Detection of salivary gland and sinonasal fusions by a next-generation sequencing based, ligation-dependent, multiplex RT-PCR assay

AIMS

The discovery of tumour type-specific gene fusion oncogenes in benign and malignant salivary gland and sinonasal (SGSN) tumours has significantly increased our knowledge about their molecular pathology and classification.

METHODS AND RESULTS

We developed a new targeted multiplexed next-generation sequencing (NGS)-based method that utilizes ligation dependent reverse-transcriptase polymerase chain reaction (LD-RT-PCR) to detect oncogenic fusion transcripts involving 116 genes, leading to 96 gene fusions known to be recurrently rearranged in these tumours. In all, 180 SGSN tumours (formalin-fixed, paraffin-embedded samples, 141 specimens and 39 core needle biopsies) from the REFCORpath (French network for rare head and neck cancers) with previously identified fusion genes by fluorescent in situ hybridisation (FISH), RT-PCR, or molecular immunohistochemistry were selected to test its specificity and sensitivity and validate its diagnostic use. Tested tumours encompassed 14 major tumours types, including secretory carcinoma, mucoepidermoid carcinoma, adenoid cystic carcinoma, salivary gland intraductal carcinoma, clear cell carcinoma, pleomorphic adenoma, adamantinoma-like Ewing Sarcoma, EWSR1::COLCA2 sinonasal sarcoma, DEK::AFF2 sinonasal carcinoma, and biphenotypic sinonasal sarcoma. In-frame fusion transcripts were detected in 97.8% of cases (176/180). Gene fusion assay results correlated with conventional techniques (immunohistochemistry [IHC], FISH, and RT-PCR) in 176/180 tumours (97.8%).

CONCLUSION

This targeted multiplexed NGS-based LD-RT-PCR method is a robust, highly sensitive method for the detection of recurrent gene fusions from routine clinical SGSN tumours. It can be easily customized to cover new fusions. These results are promising for implementing an integrated NGS system to rapidly detect genetic aberrations, facilitating accurate, genomics-based diagnoses, and accelerate time to precision therapies in SGSN tumours.

Differentiation of various salivary gland tumours using diffusion-weighted MRI and dynamic contrast-enhanced MRI

Purpose

To determine the role of functional magnetic resonance imaging techniques (diffusion-weighted magnetic resonance imaging [DW-MRI] and dynamic contrast-enhanced magnetic resonance imaging [DCE-MRI]) in the differentiation of various salivary gland tumours.

Material and methods

In this prospective study, we evaluated 32 patients with salivary gland tumours using functional MRI. Diffusion parameters (mean apparent diffusion coefficient [ADC], normalized ADC and homogeneity index [HI]),semiquantitative DCE parameters (time signal intensity curves [TICs]) and quantitative DCE parameters (K_ep, K_trans and V_e) were analysed. Diagnostic efficiencies of all these parameters were determined to differentiate benign and malignant tumours as well as to characterize 3 major subgroups of salivary gland tumours, namely pleomorphic adenoma, Warthin tumour, and malignant tumours.

Results

Mean ADC, normalized ADC and HI were insignificant in differentiating benign and malignant tumours but were significant in differentiating pleomorphic adenomas, Warthin tumours, and malignant tumours. Mean ADC was the best parameter in predicting both pleomorphic adenomas and Warthin tumours (AUC: 0.95 and 0.89, respectively). Amongst DCE parameters, only TIC pattern could differentiate between benign and malignant tumours, with an accuracy of 93.75% (AUC: 0.94). The quantitative perfusion parameters aided greatly in characterizing pleomorphic adenomas, Warthin tumours and malignant tumours. For predicting pleomorphic adenomas, the accuracy of K_ep and K_trans was 96.77% (AUC: 0.98) and 93.55% (AUC: 0.95), respectively and for predicting Warthin tumours, the accuracy of both K_ep and K_trans was 96.77% (AUC: 0.97).

Conclusions

DCE parameters (particularly TIC, K_ep and K_trans) had higher accuracy in characterizing various tumour subgroups (pleomorphic adenomas, Warthin tumours, and malignant tumours) than DWI parameters. Hence, dynamic contrast-enhanced imaging adds immense value with only a minimum time penalty to the examination.

