NTRK1 Research Articles

NTRK gene fusion and molecular pathological characteristics of mismatch repair deficient colorectal cancer

Objective: To investigate the expression pattern of pan-TRK protein in colorectal cancers with NTRK gene fusion and mismatch repair deficient (dMMR) and to analyze its molecular pathological characteristics. Methods: A total of 117 dMMR colorectal cancers diagnosed in the Department of Pathology of Henan Provincial People's Hospital, Zhengzhou, China from 2020 to 2023 were collected. Immunohistochemistry (IHC), fluorescence in situ hybridization (FISH) and DNA/RNA-based next-generation sequencing (NGS) were used to detect pan-TRK protein expression and fusion partner genes in tumors, and to further explore the correlation between pan-TRK staining patterns and partner genes. Results: IHC and FISH were performed successfully in formalin-fixed paraffin-embedded tissues from 117 dMMR colorectal cancer patients. There were 15 (15/117, 12.8%) cases with positive pan-TRK, including 6 cases with strong staining in tumor cell membrane and cytoplasm, 2 cases with weakly granular staining in tumor cytoplasm, 2 cases with moderate dot-like staining in near 5% tumor cell nuclei, 1 case with moderately to strongly granular staining in the cytoplasm and membrane of tumor cells, 1 case with moderately to weakly granular staining in about 60% of the tumor cells, 1 case with strongly staining in about 1% of the tumor cells, 1 case with moderately to strongly staining in about 3% of the tumor cells and 1 case with diffuse, moderate para-nuclear dot-like and weakly perinuclear granular staining. NTRK1 gene disruption was detected in 6 cases (6/117, 5.1%) and consistent with diffusely strong expression of pan-TRK. Based on DNA/RNA NGS, it was further confirmed that the 6 cases with NTRK1 gene disruption all carried TPM3-NTRK1 fusion gene, and all had high microsatellite instability and high tumor mutation burden. No KRAS, NRAS, BRAF V600E or TP53 gene mutations were detected. Four patients carried frame shift mutations in RNF43. Other molecular changes included 3 cases with ROS1 gene mutation, 2 cases with BRAC, ALK, and EGFR gene mutations, 2 cases with ATM gene mutation, and 2 cases with KIT gene mutation. These were missense/frame shift mutations that were associated with no clinical significance. The nine pan-TRK-positive cases without NTRK gene fusion detected with DNA-based NGS were further confirmed with RNA-based NGS, and no NTRK gene fusion was found. The sensitivity and specificity of NTRK gene fusion detected using IHC were 100.0% and 92.5%, respectively. The sensitivity and specificity of diffusely strong membranous/cytoplasmic staining were both 100.0%. Conclusions: Pan-TRK protein has various expression patterns in dMMR colorectal cancer. Its diffusely strong expression is highly suggestive of NTRK1 gene fusion. TPM3-NTRK1 gene fusion is a common form of NTRK gene fusion in dMMR colorectal cancer.

Identification of the clinical and genetic characteristics of gliomas with gene fusions by integrated genomic and transcriptomic analysis

The identification of oncogenic gene fusions in diffuse gliomas may serve as potential therapeutic targets and prognostic indicators, representing a novel strategy for treating gliomas consistent with the principles of personalized medicine. This study identified detectable oncogene fusions in glioma patients through an integrated analysis of genomic and transcriptomic data, which encompassed whole exon sequencing and next-generation RNA sequencing. In addition, this study also conducted a comparison of the genetic characteristics, tumor microenvironment, mutation burden and survival between glioma patients with or without gene fusions. A total of 68 glioma patients were enrolled in this study, including glioblastoma (GBM), low grade glioma (LGG) and diffuse midline glioma (DMG). 14 cases of GBM patients (51.9%, 14/27) were found to harbor the following 70 oncogenic gene fusions: ROS1 (n = 8), NTRK (n = 5), KIF5 (n = 5), RET (n = 3) and other infrequent gene fusions (n = 49). A total of 11 gene fusions were identified in 8 LGG patients (32.0%, 8/25) and seven gene fusions were identified in one DMG patient (16.7%, 1/6). In GBM patient group, five genes including HOXA3, ACTB, CDK5, GNA12 and CARD11 exhibited a statistically significant higher copy number amplification frequency in the GBM group without gene fusions compared to that in the GBM group with gene fusions. In LGG patient group, CDK5 gene was also found to exhibit a statistically significant higher amplification frequency in the LGG group without gene fusions. In addition, KMT2D exhibited a statistically significant higher mutation frequency in the LGG group with gene fusions compared to that in the LGG group without gene fusions. Comparison of the other genetic characteristics including immune cell infiltration score, tumor mutation burden (TMB), and microsatellite instability (MSI). The results showed no statistically significant differences were observed between fusion and non-fusion group of GBM and LGG. The survival analysis revealed that GBM patients without gene fusions exhibited a longer median survival (737 days) compared to GBM patients with gene fusions (642 days), but without a statistical significancy. Our study has identified a set of gene fusions present in gliomas, including a number of novel gene fusions that have not been previously reported. We have also elucidated the underlying genetic characteristics of glioma with gene fusions. Collectively, our findings have the potential to inform future clinical treatment strategies for patients with glioma.

