Publications by authors named "Rekhtman N"

Introduction: Thoracic SMARCA4-deficient undifferentiated tumors (SMARCA4-UTs) are a recently defined group of aggressive cancers in which the effectiveness of standard treatments for lung cancer is unknown.

Methods: We collected clinical, pathologic, and demographic variables from five institutions for patients whose tumors met criteria for SMARCA4-UTs (undifferentiated phenotype and loss of SMARCA4 (BRG1) by immunohistochemistry).

Results: We identified 92 patients with SMARCA4-UTs; 58 (63%) had stage IV disease at diagnosis and 16 (17%) developed recurrent or metastatic disease after initial diagnosis.

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Histologic features, including architectural patterns, cytologic features, and 2021 World Health Organization nuclear grade have been shown to have prognostic significance in epithelioid diffuse pleural mesothelioma (DPM). Biphasic and sarcomatoid DPM, regardless of morphology, have worse outcomes. These prognostic findings are well-established but correlation of architectural patterns, cytologic features, and nuclear grade with genetic alterations has not been well studied.

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Comprehensive molecular profiling by next-generation sequencing has revolutionized tumor classification and biomarker evaluation. However, routine implementation is challenged by the scant nature of diagnostic material obtained through minimally invasive procedures. Here, we describe our long-term experience in profiling cytology samples with an in-depth assessment of the performance, quality metrics, biomarker identification capabilities, and potential pitfalls.

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  • Approximately 10% of lung adenocarcinomas (LUAD) have mucinous histology (LUADMuc), which is linked to a lighter/absent smoking history and a higher prevalence of KRAS mutations compared to LUAD without this histology (LUADnon-muc).
  • A study analyzed features and treatment outcomes of LUADMuc and LUADnon-muc patients, revealing LUADMuc patients had less aggressive disease characteristics and a poorer response to current therapies, especially immunotherapy.
  • Overall, LUADMuc showed lower objective response rates, shorter progression-free and overall survival compared to LUADnon-muc, highlighting a need for more effective treatment strategies for this subgroup.
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  • * The effectiveness of tarlatamab in other cancer types, like DLL3-expressing metastatic pulmonary carcinoid tumors, was previously unknown and lacked approved treatment options.
  • * A patient with a metastatic atypical carcinoid tumor responded positively to tarlatamab after failing several other treatments, suggesting potential benefits for other pulmonary neuroendocrine cancers.
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The diagnosis and treatment of sinonasal small round epithelial/neuroepithelial malignancies depend on the expression of conventional neuroendocrine markers (NEMs), such as synaptophysin, chromogranin A, INSM1, and CD56/NCAM1. However, these tumors remain diagnostically challenging because of overlapping histologic and immunohistochemical features. The transcriptional regulators ASCL1, NEUROD1, POU2F3, and YAP1 are novel NEM (nNEM) used for the subtyping of small-cell lung cancer (SCLC).

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Introduction: With the implementation of low-dose computed tomography screening, multiple pulmonary tumor nodules are diagnosed with increasing frequency and the selection of surgical treatments versus systemic therapies has become challenging on a daily basis in clinical practice. In the presence of multiple carcinomas, especially adenocarcinomas, pathologically determined to be of pulmonary origin, the distinction between separate primary lung carcinomas (SPLCs) and intrapulmonary metastases (IPMs) is important for staging, management, and prognostication.

Methods: We systemically reviewed various means that aid in the differentiation between SPLCs and IPMs explored by histopathologic evaluation and molecular profiling, the latter includes DNA microsatellite analysis, array comparative genomic hybridization, TP53 and oncogenic driver mutation testing and, more recently, with promising effectiveness, next-generation sequencing comprising small- or large-scale multi-gene panels.

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Approximately 50% of patients with surgically resected early-stage lung cancer develop distant metastasis. At present, there is no in vivo metastasis model to investigate the biology of human lung cancer metastases. Using well-characterized lung adenocarcinoma (LUAD) patient-derived organoids (PDOs), we establish an in vivo metastasis model that preserves the biologic features of human metastases.