Methylation of tumour suppressor genes in benign and malignant salivary gland tumours: a systematic review and meta-analysis

The aim of the present systematic review was to critically analyse the relationship between tumour suppressor genes (TSGs) promoter methylation, a potent mechanism of gene silencing, and the development of salivary gland tumours, as well as the possible effect on clinical/histological characteristics. Review protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database (registration ID CRD42020218511). A comprehensive search of Web of Science, Scopus, PubMed, and Cochrane Central Register of Controlled Trials was performed utilizing relevant key terms, supplemented by a search of grey literature. Newcastle-Ottawa Quality Assessment Scale (NOQAS) was used for the quality assessment of included studies. Sixteen cross-sectional and 12 case-control studies were included in the review, predominantly dealing with methylation in TSGs related to DNA repair, cell cycle, and cell growth regulation and differentiation. Quantitative synthesis could be performed on P16 (inhibitor of cyclin-dependent kinase 4a), RASSF1A (Ras association domain family 1 isoform A) and MGMT (O6-methylguanine DNA methyltransferase) genes only. It showed that P16 and RASSF1A genes were more frequently methylated in salivary gland tumours compared to controls (P = .0002 and P < .0001, respectively), while no significant difference was observed for MGMT. Additionally, P16 did not appear to be related to malignant transformation of pleomorphic adenomas (P = .330). In conclusion, TSG methylation is involved in salivary gland tumour pathogenesis and several genes might play a considerable role. Further studies are needed for a better understanding of complex epigenetic deregulation during salivary gland tumour development and progression.

Centromere Protein F (CENPF): A novel marker for salivary gland pathology

Background

Salivary gland tumours are relatively uncommon, and there exists considerable diagnostic difficulty. This is due to individual lesions having diverse histopathological features, presence of number of types and variants, and overlapping histological features in different tumour entities.

Aim

The current study aimed at assessing the expression of centromere protein F (CENPF) in benign and malignant salivary gland tumours and to evaluate the efficacy of CENPF as a proliferative marker to aid in the diagnosis of malignancy so that it will help in surgical pathology practice.

Materials and Methods

The study group involved 20 cases of benign salivary gland tumours, 20 cases of malignant salivary gland tumours, and 10 normal salivary gland tissues. All the cases were subjected to immunohistochemical analysis for CENPF expression and were assessed by two independent observers and further taken up for evaluation.

Statistical Analysis

The results were analysed statistically among different groups using analysis of variance (ANOVA) or Kruskal-Wallis test with Chi-squared test using IBM's Statistical Package for the Social Sciences (SPSS) version 17.0.

Results

CENPF expression in normal salivary gland was negative with gradual increase in expression from benign salivary gland tumours to malignant salivary gland tumours. CENPF expression was high in malignant salivary gland tumours.

Conclusion

Findings of the study suggest that CENPF can be regarded as a new cell proliferation marker for malignant salivary gland tumours.

Adenoid cystic carcinoma. An indolent but aggressive tumour. Part A: from aetiopathogenesis to diagnosis

Adenoid cystic carcinoma (ACC) is a relatively rare tumour of the minor and major salivary glands. It is uncommon in the parotid gland while it is much more frequent in the submandibular gland and in minor salivary and mucinous glands (oral cavity, oropharynx, and paranasal sinuses). ACC may also arise in secretory glands located in other tissues, such as in the tracheobronchial tree, oesophagus, breast, lungs, prostate, uterine cervix, lachrymal and Bartholin’s glands, and skin. The natural history of ACC is characterised by an indolent growth rate, a relatively low probability of regional lymph node metastases and a high likelihood of haematogenous dissemination. ACC has been traditionally subdivided into three histological groups (cribriform, tubular, and solid) based on solid components of the tumour. Some studies have shown that tumours with a solid growth component have a rapid fatal course, compared to tumours without a solid growth component, but other studies have failed to correlate growth patterns with clinical course. The purpose of this review is to analyse the very large number of studies (sometimes contradictory) on ACC. In this first part, the aetiology, epidemiology, histopathology, clinical behaviour and diagnostic workup are examined.

First results of the EORTC-SPECTA/Arcagen study exploring the genomics of rare cancers in collaboration with the European reference network EURACAN

PURPOSE

Rare cancers are defined by an incidence of <6 out of 100 000 cases per year. They are under-represented in clinical research including tumour molecular analysis. The aim of Arcagen is to generate a multinational database integrating clinical and molecular information of patients with rare cancers.