Analytical performance of OncoPrism-HNSCC, an RNA-based assay to inform immune checkpoint inhibitor treatment decisions for recurrent/metastatic head and neck squamous cell carcinoma

BackgroundWhile immune checkpoint inhibitor (ICI) therapies can significantly improve outcomes for patients with recurrent/metastatic head and neck squamous cell carcinoma (RM-HNSCC), only about 15–20% benefit from such treatments. Clinical tests that guide the use of ICIs are therefore critically needed. OncoPrism-HNSCC was developed to address this need. The assay combines next generation RNA sequencing-based immunomodulatory gene expression signatures with machine learning algorithms to generate an OncoPrism score that classifies patients as having low, medium, or high likelihood of disease control in response to ICI treatment. Also, OncoPrism-HNSCC leverages the same FFPE patient tumor RNA used for ICI response prediction to identify rare cases where oncogenic rearrangements in NTRK1/2/3 or ALK genes may occur, and which may indicate the use of potentially highly effective targeted therapies. The clinical performance of OncoPrism-HNSCC has been validated. Here, we report its analytical performance in the presence of potentially confounding sources of variation.MethodsThe assay’s analytical sensitivity was assessed by varying RNA input quantity and quality, observing the effect on ICI response prediction scores. Analytical specificity was tested by spiking increasing percentages of genomic DNA into input RNA. Intra-assay and inter-assay precision were evaluated, and the analytical sensitivity, specificity, and precision of gene fusion detection were assessed. Concordance with orthogonal methods of gene fusion detection was tested on 67 FFPE clinical samples.ResultsVarying RNA inputs as low as four-fold below the nominal input amount had little effect on ICI response prediction scores. RNA quality levels below the test threshold had no significant effect. Genomic DNA spike-ins up to 30% had only a small effect on scores. The pooled standard deviation for multiple operators, reagent lots, batches, and sequencers yielded an overall variance represented by just 0.87% of the score range of the test (0–100). NTRK and ALK gene fusion detection was 100% concordant with orthogonal methods.ConclusionsRobust and reliable analytical performance of the OncoPrism-HNSCC assay supports its clinical use, even in the presence of variation typically encountered in the laboratory setting.

NTRK amplification occurs frequently in pan-TRK immunopositive dedifferentiated liposarcomas.

The neurotrophic tyrosine kinase receptor (NTRK) gene family is of rising importance as their fusions are oncogenic, and specific target drugs are available to inhibit the chimera proteins. Pan-TRK antibody, which shows the overexpression of the NTRK1-2-3 genes, is a useful tool to detect tumors with or without NTRK gene alterations, due to high negative predictive value. Though it is well known that pan-TRK immunopositivity is usually not connected to NTRK fusion, the role of other possible genetic alterations is under-researched. In our previous work, we found 3 NTRK1 amplified cases out of 6 cases with recurrent NTRK1 tyrosine kinase domain mutation pair, so we extended our investigation to a larger series to estimate amplification frequency. Pan-TRK immunopositivity was seen in 76 of the 132 dedifferentiated liposarcomas cases, followed by NTRK1-2-3 break-apart FISH tests in 76 pan-TRK positive cases to detect oncogenic fusions or other copy number alterations of these genes. None of the pan-TRK immunopositive dedifferentiated liposarcomas showed absolutely certain sign of fusion, however, 18 (28%) cases showed amplification of one of the genes, 13 had polysomy, 34 were normal, 11 were not evaluable. The extent of pan-TRK immunoreaction showed a positive correlation (p = 0.002) with the NTRK status found by FISH. Analyzing publicly available data from large series of 265 liposarcoma samples consisting of both well-differentiated and dedifferentiated liposarcoma case, 23 (8.6%) cases showed a mutual exclusive amplification of the NTRK genomic loci in a non-preselected, independent patient population indicating that our findings are presented in other cohorts. Our results underline the so far not revealed frequent occurrence of NTRK amplifications which might be important in the TRK inhibition therapy.

Design, synthesis and biological evaluation of novel 1H-indole-3-carbonitrile derivatives as potent TRK Inhibitors.

