Search Results (1,003)

Background: Diffuse Large B-cell Lymphoma (DLBCL) is a biologically heterogeneous subtype of non-Hodgkin’s lymphoma (NHL), accounting for 30–40% of cases worldwide. Despite the incorporation of rituximab into standard chemo-immunotherapy regimen, approximately one-third of patients present with relapsed or refractory disease, implicating the need for improved prognostic markers and therapeutic targets. Gene expression profiling successfully classified DLBCL into Germinal Center B-cell-like (GCB) and non-GCB subtypes, which differ in genetic alterations, response to therapy, and clinical outcome. While intrinsic tumor biology has been extensively studied, the contribution of the tumor microenvironment (TME) to disease progression and therapeutic resistance still remains incompletely understood. Methods: In this study, we investigated the mutational landscape of stromal-related genes in DLBCL and evaluated their impact on gene expression, downstream signaling pathways, and tumor progression. Results: A total of 176 DLBCL patients were screened, of which 113 were enrolled based on availability of complete clinical data. The cohort demonstrated male predominance (male:female ratio: 2.1:1), advanced disease stage in 72.6% of patients, and elevated serum lactate dehydrogenase levels in 57.5%. Based on immunohistochemistry, 43.4% cases were classified as GCB-DLBCL and 56.6% as non-GCB DLBCL. Although the International Prognostic Index (IPI) retained prognostic significance for event-free survival (EFS) and overall survival (OS), considerable heterogeneity was observed within similar risk groups. Whole-exome sequencing (WES) uncovered recurrent somatic mutations in key oncogenic and epigenetic regulators, including TNFAIP3, NFIB, NOTCH1, TSC2, EZH2, EP300, KMT2D, and B2M, with subtype-specific distribution. Pathway enrichment analysis implicated role of Notch, Wnt, mTOR, JAK-STAT, TGF-β, and antigen-presentation pathways. Comprehensive WES analysis identified multiple novel mutations in genes associated with the stromal/extracellular matrix with distinct patterns in GCB and non-GCB DLBCL, accompanied by concordant alterations in gene expression profiles, suggesting functional relevance within the TME. Functional validation through primary cell culture demonstrated significantly elevated Th2 (IL-4, IL-6, IL-10) and Th17 (IL-17) cytokines in co-cultures containing both neoplastic cells and stromal components, underscoring the role of TME in DLBCL progression. Conclusions: Taken together, this study provides novel insights into stromal mutational signatures and cytokine-mediated tumor–stroma interactions, offering potential prognostic biomarkers and therapeutic targets for the improved management of DLBCL. Full article

This scoping review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines. It summarizes advances in fibroblast activation protein inhibitor (FAPI) positron emission tomography (PET) for oncologic and fibroinflammatory diseases. FAP is expressed broadly on activated mesenchymal cells—including cancer-associated fibroblasts (CAFs) and myofibroblasts within desmoplastic tumor stroma, FAP-positive tumor cells in selected sarcomas, and activated fibroblasts in chronic fibroinflammatory disorders such as rheumatoid arthritis, Crohn’s disease, and organ fibrosis. By targeting these activated fibroblasts, [⁶⁸Ga]- and [¹⁸F]-labeled FAPI tracers provide high tumor-to-background contrast, particularly in desmoplastic and stromal-rich cancers. Compared with [¹⁸F]FDG, FAPI PET demonstrates superior lesion conspicuity in selected malignancies and enables a streamlined, non-fasting imaging workflow. Beyond oncology, FAPI PET is emerging as a promising tool for assessing cardiac fibrosis, pulmonary inflammation, and autoimmune conditions characterized by fibroblast activation. A systematic literature search of PubMed and Scopus was performed for peer-reviewed publications from 1 January 2018 to 28 February 2026. Inclusion criteria encompassed original studies, systematic reviews, meta-analyses, clinical guidelines, case series, and case reports reporting on FAPI-targeted PET in human subjects or translational models, published in English. After screening, 256 sources met the eligibility criteria and are included. The development of standardized SNMMI/EANM imaging protocols, along with ongoing multicenter trials and the first prospective phase 2 clinical trial of ⁶⁸Ga-FAPI-46 PET with histopathological confirmation, now supports the reproducible implementation of FAPI PET across institutions. FAPI PET demonstrates strong translational potential, largely due to its favorable biodistribution, safety profile, and theranostic flexibility. However, its widespread use in routine clinical practice is contingent upon large-scale clinical validation, structured reader training, and formal regulatory approval. In conclusion, FAPI PET represents a maturing molecular imaging platform targeting activated fibroblasts across oncologic and fibroinflammatory diseases. Its widespread adoption into clinical practice requires large-scale prospective trials, reader training, standardized reporting, and regulatory approval—all of which are now actively underway. Full article