PATIENTS AND METHODS

We present the retrospective feasibility cohort of patients with rare cancers, with previously collected tumour samples available from any stage. Molecular analysis was performed using FoundationOne CDx for all histologies except for sarcoma where FoundationOne Heme was used. Clinical data including demographic data, medical history, malignant history, treatment and survival data were collected.

RESULTS

Eighty-seven patients from three centres were screened; molecular data were obtained for 77 patients (41 sarcomas, 9 yolk sac tumours, 14 rare head and neck cancers, 13 thymomas). The median age at the time of diagnosis was 48 (range 28-85). Most patients had reportable genomic alterations (89%). The most common alterations were linked to cell cycle regulation (TP53, RB1, CDKN2A/B deletions and MDM2 amplification). Multiple activating single-nucleotide variants (SNVs) could be detected in the RAS/RAF family. The tumour mutational burden status was globally low across all samples with a median of 3 Muts/MB (range 0-52). Only 4 cases (ie, 4.7% of tumours) had direct actionable mutations for a treatment approved in Europe within the patient's tumour type.

CONCLUSION

The Arcagen project aims to bridge the gap and improve knowledge of the molecular landscape of rare cancers by prospectively recruiting up to 1000 patients.

Acinic cell carcinoma of the salivary gland in the adult and paediatric population: a survival analysis

BACKGROUND

Acinic cell carcinoma (AcCC) is a rare malignant neoplasm of the salivary glands and generally considered to be a low-grade tumour. Surgical treatment is often curative, but a more aggressive high-grade variant has been associated with poorer survival and propensity for distant metastasis. No standard treatment guidelines exist and the approach to treatment is varied in the published series. The aim of this study is to present the experience of three major hospitals in Sydney, Australia, in treating AcCC of the salivary gland, with a focus on clinico-pathological features of disease and their associations with survival outcomes.

METHODS

Adult and paediatric cases of AcCC of the salivary gland during the time period 1979-2018 were retrospectively included. Demographic, clinico-pathological, treatment and survival outcome data were extracted. Survival analysis was undertaken to assess the effect of clinical and pathological variables on overall and disease-free survival.

RESULTS

Thirty-two cases were reviewed (29 adult and three paediatric). Thirty tumours (93.8%) were parotid gland primary tumours. Mean overall and disease-free survival was 17.0 ± 0.7 and 16.0 ± 0.9 years, respectively. Features associated with poorer survival were cT staging >1, presence of preoperative clinical facial nerve deficit and local recurrence. Positive margins were associated with recurrence.

CONCLUSION

These data suggest that disease-free and overall survival in AcCC of the salivary gland is excellent with surgery as the first-line treatment. Poor survival outcomes are uncommon and may be associated with locally advanced disease in the presence of other well-established high-risk features.

High CXCR4 expression in adenoid cystic carcinoma of the head and neck is associated with increased risk of locoregional recurrence

AIM

Treatment options for head and neck adenoid cystic carcinoma (AdCC) are limited in advanced disease. Chemokine receptor type 4 (CXCR4) is present in various tumour types, including AdCC. Upregulation is associated with tumour recurrence and metastasis. New CXCR4-specific diagnostic and therapeutic target agents have recently been available. This study aimed to analyse CXCR4 expression in a cohort of primary head and neck AdCC.

METHODS

After histopathological revision, tumour tissues of 73 consecutive patients with AdCC over 1990-2016 were sampled on a tissue microarray. Slides were immunohistochemically stained for CXCR4 and semiquantitatively scored. Associations between protein expression and cliniopathological parameters were tested. HRs were calculated using a Cox proportional hazard model.

RESULTS

Sixty-six tumours could be analysed. CXCR4 expression was present in 81% of the tumours with a median of 29% (IQR 1-70) positive cells. Expression was univariately correlated to perineural growth (Spearman ρ .26, p=0.04) and bone invasion (Spearman ρ .32, p=0.01), but not with tumour grade.CXCR4 expression in the primary tumour was significantly higher in tumours that recurred as compared with those that did not recur (median 60%, IQR 33-72 vs 12%, IQR 1-70, Kruskal-Wallis p=0.01). After dichotomisation, >25% of CXCR4 expressions proved an independent prognosticator for a reduced recurrence-free survival (RFS) (HR 7.2, 95% CI 1.5 to 72.4, p=0.04).

CONCLUSION

CXCR4 is expressed in the majority of primary AdCCs and independently correlated to worse RFS, suggesting CXCR4 as a target for imaging and therapy purposes in patients with advanced AdCC.