Tropomyosin receptor kinase (TRK) has emerged as a promising therapeutic target in cancers driven by NTRK gene fusions. Herein, we report a highly potent TRK inhibitor, C11, developed using bioisosteric replacement and computer-aided drug design (CADD) strategies. Compound C11 demonstrated significant antiproliferative effects against TRK-dependent cell lines (Km-12), and exhibited a dose-dependent inhibition of both colony formation and cell migration. Mechanistic study revealed that C11 induced cancer cell death by arresting the cell cycle, triggering apoptosis, and reducing phosphorylated TRK levels. In vitro stability assays showed that compound C11 possessed excellent plasma stability (t1/2>480min) and moderate liver microsomal stability (t1/2=38.9min). Pharmacokinetic evaluation further indicated an oral bioavailability of 15.2% for compound C11. These results highlight compound C11 as a promising lead compound for the further development of TRK inhibitors.

Response to EGFR/NTRK/MET Co-Inhibition Guided by Paired NGS in Advanced NSCLC With Acquired EGFR L858R/T790M/C797S Mutations.

EGFR tyrosine kinase inhibitors (TKIs) have significantly improved clinical outcomes for patients with non-small cell lung cancer (NSCLC) harboring EGFR-activating mutations. However, resistance to TKI therapy often develops due to secondary EGFR mutations or the activation of bypass signalling pathways. Next-generation sequencing (NGS) can efficiently identify actionable genetic alterations throughout treatment. MET amplification is a well-established off-target resistance mechanism. Additionally, rarer mechanisms, such as NTRK1 gene fusions, have been reported. This report highlights a case of a 58-year-old male diagnosed with bone-metastatic NSCLC harboring the EGFR L858R mutation. After receiving dacomitinib and almonertinib sequentially, plasma-based NGS revealed the emergence of EGFR T790M-trans-C797S mutations, prompting a switch to a combination therapy of almonertinib and gefitinib. Upon disease progression, repeat NGS identified EGFR T790M-cis&trans-C797S mutations and a novel POT1::NTRK3 fusion in the blood. The fusion retained a complete NTRK kinase domain without frameshift variants, making it a target for treatment. Larotrectinib was incorporated into the dual EGFR-TKI regimen, forming a triplet therapy. Although this resulted in grade 3 dermatitis, the condition resolved after discontinuing gefitinib. At multiorgan progression, matched tissue- and plasma-based NGS identified MET amplification. Subsequently, the patient was started on a triple-inhibition regimen targeting EGFR, NTRK, and MET, which achieved a partial response with favorable tolerability. This is the first reported case of a novel, targetable POT1::NTRK3 fusion as a potential off-target mechanism mediating EGFR-TKI resistance, occurring alongside MET amplification in a patient with NSCLC harboring acquired EGFR L858R/T790M/C797S mutations. Concomitant inhibition of EGFR, NTRK, and MET was safe and resulted in a significant response, underscoring the importance of precision medicine guided by matched NGS.

NTRK translocation: from general to specific

The molecular-genetic profile of lung cancer is highly diverse, complicating the formation of a unified patient portrait and necessitating the incorporation of specific genetic testing into diagnosis. There are key mechanisms for the activation of oncogenes, including point mutations, copy number changes (amplifications), and fusions, which are observed in non-small cell lung cancer (NSCLC). Modern molecular-targeted therapy for patients with NSCLC increases the duration of disease control and, in some cases, can transform a once-fatal disease into a chronic condition. Currently, the standard testing panel includes the identification of mutations in the EGFR gene (exons 18–21), ALK translocations, ROS1 translocations, and BRAF V600E mutations. However, less common alterations such as RET and NTRK translocations also occur. The use of next-generation sequencing (NGS) allows for the identification of rarer genetic alterations. NTRK gene fusions are considered oncogenic factors for various solid tumors in both adults and children. The prevalence of NTRK gene alterations varies by tumor type. However, in lung cancer, this type of genetic alteration is rare, with an overall prevalence of less than 3%, and typically the occurrence rate is less than 1%. Currently, three drugs have been included in international clinical guidelines as potential treatment options for NTRK translocations, demonstrating their effectiveness. Several other drugs are at various stages of clinical trials. In this review, we will highlight the existing data for a better understanding of the patient profile with NTRK and present a clinical case.

Clinical Characteristics and Outcomes of Central Nervous System Tumors Harboring NTRK Gene Fusions.

