLL patients and all 3 with solid tumors. All four lymphoma patients survived as did another three SCC patients.

CONCLUSIONS

Chemotherapy and radiotherapy for systemic disease prolonged life rather than surgery. Patients with poor prognosis non-primary salivary tumors should be treated conservatively; surgery should be for those without widespread metastases or systemic disease. Sometimes a palliative patient may benefit from tumor debulking.

Short-term RANKL exposure initiates a neoplastic transcriptional program in the basal epithelium of the murine salivary gland

Although salivary gland cancers comprise only ∼3-6% of head and neck cancers, treatment options for patients with advanced-stage disease are limited. Because of their rarity, salivary gland malignancies are understudied compared to other exocrine tissue cancers. The comparative lack of progress in this cancer field is particularly evident when it comes to our incomplete understanding of the key molecular signals that are causal for the development and/or progression of salivary gland cancers. Using a novel conditional transgenic mouse (K5:RANKL), we demonstrate that Receptor Activator of NFkB Ligand (RANKL) targeted to cytokeratin 5-positive basal epithelial cells of the salivary gland causes aggressive tumorigenesis within a short period of RANKL exposure. Genome-wide transcriptomic analysis reveals that RANKL markedly increases the expression levels of numerous gene families involved in cellular proliferation, migration, and intra- and extra-tumoral communication. Importantly, cross-species comparison of the K5:RANKL transcriptomic dataset with The Cancer Genome Atlas cancer signatures reveals the strongest molecular similarity with cancer subtypes of the human head and neck squamous cell carcinoma. These studies not only provide a much needed transcriptomic resource to mine for novel molecular targets for therapy and/or diagnosis but validates the K5:RANKL transgenic as a preclinical model to further investigate the in vivo oncogenic role of RANKL signaling in salivary gland tumorigenesis.

Down-regulation and nuclear localization of survivin by sodium butyrate induces caspase-dependent apoptosis in human oral mucoepidermoid carcinoma

OBJECTIVE

Sodium butyrate (NaBu) is a histone deacetylase inhibitor that possesses an apoptotic ability. However, the molecular mechanism by which NaBu induces apoptosis in human oral mucoepidermoid carcinoma (MEC), a type of salivary gland tumor, remains unclear.

MATERIALS AND METHODS

The anticancer effects of NaBu and its related molecular mechanisms were determined by trypan blue exclusion assay, 4'-6-diamidino-2-phenylindole staining, live/dead assay, human apoptosis array, RT-PCR, western blotting, immunocytochemistry, preparation of nuclear fractions, and nude mice tumor xenograft.

RESULTS

In this study, we found that NaBu inhibited growth and induced apoptosis in the human oral MEC cell lines MC3 and YD15 with acetylation of histone proteins H2A and H3. NaBu apparently down-regulated survivin protein, as evidenced by the results of the human apoptosis antibody array, and modulated it at the post-translational process. Interestingly, NaBu caused nuclear translocation of survivin protein in both cell lines. NaBu also resulted in decreased expression levels of Bcl-xL mRNA and protein, leading to induction of caspase-dependent apoptosis in human oral MEC cell lines. In addition, NaBu administration inhibited tumor growth in vivo at a dosage of 500 mg/kg/day, but it did not cause any hepatic or renal toxicity.

CONCLUSION

This study provides new insights into the molecular mechanism of apoptotic actions by NaBu in human oral MEC and the basis of its clinical application for the treatment of human oral MEC.

Prognostic value of primary tumor surgery in minor salivary-gland carcinoma patients with distant metastases at diagnosis: first evidence from a SEER-based study

Purpose

The prognostic value of primary tumor surgery (PTS) in minor salivary-gland carcinoma (MiSGC) with distant metastasis (DM) at diagnosis has never been investigated. In this study, we aimed to provide the first evidence.

Patients and methods

The Surveillance, Epidemiology, and End Results (SEER) database was employed to identify MiSGC patients with DM at diagnosis. The prognostic value of PTS was evaluated by Kaplan-Meier methods, log-rank analyses, and multivariate Cox proportional-hazard regression models.

