MYB RNA detection by in situ hybridisation has high sensitivity and specificity for the diagnosis of adenoid cystic carcinoma.

Adenoid cystic carcinoma (ACC) is one of the most common primary salivary gland cancers. ACC has several benign and malignant mimics amongst salivary gland neoplasms. An accurate diagnosis of ACC is essential for optimal management of the patients and their follow-up. Upregulation of MYB has been described in 85-90% of ACC, but not in other salivary gland neoplasms. In ACC, MYB upregulation can occur as a result of a genetic rearrangement t(6;9) (q22-23;p23-24), MYB copy number variation (CNV), or enhancer hijacking of MYB. All mechanisms of MYB upregulation result in increased RNA transcription that can be detected using RNA in situ hybridisation (ISH) methods. In this study, utilising 138 primary salivary gland neoplasms including 78 ACC, we evaluate the diagnostic utility of MYB RNA ISH for distinguishing ACC from other primary salivary gland neoplasms with a prominent cribriform architecture including pleomorphic adenoma, basal cell adenoma, basal cell adenocarcinoma, epithelial myoepithelial carcinoma, and polymorphous adenocarcinoma. Fluorescent in situ hybridisation and next generation sequencing were also performed to evaluate the sensitivity and specificity of RNA ISH for detecting increased MYB RNA when MYB gene alterations were present. Detection of MYB RNA has 92.3% sensitivity and 98.2% specificity for a diagnosis of ACC amongst salivary gland neoplasms. The sensitivity of MYB RNA detection by ISH (92.3%) is significantly higher than that of the FISH MYB break-apart probe (42%) for ACC. Next generation sequencing did not demonstrate MYB alterations in cases that lacked MYB RNA overexpression indicating high sensitivity of MYB RNA ISH for detecting MYB gene alterations. The possibility that the sensitivity may be higher in clinical practice with contemporary samples as compared with older retrospective tissue samples with RNA degradation is not entirely excluded. In addition to the high sensitivity and specificity, MYB RNA testing can be performed using standard IHC platforms and protocols and evaluated using brightfield microscopy making it a time and cost-efficient diagnostic tool in routine clinical practice.

A critical analysis of the 8th edition TNM staging for head and neck cutaneous squamous cell carcinoma with lymph node metastases and comparison to N1S3 stage and ITEM risk score: A multicenter study.

BACKGROUND AND OBJECTIVES: We performed a critical analysis of the 8th edition American Joint Committee on Cancer (AJCC) staging for head and neck cutaneous squamous cell carcinoma (HNcSCC) with nodal metastases and compared the performance to the N1S3 and ITEM systems. METHODS: Multicenter study of 990 patients with metastatic HNcSCC treated with curative intent. The end points of interest were disease-specific (DSS) and overall survival (OS). Model fit was evaluated using Harrell's Concordance Index (C-index), proportion of variation explained (PVE), Akaike information criterion, and Bayesian information criterion. RESULTS: N1S3 and ITEM demonstrated good distribution into risk categories in contrast to the AJCC system, which classified the majority (90.6%) of patients as N2-3 and Stage IV due to the high rate of extranodal extension. The N2c and N3a categories appeared redundant. There was considerable discordance between systems in risk allocation on an individual patient basis. N1S3 was the best performed (DSS: C-index 0.62, PVE 10.9%; OS: C-index 0.59, PVE 4.5%), albeit with relatively poor predictive value. CONCLUSIONS: The AJCC N category and tumor node metastasis stage have poor patient distribution and predictive performance in HNcSCC. The AJCC stage, N1S3, and ITEM score all provide limited prognostic information based on objective measures highlighting the need to develop a staging system specific to HNcSCC.

NKX3.1 immunohistochemistry is highly specific for the diagnosis of mesenchymal chondrosarcomas: experience in the Australian population.