Tropomyosin receptor kinase (TRK) fusions are detected in less than 2% of central nervous system tumors. There are limited data on the clinical course of affected patients. We conducted an international retrospective cohort study of patients with TRK fusion-driven central nervous system tumors. A total of 119 patients were identified. The median age at the time of diagnosis was 4.5 years. The majority were reported to have a histology consistent with a diagnosis of high-grade glioma (HGG; 57.1%) followed by low-grade glioma (LGG; 27.7%). Pediatric patients had a better prognosis, with a median overall survival of 185.5 months compared with 24.8 months in adults (P < 0.0001). Patients with LGG also had a better outcome when compared with HGG (P = 0.0012). The objective response was 68.8% with larotrectinib compared with 38.1% for nontargeted treatment. Children with LGG had a favorable outcome compared with adult glioma and HGG. TRK inhibitors seem to improve tumor control.

Clinicopathologic and Molecular Analysis of 15 Pediatric and Young Adult Patients with High-Grade Non-anaplastic Thyroid Carcinoma.

High-grade follicular cell-derived non-anaplastic thyroid carcinomas are uncommon and typically diagnosed in the sixth to seventh decade of life. These tumors are rare in the pediatric (≤ 18 years old) and young adult (19-21 years old) populations. The molecular landscape of pediatric and young adult thyroid neoplasia has been suggested to be enriched inDICER1 gene alterations. Our intent was to evaluate pediatric and young adult high-grade follicular cell-derived non-anaplastic thyroid carcinomas for driver mutations. Thyroid carcinomas involving individuals under the age of 21 years were retrieved from our institutional archives. The patient population included 13 females and 2 males aged 9-20 years. Six patients were aged 9-16 years and nine patients were aged 19-20 years. The carcinomas were classified as poorly differentiated thyroid carcinoma (PDTC) (n = 6) and differentiated high-grade thyroid carcinoma (DHGTC) (n = 9). Two were poorly differentiated oncocytic thyroid carcinomas, and two were poorly differentiated follicular thyroid carcinomas. A well-differentiated component was not identified in 2 PDTCs. The DHGTCs were subclassified as follicular thyroid carcinoma (n = 4), classic subtype papillary thyroid carcinoma (n = 4), and oncocytic thyroid carcinoma (n = 1). Molecular evaluation revealed one differentiated high-grade follicular thyroid carcinoma, two poorly differentiated follicular thyroid carcinomas, and two PDTCs with DICER1 gene alterations. A DICER1-altered PDTC, DICER1-altered poorly differentiated follicular thyroid carcinoma, and a poorly differentiated oncocytic thyroid carcinoma had TP53 gene alterations. BRAF V600E immunohistochemistry (IHC) was positive in two cases. PanTRK IHC was positive in two cases, one of which had a confirmed SQSTM1::NTRK3 gene fusion. Immunohistochemistry for PTEN showed loss of expression in two tumors, one of which had a loss of function PTEN germline alteration. Clinical follow-up was available for 14 patients (range 24-347 months, median 101 months). Four patients had local/regional recurrences, and one patient had distant recurrences (bones and liver). At last, follow-up 10 patients were alive with no evidence of disease, 1 was alive with disease, 1 was alive with an unknown status, 1 died of disease, and 1 died of unknown causes. In summary, we report 15 additional cases of pediatric and young adult high-grade follicular cell-derived non-anaplastic thyroid carcinoma, with a subset harboring DICER1 (n = 5), NTRK (n = 2), and PTEN (n = 2) gene alterations. In this limited case series, two patients were dead at the last follow-up. Whether these findings are consistent within this patient population remains to be addressed as more patient series are published.

Congenital Insensitivity to Pain and Anhidrosis With Orthopedic and Self-Injury Complications in a 5-Year-Old Boy: A Case Report.

Congenital insensitivity to pain with anhidrosis (CIPA) is a rare autosomal recessive disorder because of NTRK1 gene mutations, leading to an inability to perceive pain and temperature and lack of sweating. Its rarity and unique clinical challenges, such as severe injuries from the inability to sense pain, make reporting cases critical. A 5-year-old boy, the third child of consanguineous parents, was referred for a fractured femur. His history includes recurrent fevers, pain insensitivity, self-mutilation, and anhidrosis with compensatory hyperhidrosis. Examination showed multiple ulcers, dry skin, missing digits, dental issues, and corneal ulcers. The neurological assessment confirmed loss of pain and temperature sensation. Genetic testing confirmed NTRK1 mutations, diagnosing CIPA. The femur fracture was treated with a hip spica cast, and injury prevention and temperature management were advised to the parents. This case underscores the importance of early diagnosis and comprehensive management of CIPA, highlights the need for genetic counseling for at-risk families, and provides insights into managing the condition's complex challenges. A multidisciplinary approach is essential to improve patient outcomes and quality of life.