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  • The study aims to understand how specific molecular changes, particularly the expression of a certain gene, influence the clinical outcomes of patients with pulmonary carcinoids, which can range from slow-growing to deadly tumors.
  • Researchers analyzed RNA sequencing data from two cohorts of pulmonary carcinoid patients (totaling 193) to determine the prognostic value of this gene expression and its relationship with telomerase activity, which is linked to tumor aggressiveness.
  • Results showed that high expression of the gene correlates with worse survival rates and is an independent predictor of poor clinical outcomes, suggesting that it could be a key factor in assessing the severity of pulmonary carcinoids.
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  • Seizure-related 6 homolog (SEZ6) is linked to neuroendocrine differentiation and has been found to be highly expressed in medullary thyroid carcinoma (MTC), as well as small cell lung carcinoma (SCLC).
  • A novel antibody drug, ABBV-011, targeting SEZ6 is currently in clinical trials for treating SCLC and neuroendocrine neoplasms, suggesting potential therapeutic applications.
  • SEZ6 shows high immunoexpression in a majority of MTC cases, making it a promising biomarker, even though it does not correlate with patient outcomes or certain mutations, highlighting its potential for targeted therapy.
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Small cell lung carcinoma (SCLC) is a highly aggressive malignancy that is typically associated with tobacco exposure and inactivation of RB1 and TP53 genes. Here, we performed detailed clinicopathologic, genomic, and transcriptomic profiling of an atypical subset of SCLC that lacked RB1 and TP53 co-inactivation and arose in never/light smokers. We found that most cases were associated with chromothripsis-massive, localized chromosome shattering-recurrently involving chromosome 11 or 12 and resulting in extrachromosomal amplification of CCND1 or co-amplification of CCND2/CDK4/MDM2, respectively.

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Comprehensive molecular profiling by next generation sequencing (NGS) has revolutionized tumor classification and biomarker evaluation. However, routine implementation is challenged by the scant nature of diagnostic material obtained through minimally invasive procedures. Here, we describe our long-term experience in profiling cytology samples with an in-depth assessment of the performance, quality metrics, biomarker identification capabilities, and potential pitfalls.

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PURPOSEThe impact of the intratumoral microbiome on immune checkpoint inhibitor (ICI) efficacy in patients with non-small-cell lung cancer (NSCLC) is unknown. Preclinically, intratumoral Escherichia is associated with a proinflammatory tumor microenvironment and decreased metastases. We sought to determine whether intratumoral Escherichia is associated with outcome to ICI in patients with NSCLC.

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  • Targeting cell surface molecules with therapies like radioligands and antibodies has been effective in treating various cancers, but the impact of lineage plasticity on these markers is still poorly understood.
  • A specific example of lineage plasticity is the transformation of prostate adenocarcinoma to neuroendocrine prostate cancer, which poses significant treatment challenges and worsens patient survival rates.
  • Research using advanced single-cell analyses and large tumor sample studies revealed significant phenotypic variability and shared gene-regulatory networks between NEPC and small cell lung cancer, raising concerns about the effectiveness of current therapies while suggesting potential for better patient selection in clinical trials.
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Small cell carcinomas (SMC) of the lung are now molecularly classified based on the expression of transcriptional regulators (NEUROD1, ASCL1, POU2F3, and YAP1) and DLL3, which has emerged as an investigational therapeutic target. PLCG2 has been shown to identify a distinct subpopulation of lung SMC with stem cell-like and prometastasis features and poor prognosis. We analyzed the expression of these novel neuroendocrine markers and their association with traditional neuroendocrine markers and patient outcomes in a cohort of bladder neuroendocrine carcinoma (NEC) consisting of 103 SMC and 19 large cell NEC (LCNEC) assembled in tissue microarrays.

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Background: Delta-like ligand 3 (DLL3) is aberrantly expressed on the surface of small-cell lung cancer (SCLC) and neuroendocrine prostate cancer cells. We assessed the safety and feasibility of the DLL3-targeted imaging tracer [Zr]Zr-DFO-SC16.56 (composed of the anti-DLL3 antibody SC16.

