Publications by authors named "Alexander Lazar"

Molecular subtypes, such as defined by The Cancer Genome Atlas (TCGA), delineate a cancer's underlying biology, bringing hope to inform a patient's prognosis and treatment plan. However, most approaches used in the discovery of subtypes are not suitable for assigning subtype labels to new cancer specimens from other studies or clinical trials. Here, we address this barrier by applying five different machine learning approaches to multi-omic data from 8,791 TCGA tumor samples comprising 106 subtypes from 26 different cancer cohorts to build models based upon small numbers of features that can classify new samples into previously defined TCGA molecular subtypes-a step toward molecular subtype application in the clinic.

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this study aims to evaluate the survival outcomes of patients suffering from head and neck synovial sarcoma (HNSS), especially in relation to patients with a localized disease at diagnosis. this retrospective chart review includes 57 patients diagnosed with primary HNSS between 1981 and 2020 who presented with a localized disease at diagnosis. Overall survival (OS) from diagnosis, local recurrence-free survival (LRFS), and metastasis-free survival (MFS) from the end of the primary tumor treatment are estimated.

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Dysregulated FGF23 production is a demonstrated cause of hypophosphatemia and osteomalacia. Diseases associated with these conditions include phosphaturic mesenchymal tumor (PMT) causing tumor induced osteomalacia, various forms of rickets, and fibrous dysplasia (FD). Coexistence of 2 conditions that can increase FGF23 concentrations is rare.

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Purpose: FHD-609, a potent, selective, heterobifunctional degrader of bromodomain-containing protein 9 (BRD9), was evaluated for treatment of patients with advanced synovial sarcoma (SS) or SMARCB1-deficient tumors.

Patients And Methods: In this multinational, open-label, phase 1 study (NCT04965753), patients received FHD609 intravenously at escalating doses either twice weekly (BIW) (5 to 80 mg; n=40) or once weekly (QW) (40 to 120 mg; n=15).

Results: Fifty-five patients received FHD-609 for a median of 43 days.

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Malignant peripheral nerve sheath tumor (MPNST) development is characterized by an altered DNA methylation landscape, which presents a promising area for developing MPNST-specific biomarkers for screening patients with NF1. Genome-wide DNA methylation profiling of a cohort of 13 patients with MPNST (29 samples of tumor and adjacent neurofibroma tissues) and of NF1-MPNST cell lines was performed to identify and validate candidate MPNST-specific CpG sites (CpGs). A logistic regression prediction model was constructed to select MPNST-specific CpGs distinct from adjacent neurofibromas and normal tissues.

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Delta-like Ligand 3 (DLL3) targeting therapies are promising in small cell lung cancer (SCLC) treatment. However, DLL3 expression in SCLC and other neuroendocrine neoplasms (NEN) is heterogeneous and not well characterized. We describe the landscape of DLL3 at the mRNA and protein levels across SCLC, large cell neuroendocrine carcinoma (LCNEC), and non-small cell lung cancer.

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Consensus recommendation published in 2017 histologically defining atypical neurofibromatous neoplasm of uncertain biologic potential (ANNUBP) and malignant peripheral nerve sheath tumor (MPNST) were codified in the 2021 WHO Classification of Tumors of the Central Nervous System and the 2022 WHO Classification of Tumors of Soft Tissue and Bone. However, given the shift in diagnostic pathology toward the use of integrated histopathologic and genomic approaches, the incorporation of additional molecular strata in the classification of Neurofibromatosis Type 1 (NF1)-associated peripheral nerve sheath tumors should be formalized to aid in accurate diagnosis and early identification of malignant transformation to enable appropriate intervention for affected patients. To this end, we assembled a multi-institutional expert pathology working group as part of a "Symposium on Atypical Neurofibroma: State of the Science".