CTNI-07. LONG-TERM EFFICACY AND SAFETY OF LAROTRECTINIB IN PATIENTS WITH TRK FUSION PRIMARY CENTRAL NERVOUS SYSTEM (CNS) TUMORS: AN UPDATED ANALYSIS

Abstract BACKGROUND Larotrectinib is a highly selective TRK inhibitor approved for TRK fusion tumor-agnostic use. We report updated data on larotrectinib-treated patients with TRK fusion primary CNS tumors. METHODS Patients enrolled in 2 clinical trials (NCT02637687 [SCOUT], NCT02576431 [NAVIGATE]) were included. Responses were independent review committee (IRC)-assessed (RANO). Patients from SCOUT could stop larotrectinib in the absence of on-treatment progression (wait-and-see). Data cutoff: July 2023. RESULTS Fifty-five patients (38 aged &amp;lt;18 years at enrolment) were evaluated, including 16 with non-measurable disease at baseline. Tumor histologic groups included: high-grade glioma (HGG; n=32), low-grade glioma (LGG; n=15), and other (n=8). For all patients (n=55), ORR was 27% (95% CI 16-41): 3 CR, 12 PR, 24 SD (15 for &amp;gt;24 weeks), 12 PD, and 4 not evaluable. For pediatric patients (n=38), ORR was 37% (95% CI 22-54). ORR in patients with measurable disease only was 38% (95% CI 23-55) for all patients (n=39) and 52% (95% CI 32-71) for pediatric patients (n=27). The 24-week disease control rates were 55% (95% CI 41-68) and 74% (95% CI 57-87) for all patients and pediatric patients, respectively. Median time to response, DoR, PFS, and OS were 2, 12 (95% CI 6-not estimable [NE]), 12 (95% CI 7-20), and 38 months (95% CI 23-NE), respectively. Treatment duration ranged from 1 to 64+ months. At data cutoff, 1 pediatric patient with HGG and 4 with LGG entered wait-and-see; median duration of first wait-and-see period was 20 months (range 4-29). One pediatric patient with LGG resumed treatment following disease progression in wait-and-see. Treatment-related adverse events were predominantly Grade 1/2. CONCLUSION Larotrectinib demonstrated rapid, durable responses and manageable safety in patients with TRK fusion primary CNS tumors. This supports the adoption of NGS panels containing NTRK gene fusions when testing patients to identify those who might benefit from TRK inhibitor therapy.

Association of NTRK2 gene with suicidality: a meta-analysis.

Previous studies have shown that genes in brain development pathways may have important roles in affecting risk of suicidal behaviors, with our previous meta-analysis supporting a role of the brain-derived neurotrophic factor (BDNF) gene. NTRK2 is a gene that encodes the neurotrophic receptor tyrosine kinase 2, which is a receptor for BDNF. In the current study, we aim to examine the potential association between NTRK2 single nucleotide polymorphism (SNPs) and suicidal ideation/behaviors. We first conducted a literature search using keywords like 'NTRK2', 'TRKB', and 'suicid*' to identify papers on NTRK2 SNPs and suicidal ideation/behaviors. In addition, we have individual-level genotype data for all the identified SNPs in literature search. We used the R meta package to perform meta-analyses on both the genotype count and the allele count data. Moreover, we performed meta-analyses on specific haplotypes within each haplotype block. Following our literature search and meta-analyses on 20 NTRK2 SNPs across up to 8467 samples, we found three SNPs, rs10868235 [N = 5,318, odds ratio (OR) = 1.34, P = 0.02], rs1867283 (N = 5,134, OR = 0.73, P = 0.04), and rs1147198 (N = 5,132, OR = 1.36, P = 0.03) to be nominally associated with suicidal attempts. Those three findings, however, did not survive multiple-testing corrections. Also, none of the haplotype blocks showed significant involvement in suicidality. Our results suggest that the NTRK2 gene may not have a major role in suicidality. Future efforts, however, should explore gene-gene interaction and pathway analyses.

The genomic landscape of papillary thyroid carcinoma on next-generation sequencing in patients undergoing total thyroidectomy.