Results

Of the 152 eligible patients included in our study, 50 (32.9%) had undergone PTS. Kaplan-Meier analyses showed that the PTS group had >20% increase in 1- and 2-year overall survival (OS) and cancer-specific survival (CSS) compared with their counterparts without PTS (PTS group vs no-PTS group, 1-year OS 66.1% vs 43.9%, 1-year CSS 69.9% vs 44.9%, 2-year OS 56.6% vs 24.2%, 2-year CSS 59.9% vs 25.7%). Compared with the no-PTS group, multivariate analyses also demonstrated a significantly decreased risk of overall mortality (HR 0.601, 95% CI 0.379-0.952; P=0.031) and cancer-specific mortality (HR 0.547, 95% CI 0.336-0.891; P=0.015) in the PTS group. Subgroup multivariate analyses revealed patients with T1-T3 oropharynx, nasal cavity, or paranasal sinus primary MiSGC, especially adenoid cystic carcinoma, might benefit from PTS (all P<0.05).

Conclusion

PTS is associated with improved survival in highly selected MiSGC patients and may be considered in future clinical practice. However, prospective studies with larger sample size are still necessary to validate our findings.

Facial nerve tractography: A new tool for the detection of perineural spread in parotid cancers

OBJECTIVES

To determine whether facial nerve MR tractography is useful in detecting PeriNeural Spread in parotid cancers.

METHODS

Forty-five participants were enrolled. Thirty patients with surgically managed parotid tumors (15 malignant, 15 benign) were compared with 15 healthy volunteers. All of them had undergone 3T-MRI with diffusion acquisition and post-processing constrained spherical deconvolution-based tractography. Parameters of diffusion-weighted sequences were b-value 1,000 s/mm², 32 directions. Two radiologists performed a blinded visual reading of tractographic maps and graded the facial nerve average pathlength and fractional anisotropy (FA). We also compared diagnostic accuracy of tractography with morphological MRI sequences to detect PeriNeural Spread. Non-parametric methods were used.

RESULTS

Average pathlength was significantly higher in cases with PeriNeural Spread (39.86 mm [Quartile1: 36.27; Quartile3: 51.19]) versus cases without (16.23 mm [12.90; 24.90]), p<0.001. The threshold above which there was a significant association with PeriNeural Spread was set at 27.36 mm (Se: 100%; Sp: 84%; AUC: 0.96, 95% CI 0.904-1). There were no significant differences in FA between groups. Tractography map visual analyses directly displayed PeriNeural Spread in distal neural ramifications with sensitivity of 75%, versus 50% using morphological sequences.

CONCLUSIONS

Tractography could be used to identify facial nerve PeriNeural Spread by parotid cancers.

KEY POINTS

• Tractography could detect facial nerve PeriNeural Spread in parotid cancers. • The average pathlength parameter is increased in case of PeriNeural Spread. • Tractography could map PeriNeural Spread more precisely than conventional imaging.

Management of salivary gland carcinomas - a review

Salivary gland carcinomas are a heterogeneous group of tumors with many histological subtypes which occur in both major and minor salivary glands. However, they have a relatively low of incidence. Their rarity limits study size and the ability to perform phase III trials. Therefore, to date, the entire management is usually varied. Certain published studies have paid more attention to the systemic therapy in the management of metastatic or locally recurrent salivary gland cancer, while little effort has been made to study the entire management for this lesions. Although results of treatment for patients with salivary gland carcinoma have improved in recent years, the treatment of salivary gland cancers is still not standardized. And some patients who haven’t received optimal treatment strategies had a reduced survival. In this review, the topics covered include surgery and radiotherapy, selective neck dissection, chemotherapy, and targeted therapy, which aimed to summarize the optimal management approaches and to develop recommendations for managing this lesions. For these rare cancers, there is also a need for a determined, coordinated effort to conduct high-quality clinical trials.

Recurrent parotid gland carcinoma: how effective is salvage surgery?

OBJECTIVE

Recurrent parotid gland carcinomas (PGCs) are poorly characterized and studies focusing on this topic are rare due to their low incidence. The goal of this study is to analyze the therapeutic strategies, prognostic factors, and oncological outcomes of a series of patients with recurrent PGCs.