Background/Objectives: Trichoblastoma is a benign follicular adnexal tumor that typically arises on the head and neck. Large variants at atypical locations pose considerable diagnostic challenges because their clinical presentation can be indistinguishable from malignant soft tissue neoplasms. Herein, we describe a case of trichoblastoma presenting as a large subcutaneous thigh mass that was correctly diagnosed by fine-needle aspiration cytology. Case Presentation: A 49-year-old male presented with a 7 cm, slowly enlarging, subcutaneous mass in the left thigh of 20 years’ duration. Magnetic resonance imaging raised the possibility of a low-grade sarcoma. Fine-needle aspiration cytology yielded cohesive clusters of basaloid cells with peripheral palisading, delicate spindle-shaped follicular stromal cells intimately admixed with the epithelial component, and orangeophilic keratinous material in the background. The absence of nuclear atypia, mitotic figures, and mucinous stroma supported a preoperative cytological diagnosis of a benign follicular germinative tumor consistent with trichoblastoma, thereby guiding conservative surgical excision. Histopathological examination confirmed the diagnosis. Immunohistochemistry revealed focally positive BerEP4, CD34-positive stroma, negative androgen receptor, and positive bcl-2, consistent with trichoblastoma and distinguishing the tumor from basal cell carcinoma. The patient remained recurrence-free 12 months after surgery. Conclusions: Careful assessment of characteristic cytomorphological features, particularly a dual population of basaloid epithelial cells with peripheral palisading and specialized follicular stromal cells, is vital for the accurate preoperative cytological characterization of trichoblastoma, even at atypical anatomical sites. Full article

Lipoblastomas are rare, benign tumors arising from embryonic white fatty precursor cells that continue to proliferate in the postnatal period. We present a case of a minimally differentiated lipoblastoma with myxoid features. Our patient was an 18-month-old female with a painless solid tumefaction in the middle third of the right leg. Histopathologically, the nodular tumor mass consisted of lipoblasts embedded in a myxoid stroma. Immunohistochemistry showed strong diffuse positivity for S100, CD34, CD56, NSE and rare Ki67+ cells. FOXO1 polyploidy was detected in 30% of cells by FISH. Using target RNA sequencing, we detected a CHCHD7::PLAG1 fusion gene showing that the first exons of CHCHD7 were fused to either exon 2 or exon 3 of PLAG1. Our case demonstrates that due to the histomorphologic overlaps, the molecular diagnostics can be essential for the confirmation of the diagnosis of lipoblastoma. Full article

Background/Objectives: Seromucinous hamartoma (SH) is an extremely rare benign glandular lesion arising in the nasal cavity and paranasal sinuses, characterized by proliferation of serous and mucinous glands. Preoperative diagnosis by biopsy is extremely uncommon, making it a diagnostic challenge. We report a case of SH and discuss its diagnostic difficulties and management. Case Presentation: A 52-year-old man presented with right-sided nasal obstruction. A lobulated mass in the posterior right nasal cavity was incidentally detected during transnasal endoscopy. The lesion persisted for one year without reduction. CT, MRI, and biopsy failed to provide a definitive diagnosis. The patient was referred to our department, and endoscopic surgery under general anesthesia was performed. The tumor was removed en bloc. Histopathological examination revealed glandular proliferation of mixed serous and mucinous glands within the subepithelial stroma, consistent with SH. Discussion: Preoperative diagnosis is difficult due to insufficient biopsy depth and limited recognition of this rare entity. Since the surface epithelium shows no atypia, identification of subepithelial glandular proliferation is essential. Larger and deeper biopsy specimens and communication with pathologists may improve diagnostic yield. Surgical excision is the treatment of choice. As SH often arises in the posterior nasal cavity and is highly vascular, en bloc resection under general anesthesia is recommended. Conclusions: Recognition of SH is important to improve diagnostic accuracy. Appropriate biopsy strategy and surgical planning based on tumor location are essential. Full article