Mesenchymal chondrosarcoma (MC) is a rare sarcoma that typically arises in adolescents and young adults and characteristically harbours a HEY1-NCOA2 gene fusion. A recent study has shown that NKX3.1 immunohistochemistry (IHC) is highly specific and sensitive in MCs. NKX3.1 is a nuclear marker expressed in prostatic tissue and is widely used in most laboratories to determine prostatic origin of metastatic tumours. In the current study we investigated whether this stain can be used in the diagnostic workup of MC, as it may assist in triaging cases for further molecular testing, by assessing its expression in a cohort of MCs and in a wide spectrum of sarcoma types. Furthermore, we aimed to elucidate if expression of NKX3.1 by MCs is related to androgen receptor (AR) expression. We identified NKX3.1 positive nuclear staining in 9 of 12 individual patients of MC (n=20 of 25 samples when taking into account separate episodes). Four of the five negative specimens had been previously subjected to acid-based decalcification. NKX3.1 was negative in 536 samples from 16 non-MC sarcomas derived from largely tissue microarrays (TMAs). Overall, we identified 80% sensitivity and 100% specificity for NKX3.1 IHC in MCs. The sensitivity increased to 95.2% when acid-based decalcified specimens were excluded from the analysis. No correlation between NKX3.1 expression and AR IHC was identified. In summary, our findings indicate that NKX3.1 nuclear positivity is highly sensitive and specific for MC, provided that ethylenediaminetetraacetic acid (EDTA)-based rather than acid-based decalcification is used for sample processing. NKX3.1 IHC in the right clinical and histopathological setting can potentially be sufficient for the diagnosis of MC, reserving molecular confirmation only for equivocal cases.

Prognostic value of the 8th edition American Joint Commission Cancer nodal staging system for patients with head and neck cutaneous squamous cell carcinoma: A multi-institutional study.

BACKGROUND: The 8th edition American Joint Committee on Cancer staging manual (AJCC8) introduced a separate staging system for head and neck cutaneous squamous cell carcinoma (HNcSCC) which parallels mucosal SCC and incorporates extranodal extension (ENE). This study aims to evaluate its prognostic utility. METHODS: Univariate analysis of 1146 patients with metastatic HNcSCC from four Australian cancer centers was performed according to both AJCC 7th (AJCC7) and the 8th editions. RESULTS: AJCC8 increased classification of 924 (80.6%) patients to either pN2a or pN3b and 341 patients (29.8%) from stage III to IV compared to AJCC7. The disease-specific survival (DSS) was not significantly different between pN1, pN2 or pN3a categories per AJCC8. Estimates of model performance for the AJCC8 pN staging revealed modest predictive capacity (Harrell's C of 0.62 for DSS). CONCLUSIONS: The risk stratification according to pN classification of AJCC8 staging system performed poorly as a prognostic indicator.

PD-1 blockade using pembrolizumab in adolescent and young adult patients with advanced bone and soft tissue sarcoma.

BACKGROUND: Sarcomas represent 10%-15% of cancers in adolescent and young adult (AYA) patients, and survival for those with metastatic disease or relapse is poor. Immunotherapy with checkpoint inhibition has improved outcomes in multiple tumor types, but data in advanced sarcomas, particularly within the AYA population, are limited. AIM: We aim to evaluate response and toxicity for AYA patients with sarcoma treated with pembrolizumab. METHODS AND RESULTS: We retrospectively reviewed AYA patients with advanced bone and soft tissue sarcoma who received self-funded pembrolizumab between May 2015 and January 2019. Eighteen patients were identified. One patient with Ewing sarcoma had a sustained complete response to therapy. Two patients with alveolar soft part sarcoma received a clinical benefit from pembrolizumab: one had a radiological partial response with an excellent clinical response and one patient achieved stable disease. Four patients died of disease prior to first scheduled assessment and thus were not evaluable. The remaining eleven patients had progressive disease. CONCLUSION: The role of immunotherapy in AYA sarcoma warrants further investigation. Biomarkers of response need to be further evaluated in order to guide patient selection.

The American Joint Committee on Cancer staging for metastatic head and neck cutaneous squamous cell carcinoma: A multi-institutional study of within-stage heterogeneity and impact on prognostic performance.