Prognostic value of CRTC1-MAML2 translocation in salivary mucoepidermoid carcinoma: Systematic review and meta-analysis

The presence of the CRTC1-MAML2 translocation has been described in mucoepidermoid carcinoma (MEC) as a predictor of better survival rates. However, the real prognostic value of the translocation has been debated due to recent controversial findings. The aim of this study was to perform a systematic review to understand the prognostic potential of the CRTC1-MAML2 translocation in MEC. An electronic search was carried out using the MEDLINE/PubMed, EMBASE and Scopus databases. Articles that assessed the association between the CRTC1-MAML2 translocation and survival of MEC patients were selected for the systematic review. Ten published articles were included in the qualitative synthesis. The prevalence of the translocation varied from 33.7% to 69.7%. Seven studies observed a significant association between the presence of the CRTC1-MAML2 translocation and a favourable clinical outcome, which could improve disease-free, disease-specific or overall survival. Five studies were included in the quantitative synthesis. Fixed-effects model confirmed that translocation-positive patients have a decreased risk of death (combined odds ratio 0.08, 95% confidence interval - 0.03-0.23, P < .00001). The detection of the CRTC1-MAML2 translocation appears to be useful as a prognostic factor in MEC. However, the level of evidence is not as high as it could be once important limitations were found in the published studies.

Complications of radio- and radiochemotherapy in patients undergoing major salivary gland cancer surgery

PURPOSE

The aim of this retrospective study was to present the prevalence of early and late radiation-induced reaction and factors affecting its formation and severity in patients after adjuvant radio- or radiochemotherapy in salivary gland cancer.

MATERIAL AND METHODS

A total of 113 patients with early and 91 with late radiation-induced reaction, irradiated in 2006-2016 were enrolled in the study. The frequency of acute mucosal radiation-induced reaction, time of onset, intensity, healing time, as well as the incidence of late radiation-induced reaction from the skin and subcutaneous tissue were analyzed. Factors that could influence the development and intensity of reaction were identified.

RESULTS

Acute severity and the presence of late radiation-induced reaction do not affect overall survival. Dosage in the tumor bed site, as well as the dosage in the nodal region, affect the severity of the acute radiation-induced mucosal reaction. The severity of the early radiation-induced reaction is higher in men, more advanced patients (higher T and N+ in TNM classification), irradiated into a larger area, and those in whom two-dimensional planning and complementary chemoradiotherapy were applied. The late reaction of the skin and subcutaneous tissue was dominated by patients irradiated in the nodal regions and those with a higher intensity of early radiation-induced reaction.

CONCLUSIONS

Supplementary radiotherapy or radiochemotherapy in salivary gland cancer is associated with acceptable toxicity which has no effect on overall survival.

Management of accessory parotid gland tumours: 32-year experience from a single institution and review of the literature

Accessory parotid gland tumours (APGTs) are very rare. Regarding their anatomical location, an adequate surgical approach is necessary to provide safe resection and satisfactory postoperative results. The aims of this study were to present our tertiary centre experience in surgical treatment and management of APGTs and to review the literature regarding their treatment, particularly in terms of surgical modalities. Data of 13 patients with primarily surgically treated APGTs have been collected and analysed. Well-documented English-literature articles of surgically treated APGTs have been extracted from the PubMed, Scopus and Web of Science databases ending in May 2018, and analysed. Mean age at diagnosis was 41.1 years. The most common benign histological subtype was pleomorphic adenoma (53.8%), while mucoepidermoid carcinoma (23.1%) was most common in malignant counterparts. The malignancy rate was 38.5%. Postoperative results were satisfactory, and the follow-up period was uneventful in all patients except one who died of locoregional recurrence. A total of 57 papers with reported series in APGTs have been identified with a total of 306 APGT cases. From oncological, functional and aesthetic standpoints, approaches through a standard parotidectomy provide satisfactory results.