Thyroidectomy is increasingly performed for suspected malignancy. This cohort study aimed to identify genetic markers associated with malignancy and determine the molecular landscape of papillary thyroid carcinoma (PTC) through next-generation sequencing (NGS) in patients undergoing total thyroidectomy. Among 116 surgical candidates, 103 patients (age=42.9±13.7years; Male: Female=14:89) with benign or malignant thyroid nodules were eligible. Live thyroid tissue samples harvested intraoperatively with adequate DNA and RNA yield were subjected to NGS on the Illumina NovaSeq 6000 platform for genomic and transcriptomic analysis, respectively. Histopathology comprised 20 malignant (19.4%) and 83 benign (80.6%) cases, including 16 PTC (15.5%) cases. On NGS, single nucleotidepolymorphisms (SNPs) in NTRK1 at NC_000001.11:156879016 on chromosome 1 and ALK at NC_000002.12:29717663 on chromosome 2 were frequent in malignant lesions (p<0.05). A SNP in ALK at NC_000002.12:29193706 was consistently a homozygous alternate alleleacross the cohort. DNA-sequencing of PTC lesions identified recurrentsomatic mutations in BRAF (100%), ALK (56.3%), RET (18.8%), PIK3CA (12.5%), NTRK1 (12.5%), NTRK2 (87.5%), NTRK3(12.5%), NRAS(6.3%), and PTCH1 (31.3%) genes. RNA sequencing revealednovelfusiongenes, including MKRN1-BRAF, RN7SL1-CDH1, IRF2BPL-MED12, MED12-IRF2BPL, CPM-MDM2, and AC005895.3-PDGFRB. Inreceiveroperative characteristics analysis, the AUCs ofALKmutationpredictingrecurrence and metastases were 0.818 and 0.783. This Indian study identified novel somatic mutations and fusion genes in PTC, revealing a distinct genomic landscape with implications in precision diagnostics and personalized therapies. NGS with intraoperative live sampling shows promise in prognostication and therapeutic optimization of advanced/metastatic PTC cases. CTRI/2020/09/027607dt 04/09/2020; REF/2020/08/036119.

Evolving Patient-Centred Therapies for Metastatic NSCLC

The metastatic non-small cell lung cancer (mNSCLC) treatment landscape has vastly expanded over the past two decades as a result of advancements in biomarker testing. However, unmet needs remain both in terms of treatment options for some patient groups, and patient support throughout the treatment journey. In this symposium, Jarushka Naidoo, Consultant Medical Oncologist, Beaumont RCSI Cancer Centre, Dublin, Ireland; Terri Conneran, KRAS Kickers, Charlotte, North Carolina, USA; Luis Paz-Ares, Chair of the Medical Oncology Department, Hospital Universitario 12 de Octubre, Madrid, Spain; and Alexander Drilon, Chief of Early Drug Development and Thoracic Oncology, Memorial Sloan Kettering Cancer Center, New York, USA, focused on patient-centric approaches to mNSCLC treatment, starting with a patient and patient advocacy group perspective on what patients want from their care team during their treatment journey. The panel also discussed both immuno-oncology (I-O) monotherapy and combination therapy, including dual I-O therapies for patients with programmed death-ligand 1 (PD-L1) tumour expression &lt;1%, as well as the treatment landscape for KRASG12C-mutated mNSCLC, and ongoing trials of KRAS-targeted agents. In addition, the latest data on tyrosine kinase inhibitors (TKI) for patients with alterations in ROS1 and NTRK genes were discussed, focusing on next-generation TKIs. Finally, the panel discussed patient cases, taking into account specific considerations and how to best approach treatment decisions.

Living without pain: A 10-year study of congenital insensitivity to pain with anhidrosis.

Congenital Insensitivity to Pain with Anhidrosis (CIPA) is a rare hereditary neuropathy caused by NTRK1 gene mutations, predisposing patients to recurrent infections and chronic wounds. Long-term studies on microbial and clinical outcomes in CIPA are limited. This study presents analysis of infection patterns, antibiotic resistance, and clinical outcomes in CIPA patients. A comprehensive ten-year retrospective cohort study was conducted at Soroka University Medical Center, Beer Sheva, Israel, from January 2014 to January 2023. Electronic medical records were reviewed to identify 63 CIPA patients, all were of consanguineous Bedouin families. Data collection included demographic details, clinical presentations, genetic analysis, documentation of infections, wound sites, hospital duration, and surgical interventions. Staphylococcus aureus, notably methicillin-resistant, dominated, with Gram-negative bacteria common in lower limbs. The study noted reduced extended-spectrum beta-lactamase bacteria and linked demographic factors to infection traits, antibiotic resistance, and surgical needs. This study provides valuable insights into the clinical and microbial patterns of CIPA, highlighting dynamic shifts in microbial compositions and antibiotic resistance profiles over time. Staphylococcus aureus, and Gram-negative bacteria particularly in lower limb infections, pose significant challenges in patient management. The findings underscore the importance of tailored approaches to address evolving microbial profiles and optimize patient care in CIPA. Key Message: This is the largest cohort study on CIPA to date, highlighting the dominance of Staphylococcus aureus, including methicillin-resistant strains, and significant Gram-negative bacterial infections in lower limbs. Contribution to Literature: It draws parallels between infection dynamics in CIPA and diabetic foot ulcers, emphasizing similar challenges due to neuropathy and ischemia, enhancing understanding of infection susceptibility and management in neuropathic conditions. The findings inform clinical practices by detailing infection and resistance patterns, supporting the development of targeted treatment strategies to improve outcomes for CIPA and similar conditions.