BACKGROUND: The American Joint Committee on Cancer (AJCC) staging for head and neck cutaneous squamous cell carcinoma (HNcSCC) stratifies risk poorly. We hypothesized that this results from prognostic heterogeneity within N and TNM groups. METHODS: Retrospective analysis of disease-specific survival (DSS) in a multicenter study of 1146 patients with nodal metastases from HNcSCC. RESULTS: The majority of patients were classified as pN2a or pN3b (83.1%) and TNM stage IV (90.6%). On multivariate analysis, there was statistically significant prognostic heterogeneity within these groups based on the number and size of nodal metastases, immunosuppression, and perineural invasion. When stage IV patients were categorized into low, moderate, and high-risk groups based on adverse features, there was wide variation in prognosis with 5-year DSS ranging from 90% to 60% (P < .001). CONCLUSIONS: The AJCC staging system stratifies risk poorly in HNcSCC due to significant prognostic heterogeneity within pN2a, pN3b, and stage IV groups.

Molecular patterns in salivary duct carcinoma identify prognostic subgroups.

Salivary duct carcinoma (SDCa) is a rare cancer with high rate of metastases and poor survival despite aggressive multimodality treatment. This study analyzes the genetic changes in SDCa, their impact on cancer pathways, and evaluates whether molecular patterns can identify subgroups with distinct clinical characteristics and outcome. Clinicopathologic details and tissue samples from 66 patients (48 males, 18 females) treated between 1995 and 2018 were obtained from multiple institutions. Androgen receptor (AR) was assessed by immunohistochemistry, and the Illumina TruSight 170 gene panel was used for DNA sequencing. Male gender, lympho-vascular invasion, lymph node metastasis, and smoking were significant predictors of disease-free survival. AR was present in 79%. Frequently encountered alterations were mutations in TP53 (51%), PIK3CA (32%) and HRAS (22%), as well as amplifications of CDK4/6 (22%), ERBB2 (21%), MYC (16%), and deletions of CDKN2A (13%). TP53 mutation and MYC amplifications were associated with decreased disease-free survival. Analysis of cancer pathways revealed that the PI3K pathway was most commonly affected. Alterations in the cell cycle pathway were associated with impaired disease-free survival (HR 2.6, P = 0.038). Three subgroups based on AR and ERBB2 status were identified, which featured distinct molecular patterns and outcome. Among AR positive SDCa, HRAS mutations were restricted to AR positive tumors without ERBB2 amplification and HRAS mutations featured high co-occurrence with PIK3CA alterations, which seems specific to SDCa. AR negative SDCa were associated with poor disease-free survival in multivariate analysis (HR 4.5, P = 0.010) and none of these tumors exhibited ERBB2 amplification or HRAS mutations. AR and ERBB2 status in SDCa thus classifies tumors with distinct molecular profiles relevant to future targeted therapy. Furthermore, clinical factors such as smoking and molecular features such as MYC amplification may serve as markers of poor prognosis of SDCa.

Positive survival trend in metastatic head and neck cutaneous squamous cell carcinoma over four-decades: Multicenter study.

BACKGROUND: This study assessed changes over time of survival of head and neck cutaneous squamous cell carcinoma (HNcSCC) with lymph node metastases. METHODS: A multicenter analysis of 1301 patients with metastatic HNcSCC treated between 1980 and 2017. Differences in disease-specific survival (DSS) and overall survival (OS) by decade were assessed using multivariate Cox regression. RESULTS: Over the study period, we noted an increase in the proportion of patients aged over 80 years (3.9%-31.7%; P < .001) and immunosuppression (1.9%-9.9%; P = .03). After adjusting for number and size of metastatic nodes, extranodal extension, perineural invasion, immunosuppression, treatment, and institution, there was a reduction in risk of cancer-related mortality from 0.47 in 1990-1999 (P = .04) to 0.30 in 2000-2009 (P < .001) when compared to 1980-1989. This remained stable at 0.30 in 2010-2017 (P = .001). OS remained stable after 1990. CONCLUSION: Despite an aging and more frequently immunosuppressed population, fewer patients are dying from metastatic HNcSCC.

The Milan System for Reporting Salivary Gland Cytopathology-Proposed modifications to improve clinical utility.