Warthin's tumour in oral and maxillofacial regions: an 18-year retrospective study of 1084 cases in an eastern-Chinese population

There is little information in the English-language literature regarding Warthin's tumour (WT) in the eastern-Chinese population. A large retrospective study (1084 primary tumours over a period of 18years) was carried out to investigate the clinicopathological features (patients' gender, age and tumour location) of these tumours in this population. A total of 994 (91.7%) patients were male and 90 (8.3%) were female, with a male/female ratio of 11:1. The mean age was 56.48years (range 20-89years), with a peak incidence in the fifth to seventh decade (82.1%). The favorite primary site of the tumour was the parotid gland (n=1055), followed by intra-/peri-parotid lymph nodes (n=13), upper neck (n=10), submandibular gland (n=4) and upper lip (n=1). Multifocal WTs arose in 9.5% (103 patients) of cases whereas bilateral multifocal WTs were found in 0.65% (seven patients). In 24 (2.2%) patients, WT were found to coexist with other different types of neoplasm synchronously. The most common subtype of metaplasia was the squamous metaplasia (166/250, 66.4%). The usual treatment measure is (bilateral) superficial parotidectomy and the patients should be followed long term, in view of possible metachronous WT, even after prolonged time intervals.

Prognostic factors in head and neck mucoepidermoid carcinoma: experience at a single institution based on 64 consecutive patients over a 28-year period

Mucoepidermoid carcinoma (MEC) is the most common malignancy of the salivary glands. The clinical behaviour of MEC is largely unpredictable, ranging from indolent tumour growth to highly aggressive metastatic spread. The objective of this study was to determine the clinicopathological predictors of recurrence and survival in patients with head and neck MEC. The medical records of 64 patients who underwent surgical treatment for head and neck MEC between 1982 and 2010 were reviewed. The main outcome measures were disease-free survival (DFS) and overall survival (OS). Clinicopathological parameters evaluated were age, sex, anatomical subsite, histological grade, tumour stage, tumour size, adjuvant therapy, and nodal and margin status. For the entire cohort, the 5-year DFS was 82.8% and the 5-year OS was 67.2%. Histological grade and tumour subsite were statistically significant predictors of OS. Furthermore, tumour stage and nodal status were statistically significant predictors with respect to OS. Advanced tumour stage, high histological grade, submandibular/sublingual localization, and positive nodal status were independent predictors of the prognosis in patients with head and neck MEC. Further studies into the molecular biology of MEC are needed in order to provide new therapeutic strategies for patients with locally aggressive and highly metastatic carcinomas.

Particular aspects in the cytogenetics and molecular biology of salivary gland tumours - current review of reports

Salivary gland tumours are a group of lesions whose heterogeneity of biological and pathological features is widely reflected in the molecular aspect. This is demonstrated by an increasing number of studies in the field of genetics of these tumours.

The aim of this study was to collect the most significant scientific reports on the cytogenetic and molecular data concerning these tumours, which might facilitate the identification of potential biomarkers and therapeutic targets. The analysis covered 71 papers included in the PubMed database. We focused on the most common tumours, such as pleomorphic adenoma, Warthin tumour, mucoepidermoid carcinoma, and others. The aim of this study is to present current knowledge about widely explored genotypic alterations (such as PLAG1 gene in pleomorphic adenoma or MECT1 gene in mucoepidermoid carcinoma), and also about rare markers, like Mena or SOX10 protein, which might also be associated with tumourigenesis and carcinogenesis of these tumours.

Lack of PRKD2 and PRKD3 kinase domain somatic mutations in PRKD1 wild-type classic polymorphous low-grade adenocarcinomas of the salivary gland

AIMS

Polymorphous low-grade adenocarcinoma (PLGA) is the second most common intra-oral salivary gland malignancy. The vast majority of PLGAs harbour a PRKD1 E710D hot-spot somatic mutation or somatic rearrangements of PRKD1, PRKD2 or PRKD3. Given the kinase domain homology among PRKD1, PRKD2 and PRKD3, we sought to define whether PLGAs lacking PRKD1 somatic mutations or PRKD gene family rearrangements would be driven by somatic mutations affecting the kinase domains of PRKD2 or PRKD3.

METHODS AND RESULTS

DNA was extracted from eight microdissected PLGAs lacking PRKD1 somatic mutations or PRKD gene family rearrangements. Samples were thoroughly centrally reviewed, microdissected and subjected to Sanger sequencing of the kinase domains of the PRKD2 and PRKD3 genes. None of the PLGAs lacking PRKD1 somatic mutations or PRKD gene family rearrangements harboured somatic mutations in the kinase domains of the PRKD2 or PRKD3 genes.

CONCLUSION

PLGAs lacking PRKD1 somatic mutations or PRKD gene family rearrangements are unlikely to harbour somatic mutations in the kinase domains of PRKD2 or PRKD3. Further studies are warranted to define the driver genetic events in this subgroup of PLGAs.

