Sinonasal DLBCL: molecular profiling identifies subtypes with distinctive prognosis and targetable genetic features.

ABSTRACT: Primary sinonasal diffuse large B-cell lymphoma (PSDLBCL) is a rare lymphoma with a variable prognosis and a unique relapse/dissemination pattern involving the central nervous system and skin. The underlying molecular mechanisms leading to this heterogeneity and progression pattern remain uncharted, hampering patient-tailored treatment. To investigate associated mechanisms, we analyzed clinical data and used immunohistochemistry, gene-expression profiling, cytogenetics, and next-generation sequencing in a cohort of 117 patients with PSDLBCL. The distribution in cell-of-origin (COO) was 68 (58%) activated B-cell (ABC), 44 (38%) germinal center B-cell (GCB), and 5 (4%) unclassifiable. COO was significantly associated with progression-free survival (PFS) and lymphoma-specific mortality (LSM) in both the overall cohort (5-year PFS: ABC, 43% vs GCB, 73%; LSM: ABC, 45% vs GCB, 14%) and in the subgroup of patients receiving immunochemotherapy (5-year PFS: ABC, 55% vs GCB, 85%; LSM: ABC, 28% vs GCB, 0%). ABC lymphomas were mainly MCD class, showing a high prevalence of MYD88 (74%) and CD79B (35%) mutations compared with GCB lymphomas (MYD88 23%; CD79B 10%) (P < .01). The ABC subtype frequently displayed cMYC/BCL2 coexpression (76% vs 18% GCB; P < .001) and HLA-II loss (48% vs 10% GCB; P < .001). PD-L1 expression and copy-number alterations were rare. All lymphomas were Epstein-Barr virus-negative. Our data suggest molecular profiling as a potent tool for detecting prognostic subgroups in PSDLBCL, exposing links to known relapse/dissemination sites. The ABC subgroup's MCD genetic features, shared with lymphomas at other nonprofessional lymphoid sites, make them potential candidates for targeted B-cell and toll-like receptor signaling therapy.

Real-World Data on Combined EGFR-TKI and Crizotinib Treatment for Acquired and De Novo MET Amplification in Patients with Metastatic EGFR-Mutated NSCLC.

Amplification of the mesenchymal epithelial transition (MET) gene is a mechanism of acquired resistance to epidermal growth factor receptor (EGFR)-tyrosine-kinase-inhibitors (TKIs) in over 20% of patients with advanced EGFR-mutated (EGFRm+) non-small lung cancer (NSCLC). However, it may also occur de novo in 2-8% of EGFRm+ NSCLC cases as a potential mechanism of intrinsic resistance. These patients represent a group with unmet needs, since there is no standard therapy currently approved. Several new MET inhibitors are being investigated in clinical trials, but the results are awaited. Meanwhile, as an alternative strategy, combinations of EGFR-TKIs with the MET/ALK/ROS1-TKI Crizotinib may be used in this setting, despite this use is principally off-label. Thus, we studied five of these MET amplified cases receiving EGFR-TKI and Crizotinib doublet after progression on EGFR-TKI treatment to assess the benefits and challenges related to this combination and the possible occurrence of genomic and phenotypic co-alterations. Furthermore, we compared our cases with other real-world reports on Crizotinib/EGFR-TKI combinations, which appeared effective, especially in patients with high-level MET amplification. Yet, we observed that the co-occurrence of other genomic and phenotypical alterations may affect the response to combined EGFR-TKI and Crizotinib. Finally, given the heterogeneity of MET amplification, the diagnostic methods for assessing it may be discrepant. In this respect, we observed that for optimal detection, immunohistochemistry, fluorescence in situ hybridization, and next-generation sequencing should be used together, as these methods possess different sensitivities and complement each other in characterizing MET amplification. Additionally, we addressed the issue of managing EGFR-mutated NSCLC patients with de novo MET amplification causing primary EGFR-TKI resistance. We conclude that, while data from clinical trials with new MET inhibitors are still pending, adding Crizotinib to EGFR-TKI in NSCLC patients acquiring MET amplification at progression on EGFR-TKI monotherapy is a reasonable approach, with a progression-free survival of 3-19 months.

Dyslipidemia, inflammation, calcification, and adiposity in aortic stenosis: a genome-wide study.