PATIENTS AND METHODS

Retrospective chart review (1997-2012) of patients with recurrent PGCs was initially treated with curative intent.

RESULTS

We identified 20 patients with recurrent PGCs. Eleven patients presented isolated local, regional, or distant metastases, while the rest had recurrences in multiple sites. Recurrent tumors tended to present more advanced T-stage (p = 0.01) and overall stage (p < 0.001), but not N-stage (p = 0.74) when compared to the initial tumors. Half the patients (50%) had distant metastases at the moment of recurrence diagnosis, and another three developed them after attempted salvage surgery. Only 8/20 patients with isolated local or regional recurrences were surgically salvaged with extended revision parotidectomy and neck dissection, respectively. The remaining 12 patients were managed on palliative basis. Overall survival (31.70 months vs. 20.73 months) and progression-free survival (28.70 months vs. 13.61 months) were not significantly different in patients managed surgically vs. palliatively.

CONCLUSION

Recurrent PGCs are aggressive neoplasms with a high rate of distant metastases. Surgical salvage can be considered in patients with limited local and/or regional recurrences. The alternative to surgical salvage is palliative management with different chemotherapeutic regimens. Survival does not differ between the two strategies in the present series.

Benign tumors of the parotid gland: a retrospective study of 339 patients

AIM

Among 339 patients operated for benign tumor of the parotid gland: the recurrences and the postoperative complications rates were compared WITH those published in literature.

MATERIALS AND METHODS

About 339 patients operated: 274 primarily and 65 for recurrence or residual tumor.

VARIABLES

sex, age, surgical techniques, pre- or postoperative radiotherapy, histology, size and localization of the tumors, disease free intervals, recurrences and postoperative complications.

RESULTS

177 men and 162 women. Median age: 55 years and mean follow-up: 10.4 years. About 39 patients had adjuvant radiotherapy (11.5%). After primary surgery, four patients experienced recurrences (1.5%). After salvage surgery, eight patients recurred (12.3%). The recurrence rate was the highest among pleomorphic adenomas. Facial paralysis was more frequent after salvage surgery.

DISCUSSION

Recurrence rate 10 years later was lower after primary than after salvage surgery (p = 0.01). There was no relation between adjuvant radiotherapy and recurrence rate probably because the low rate of recurrences.

CONCLUSION

Recurrence rate after primary surgery is lower after superficial or total parotidectomy than after other surgical techniques. Pleomorphic adenomas have the highest rate of recurrences. Age and sex have no significant influence over the rate of recurrences. The most frequent postoperative complications are facial paralysis and Frey's syndrome.

Preoperative evaluation and surgical planning of submandibular gland tumors

BACKGROUND

Roughly half of submandibular gland neoplasms are malignant. Because preoperative information on the nature of these tumors remains limited, both preoperative evaluation and assessment of the extent of primary surgery warrant guidelines that are more accurate.

METHODS

We evaluated the preoperative examinations and management of all submandibular gland neoplasms treated surgically at the Helsinki University Hospital between 2000 and 2010.

RESULTS

Of the 83 tumors, 58 (70%) were benign and 25 (30%) were malignant. Of the benign tumors, 54 (93%) were pleomorphic adenomas. The cytology in 8 patients (10%) was class IV or V, and in 12 patients was class III; the tumors in 9 of these 12 patients turned out to be malignant. Of all malignancies, 10 (40%) required additional more extensive surgery.

CONCLUSION

Ultrasound-guided fine-needle aspiration cytology (FNAC) proved useful, with limitations, in preoperative examination. Surgeons should always obtain wide margins whenever possible, even when clinical means or cytology indicates no malignancy. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1071-1077, 2017.

Invasive myoepithelial carcinoma ex pleomorphic adenoma of the major salivary gland: two case reports

BACKGROUND

Myoepithelial carcinoma (MEC) is a rare salivary gland tumor. Its long-term prognosis remains unknown because of the paucity of reported cases with long-term follow-up. Although some case series exist, the clinical features of MEC vary considerably depending on the site of origin. Therefore, accumulation of these rare cases is important.