Rare Presentation of Extraskeletal Osteosarcoma Mimicking Phyllodes Tumor

Abstract Introduction/Objective A 57-year-old female presented with a palpable mass in the left breast, measuring up to 9 cm by ultrasound. core needle biopsy identified an atypical spindle cell lesion. The differential diagnosis included a metaplastic carcinoma, borderline phyllodes tumor, malignant phyllodes tumor with potential sarcomatous transformation. Methods/Case Report Histological examination of the tumor was performed, and immunohistochemical stains were conducted to characterize the lesion. Further consultation with a specialized pathologist at the University of Michigan was sought to confirm the diagnosis. Molecular analysis was performed to assess for specific genetic alterations and expression patterns. The histological examination revealed a proliferation of atypical spindle cells forming a fascicular and storiform pattern, with numerous large, pleomorphic, multinucleated tumor cells and a high mitotic rate. Immunohistochemical stains showed strong positivity for CD10 and vimentin, with focal weak expression for desmin, and negativity for a broad panel of cytokeratins and other markers. Consultation with Dr. Abbott at the University of Michigan supported the diagnosis of extraskeletal osteosarcoma. Molecular analysis revealed PD-L1 expression and absence of NTRK gene fusions. FISH analysis showed suggestive alterations including loss of BRAF gene, loss of MYC, and suggestive gains or polysomy of PTEN gene. Results (if a Case Study enter NA) NA Conclusion The case represents a rare presentation of extraskeletal osteosarcoma in the breast, with distinctive histological and immunohistochemical features. The comprehensive workup including histology, immunohistochemistry, and molecular analysis aids in accurate diagnosis and potential therapeutic implications. Further research may elucidate the underlying mechanisms and treatment options for this uncommon malignancy.

NTRK Gene Expression Analysis in Oral Squamous Cell Carcinoma Mexican Population.

Oral cancer holds the sixth position in malignancies worldwide; 90% correspond to oral squamous cell carcinoma (OSCC). Diverse reports suggest that NTRK genes and their receptors are key oncogenesis regulators to tumor progression in human cancers. Objective: To analyze the NTRK and Trk expression and their association with clinicopathological features of OSCC in Mexican patients' samples. Material and Methods: We analyzed 95 OSCC cases of pan-trk immunoexpression through a software-assisted method. Gene expression was analyzed by RT-qPCR employing the ΔΔCT method. Kruskal-Wallis and Spearman's correlation tests were performed. Results: Our mean age was 62.4 (±16.9) years. A total of 37 cases were tumors in the lateral border of the tongue. Age was significantly associated with the anatomical site. 42% (40 of 95) cases were pan-trk positive. A total of 21 cases showed intense immunoexpression predominantly in poorly differentiated OSCC, with a significant correlation between immunoexpression and age and gender. Gene expression showed that poorly differentiated cases exhibited higher NTRK2 expression, while well-differentiated cases demonstrated NTRK3 significantly higher expression. Conclusions: Our results suggest that NTRK family expression is present in OSCC, with differential expression related to differentiation degree. Additional information about their activation or mutational status could reinforce their potential as a possible primary or adjuvant treatment target.

Updated EANO guideline on rational molecular testing of gliomas, glioneuronal, and neuronal tumors in adults for targeted therapy selection - Update 1.

The standard of care for adult patients with gliomas, glioneuronal and neuronal tumors consists of combinations of surgery, radiotherapy, and chemotherapy. For many systemic cancers, targeted treatments are a major part of the standard treatment, however, the predictive significance of most of the targets for treatment in systemic cancer are less well established in central nervous system (CNS) tumors . In 2023 the EANO Guideline Committee presented evidence based recommendations for rational testing of molecular targets for targeted treatments. From all targets reviewed, only testing for BRAF V600E mutations was of proven clinical benefit; despite regulatory approvals for tumor agnostic treatment of NTRK gene fusions and high Tumor Mutational Burden (TMB) for patients with adult brain tumors, the evidence of clinical benefit for patients was still limited . This guideline has a modular structure, allowing regular updating of individual sections and adding new ones. The present version (Update 1) presents a review of the rationale of testing for PTEN, H3F3A, MTAP, RET and IDH, and presents an update of the text on TMB high and mismatch repair deficiency. It also presents an overview of therapeutic yield of routine next generation sequencing for mutations and fusion detection. The supplement accompanying this version contains the in depth review of all targets, whereas in the main manuscript the final recommendations of the revised and new targets are presented. Updates will be made on a regular basis.