Background/Objectives: CD138 (syndecan-1) is a cell-surface heparan sulfate proteoglycan involved in cell–matrix interactions and growth factor signaling, and it has been implicated in tumor progression. However, the clinical significance of compartment-specific CD138 expression in breast cancer remains unclear. In this study, we investigated the prognostic and transcriptomic features of compartment-specific CD138 expression in invasive breast cancer. Methods: We performed an integrated analysis of immunohistochemistry and RNA sequencing of 111 invasive ductal carcinoma specimens. Tumors were classified into four groups according to CD138 expression in the tumor and stromal compartments. Clinicopathological data and survival outcomes were obtained from medical records, and transcriptomic profiles were analyzed using RNA sequencing. Results: The tumor-positive/stroma-negative phenotype (Group 1) was associated with poorer recurrence-free survival than the other phenotypes. According to multivariable Cox regression analysis, Group 1 remained an independent prognostic factor after adjustment for age, lymph node status, and Ki-67 index (hazard ratio, 5.493; p = 0.0028). Group 1 was also associated with lymph node metastasis and HER2 expression. All brain metastases occurred in Group 1, although the number of events was low. Transcriptomic profiling identified the upregulation of small nucleolar RNAs in Group 1 tumors, with the enrichment of pathways related to ribosome biogenesis, RNA processing, and translational regulation. Conclusions: Compartment-specific CD138 expression identifies an aggressive breast cancer phenotype with distinct transcriptomic features. This phenotype may have prognostic value and warrants validation using larger, independent cohorts. Full article

Exosomal microRNAs (miRNAs) are key mediators of intercellular communication in the breast cancer tumor microenvironment (TME), facilitating bidirectional signaling between malignant cells and the desmoplastic stroma. This review explores current evidence on their dual roles as drivers of stromal remodeling and as circulating biomarkers of therapeutic resistance across major breast cancer subtypes, including triple-negative breast cancer (TNBC), hormone receptor-positive (ER+/PR+) disease, and HER2-amplified tumors. We outline how miR-9, miR-21, and miR-181 family members promote cancer-associated fibroblast (CAF) activation, increase extracellular matrix (ECM) stiffness, and sustain a reverse Warburg phenotype. We then detail subtype-specific resistance mechanisms: miR-181 family members suppress BCLAF1 to block doxorubicin-induced apoptosis; miR-221/222 downregulates ESR1 and p27Kip1 to confer tamoxifen resistance; miR-155 impairs homologous recombination in TNBC; and miR-1246 sustains PI3K/AKT signaling in HER2-positive disease. We also evaluate circulating exosomal miRNA panels as liquid biopsy tools for predicting chemotherapy response and tracking resistance emergence. Finally, we discuss therapeutic strategies including antagomirs, miRNA replacement therapy and engineered exosome platforms, and address key challenges such as assay standardization and regulatory hurdles, that must be overcome for clinical translation. Full article

Tumor Treating Fields (TTFields) represent a novel, non-invasive therapeutic modality in oncology that employs low-intensity, intermediate-frequency alternating electric fields to disrupt mitotic processes and induce cancer cell death. This review integrates mechanistic, preclinical, and emerging clinical evidence supporting the integration of TTFields with immunotherapeutic strategies in pancreatic ductal adenocarcinoma (PDAC). Although immunotherapy has transformed the treatment landscape across multiple malignancies, its efficacy in PDAC remains limited due to the tumor’s dense stroma, immunosuppressive microenvironment, and low immunogenicity. Preclinical investigations suggest that TTFields may potentiate immune-based therapies by enhancing antigen presentation, modulating the tumor microenvironment (TME), and attenuating mechanisms of immune resistance. We highlight studies evaluating TTFields in combination with immune checkpoint inhibitors (ICI), adoptive cellular therapies, and cancer vaccines, emphasizing their potential synergistic effects in PDAC. Clinically, the phase II PANOVA-2 trial demonstrated feasibility and encouraging survival outcomes with TTFields in combination with gemcitabine and nab-paclitaxel, providing the rationale for the ongoing phase III PANOVA-3 trial and the phase II PANOVA-4 trial, which combines TTFields with chemotherapy and atezolizumab. Additional clinical experiences in glioblastoma (GBM) and non-small-cell lung cancer (NSCLC) further substantiate the broader applicability of TTFields as an immunomodulatory adjunct. Remaining challenges include optimizing treatment sequencing, identifying predictive biomarkers, and managing TTFields-associated toxicities. Collectively, current evidence positions TTFields as a promising strategy to augment immunotherapy in PDAC, warranting further translational and clinical investigation to establish its role in reshaping therapeutic paradigms. Full article