AIMS: Although highly heritable, the genetic etiology of calcific aortic stenosis (AS) remains incompletely understood. The aim of this study was to discover novel genetic contributors to AS and to integrate functional, expression, and cross-phenotype data to identify mechanisms of AS. METHODS AND RESULTS: A genome-wide meta-analysis of 11.6 million variants in 10 cohorts involving 653 867 European ancestry participants (13 765 cases) was performed. Seventeen loci were associated with AS at P ≤ 5 × 10-8, of which 15 replicated in an independent cohort of 90 828 participants (7111 cases), including CELSR2-SORT1, NLRP6, and SMC2. A genetic risk score comprised of the index variants was associated with AS [odds ratio (OR) per standard deviation, 1.31; 95% confidence interval (CI), 1.26-1.35; P = 2.7 × 10-51] and aortic valve calcium (OR per standard deviation, 1.22; 95% CI, 1.08-1.37; P = 1.4 × 10-3), after adjustment for known risk factors. A phenome-wide association study indicated multiple associations with coronary artery disease, apolipoprotein B, and triglycerides. Mendelian randomization supported a causal role for apolipoprotein B-containing lipoprotein particles in AS (OR per g/L of apolipoprotein B, 3.85; 95% CI, 2.90-5.12; P = 2.1 × 10-20) and replicated previous findings of causality for lipoprotein(a) (OR per natural logarithm, 1.20; 95% CI, 1.17-1.23; P = 4.8 × 10-73) and body mass index (OR per kg/m2, 1.07; 95% CI, 1.05-1.9; P = 1.9 × 10-12). Colocalization analyses using the GTEx database identified a role for differential expression of the genes LPA, SORT1, ACTR2, NOTCH4, IL6R, and FADS. CONCLUSION: Dyslipidemia, inflammation, calcification, and adiposity play important roles in the etiology of AS, implicating novel treatments and prevention strategies.

Glioneuronal tumor with ATRX alteration, kinase fusion and anaplastic features (GTAKA): a molecularly distinct brain tumor type with recurrent NTRK gene fusions.

Glioneuronal tumors are a heterogenous group of CNS neoplasms that can be challenging to accurately diagnose. Molecular methods are highly useful in classifying these tumors-distinguishing precise classes from their histological mimics and identifying previously unrecognized types of tumors. Using an unsupervised visualization approach of DNA methylation data, we identified a novel group of tumors (n = 20) that formed a cluster separate from all established CNS tumor types. Molecular analyses revealed ATRX alterations (in 16/16 cases by DNA sequencing and/or immunohistochemistry) as well as potentially targetable gene fusions involving receptor tyrosine-kinases (RTK; mostly NTRK1-3) in all of these tumors (16/16; 100%). In addition, copy number profiling showed homozygous deletions of CDKN2A/B in 55% of cases. Histological and immunohistochemical investigations revealed glioneuronal tumors with isomorphic, round and often condensed nuclei, perinuclear clearing, high mitotic activity and microvascular proliferation. Tumors were mainly located supratentorially (84%) and occurred in patients with a median age of 19 years. Survival data were limited (n = 18) but point towards a more aggressive biology as compared to other glioneuronal tumors (median progression-free survival 12.5 months). Given their molecular characteristics in addition to anaplastic features, we suggest the term glioneuronal tumor with ATRX alteration, kinase fusion and anaplastic features (GTAKA) to describe these tumors. In summary, our findings highlight a novel type of glioneuronal tumor driven by different RTK fusions accompanied by recurrent alterations in ATRX and homozygous deletions of CDKN2A/B. Targeted approaches such as NTRK inhibition might represent a therapeutic option for patients suffering from these tumors.

Association of PCSK9 Loss-of-Function Variants With Risk of Heart Failure.