CASE PRESENTATION

Case 1: An 89-year-old man presented with a 10-year history of a mass originating from the right parotid gland and involving the neck. The mass grew rapidly for 3 months, reaching approximately 8 cm. There was no facial paralysis. MEC ex pleomorphic adenoma (PA) was suspected. Superficial parotid gland resection was performed in 2013; the tumor grade was pT3N0M0, and the resection margins were free of carcinoma. Because of several high-risk factors for metastasis (i.e., invasive carcinoma ex PA, high MIB1 index, and mutant p53 protein positivity), radiotherapy and chemotherapy were recommended as adjuvant therapy. Although the patient refused adjuvant therapy, he was recurrence-free at 36 months after surgery. Case 2: A 54-year-old woman presented with a >10-year history of a right submandibular mass, which grew rapidly for 1 year, reaching approximately 6 cm. Preoperative diagnosis was PA of the right submandibular gland. Submandibular gland resection was performed in 2013. Pathological analysis revealed invasive MEC ex PA, pT3N0M0; in addition, the carcinoma portion had an extra capsule and had invaded the platysma muscle close to the margin. An MIB1 index of 40 % and mutant p53 protein positivity indicated a high risk for metastasis. Additional resection and right neck dissection revealed no residual carcinoma. The patient refused adjuvant chemotherapy. One year after surgery, metastasis to the right pulmonary hilar node and both lungs were detected. Chemotherapy prevented recurrent growth of the lesion and extended survival. The patient was alive with cancer 30 months after the first surgery.

CONCLUSIONS

High expression of the Ki67 labeling index might reflect prognosis of these cases. Chemotherapy for distant metastasis was effective, as expected. Further accumulation of cases and long follow-up data are needed to elucidate the pathophysiology and prognosis of MEC ex PA.

Lung metastasectomy in adenoid cystic cancer: Is it worth it?

BACKGROUND AND PURPOSE

Adenoid cystic carcinoma (ACC) of salivary glands is characterized by long-term distant metastasis, most commonly in lungs. No agreement has been reached about the role of surgical treatment of pulmonary lesions. We evaluated the long-term results of lung metastasectomy for ACC in order to identify factors that should be taken into account in selecting patients eligible for surgery and treatment planning.

PATIENTS AND METHODS

A retrospective study was conducted on 109 patients selected from our institutional experience and from the International Registry of Lung Metastases. Survival was calculated by Kaplan-Meier estimate and prognostic factors endowed with a predictive power for most other metastatic cancers were investigated.

RESULTS

The cumulative survival was 66.8% at 5years and 40.5% at 10years. In patients with a disease-free interval (DFI) greater than 36months, the overall survival was 76.5% at 5years. Survival in case of complete surgical resection was 69.5% at 5years. Multivariate analysis confirmed DFI and completeness of resection resulted in the best prognostic variables.

DISCUSSION

Lung metastasectomy should be considered as a therapeutic option to achieve local control of disease when 2 conditions are met: (1) complete surgical resection is feasible and (2) the time to pulmonary relapse after primary tumor treatment is greater than 36months. Symptomatic benefits of an incomplete lung resection in slow-growing tumors such as ACC remain uncertain. The turning point in the management of disseminated cancers will be clarified with biological profiling of ACC and the development of targeted therapies.

Therapeutic Inhibition of the MDM2-p53 Interaction Prevents Recurrence of Adenoid Cystic Carcinomas