BACKGROUND: Fine-needle aspiration of a salivary gland lesion is a well-established diagnostic procedure that aids management decisions. Recently, the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) classification has been proposed in order to improve the reproducibility and communication in the management of salivary gland lesions. METHODS: A total of 375 patient's cytological reports collected between January 2010 and December 2017 were reviewed and reclassified according to MSRSGC and a risk of malignancy was calculated for each of the category. RESULTS: The rate of malignancy in MSRSGC classification was 19.0%, 11.8%, 25.0%, 5.5%, 50.0%, 71.4%, and 94.6% for each of the category (I, II, III, IVa, IVb, V, and VI), respectively. CONCLUSION: The MSRSGC classification is a valuable tool in everyday practice. The modified version of MSRSGC aims to improve the surgical relevance and facilitate uniform management.

Clinical Utility of In Situ Hybridization Assays in Head and Neck Neoplasms.

Head and neck pathology present a unique set of challenges including the morphological diversity of the neoplasms and presentation of metastases of unknown primary origin. The detection of human papillomavirus and Epstein-Barr virus associated with squamous cell carcinoma and newer entities like HPV-related carcinoma with adenoid cystic like features have critical prognostic and management implications. In salivary gland neoplasms, differential diagnoses can be broad and include non-neoplastic conditions as well as benign and malignant neoplasms. The detection of specific gene rearrangements can be immensely helpful in reaching the diagnosis in pleomorphic adenoma, mucoepidermoid carcinoma, secretory carcinoma, hyalinizing clear cell carcinoma and adenoid cystic carcinoma. Furthermore, molecular techniques are essential in diagnosis of small round blue cell neoplasms and spindle cell neoplasms including Ewing sarcoma, rhabdomyosarcoma, synovial sarcoma, biphenotypic sinonasal sarcoma, dermatofibrosarcoma protuberans, nodular fasciitis and inflammatory myofibroblastic tumor. The detection of genetic rearrangements is also important in lymphomas particularly in identifying 'double-hit' and 'triple-hit' lymphomas in diffuse large B cell lymphoma. This article reviews the use of in situ hybridization in the diagnosis of these neoplasms.

Biomarkers for ALK and ROS1 in Lung Cancer: Immunohistochemistry and Fluorescent In Situ Hybridization.

CONTEXT: - A small proportion of non-small cell lung cancers harbor rearrangements of ALK or ROS1 genes, and these tumors are sensitive to targeted tyrosine kinase inhibitors. It is crucial for pathologists to accurately identify tumors with these genetic alterations to enable patients to access optimal treatments and avoid unnecessary side effects of less effective agents. Although a number of different techniques can be used to identify ALK- and ROS1-rearranged lung cancers, immunohistochemistry and fluorescence in situ hybridization are the mainstays. OBJECTIVE: - To review the role of immunohistochemistry in assessment of ALK and ROS1 rearrangements in lung cancer, focusing on practical issues in comparison with other modalities such as fluorescence in situ hybridization. DATA SOURCES: - This manuscript reviews the current literature on ALK and ROS1 detection using immunohistochemistry and fluorescence in situ hybridization as well as current recommendations. CONCLUSIONS: - Although fluorescence in situ hybridization remains the gold standard for detecting ALK and ROS1 rearrangement in non-small cell lung cancer, immunohistochemistry plays an important role and can be an effective screening method for detection of these genetic alterations, or a diagnostic test in the setting of ALK.

Somatic mutations in salivary duct carcinoma and potential therapeutic targets.

BACKGROUND: Salivary duct carcinomas (SDCa) are rare highly aggressive malignancies. Most patients die from distant metastatic disease within three years of diagnosis. There are limited therapeutic options for disseminated disease. RESULTS: 11 cases showed androgen receptor expression and 6 cases showed HER2 amplification. 6 Somatic mutations with additional available targeted therapies were identified: EGFR (p.G721A: Gefitinib), PDGFRA (p.H845Y: Imatinib and Crenolanib), PIK3CA (p.H1047R: Everolimus), ERBB2 (p.V842I: Lapatinib), HRAS (p.Q61R: Selumetinib) and KIT (p.T670I: Sorafenib). Furthermore, alterations in PTEN, PIK3CA and HRAS that alter response to androgen deprivation therapy and HER2 inhibition were also seen. MATERIALS AND METHODS: Somatic mutation analysis was performed on DNA extracted from 15 archival cases of SDCa using the targeted Illumina TruSeq Amplicon Cancer Panel. Potential targetable genetic alterations were identified using extensive literature and international somatic mutation database (COSMIC, KEGG) search. Immunohistochemistry for androgen receptor and immunohistochemistry and fluorescent in situ hybridization for HER2 were also performed. CONCLUSIONS: SDCa show multiple somatic mutations, some that are amenable to pharmacologic manipulation and others that confer resistance to treatments currently under investigation. These findings emphasize the need to develop testing and treatment strategies for SDCa.