Importance: An animal (mouse) study indicated that deficiency of proprotein convertase subtilisin/kexin type 9 (PCSK9) causes cardiac remodeling and heart failure (HF). Cardiac remodeling after PCSK9-inhibitor treatment is a concern for patients and for development of treatment directed against PCSK9. Objective: To determine whether genetic variants in the PCSK9 gene are associated with altered cardiac structure, cardiac function, and HF in humans. Design, Setting, Participants: This was a nested case-control study within the UK Biobank. Between March 13, 2006, and October 1, 2010, the UK Biobank enrolled 502 480 individuals aged 40 to 69 years. This study focused on a subset of those individuals, who completed cardiac magnetic resonance (CMR) imaging and had available genetic data. Analyses were conducted between November 2, 2021, and October 28, 2022. Exposures: Carrier status of predicted loss-of-function (pLoF) PCSK9 variants, R46L missense variant, and a genetic risk score (GRS). Main Outcomes and Measures: A total of 11 CMR imaging measurements, generated using a machine learning algorithm, and HF diagnosis. Results: In up to 35 135 individuals with CMR images, 18 252 (52%) were female individuals, and mean (SD) age was 55.0 (7.4) years. No significant association between PCSK9 carrier status and CMR indices were found for left ventricular mass (pLoF: ß = -1.01; 95% CI, -2.99 to 0.98; P = .32; R46L: ß = -0.18; 95% CI, -0.55 to 0.19; P = .35; GRS: ß = -0.19; 95% CI, -0.50 to 0.11; P = .22) and left ventricular ejection fraction (pLoF: ß = 0.43; 95% CI, -1.32 to 2.18; P = .63; R46L: ß = -0.19; 95% CI, -0.52 to 0.14; P = .26; GRS: ß = -0.08; 95% CI, -0.35 to 0.20; P = .58) or HF (pLoF: odds ratio [OR], 1.14; 95% CI, 0.56-2.05; P = .69; R46L: OR, 0.99; 95% CI, 0.90-1.10; P = .91; GRS: OR, 1.04; 95% CI, 0.96-1.13; P = .32). Conclusions and Relevance: Results of this case-control study suggest that there was no association between PCSK9 genetic variants and altered cardiac structure, cardiac function, or HF in humans.

Gene expression analysis during progression of malignant meningioma compared to benign meningioma.

OBJECTIVE: Meningioma is the most common primary intracranial neoplasm. Only 1%-3% of meningiomas are malignant according to the 2016 WHO criteria (WHO grade III). High-grade meningiomas present specific gene expression signatures indicating aggressive growth or recurrence. However, changes in gene expression and in neuroinflammatory gene expression signatures in WHO grade III meningiomas and during progression from WHO grade I or II to grade III are unknown. METHODS: The authors used a NanoString targeted gene expression panel with focus on 787 genes relevant in meningioma pathology and neuroinflammatory pathways to investigate patients with grade III meningiomas treated at Rigshospitalet from 2000 to 2020 (n = 51). A temporal dimension was added to the investigation by including samples from patients' earlier grade I and II meningiomas and grade III recurrences (n = 139 meningiomas). The authors investigated changes in neuroinflammatory gene expression signatures in 1) grade I meningiomas that later transformed into grade III meningiomas, and 2) grade III meningiomas compared with nonrecurrent grade I meningiomas. RESULTS: The authors' data indicate that FOXM1, TOP2A, BIRC5, and MYBL2 were enriched and the HOTAIR regulatory pathway was enriched in grade III meningiomas compared with nonrecurrent grade I meningiomas. They discovered a separation of malignant and benign meningiomas based only on genes involved in microglia regulation with enrichment of P2RY12 in grade I compared with grade III meningiomas. Interestingly, FOXM1 was upregulated in premalignant grade I meningioma years before the grade III transformation. CONCLUSIONS: The authors found gene expression changes in low-grade meningiomas that predated histological transformation to grade III meningiomas. Neuroinflammation genes distinguished grade III from grade I meningiomas.

Polygenic risk score for ACE-inhibitor-associated cough based on the discovery of new genetic loci.