Tumor budding is increasingly recognized as a histopathologic feature associated with invasive behavior in gastrointestinal malignancies. While its prognostic value is well established in colorectal carcinoma, its significance in gastric adenocarcinoma remains less clearly defined because of marked morphologic heterogeneity, variable growth patterns, and the absence of gastric-specific assessment criteria. Multiple studies have associated high budding density with adverse clinicopathologic features, including lymph node metastasis, lymphovascular invasion, advanced tumor stage, and poorer survival, particularly in intestinal-type tumors. However, these associations are more difficult to interpret in diffuse-type and mixed carcinomas, where intrinsic discohesion and architectural variability complicate the distinction between true budding and baseline growth patterns. Beyond prognostic assessment, tumor budding has been linked to localized alterations in cell adhesion, cytoskeletal organization, tumor–stroma interaction, and partial epithelial–mesenchymal transition. Emerging evidence also suggests that its biological significance may differ across molecular subtypes of gastric cancer. This review examines the current evidence on the definition, morphologic spectrum, methodological limitations, and biologic context of tumor budding in gastric adenocarcinoma. We propose that, in gastric cancer, tumor budding is best interpreted not as a uniformly applicable scoring parameter, but as a context-dependent morphologic indicator of invasive tumor remodeling whose meaning varies according to tumor architecture, stromal interface, and molecular subtype. Full article

Dickkopf-1 (DKK1) is a 266-amino-acid secreted glycoprotein originally identified as a high-affinity antagonist of the canonical Wnt/β-catenin signaling pathway and has emerged as a complex regulator in oncology. While historically considered as a tumor suppressor due to its ability to abrogate Wnt-driven proliferation, recent discoveries highlight a paradoxical pro-oncogenic role across various malignancies. The molecular mechanisms by which DKK1 promotes tumor progression, metastasis, and immune evasion are driven by its interaction with cell-surface receptors, specifically LRP5/6 and CKAP4. The DKK1-CKAP4 axis independently activates PI3K/AKT signaling, facilitating epithelial–mesenchymal transition (EMT), chemoresistance, and the formation of osteolytic bone lesions. Furthermore, DKK1 serves as a critical orchestrator of the tumor microenvironment (TME) by driving comprehensive immune reprogramming. It mediates the recruitment of myeloid-derived suppressor cells (MDSCs) and inactivates cytotoxic CD8⁺ T cells and natural killer (NK) cells, thereby fostering an immunosuppressive tumor microenvironment and resistance to checkpoint inhibitors. Interestingly, cancer-associated fibroblasts (CAFs) are a primary source of DKK1 in the stroma, where they facilitate immune evasion. Clinically, elevated circulating DKK1 levels correlate with advanced disease stages, increased metastatic potential, and poor overall survival in solid and hematological tumors. When used in combination with established biomarkers, serum DKK1 levels demonstrate significant utility for early detection and therapeutic monitoring. Given its intricate impact on malignancy, DKK1 has become a promising therapeutic target, with ongoing clinical trials investigating neutralizing antibodies such as DKN-01 to disrupt its oncogenic and immunosuppressive signaling. Understanding the context-dependent nature of DKK1 signaling remains essential for refining its application as both a biomarker and a component of emerging precision immunotherapy strategies. By prioritizing the literature from the last decade, this review characterizes DKK1 as a key mediator of tumor progression and immune reprogramming, while assessing its clinical potential as a biomarker and therapeutic target. Full article