Diagnostic and prognostic utility of Mastermind-like 2 (MAML2) gene rearrangement detection by fluorescent in situ hybridization (FISH) in mucoepidermoid carcinoma of the salivary glands.

OBJECTIVE: Mucoepidermoid carcinoma (MEC) is the most common salivary gland malignancy, with a proportion harboring MAML2 rearrangement. This study evaluates the diagnostic and prognostic utility of MAML2 rearrangement in MEC. STUDY DESIGN: Salivary gland malignancies at a single institution (1989-2014) were reviewed to identify MECs. Histopathologic evaluation, immunohistochemistry, and fluorescent in situ hybridization (FISH) were performed. RESULTS: Forty-one cases of MEC were identified, with mean age of 47 years and mean tumor size of 21 mm. Seven locoregional recurrences and five MEC-related deaths were seen over a 22-year follow-up period. Thirty-eight cases were suitable for FISH, and 31 (82%) cases were positive for MAML2 rearrangement, including the oncocytic and clear cell variants of MEC. FISH was negative in the morphologic mimics of MEC. MAML2 rearrangement was significantly associated with longer survival. CONCLUSIONS: MAML2 rearrangement is common and specific for MEC, which makes it a useful diagnostic tool. MAML2 rearrangement also predicts a favorable prognosis.

Salivary duct carcinoma: Clinicopathologic features, morphologic spectrum, and somatic mutations.

BACKGROUND: Accurate diagnosis of salivary duct carcinoma requires a high index of suspicion and clinicopathologic correlation. Hallmark genetic changes that may provide novel therapeutic options are being explored. METHODS: One hundred ninety salivary gland malignancies at Royal Prince Alfred Hospital (from 1989-2014) were reviewed. Human epidermal growth factor receptor 2 (HER2) and androgen receptor status were determined along with multigene profiling. RESULTS: Twenty-three salivary duct carcinomas were identified, predominantly in men in their fifth to ninth decades of life. Facial nerve palsy (12%) and cervical lymph node metastases (82%) were present, and 96% received postoperative adjuvant therapy. Histologically, the tumors resembled high-grade invasive and in situ ductal carcinoma of the breast. Micropapillary, papillary, sarcomatoid, oncocytic, and mucinous variants were seen. The tumors showed androgen receptor (70%), HER2 amplification (30%), and HRAS, AKT1, PIK3CA, and NRAS mutations (22%; cumulative). The 5-year disease-free survival was 36%. CONCLUSION: Salivary duct carcinoma demonstrates a wide histopathologic spectrum. Treatment strategies need to take androgen receptor, HER2 amplification, and PIK3CA mutation into account. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1838-E1847, 2016.

Mammary analogue secretory carcinoma: an evaluation of its clinicopathological and genetic characteristics.

Mammary analogue secretory carcinoma (MASC) is a recently described salivary gland malignancy. We evaluate the clinicopathological characteristics and long-term clinical behaviour of MASCs. A total of 190 primary salivary gland malignancies at a single institution were reviewed along with relevant immunohistochemical and fluorescent in situ hybridisation (FISH) studies to identify MASCs. Nine MASCs were identified predominantly in the parotid with an equal incidence in men and women and mean age of 36 years. The tumour size ranged from 14 to 50 mm (mean 22 mm). MASCs were composed of monotonous cells with vacuolated eosinophilic cytoplasm and a small nucleus with a distinctive nucleolus. All cases showed immunoreactivity with S-100, MUC4, CK7 and mammoglobin, and lacked immunoreactivity with DOG1, p63, CK5/6 and calponin. ETV6 rearrangement was seen in all cases. No mutations were identified using the OncoCarta Panel v1.0 Kit. Follow up was available for 0.4 to 22 years (median 4 years). Intraparotid lymph node involvement and local recurrence were seen in one patient each. There were no distant metastases. MASCs have specific histopathological features and immunohistochemical profile that distinguish them from their mimics. FISH plays a confirmatory role. An indolent long-term clinical course was observed in this cohort despite involvement of intraparotid lymph node and microscopically involved/close margins.