8788 Implications of NTRK gene fusion in Papillary thyroid cancer

Abstract Disclosure: W. Medina-Torres: None. L. El Musa Penna: None. J. Segarra-Villafane: None. L.R. Sepulveda-Garcia: None. Z. Maisonet -Feliciano: None. I.C. Arroyo: None. M. Ramirez: None. M. Alvarado: None. L.A. Gonzalez-Rodriguez: None. V.J. Carlo: None. Thyroid cancer (TC) is the most common endocrine cancer. Papillary thyroid carcinoma (PTC) is the predominant contributor of this occurrence, comprising approximately 80% of all thyroid carcinomas. PTC has a good prognosis with a 5-year survival rate of more than 90% after resection. Nonetheless, factors such as tumor size, multifocality, nodal and distant metastases, characterize more aggressive cases including tall cell variant, columnar cell variant, and hobnail variant Aside from staging parameters, PTC behavior is mostly determined by morphologic variant. This is the case of 31 y/o female without known past medical history who was evaluated at endocrinology clinic due to a fine needle thyroid aspiration (FNA) positive for PTC, tall cell variant. Total thyroidectomy with central compartment dissection was performed. Pathology report presented a main tumoral mass of 3 cm but permeating multinodular pattern involving the entire gland with focal extrathyroidal extension, positive margins and six level VI positive lymph nodes. As per report, the tumor presented both papillary and follicular patterns of growth and other findings including oncocytic change, foci of clear cell change, low mitotic rate, and most notably "reverse polarization”. This pattern has the pathological features suggestive of the novel NTRK gene fusion mutation. The patient was treated with radioactive iodine (RAI) and one year post treatment there was evidence of elevated Thyroglobulin level at 904 ng/mLand thyroglobulin Ab at 2.48 IU/mL. A WBS +SPECT was done resulting in small uptake at left posterior thyroid bed and pulmonary intake. A chest CT revealed multiple bilateral sub centimeter nodules. Based on this result, a second course of RAI was given. Follow up neck ultrasound and chest CT presented persistent left level VI lymph nodes, increased amount of bilateral sub-centimeter pulmonary nodules and new thoracic(T11) lesion. FNA of left neck lymph nodes were positive for metastatic PTC for which left neck dissection was performed. Evaluation for actionable somatic mutations was requested based on resistance behavior, remarkable for TRIM33-NTRK1 chromosomal rearrangement. Patient was evaluated by Oncology service who started Larotrectinib treatment since it was approved for NTRK driven malignancies. Six-month post therapy patient achieved clinical and biochemical improvement. In the thyroid, NTRK-driven malignancies are rare and aggressive but treatable, in the evolving genomic era. As reviewed in the literature, NTRK fusion-positive TC exhibits distinctive clinicopathological features that could aid in identifying potential patients. Thus, in such patients who have PTC with non-classic pathologic patterns, specific molecular profile of the main tumor may have significant prognostic value that must be integrated into stratification system in order to provide target therapy on time. Presentation: 6/3/2024

Atypical Presentation of Congenital Insensitivity to Pain With Anhidrosis Leading to Diagnostic Odyssey.

Congenital insensitivity to pain with anhidrosis (CIPA) (OMIM 256800) is a rare autosomal-recessive condition, also known as hereditary sensory and autonomic neuropathy type IV (HSAN-IV). The most commonly reported features include anhidrosis, intellectual disability, self-mutilation, febrile episodes, impaired temperature perception, recurrent infections and/or autonomic nervous system impairment. Major joint destruction and joint deformity known as Charcot (neuropathic) joints are also seen in CIPA patients attributed to insensitivity to joint pain. We present a case of a 46-year-old female affected with CIPA with a known NTRK1 variant and previously unidentified variant. Minigene reporter constructs were generated encompassing the exon 8 to exon 13 of the NTRK1 gene using the reference sequence and one harboring c.1483 + 5G > A variant identified in our proband. Minigene constructs were transfected into HEK293T cells, and the transcript was analysed for splicing to evaluate the effect of this variant in splicing. The patient (46-year-old female) exhibited right ankle joint deformity around 5 years of age. Patient also experienced lumbar compression and knee damage in adulthood. She had undergone a significant number of evaluations without clear diagnosis. Her presentation lacked many of the common clinical presentations of CIPA, and therefore, the focus of her evaluation was directed towards her unexplained joint deformities. Exome sequencing revealed a known pathogenic variant in NTRK1 (c.851-33T > A:p.? [Intron 7]) and a novel NTRK1 variant (c.1483 + 5G > A:p.? [Intron 11]), which was later re-classified as likely pathogenic. The patient was started on a biologic disease-modifying anti-rheumatic medication (bDMARD) due to a possible inflammatory etiology of her joint deformity. Molecular diagnosis allowed for modification of her treatment and surveillance strategies. Our minigene splicing assay demonstrated that the presence of the c.1483 + 5G > A variant has a negative effect on splicing, supporting the pathogenicity of this novel variant.