NTRK fusion analysis reveals enrichment in Middle Eastern BRAF wild-type PTC

2021 ◽  
Author(s):  
Yan Kong ◽  
Rong Bu ◽  
Sandeep Kumar Parvathareddy ◽  
Abdul K Siraj ◽  
Nabil Siraj ◽  
...  

Objective: Fusions involving neurotrophic tyrosine receptor kinase (NTRK) are known oncogenic drivers in a broad range of tumor types. It recently gained attention as predictor of targeted therapy since selective NTRK inhibitors are now approved in US and Europe for patients with solid tumors harboring gene fusions. However, estimation of NTRK gene fusion/alteration frequency and its clinico-pathological characteristics in papillary thyroid cancer (PTC) is limited, especially in a population with high incidence for PTC like Middle Eastern population. This study aims to characterize the NTRK gene fusion frequency and investigate the utility of pan-Trk immunohistochemistry (IHC) as predictor of NTRK fusion in a large cohort of Middle Eastern PTC. Methods: FISH analysis for NTRK gene fusions and pan-Trk IHC was performed on 315 Middle Eastern PTCs. Correlation of NTRK gene fusion and protein expression with clinico-pathological markers and patient outcome were determined. Results: In our cohort, 6.0% (19/315) patients showed NTRK gene fusions and were significantly associated with pediatric PTC (p = 0.0143), lymph node metastasis (p = 0.0428) and BRAF wild-type tumors (p < 0.0001). Pan-Trk IHC was positive in 9.2% (29/315) of cases and significantly associated with NTRK fusions, with a sensitivity of 73.7% and specificity of 94.9% in this cohort. Conclusions: This study confirms the presence of NTRK fusions in Middle Eastern PTC which is significantly enriched in BRAF wild-type as well as pediatric age group and proposes the usefulness of IHC to screen for PTC patients with NTRK fusion that might benefit from TRK inhibitors.

2021 ◽  
pp. jclinpath-2021-207825
Author(s):  
Umberto Malapelle ◽  
Francesco Pepe ◽  
Pasquale Pisapia ◽  
Annalisa Altimari ◽  
Claudio Bellevicine ◽  
...  

AimsGene fusions assays are key for personalised treatments of advanced human cancers. Their implementation on cytological material requires a preliminary validation that may make use of cell line slides mimicking cytological samples. In this international multi-institutional study, gene fusion reference standards were developed and validated.MethodsCell lines harbouring EML4(13)–ALK(20) and SLC34A2(4)–ROS1(32) gene fusions were adopted to prepare reference standards. Eight laboratories (five adopting amplicon-based and three hybridisation-based platforms) received, at different dilution points two sets of slides (slide A 50.0%, slide B 25.0%, slide C 12.5% and slide D wild type) stained by Papanicolaou (Pap) and May Grunwald Giemsa (MGG). Analysis was carried out on a total of 64 slides.ResultsFour (50.0%) out of eight laboratories reported results on all slides and dilution points. While 12 (37.5%) out of 32 MGG slides were inadequate, 27 (84.4%) out of 32 Pap slides produced libraries adequate for variant calling. The laboratories using hybridisation-based platforms showed the highest rate of inadequate results (13/24 slides, 54.2%). Conversely, only 10.0% (4/40 slides) of inadequate results were reported by laboratories adopting amplicon-based platforms.ConclusionsReference standards in cytological format yield better results when Pap staining and processed by amplicon-based assays. Further investigation is required to optimise these standards for MGG stained cells and for hybridisation-based approaches.


2013 ◽  
Vol 31 (15_suppl) ◽  
pp. e21523-e21523
Author(s):  
Milena Urbini ◽  
Annalisa Astolfi ◽  
Valentina Indio ◽  
Maristella Saponara ◽  
Margherita Nannini ◽  
...  