Alterations in the mitochondrial responses to PENAO as a mechanism of resistance in ovarian cancer cells.

OBJECTIVE: The purpose of this study was to test PENAO, a promising new organoarsenical that is in phase 1 testing in patients with solid tumours, on a range of ovarian cancer cell lines with different histotypes, and to understand the molecular basis of drug resistance exhibited by the endometrioid ovarian cancer cell line, SKOV-3. METHODS: Proliferation arrest and cell death induced by PENAO in serous (OVCAR-3), endometrioid (SKOV-3, TOV112D), clear cell (TOV21G) and mucinous (EFO27) ovarian cancer cells in culture, and anti-tumour efficacy in a murine model of SKOV-3 and OVCAR-3 tumours, were measured. Cells were analysed for cell cycle arrest, cell death mechanisms, reactive oxygen species production, mitochondrial depolarisation, oxygen consumption and acid production. RESULTS: PENAO demonstrated promising anti-proliferative activity on the most common (serous, endometrioid) as well as on rare (clear cell, mucinous) subtypes of ovarian cancer cell lines. No cross-resistance with platinum-based drugs was evident. Endometrioid SKOV-3 cells were, however, shown to be resistant to PENAO in vitro and in a xenograft mouse model. This resistance was due to an ability to cope with PENAO-induced oxidative stress, notably through heme oxygenase-1 induction, and a shift in metabolism towards glycolysis. The adaptive glycolytic shift in SKOV-3 was targeted using a mTORC1 inhibitor in combination with PENAO. This strategy was successful with the two drugs acting synergistically to inhibit cell proliferation and to induce cell death via apoptosis and autophagy. CONCLUSION: Mitochondria/mTOR dual-targeting therapy may constitute a new approach for the treatment of recurrent/resistant forms of epithelial ovarian cancer.

BRAF mutations in non-small cell lung cancer.

BACKGROUND: BRAF is a proto-oncogene encoding a serine/threonine protein kinase which promotes cell proliferation and survival. BRAF mutations are commonly seen in melanoma and papillary thyroid carcinoma. We aimed to investigate the prevalence and clinicopathological features of BRAF mutations in non-small cell lung cancer (NSCLC) cases submitted for routine mutation testing at our institution. METHODS: Mutation analysis for BRAF, EGFR and KRAS was performed using Sequenom MassARRAY platform with OncoCarta panel v1.0. Pathological features were reviewed and immunohistochemistry for BRAF V600E was also performed. RESULTS: Seven out of 273 cases (2.6%) had BRAF mutations (three males and four females, median age 70 years, all smokers), with six adenocarcinomas and one NSCLC, not otherwise specified (NOS). All had wild-type EGFR and KRAS. The identified BRAF mutations were V600E (4/7, 58%), K601N, L597Q and G469V. BRAF V600E immunohistochemistry was positive in two cases with V600E and negative in one case with K601N (tissue available in three cases only). No significant difference in age or gender was found (BRAF mutant vs. wild-type). CONCLUSIONS: BRAF mutations occur in a small proportion of NSCLC that lack other driver mutations. The clinicopathological profile differs from that of EGFR mutant tumours. The potential benefits of BRAF-inhibitors should be investigated.

Punch biopsy of melanoma causing tumour cell implantation: another peril of utilising partial biopsies for melanocytic tumours.

The recommended initial management for suspected melanoma is excisional biopsy. The use of partial biopsies of melanocytic tumours poses potential problems including misdiagnosis due to either unrepresentative sampling or the difficulty in evaluating important diagnostic features; an inaccurate assessment of Breslow thickness and other important prognostic features; and the induction of changes capable of mimicking melanoma (i.e., pseudomelanoma). Misdiagnosis, in turn, may lead to inappropriate management of the patient and an adverse outcome. In this report we document a previously unrecognised pitfall of partial biopsies of melanocytic tumours: implantation of tumour cells at the biopsy site potentially leading to the overestimation of tumour thickness or a misdiagnosis of the presence of microsatellites in the subsequent wide excision specimen.