AIMS: To search for sequence variants associated with ACEi discontinuation and to test their association with ACEi-associated adverse drug reactions (ADRs). METHODS AND RESULTS: A genome-wide association study (GWAS) on ACEi discontinuation was conducted, including 33 959 ACEi-discontinuers and 44 041 controls. Cases were defined as persons who switched from an ACEi treatment to an angiotensin receptor blocker. Controls were defined as persons who continued ACEi treatment for at least 1 year. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were computed for ACEi discontinuation risk by mixed model regression analysis. Summary statistics from the individual cohorts were meta-analyzed with a fixed-effects model. To test for association with specific ACEi-associated ADRs, any genome-wide significant (P < 5 × 10-8) ACEi discontinuation variants was tested for association with ACEi-associated cough and angioedema. A polygenetic risk score (PRS) based on ACEi discontinuation GWAS data was constructed and tested for association with ACEi-associated cough and angioedema in two population-based samples. In total, seven genetic genome-wide loci were identified, of which six were previously unreported. The strongest association with ACEi discontinuation was at 20q13.3 (NTSR1; OR: 1.21; 95% CI: 1.17-1.24; P = 2.1 × 10-34). Five of seven lead variants were associated with ACEi-associated cough, whereas none were associated with ACEi-associated angioedema. The ACEi discontinuation PRS was associated with ACEi-associated cough in a dose-response manner but not with ACEi-associated angioedema. ACEi discontinuation was genetically correlated with important causes for cough, including gastro-esophageal reflux disease, allergic rhinitis, hay fever, and asthma, which indicates partly shared genetic underpinning between these traits. CONCLUSION: This study showed the advantage of using prescription patterns to discover genetic links with ADRs. In total, seven genetic loci that associated with ACEi discontinuation were identified. There was evidence of a strong association between our ADR phenotype and ACEi-associated cough. Taken together, these findings increase insight into the pathophysiological processes that underlie ACEi-associated ADRs.

Constitutional POLE variants causing a phenotype reminiscent of constitutional mismatch repair deficiency.

Heterozygous POLE or POLD1 germline pathogenic variants (PVs) cause polymerase proofreading associated polyposis (PPAP), a constitutional polymerase proofreading deficiency that typically presents with colorectal adenomas and carcinomas in adulthood. Constitutional mismatch-repair deficiency (CMMRD), caused by germline bi-allelic PVs affecting one of four MMR genes, results in a high propensity for the hematological, brain, intestinal tract, and other malignancies in childhood. Nonmalignant clinical features, such as skin pigmentation alterations, are found in nearly all CMMRD patients and are important diagnostic markers. Here, we excluded CMMRD in three cancer patients with highly suspect clinical phenotypes but identified in each a constitutional heterozygous POLE PV. These, and two additional POLE PVs identified in published CMMRD-like patients, have not previously been reported as germline PVs despite all being well-known somatic mutations in hyper-mutated tumors. Together, these five cases show that specific POLE PVs may have a stronger "mutator" effect than known PPAP-associated POLE PVs and may cause a CMMRD-like phenotype distinct from PPAP. The common underlying mechanism, that is, a constitutional replication error repair defect, and a similar tumor spectrum provide a good rationale for monitoring these patients with a severe constitutional polymerase proofreading deficiency according to protocols proposed for CMMRD.

Prolonging fixation time of an alternative fixative to formalin for dermatological samples using standard laboratory protocols.

AIMS: Though formalin remains to be the gold standard fixative in pathology departments, analytical challenges persist for nucleic acid evaluations. In our laboratory, formalin fixation of skin samples in particular impairs diagnostic accuracy and demands repetition of biopsies and analytical procedures. PAXgene Tissue Systems may be an alternative; however, according to manufacturer specifications it only allows fixation for 48 hours before having to add a stabiliser. This may be a challenge in laboratories, which are closed in weekends and bank holidays. Our aim was to validate this alternative fixative for dermatological samples with prolonged fixation times using standard laboratory protocols developed for formalin-fixed specimens. We compared the results with gold standard formalin fixation. METHODS: Skin specimens were formalin or PAXgene fixed for either 2 hours, 24 hours, 3 days or 7 days, paraffin-embedded, analysed and scored by observers. RESULTS: Generally, formalin outperformed PAXgene fixation in H&E stains and fluorescence in situ hybridisation (FISH), but both seem usable for diagnostics. Time of PAXgene fixation did not have an impact on alcian blue-Van Gieson (ABVG), H&E (p=0.48), nor immunohistochemistry (p=0.74). There was a tendency towards best PAXgene performance at 24 hours of fixation for FISH, and for DNA integrity analysis 24 hours or 3 days. CONCLUSIONS: Prolonging PAXgene fixation time to 3 days before adding stabiliser does not seem to have major impact on performance of general diagnostic analysis, but our preliminary results show optimisation of internal protocols are needed. PAXgene is an expensive alternative and may be confined to some dermatological samples.