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The aim of the study was to report the outcome of primary localized low-grade fibromyxoid sarcoma (LGFMS), sclerosing epithelioid fibrosarcoma (SEF), and hybrid LGFMS/SEF (H-LGFMS/SEF). Patients with primary localized LGFMS, SEF, or H-LGFMS/SEF, surgically treated with curative intent from January 2000 to September 2022, were enrolled from 14 countries and 27 institutions. Pathologic inclusion criteria were predefined by expert pathologists.

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Article Synopsis
  • Solitary fibrous tumor (SFT) is a rare type of tumor that can occur in various body parts and is often linked to specific genetic fusions, with 10-30% of cases becoming metastatic.
  • A study involving DNA methylation analysis of 79 SFTs revealed distinct epigenetic changes linked to their primary sites, identifying key genes such as EGFR and TBX15 that showed differing levels of expression based on the tumor's location and genetic fusion type.
  • TBX15 emerged as a significant marker, with changes in its methylation and expression strongly correlating to the tumor's tissue of origin, suggesting it could help differentiate between new tumors and metastases without needing extensive genomic analysis.
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  • A new subset of macrophages called iron-rich tumor-associated macrophages (iTAMs) was identified, marked by high levels of intracellular iron and involvement in angiogenesis and immunosuppression in tumors.
  • Two types of iTAMs were characterized based on their location and gene expression: perivascular (pviTAM) and stromal (stiTAM).
  • The endothelin receptor type B (Ednrb) was identified as a specific marker for iTAMs, and its deletion reduced tumor growth, while the transcription factor Bach1 was found to regulate iTAM functions by inhibiting Ednrb expression.
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Multi-modal spatial omics data are invaluable for exploring complex cellular behaviors in diseases from both morphological and molecular perspectives. Current analytical methods primarily focus on clustering and classification, and do not adequately examine the relationship between cell morphology and molecular dynamics. Here, we present MorphLink, a framework designed to systematically identify disease-related morphological-molecular interplays.

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  • The study examines gene regulatory changes associated with cancer by analyzing chromatin accessibility across eight different tumor types, revealing the influence of copy number alterations on tumor characteristics.
  • Researchers found specific chromatin signatures in cancer that are closely related to healthy cell types, particularly noting similarities between basal-like breast cancer and secretory-type luminal epithelial cells.
  • Advanced neural network models highlighted the significance of noncoding mutations near cancer-associated genes, suggesting that widely dispersed mutations in cancer have important functional roles in gene regulation.
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Background: The course of subclinical gastrointestinal stromal tumors (GISTs) is variable. The management of small GISTs is not well-defined.

Methods: Records of patients presenting with small GISTs with documented follow-up appointment at our institution between 2016 and 2022 were identified and reviewed.

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Objective: We evaluated survival outcomes by primary tumor site in synovial sarcoma (SS) patients with localized and metastatic disease at diagnosis.

Methods: We conducted a retrospective review of 504 SS patients diagnosed from 1974 to 2020. Kaplan-Meier method, log-rank test, and Cox-proportional hazards regression were used.

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Article Synopsis
  • Scientists are using a new method called spatial transcriptomics (ST) to learn how cells interact in tumors, but current tools don't take important details into account.
  • They created a better tool called METI that helps to understand where cancer cells are and how they work together by looking at cell shapes and gene information.
  • METI has been tested on different types of cancer tissues and showed it works better than older tools in analyzing these complex cell environments.
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  • Atypical intradermal smooth muscle neoplasm, or cutaneous leiomyosarcoma, is a rare skin tumor that grows slowly and usually isn't very aggressive.
  • A study looked at 95 patients with this tumor from 2002 to 2021, mostly men around 58 years old, with most tumors appearing as painless lumps on the legs or arms.
  • After treatment, the majority of patients (96%) stayed free of the disease for five years, showing that the outcomes were mostly good.
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Rhabdomyosarcomas are the most common soft tissue sarcoma in children, and pediatric alveolar rhabdomyosarcoma (ARMS) prognosis has improved based on cooperative studies. However, in adults, ARMS is significantly rarer, has poorer outcomes, and currently lacks optimal treatment strategies. This study aimed to evaluate the clinical outcome of an adult ARMS population with different front-line systemic chemotherapies and determine if any chemotherapy regimen is associated with improved survival.