Adenoid cystic carcinoma of the maxillary sinus: a clinical-pathological report of 10 years of experience from a single institution

Adenoid cystic carcinoma (ACC) is the most common malignant salivary gland tumour of the maxillary sinus. The present study describes 24 cases seen over a period of 10 years at the Brazilian National Cancer Institute. Socio-demographic, clinical, pathological, and follow-up data were retrieved from the medical files for the period 1997-2006. The mean age of the patients was 51.1 years. Twenty-one (87.5%) presented advanced tumours. The main signs and symptoms found were a tumour mass (87.5%), pain (50%), nasal obstruction (25%), and epistaxis (20.8%). Most cases (62.5%) were treated with surgery and radiation therapy. Follow-up data showed two patients (8.3%) with residual disease, local recurrences in four (16.7%) patients, and distant metastasis in five (20.8%). The overall 5- and 10-year survival rates were 72.61% and 62.11%, respectively. Maxillary sinus ACC has an aggressive but indolent behaviour, typically presenting at an advanced T stage that reflects a poor prognosis for patients.

Vascular endothelial growth factor (VEGF) expression and microvascular density in salivary gland tumours

This study investigates whether salivary tumours with different morphology and evolution also differ in terms of neovascularization and VEGF expression and the prognostic value of the results. Surgical specimens from 45 patients - 8 pleomorphic adenomas (PA), 7 Warthin tumours (WT), 5 basal cell adenomas (BA), 6 carcinomas ex-pleomorphic adenoma (CEPA), 6 mucoepidermoid carcinomas (MEC), 5 acinic cell carcinomas (AC), 4 adenoid cystic carcinomas (ACC) and 4 adenocarcinomas not otherwise specified (ADK NOS) - were immunostained. In malignant salivary tumours, the following mean microvascular density (MVD) values were recorded (± SD = Standard Deviation): 27.61 (SD ± 2.27) in cases with CEPA, 27.08 (DS ± 7.81) in AC and 32.93 (SD ± 7.76) in ADK NOS, with lower values for MEC 24.31(SD ± 2.88) and for ACC 22.13 (SD ± 5.44). For benign tumours, an MVD of 35.71 (SD ± 2.09) was recorded in WT and lower average values in PA (MVD = 14.84; SD ± 4.86) and in BA (MVD = 23.96; SD ± 9.13). MVD did not correlate with the investigated clinicopathological parameters. The VEGF expression is significantly more important (p = 0.001) in malignant salivary tumours as compared with benign ones. The VEGF expression and the microvascularization in salivary gland tumours are important elements to be considered when formulating a diagnosis and assessing case evolutions in patients with such tumours.

Immunohistochemical expression of oestrogen receptor-α and progesterone receptor in salivary gland tumours

BACKGROUND

The mammary and salivary glands are tubulo-acinar exocrine glands, sharing similar morphological characteristics and tumour histology. It is logical to postulate that they may have similar tumour biology. This study was carried out to define the expression of oestrogen-α (ER-α) and progesterone (PR) in salivary gland tumours (SGTs) presenting at the University College Hospital, Ibadan.

METHODS

Formalin-fixed, paraffin-embedded tissue samples of different salivary gland neoplasms were processed for antibodies to ER-α and PR using the specifications of the manufacturer. Two independent investigators reviewed the slides scoring the pattern and intensity of staining as follows: negative (0), weakly positive (+1), moderately positive (+2) and strongly positive (+3). Data were analysed using version 16 of the Statistical Package for Social Sciences (SPSS16). The level of significance was set at P < 0.05.

RESULTS

A total of 40 SGTs from 19 males (47.5%) and 21 females (52.5%) were utilised. There were 15 benign and 25 malignant SGTs. ER expression in benign SGTs was 6.7%, while in malignant SGTs, it was 28.0%. There was no statistically significant difference in the gender and mean age distribution between patients with or without positive ER-α expression (χ(2) = 0.37, P = 0.59 Fisher's exact test; t = 0.054, P = 0.96, respectively). About 66.7% of high-grade SGTs was positive for ER while only 20% of the low-grade lesions were positive.

CONCLUSION

This study showed that ER-α was expressed more in the high-grade malignant SGTs compared with the low-grade malignant SGTs and the benign SGTs.