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Purpose: Recurrent small-cell lung cancer (SCLC) has few effective treatments. The EZH2-SLFN11 pathway is a driver of acquired chemoresistance that may be targeted.

Patients And Methods: This phase I/II trial investigated valemetostat, an EZH1/2 inhibitor, with fixed-dose irinotecan in patients with recurrent SCLC.

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Objective: There is a lack of knowledge regarding the use of prognostic features in stage I lung adenocarcinoma (LUAD). Thus, we investigated clinicopathologic features associated with recurrence after complete resection for stage I LUAD.

Methods: We performed a retrospective analysis of patients with pathologic stage I LUAD who underwent R0 resection from 2010 to 2020.

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The new grading system for lung adenocarcinoma proposed by the International Association for the Study of Lung Cancer (IASLC) defines prognostic subgroups on the basis of histologic patterns observed on surgical specimens. This study sought to provide novel insights into the IASLC grading system, with particular focus on recurrence-specific survival (RSS) and lung cancer-specific survival among patients with stage I adenocarcinoma. Under the IASLC grading system, tumors were classified as grade 1 (lepidic predominant with <20% high-grade patterns [micropapillary, solid, and complex glandular]), grade 2 (acinar or papillary predominant with <20% high-grade patterns), or grade 3 (≥20% high-grade patterns).

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In this PRO-CON debate, you will read very different perspectives about a simple question regarding an observation under the microscope: What is the significance of tumor cells in the air spaces of the lung parenchyma beyond the tumor edge of a resected lung cancer? An important underlying question is whether this entire PRO-CON debate is a mere academic exercise or whether spread through air spaces (STAS), as currently defined, describes a clinically useful phenomenon. The journey of STAS began with a complete paradigm shift to reverse the thinking that all air space tumor cells beyond the edge of lung cancers are an artifact. This led to a new concept where STAS could be separated from artifacts with a definition that has proven to be clinically useful.

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Purpose: Small cell lung cancer (SCLC) often metastasizes to the brain and has poor prognosis. SCLC subtypes distinguished by expressing transcriptional factors ASCL1 or NEUROD1 have been identified. This study investigates the impact of transcription factor-defined SCLC subtype on incidence and outcomes of brain metastases (BMs).

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Targeting cell surface molecules using radioligand and antibody-based therapies has yielded considerable success across cancers. However, it remains unclear how the expression of putative lineage markers, particularly cell surface molecules, varies in the process of lineage plasticity, wherein tumor cells alter their identity and acquire new oncogenic properties. A notable example of lineage plasticity is the transformation of prostate adenocarcinoma (PRAD) to neuroendocrine prostate cancer (NEPC)--a growing resistance mechanism that results in the loss of responsiveness to androgen blockade and portends dismal patient survival.

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Small-cell lung carcinoma (SCLC) cell lines have been widely utilized as a preclinical model of this highly aggressive disease. However, since their creation decades ago, novel tumor entities have been defined that might clinicopathologically mimic SCLC, which notably includes thoracic SMARCA4-deficient undifferentiated tumor (SMARCA4-UT). Multiomic reassessment of the presumed SCLC cell lines with high YAP1 expression reveals that nearly all of these tumors represent unsuspected SMARCA4-UT.

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Non-small cell lung carcinomas (NSCLCs) commonly present as 2 or more separate tumors. Biologically, this encompasses 2 distinct processes: separate primary lung carcinomas (SPLCs), representing independently arising tumors, and intrapulmonary metastases (IPMs), representing intrapulmonary spread of a single tumor. The advent of computed tomography imaging has substantially increased the detection of multifocal NSCLCs.

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Background: Delta-like ligand 3 (DLL3) is aberrantly expressed on the cell surface in many neuroendocrine cancers including small cell lung cancer (SCLC) and neuroendocrine prostate cancer (NEPC). Several therapeutic agents targeting DLL3 are in active clinical development. Molecular imaging of DLL3 would enable non-invasive diagnostic assessment to inform the use of DLL3-targeting therapeutics or to assess disease treatment response.

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