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Initially described as a highly specific immunohistochemical marker for carcinomas of mammary origin, trichorhinophalangeal syndrome type 1 (TRPS1) has subsequently been detected in a variety of other non-mammary tumors. In this study, we examined the immunohistochemical expression of TRPS1 in 114 peripheral nerve sheath tumors, including 43 malignant peripheral nerve sheath tumors (MPNSTs), 58 schwannomas, including 9 cellular neurofibromas, and 13 neurofibromas, including 1 atypical neurofibroma. Notably, TRPS1 was expressed in 49% of MPNSTs and was absent in all schwannomas and neurofibromas.

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  • Nonsurgical treatments like the levonorgestrel intrauterine device (LIUD) are being explored for managing endometrial atypical hyperplasia (AH) and endometrioid endometrial cancer (EEC), highlighting a need for long-term efficacy data.
  • In a study of 43 patients initially responding to LIUD, 39% relapsed, with significant factors for shorter duration of response including younger age and lack of response at the 6-month mark.
  • Molecular analysis during the study revealed changes in immune cell populations and pathways involved in relapse, suggesting immune mechanisms play a crucial role in the treatment's effectiveness.
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The Wnt receptor ROR1 has generated increased interest as a cancer therapeutic target. Research on several therapeutic approaches involving this receptor is ongoing; however, ROR1 tissue expression remains understudied. We performed an immunohistochemistry analysis of ROR1 protein expression in a large cohort of multiple tumor and histologic types.

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Background: Undifferentiated pleomorphic sarcomas (UPSs) are amongst the most common subtypes of soft-tissue sarcomas. Few real-world data on the use of immune checkpoint blockade (ICB) in UPS patients and other high-grade pleomorphic STS patients are available.

Purpose: The purpose of our study is to describe the efficacy and toxicity of ICB in patients with advanced UPSs and other high-grade pleomorphic sarcomas treated at our institution.

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The vast majority of gastrointestinal stromal tumors (GISTs) are driven by activating mutations in , , or components of the succinate dehydrogenase (SDH) complex (, , , and genes). A small fraction of GISTs lack alterations in , , and . We aimed to further characterize the clinical and genomic characteristics of these so-called "triple-negative" GISTs.

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Most malignant peripheral nerve sheath tumors (MPNSTs) are clinically aggressive high-grade sarcomas, arising in individuals with neurofibromatosis type 1 (NF1) at a significantly elevated estimated lifetime frequency of 8%-13%. In the setting of NF1, MPNSTs arise from malignant transformation of benign plexiform neurofibroma and borderline atypical neurofibromas. Composed of neoplastic cells from the Schwannian lineage, these cancers recur in approximately 50% of individuals, and most patients die within five years of diagnosis, despite surgical resection, radiation, and chemotherapy.

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Next-generation sequencing (NGS) is increasingly being utilized as an ancillary tool for diagnostically challenging melanocytic neoplasms. It is incumbent upon the pathology community to perform studies assessing the benefits and limitations of these tools in specific diagnostic scenarios. One of the most challenging diagnostic scenarios faced by skin pathologists involves accurate diagnosis of desmoplastic melanocytic neoplasms (DMNs).

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Targeting the DNA damage response (DDR) pathway is an emerging therapeutic approach for leiomyosarcoma (LMS), and loss of RNase H2, a DDR pathway member, is a potentially actionable alteration for DDR-targeted treatments. Therefore, we designed a protein- and genomic-based RNase H2 screening assay to determine its prevalence and prognostic significance. Using a selective RNase H2 antibody on a pan-tumor microarray (TMA), RNase H2 loss was more common in LMS (11.

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