e21523 Background: A subset of KIT/PDGFRA wild-type GIST (WT) harbour mutations in SDH units. In the majority of the remaining cases of WT GIST no other molecular events are identified.We performed a RNA-seq in a WT GIST without mutations in SDH genes using next generation approach to discover molecular events in this GIST population. Methods: In 2003, a 63-year old woman underwent surgery for an ileal GIST (size 6 cm, MI 6/50HPF).After 6 years, she developed a recurrence with a single hepatic lesion. The KIT and PDGFRA analysis of the lesion did not show mutations. Therefore, she did not receive imatinib but she underwent a surgical removal. The analysis of all SDH units did not show mutations. So paired-end RNA-seq (75X2) was performed with Illumina HiScanSQ platform. After mapping the short reads on the human genome(HG19), SNVs and InDels were called by SNVMix2 with an accurate filtering procedures including predictors of mutations effect at protein level. Gene fusions discovery was done considering the agreement between DeFuse, ChimeraScan and FusionMap tools and validated by SangerSequencing using primers spanning the mRNA breakpoints. Results: Four different gene fusions and 206 non-synonymous SNVs were discovered, of which 62 were called deleterious by at least one predictor, and they are undergoing further validation. SPRED2-NELFCD gene fusion originated from an interchromosomal translocation-inversion between chr 20 and 2. The event involved exon1 of SPRED2 and exon11 of NELFCD, probably leading to inactivation of both genes. NELFCD encodes a component of the NELF complex that negatively regulates transcription elongation by RNA pol II, while SPRED2 is a member of the Sprouty /SPRED family that repress growth factor-induced activation of the MAPK/ERK pathway. The other three events were intrachromosomal aberrations: MARK2-PPFIA1 and PLA2G16-ATL3 on chr 11 and ASCC1-C10orf11 on chr 10. Only the first event led to an in-frame fusion (MARK2 ex1- PPFIA1 ex2) probably dysregulating the expression of the downstream gene. Conclusions: This is the first evidence of gene fusions in GIST. The oncogenetic role and the tumor frequency of these events deserve to be studied.


Diagnostics ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 521
Author(s):  
Rossella Bruno ◽  
Gabriella Fontanini

Gene fusions have a pivotal role in non-small cell lung cancer (NSCLC) precision medicine. Several techniques can be used, from fluorescence in situ hybridization and immunohistochemistry to next generation sequencing (NGS). Although several NGS panels are available, gene fusion testing presents more technical challenges than other variants. This is a PubMed-based narrative review aiming to summarize NGS approaches for gene fusion analysis and their performance on NSCLC clinical samples. The analysis can be performed at DNA or RNA levels, using different target enrichment (hybrid-capture or amplicon-based) and sequencing chemistries, with both custom and commercially available panels. DNA sequencing evaluates different alteration types simultaneously, but large introns and repetitive sequences can impact on the performance and it does not discriminate between expressed and unexpressed gene fusions. RNA-based targeted approach analyses and quantifies directly fusion transcripts and is more accurate than DNA panels on tumor tissue, but it can be limited by RNA quality and quantity. On liquid biopsy, satisfying data have been published on circulating tumor DNA hybrid-capture panels. There is not a perfect method for gene fusion analysis, but NGS approaches, though still needing a complete standardization and optimization, present several advantages for the clinical practice.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Weijie Chen ◽  
Huimei Wang ◽  
Dongxian Jiang ◽  
Lijuan Luan ◽  
Yuhong Zhou ◽  
...  

Abstract Background Mesenchymal sarcomas are tumors that originate from mesenchymal tissue. Most mesenchymal sarcomas can be accurately classified, but some are unclassifiable in clinical practice. Molecular detection methods enable patients to benefit from molecular-targeted therapies for many cancers, including lung, breast, and bowel cancers. Further, even unclassified tumors can have therapeutic targets. NTRK gene fusions are sporadic genetic alterations that occur across tumor entities. If NTRK gene fusions are detected, TRK inhibitors can be used regardless of the tumor entity. Case presentation This report describes a case with an unclassifiable mesenchymal sarcoma carrying a neurotrophic tyrosine receptor kinase NTRK1-KHDRBS1 gene fusion that was diagnosed and treated at multiple hospitals. Diagnostic work-up included pathological and immunohistochemical analysis, which excluded angiosarcoma, dendritic cell sarcoma, and pseudomyogenic hemangioendothelioma. The patient achieved a long-term survival without tumor relapse after treatment with crizotinib. Conclusions This case will be of significant interest to pathologists because, despite the tumor being unclassified, a molecular target was identified. Although the FDA does not currently approve crizotinib for treatment of patients harboring NTRK gene fusions, this case provides new insights for diagnosis and treatment of mesenchymal sarcomas with NTRK1 gene translocations. Similar to ALKomas, which can be successfully treated using NTRK molecular-targeted therapy, tumors with NTRK gene translocations can be classified as NTRKomas, even when they occur at different organ sites, and with varying histological morphologies, and immunophenotypes.