Purpose: Conventional chemotherapy has modest efficacy in advanced adenoid cystic carcinomas (ACC). Tumor recurrence is a major challenge in the management of ACC patients. Here, we evaluated the antitumor effect of a novel small-molecule inhibitor of the MDM2-p53 interaction (MI-773) combined with cisplatin in patient-derived xenograft (PDX) ACC tumors.Experimental Design: Therapeutic strategies with MI-773 and/or cisplatin were evaluated in SCID mice harboring PDX ACC tumors (UM-PDX-HACC-5) and in low passage primary human ACC cells (UM-HACC-2A, -2B, -5, -6) in vitro The effect of therapy on the fraction of cancer stem cells (CSC) was determined by flow cytometry for ALDH activity and CD44 expression.Results: Combined therapy with MI-773 with cisplatin caused p53 activation, induction of apoptosis, and regression of ACC PDX tumors. Western blots revealed induction of MDM2, p53 and downstream p21 expression, and regulation of apoptosis-related proteins PUMA, BAX, Bcl-2, Bcl-x_L, and active caspase-9 upon MI-773 treatment. Both single-agent MI-773 and MI-773 combined with cisplatin decreased the fraction of CSCs in PDX ACC tumors. Notably, neoadjuvant MI-773 and surgery eliminated tumor recurrences during a postsurgical follow-up of more than 300 days. In contrast, 62.5% of mice that received vehicle control presented with palpable tumor recurrences within this time period (P = 0.0097).Conclusions: Collectively, these data demonstrate that therapeutic inhibition of MDM2-p53 interaction by MI-773 decreased the CSC fraction, sensitized ACC xenograft tumors to cisplatin, and eliminated tumor recurrence. These results suggest that patients with ACC might benefit from the therapeutic inhibition of the MDM2-p53 interaction. Clin Cancer Res; 23(4); 1036-48. ©2016 AACR.

Treatment outcome of ion beam therapy in eight patients with head and neck cancers

Ion beam therapy has enabled us to treat formerly untreatable malignant tumors. The aim of the present study was to investigate the long-term follow-up course of patients with head and neck cancers who received ion beam therapy. The subjects were 8 patients (3 men and 5 women aged 43-78 years) with head and neck cancers who visited our department from 2006 to 2015 and received ion beam therapy. Six patients received carbon ion beam therapy, and the other two patients received proton beam therapy. The medical records of the patients were retrospectively analyzed. The primary site was the nasal and paranasal sinuses in six cases, nasopharynx in one case, and external auditory canal in one case. The histological type was olfactory neuroblastoma, malignant melanoma, and adenoid cystic carcinoma in two cases each, and chondrosarcoma and squamous cell carcinoma in one case each. The exposure dose ranged from 64 to 70.4 GyE. The average follow-up period was 42.0 months. Early adverse events were generally mild, and complete therapeutic response was obtained in all cases. However, five patients developed severe late complications including craniospinal dissemination, osteoradionecrosis of the maxilla and skull base, brain necrosis, and loss of eyesight. Three patients died of distant metastasis, local recurrence and/or brain necrosis within 2 years, and four patients have been surviving with distant metastasis or severe late complications. Ion beam therapy exhibits outstanding antitumor effects, but the severe late complications of the therapy must also be recognized.

The landscape of gene fusions and somatic mutations in salivary gland neoplasms - Implications for diagnosis and therapy

Recent studies of the genomic landscape of salivary gland tumors have provided important insights into the molecular pathogenesis of these tumors. The most consistent alterations identified include a translocation-generated gene fusion network involving transcription factors, transcriptional coactivators, tyrosine kinase receptors, and other kinases. In addition, next-generation sequencing studies of a few subtypes of salivary neoplasms have revealed hotspot mutations in individual genes and mutations clustering to specific pathways frequently altered in cancer. Although limited, these studies have opened up new avenues for improved classification and targeted therapies of salivary gland cancers. In this review, we summarize the latest developments in this field, focusing on tumor types for which clinically important molecular data are available.