Regional Differences in Neuroinflammation-Associated Gene Expression in the Brain of Sporadic Creutzfeldt-Jakob Disease Patients.

Neuroinflammation is an essential part of neurodegeneration. Yet, the current understanding of neuroinflammation-associated molecular events in distinct brain regions of prion disease patients is insufficient to lay the ground for effective treatment strategies targeting this complex neuropathological process. To address this problem, we analyzed the expression of 800 neuroinflammation-associated genes to create a profile of biological processes taking place in the frontal cortex and cerebellum of patients who suffered from sporadic Creutzfeldt-Jakob disease. The analysis was performed using NanoString nCounter technology with human neuroinflammation panel+. The observed gene expression patterns were regionally and sub-regionally distinct, suggesting a variable neuroinflammatory response. Interestingly, the observed differences could not be explained by the molecular subtypes of sporadic Creutzfeldt-Jakob disease. Furthermore, analyses of canonical pathways and upstream regulators based on differentially expressed genes indicated an overlap between biological processes taking place in different brain regions. This suggests that even smaller-scale spatial data reflecting subtle changes in brain cells' functional heterogeneity and their immediate pathologic microenvironments are needed to explain the observed differential gene expression in a greater detail.

Changing ALK-TKI-Resistance Mechanisms in Rebiopsies of ALK-Rearranged NSCLC: ALK- and BRAF-Mutations Followed by Epithelial-Mesenchymal Transition.

Anaplastic lymphoma-kinase (ALK)-rearranged non-small cell lung cancer (NSCLC) is prone to developing heterogeneous, only partly known mechanisms of resistance to ALK-tyrosine-kinase-inhibitors (ALK-TKIs). We present a case of a 38-year old male, who never smoked with disseminated ALK-rearranged (EML4 (20) - ALK (20) fusion variant 2) lung adenocarcinoma, who received four sequentially different ALK-TKIs and two lines of chemotherapy in-between. We observed significant clinical benefit by the first three ALK-TKIs (Crizotinib, Ceritinib, Alectinib) and chemotherapy with Pemetrexed, resulting in overall survival over 3 years. Longitudinal assessment of progressions by rebiopsies from hepatic metastases showed different mechanisms of resistance to each ALK-TKI, including secondary ALK-mutations and the downstream p.V600E BRAF-mutation that had not been linked to second-generation ALK-TKIs before. Ultimately, in connection with terminal rapid progression and resistance to Alectinib and Lorlatinib, we identified phenotypical epithelial-mesenchymal transition (EMT) of newly occurred metastatic cells, a phenomenon not previously related to these two ALK-TKIs. This resistance heterogeneity suggests a continuously changing disease state. Sequential use of different generation's ALK-TKIs and combination therapies may yield prolonged responses with satisfactory quality of life in patients with advanced ALK-positive NSCLC. However, the development of EMT is a major hurdle and may explain rapid disease progression and lack of response to continued ALK-inhibition.

Molecular Characterization of the Danish Prion Diseases Cohort With Special Emphasis on Rare and Unique Cases.

The purpose of this study was to perform an updated reclassification of all definite prion disease cases with available fresh-frozen samples referred to the Danish Reference Center over the past 40 years, putting a special emphasis on the molecular characterization of novel disease subtypes. Investigation of the Danish prion diseases cohort revealed rare sporadic Creutzfeldt-Jakob disease cases with mixed subtypes and subtypes with previously uncharacterized white matter plaques, a new case of sporadic fatal insomnia, and 3 novel mutations, including 2 large octapeptide repeat insertions, and a point mutation in the prion protein gene. The evaluation of methionine and valine distribution at codon 129 among the prion disease patients in the cohort revealed the increased prevalence of methionine homozygotes compared to the general population. This observation was in line with the prevalence reported in other Caucasian prion disease cohort studies. Reclassification of the old prion diseases cohort revealed unique cases, the molecular characterization of which improves prion diseases classification, diagnostic accuracy, genetic counseling of affected families, and the understanding of disease biology.

Whole genome and transcriptome sequencing of post-mortem cardiac tissues from sudden cardiac death victims identifies a gene regulatory variant in NEXN.