2021 ◽  
Author(s):  
Limin Zhu ◽  
Brian Hobbs ◽  
Jason Roszik ◽  
Vijaykumar Holla ◽  
David S. Hong

Abstract BackgroundSeveral TRK inhibitors have demonstrated clinical efficacy in patients with solid tumors harboring NTRK gene fusions. However, the natural history and prognostic implications of NTRK fusions in solid tumors remain unknown.MethodsA cohort of 77 MD Anderson Cancer Center patients (MDACC) with NTRK gene fusions was identified and retrospectively compared to a second cohort from the Cancer Genome Atlas (TCGA) database. Due to paucity of events in early stage cancers and lack of TCGA data in rare tumors, 25 randomly selected MDACC patients were matched to 122 TCGA patients without NTRK gene fusion. Next we assessed the associations between NTRK gene fusion and overall (OS) and progression-free survivals (PFS).ResultsAmong the 77 MDACC patients with NTRK gene fusions, 18 NTRK fusion partners were identified. There were insufficient OS events for analysis in the matched cohort. PFS was not significantly different (p=0.49) between the NTRK-fusion positive MDACC patients (median PFS 786 weeks, 95% CI 317-NE) and the NTRK-fusion negative TCGA patients (median PFS NE). The adjusted hazard ratio comparing TCGA patients to MDACC patients was HR=0.72 (95% CI: 0.23-2.33), which trended towards a reduced rate of progression or death experienced by TCGA patients.ConclusionsThis study did not identify statistically significant associations between NTRK fusion and PFS. Nonsignificant trends estimated increases in the risk of progression or death events for patients with NTRK fusions when compared to matched controls. Our findings help illuminate the influence of NTRK fusions on the natural history of a variety of solid tumors.


2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 8023-8023 ◽  
Author(s):  
Robert Charles Doebele ◽  
Aria Vaishnavi ◽  
Marzia Capelletti ◽  
Anh T. Le ◽  
Severine Kako ◽  
...  

8023 Background: The identification and therapeutic targeting of oncogenic drivers in lung adenocarcinoma has led to significant clinical improvements for patients with EGFR mutations or ALK fusions. However, many lung cancer patients do not yet have an identified oncogenic driver and the discovery of new actionable oncogenic drivers is thus an active area of investigation. Methods: Tumor samples from 36 ‘pan-negative’ (EGFR, KRAS, ALK, and ROS1) lung adenocarcinoma patients were analyzed using a next generation sequencing (NGS) test performed in a CLIA-certified lab (Foundation Medicine, Cambridge, MA). Fluorescence in situ hybridization (FISH) screening using a novel NTRK1 break-apart assay was performed on an additional 61 pan-negative samples. Cells expressing the novel NTRK1 fusions were assayed for transformation and pharmacologic inhibition. Results: Two tumor samples were identified with gene fusions containing the kinase domain of TrkA, encoded by NTRK1, including one each with an MPRIP-NTRK1 (M21;N14) and CD74-NTRK1 (C8;N12) fusion. RT-PCR confirmed mRNA expression and identity of the fusion partner and FISH analysis detected split 5’/3’ signals corresponding to the NTRK1 gene. A third sample was identified by FISH analysis. Cloning and expression of MPRIP- and CD74-NTRK1 into NIH3T3 and Ba/F3 cells show constitutive activation of the TrkA kinase domain and transformation. Treatment of cells expressing NTRK1 fusions with several candidate pan-Trk inhibitors (ARRY-772, -523, and -470) as well as CEP-701 and crizotinib demonstrate decreased phosphorylation of the fusion oncoprotein and inhibition of cell proliferation. Treatment of the index patient harboring the MPRIP-NTRK1fusion with crizotinib led to minor transient tumor shrinkage. Conclusions: We identified a novel class of oncogenes, NTRK1 fusions, in lung adenocarcinomas that can be detected by NGS or FISH. Additional studies to determine the frequency and characteristics of NTRK1 fusions in lung cancer are ongoing. Our findings suggest prospective clinical trials of Trk inhibitors in NTRK1 fusion positive patients may be warranted. Support: CO Bioscience Discovery and Evaluation Grant and CO Clinical and Translational Sciences Institute Grant.


2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 11580-11580 ◽  
Author(s):  
Anna F. Farago ◽  
Martin S Taylor ◽  
Robert Charles Doebele ◽  
Alexander I. Spira ◽  
Theresa A Boyle ◽  
...  