Anti-tumor effect of inhibition of IL-6 signaling in mucoepidermoid carcinoma

Mucoepidermoid carcinoma (MEC) is the most frequent malignant salivary gland cancer. Response to chemoradiotherapy is modest, and therefore radical surgery remains the standard-of-care. Emerging evidence suggests that Interleukin (IL)-6 signaling correlates with the survival of cancer stem cells and resistance to therapy. Here, we investigated whether inhibition of IL-6 receptor (IL-6R) signaling with tocilizumab (humanized anti-human IL-6R antibody) sensitizes MEC to chemotherapy using human mucoepidermoid carcinoma cell lines (UM-HMC) and correspondent xenograft models. In vitro, we observed that tocilizumab inhibited STAT3 phosphorylation but had no measurable effect in MEC cell viability (UM-HMC-1,-3A,-3B). In contrast, the anti-tumor effect of single agent tocilizumab on MEC xenografts was comparable to paclitaxel or cisplatin. Combination of tocilizumab with cisplatin or paclitaxel enhanced the inhibitory effect of chemotherapy on xenograft growth (P < 0.05), time to failure (P < 0.01), decreased vascular endothelial growth factor (VEGF) expression and tumor microvessel density (P < 0.05) without added systemic toxicities. Notably, tocilizumab decreased the fraction of MEC cancer stem cells (ALDH(high)CD44(high)) in vitro, and prevented paclitaxel-induced increase in the fraction of cancer stem cells in vivo (P < 0.05). Collectively, these findings demonstrate that tocilizumab enhances the anti-tumor effect of conventional chemotherapy in preclinical models of mucoepidermoid carcinoma, and suggest that patients might benefit from combination therapy with an inhibitor of IL-6R signaling and chemotherapeutic agent such as paclitaxel.

Mutational landscape of lacrimal gland carcinomas and implications for treatment

BACKGROUND

Lacrimal gland carcinomas are rare. Identification of molecular abnormalities underlying lacrimal gland carcinogenesis is critical to the development of new targeted therapies for lacrimal gland carcinomas. The purpose of our study was to look for mutations that can be targeted as new treatments for lacrimal gland carcinomas.

METHODS

Genomic DNA from patients with lacrimal gland epithelial neoplasms was analyzed. The Sequenom matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass ARRAY platform was used to profile 168 common oncogenic point mutations in 40 genes. Mutation frequency was assessed overall and by histologic diagnosis. These genetic mutations were then correlated with clinical outcomes in the patients.

RESULTS

The study included 14 men and 10 women with a median age of 45 years (range, 17-75 years). The histologic diagnoses were as follows: adenoid cystic carcinoma (n = 16), low-grade carcinoma ex pleomorphic adenoma (n = 2), high-grade carcinoma ex pleomorphic adenoma (n = 2), squamous carcinoma (n = 1), and pleomorphic adenoma (n = 3). Analysis revealed 18 oncogenic mutations in 13 patients: KRAS mutations in 10 patients (46%), NRAS mutations in 2 patients (8%), MET mutations in 3 patients (13%), PIK3CA mutation in 1 patient (4%), and BRAF mutation in no patients. About half of the patients with adenoid cystic carcinoma had oncogenic mutations (7 of 16; 44%). Of the 16 patients with adenoid cystic carcinoma, 5 had KRAS mutations, 1 had MET mutations, and 1 had an NRAS mutation.

CONCLUSION

KRAS, NRAS, and MET mutations are frequent in epithelial neoplasms of the lacrimal gland, with the highest rate of mutations found in adenoid cystic carcinoma. Therapies targeting these genes may be effective treatments for lacrimal gland carcinomas. © 2015 Wiley Periodicals, Head Neck 38: E-E, 2016.

Reconstruction of facial nerve after radical parotidectomy

CONCLUSION

Most patients benefitted from immediate facial nerve grafting after radical parotidectomy. Even weak movement is valuable and can be augmented with secondary static operations. Post-operative radiotherapy does not seem to affect the final outcome of facial function.

OBJECTIVES

During radical parotidectomy, the sacrifice of the facial nerve results in severe disfigurement of the face. Data on the principles and outcome of facial nerve reconstruction and reanimation after radical parotidectomy are limited and no consensus exists on the best practice.

METHOD

This study retrospectively reviewed all patients having undergone radical parotidectomy and immediate facial nerve reconstruction with a free, non-vascularized nerve graft at the Helsinki University Hospital, Helsinki, Finland during the years 1990-2010. There were 31 patients (18 male; mean age = 54.7 years; range = 30-82) and 23 of them had a sufficient follow-up time.