BACKGROUND: Sudden cardiac death (SCD) is a major public health problem and constitutes a diagnostic and preventive challenge in forensic pathology, especially for cases with structural normal hearts at autopsy, so-called sudden arrhythmic death syndrome (SADS). The identification of new genetic risk factors that predispose to SADS is important, because they may contribute to establish the diagnosis and increase the understanding of disease pathways underlying SADS. Pathogenic mutations in the protein coding regions of cardiac genes were found in relation to SADS. However, much remains unknown about variants in non-coding regions of the genome. METHODS AND RESULTS: In this study, we explored the potential of whole genome sequencing (WGS) and whole transcriptome sequencing (WTS) to find DNA variants in SCD victims with structural normal hearts. With focus on the non-coding regulatory regions, we re-examined a cohort of 13 SADS and sudden unexplained death in infancy (SUDI) victims without disease causing DNA variants in recognized cardiac genes. The genetic re-examination of DNA was carried out using frozen tissue samples and WTS was carried out using five distinct formalin fixed and paraffin embedded (FFPE) cardiac tissue samples from each individual, including anterior and posterior walls of the left ventricle, ventricular papillary muscle, septum, and the right ventricle. We identified 23 candidate variants in regulatory sequences of cardiac genes, including a variant in the promotor region of NEXN, c.-194A>G, that was found to be statistically significantly (p < 0.05) associated with decreased expression of NEXN and cardiac hypertrophy. CONCLUSION: With the use of post-mortem FFPE tissues, we highlight the potential of using WTS investigations and compare gene expression levels with DNA variation in regulatory non-coding regions of the genome for a better understanding of the genetics of cardiac diseases leading to SCD.

Next-generation sequencing of endoscopic ultrasound guided microbiopsies from pancreatic cystic neoplasms.

AIMS: Interpretation of cytology samples from pancreatic cysts is challenging. A novel microbiopsy forceps used during endoscopic ultrasound examinations offers new opportunities for histological examination of tissue from pancreatic cysts as well as next-generation sequencing. The aim of this study was to analyse the results of next-generation sequencing of microbiopsies from pancreatic cysts. METHODS AND RESULTS: Microbiopsies from 27 patients were obtained, 23 of which were subjected to next-generation sequencing. Sixteen intraductal papillary mucinous neoplasms harboured mutations in genes regulating cell cycle and repair, and three were without mutations. Most frequent mutations were found in the KRAS and GNAS genes, and these were often concomitant. Three serous cystic neoplasms were without mutations, while with regard to histology, a non-diagnostic microbiopsy harboured a KRAS and a TP53 mutation and was deemed malignant after clinical follow-up. Three patients underwent surgery, and the point mutations detected in the microbiopsies were confirmed in the resected specimens. We identified one resected sample with an additional GNAS mutation which was not identified in the microbiopsy. CONCLUSIONS: Next-generation sequencing of microbiopsies may have the potential to improve diagnostic decision-making.

Intrinsic resistance to EGFR-Tyrosine Kinase Inhibitors in EGFR-Mutant Non-Small Cell Lung Cancer: Differences and Similarities with Acquired Resistance.

Activating mutations in the epidermal growth factor receptor gene occur as early cancer-driving clonal events in a subset of patients with non-small cell lung cancer (NSCLC) and result in increased sensitivity to EGFR-tyrosine-kinase-inhibitors (EGFR-TKIs). Despite very frequent and often prolonged clinical response to EGFR-TKIs, virtually all advanced EGFR-mutated (EGFRM+) NSCLCs inevitably acquire resistance mechanisms and progress at some point during treatment. Additionally, 20-30% of patients do not respond or respond for a very short time (<3 months) because of intrinsic resistance. While several mechanisms of acquired EGFR-TKI-resistance have been determined by analyzing tumor specimens obtained at disease progression, the factors causing intrinsic TKI-resistance are less understood. However, recent comprehensive molecular-pathological profiling of advanced EGFRM+ NSCLC at baseline has illustrated the co-existence of multiple genetic, phenotypic, and functional mechanisms that may contribute to tumor progression and cause intrinsic TKI-resistance. Several of these mechanisms have been further corroborated by preclinical experiments. Intrinsic resistance can be caused by mechanisms inherent in EGFR or by EGFR-independent processes, including genetic, phenotypic or functional tumor changes. This comprehensive review describes the identified mechanisms connected with intrinsic EGFR-TKI-resistance and differences and similarities with acquired resistance and among clinically implemented EGFR-TKIs of different generations. Additionally, the review highlights the need for extensive pre-treatment molecular profiling of advanced NSCLC for identifying inherently TKI-resistant cases and designing potential combinatorial targeted strategies to treat them.