11580 Background: Gene fusions involving NTRK1/2/3 can generate oncoproteins containing the kinase domains of TRKA/B/C, respectively. Inhibition of TRK signaling has led to dramatic responses across tumor types with NTRK fusions. An estimated 0.1 – 1% of NSCLCs harbor NTRK fusions. To date, clinical and radiographic responses to TRK inhibitors have been reported for 2 NTRK fusion-positive NSCLCs (Farago et al., 2015; Hong et al., 2016). Despite the potential benefit of identifying these fusions, the clinicopathologic features of NTRK fusion NSCLCs are not well characterized. Methods: Physicians across multiple institutions contributed deidentified cases to an NTRK fusion NSCLC database. A central pathologist (M.M.) reviewed tumor histology in cases with available tissue. Results: 10 NSCLC cases with NTRK gene fusions were identified. Of these, TRK kinase domain-containing potentially activating fusions were verified by next-generation sequencing (NGS) in 7, forming the study cohort. Fusions involved NTRK1 (6) and NTRK3 (1) with 6 different partners. Four (57%) patients were male. Median age at diagnosis was 47.6 years (range 27.9 – 86.0). The average smoking pack year history was 8.9 (range 0 to 30). Five (71%) presented with metastatic disease. No concurrent alterations in KRAS, EGFR, ALK, ROS1, or other known drivers were identified in the study cohort cases. On pathologic review of 4 cases, all were adenocarcinoma, including 2 invasive mucinous adenocarcinomas and 1 adenocarcinoma with neuroendocrine features. Of the 3 remaining non-study cohort cases, 1 was a non-kinase domain-containing NTRK1 fusion with a concurrent KRAS G12C mutation, 1 was an NTRK2 intragenic deletion disrupting the exon 18 3’ splice site, and 1 was an NTRK1 alteration detected by FISH but not verified by NGS and with a concurrent HER2 L755P mutation. Conclusions: NTRK fusions occur in both men and women across wide ranges in age and smoking history. We therefore suggest that all NSCLC adenocarcinomas without other oncogenic driver alterations be screened for NTRK fusions. Notably, not all NTRK alterations are activating, requiring validation of the specific position of the fusion.


2019 ◽  
Vol 180 (4) ◽  
pp. 235-241 ◽  
Author(s):  
K van der Tuin ◽  
M Ventayol Garcia ◽  
W E Corver ◽  
M N Khalifa ◽  
D Ruano Neto ◽  
...  

ObjectiveGene alterations leading to activation of the MAPK pathway are of interest for targeted therapy in patients with advanced radioactive iodine refractory (RAI-R) thyroid carcinoma. Due to technical reasons gene fusion analysis in RNA isolated from formalin-fixed tumor tissues has till now been limited. The objective of the present study was to identify targetable gene rearrangements in RNA isolated from formalin-fixed RAI-R thyroid carcinomas.DesignRetrospective study in 132 patients with RAI-R thyroid carcinoma (59 papillary-, 24 follicular-, 35 Hürthle cell- and 14 anaplastic thyroid carcinoma).MethodsTotal nucleic acid (undivided DNA and RNA) was isolated from formalin-fixed tissue. Extensive gene fusion analysis was performed in all samples that tested negative for pathogenicBRAF,NRAS,HRASandKRASvariants.ResultsSeven targetable gene fusions were identified in the remaining 60 samples without known DNA variants. This includes frequently reported gene fusions such asCCDC6/RET(PTC1),PRKAR1A/RET(PTC2) andETV6/NTRK3, and gene fusions that are less common in thyroid cancer (TPM3/NTRK1,EML4/ALKandEML4/NTRK3). Of note, most gene fusions were detected in papillary thyroid carcinoma and MAPK-associated alterations in Hürthle cell carcinomas are rare (2/35).ConclusionTargetable gene fusions were found in 12% of RAI-R thyroid carcinoma without DNA variants and can be effectively identified in formalin-fixed tissue. These gene fusions might provide a preclinical rationale to include specific kinase inhibitors in the treatment regimen for these patients. The latter intends to restore iodine transport and/or take advantage of the direct effect on tumor cell vitality once progressive disease is seen.


2021 ◽  
Vol 8 ◽  
Author(s):  
Fernando Schmitt ◽  
Alessia Di Lorito ◽  
Philippe Vielh

Cytology samples are suitable for the study of genotypic and phenotypic changes observed in different tumors. Being a minimally invasive technique, cytology sampling has been used as an acceptable alternative to track the alterations associated with tumor progression. Although the detection of gene mutations is well-established on cytology, in the last few years, gene fusion detections are becoming mandatory, especially in some tumor types such as lung cancer. Different technologies are available such as immunocytochemistry, fluorescence in situ hybridization, reverse transcription-polymerase chain reaction, and massive parallel sequencing approaches. Considering that many new drugs targeted fusion proteins, cytological samples can be of use to detect gene fusions in solid and lymphoproliferative tumor patients. In this article, we revised the use of several techniques utilized to check gene fusions in cytological material.


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