RESULTS

Facial nerve function recovery was seen in 18 (78%) of the 23 patients with a minimum of 2-year follow-up and adequate reporting available. Only slight facial movement was observed in five (22%), moderate or good movement in nine (39%), and excellent movement in four (17%) patients. Twenty-two (74%) patients received post-operative radiotherapy and 16 (70%) of them had some recovery of facial nerve function. Nineteen (61%) patients needed secondary static reanimation of the face.

Technical guidelines for head and neck cancer IMRT on behalf of the Italian association of radiation oncology - head and neck working group

Performing intensity-modulated radiotherapy (IMRT) on head and neck cancer patients (HNCPs) requires robust training and experience. Thus, in 2011, the Head and Neck Cancer Working Group (HNCWG) of the Italian Association of Radiation Oncology (AIRO) organized a study group with the aim to run a literature review to outline clinical practice recommendations, to suggest technical solutions and to advise target volumes and doses selection for head and neck cancer IMRT. The main purpose was therefore to standardize the technical approach of radiation oncologists in this context. The following paper describes the results of this working group. Volumes, techniques/strategies and dosage were summarized for each head-and-neck site and subsite according to international guidelines or after reaching a consensus in case of weak literature evidence.

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.

Characterization of tumorigenic cell lines from the recurrence and lymph node metastasis of a human salivary mucoepidermoid carcinoma

The long-term outcome of patients with mucoepidermoid carcinoma is poor. Limited availability of cell lines and lack of xenograft models is considered a major barrier to improved mechanistic understanding of this disease and development of effective therapies.

OBJECTIVE

To generate and characterize human mucoepidermoid carcinoma cell lines and xenograft models suitable for mechanistic and translational studies.

METHODS

Five human mucoepidermoid carcinoma specimens were available for generation of cell lines. Cell line tumorigenic potential was assessed by transplantation and serial in vivo passaging in immunodeficient mice, and cell line authenticity verified by short tandem repeat (STR) profiling.

RESULTS

A unique pair of mucoepidermoid carcinoma cell lines was established from a local recurrence (UM-HMC-3A) and from the metastatic lymph node (UM-HMC-3B) of the same patient, 4 years after surgical removal of the primary tumor. These cell lines retained epithelial-like morphology through 100 passages in vitro, contain the Crtc1-Maml2 fusion oncogene (characteristic of mucoepidermoid carcinomas), and express the prototypic target of this fusion (NR4A2). Both cell lines generated xenograft tumors when transplanted into immunodeficient mice. Notably, the xenografts exhibited histological features and Periodic Acid Schiff (PAS) staining patterns that closely resembled those found in human tumors. STR profiling confirmed the origin and authenticity of these cell lines.

CONCLUSION

These data demonstrate the generation and characterization of a pair of tumorigenic salivary mucoepidermoid carcinoma cell lines representative of recurrence and lymph node metastasis. Such models are useful for mechanistic and translational studies that might contribute to the discovery of new therapies for mucoepidermoid carcinoma.

Prognostic significance of PDCD4 expression in human salivary adenoid cystic carcinoma

Programmed cell death 4 (PDCD4) has been recognized as a tumor suppressor gene that may inhibit neoplastic transformation and tumor promotion/progression. It was demonstrated that PDCD4 expression was associated with prognosis of multiple types of tumors and cancers. However, PDCD4 expression in salivary adenoid cystic carcinoma (ACC) has not been studied. We analyzed PDCD4 protein level by immunohistochemistry in 96 cases of ACC and found that PDCD4 expression was downregulated in 64.6 % (62/96) of tumor samples compared with adjacent nontumor salivary gland tissues. Moreover, decreased PDCD4 expression was significantly associated with clinical stage of the disease (P < 0.01). Analyses of overall survival and disease-specific survival by Kaplan-Meier method revealed that poor prognosis of ACC patients was associated with decreased PDCD4 expression (χ (2) = 5.971, P = 0.013; χ (2) = 4.274, P = 0.029). Furthermore, multivariate Cox model analysis demonstrated that PDCD4 expression was an independent risk factor for ACC (P < 0.05). Thus, our study suggested, for the first time, that PDCD4 expression might have an essential role in the progression of ACC.