Biomarkers in tumors of the central nervous system - a review.

Until recently, diagnostics of brain tumors were almost solely based on morphology and immunohistochemical stainings for relatively unspecific lineage markers. Although certain molecular markers have been known for longer than a decade (combined loss of chromosome 1p and 19q in oligodendrogliomas), molecular biomarkers were not included in the WHO scheme until 2016. Now, the classification of diffuse gliomas rests on an integration of morphology and molecular results. Also, for many other central nervous system tumor entities, specific diagnostic, prognostic and predictive biomarkers have been detected and continue to emerge. Previously, we considered brain tumors with similar histology to represent a single disease entity. We now realize that histologically identical tumors might show alterations in different molecular pathways, and often represent separate diseases with different natural history and response to treatment. Hence, knowledge about specific biomarkers is of great importance for individualized treatment and follow-up. In this paper we review the biomarkers that we currently use in the diagnostic work-up of brain tumors.

The HTN3-MSANTD3 Fusion Gene Defines a Subset of Acinic Cell Carcinoma of the Salivary Gland.

The spectrum of tumors arising in the salivary glands is wide and has recently been shown to harbor a network of tumor-specific fusion genes. Acinic cell carcinoma (AciCC) is one of the more frequently encountered types of salivary gland carcinoma, but it has remained a genetic orphan until recently when a fusion between the HTN3 and MSANTD3 genes was described in one case. Neither of these 2 genes is known to be implicated in any other malignancy. This study was undertaken to investigate whether the HTN3-MSANTD3 fusion is a recurrent genetic event in AciCC and whether it is a characteristic of one of its histological variants. Of the 273 AciCCs screened, 9 cases showed rearrangement of MSANTD3 by break-apart fluorescence in situ hybridization, 2 had 1 to 2 extra signals, and 1 had gain, giving a total of 4.4% with MSANTD3 aberrations. In 6 of 7 available cases with MSANTD3 rearrangement, the HTN3-MSANTD3 fusion transcript was demonstrated with real-time polymerase chain reaction. Histologically, all fusion-positive cases were predominantly composed of serous tumor cells growing in solid sheets, with serous tumor cells expressing DOG-1 and the intercalated duct-like cell component being CK7 positive and S-100 positive in 6/9 cases. All but one case arose in the parotid gland, and none of the patients experienced a recurrence during follow-up. In contrast, the case with MSANTD3 gain metastasized to the cervical lymph nodes and lungs. In conclusion, we find the HTN3-MSANTD3 gene fusion to be a recurrent event in AciCC with prominent serous differentiation and an indolent clinical course.

Primary Secretory Carcinoma of the Lacrimal Gland: Report of a New Entity.

PURPOSE: Secretory carcinoma has been described in the breast, salivary glands, skin, and other organs, but has not been reported in the lacrimal gland to date. Since lacrimal and salivary glands show similar tumors, we hypothesized that lacrimal secretory carcinoma may exist but has been misclassified in the past. DESIGN: We undertook a retrospective review of all lacrimal gland tumors at 2 tertiary institutions with centralized ocular pathology practices. METHODS: A total of 350 lacrimal tumors were reviewed by the authors. Candidate tumors were tested for ETV-NTRK rearrangement by fluorescence in situ hybridization and the presence of the translocation was confirmed by next-generation sequencing. RESULTS: We identified a single case of secretory carcinoma. The diagnosis was confirmed by demonstrating specific immunohistochemical profile and the presence of ETV6-NTRK3 gene fusion, which is characteristic of secretory carcinoma of other sites. The tumor occurred in a young man who was treated with surgery alone with no recurrence during 12 years of follow-up. CONCLUSION: Secretory carcinoma is a new lacrimal gland carcinoma type that should be added to the spectrum of low-grade lacrimal gland tumors.