Chordoma is a rare malignant neoplasm of the axial skeleton, arising from notochordal remnants. No approved systemic therapies exist, and the 10-year overall survival is below 60%. Accurate molecular and pathological classification is a prerequisite for improved prognostication and the identification of actionable therapeutic targets; however, molecular classification of chordoma remains significantly less advanced than that of other neoplasms. This narrative review synthesizes proposed classification frameworks for chordoma across histological, radiological, surgical, genomic, epigenomic, transcriptomic, and proteomic domains. PubMed and CENTRAL were searched on 1 February 2026 using five queries: ‘chordoma classification’, ‘chordoma DNA sequencing’, ‘chordoma RNA sequencing’, ‘chordoma methylation’, and ‘chordoma copy number’. Original research articles describing more than one patient and reporting a classification or subtyping framework were included; review articles, case reports, and non-English publications were excluded. Sample size and the use of a validation dataset were identified for each study. Results were synthesized qualitatively. A total of 108 studies encompassing 6349 individuals were included. Across six domains, four cross-cutting themes with prognostic and potential theranostic value emerged: copy number alterations, particularly CDKN2A/B loss; SWI/SNF complex dysfunction; stroma–tumor ratio; and immune microenvironment heterogeneity. Full article

Background/Objectives: Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease with limited treatment options. Patients are treated with DNA damaging chemotherapies which act by inducing DNA damage in rapidly dividing tumor cells. Unfortunately, these tumors frequently develop treatment resistance, underscoring the need to understand resistance mechanisms in order to develop better treatment strategies. DNA damage response (DDR) detects and repairs DNA damage, and the DDR pathway has been shown to contribute to chemoresistance. Another factor known to drive chemoresistance in PDAC is the dense stroma, composed of extracellular matrix proteins secreted by cancer-associated fibroblasts (CAFs). Our recent work identified a CAF-induced resistance mechanism involving N-myc downstream regulated gene 1 (NDRG1). CAF-induced signaling resulted in the phosphorylation of NDRG1 and NDRG1-dependent DNA repair and protection from chemotherapies. Loss of NDRG1 resulted in increased chemotherapy-induced DNA damage and decreased replication fork speed and recovery. Methods: To gain insight into the molecular mechanism of NDRG1-mediated DNA repair and replication, we performed a BioID screen to identify binding partners of NDRG1. We further assessed the mechanistic roles of the identified interaction partners on DNA repair using DNA replication and repair assays such as the Comet assay and DNA fiber assays. Results: Our BioID screen identified meiotic recombination 11 (MRE11) protein, a nuclease involved in DDR, as a putative NDRG1 interacting protein. Interaction between MRE11 and NDRG1 was enriched during the late S/early G2 cell cycle phases and under replication stress. However, this interaction is likely indirect as the interaction only occurred in a cellular context and not with in vitro purified proteins. Blocking NDRG1 phosphorylation or blocking MRE11 exonuclease activity both resulted in protection of newly synthesized DNA at stalled replication forks. In NDRG1 knockout cells, blocking MRE11 led to decreased protection of nascent DNA, suggesting that NDRG1 and MRE11 may be acting in the same pathway and that NDRG1 is required for MRE11’s activity at stalled forks. Conclusions: In summary, our work has uncovered a protein complex between NDRG1 and MRE11 that may play a key role in chemoresistance due to its role in the processing of stalled replication forks. Full article

Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest malignancies, characterized by early metastasis, dense desmoplastic stroma and a profoundly immunosuppressive, lymphocyte-depleted tumor microenvironment that severely limits the efficacy of current systemic and immunotherapeutic approaches. Oncolytic viruses (OVs), which selectively replicate in and lyse malignant cells while activating antitumor immunity, have emerged as attractive candidates to convert this “cold” tumor into a more inflamed and therapeutically responsive disease. In this review, we summarize clinical evidence on the main OV platforms evaluated in PDAC, including adenovirus, herpes simplex virus, vaccinia virus, parvovirus and reovirus, with a focus on clinical trials. Across these classes of viruses, intratumoral administration has consistently proven feasible and generally well tolerated, with frequent evidence of viral replication, microenvironmental remodeling and immune activation, but only modest and often transient antitumor responses in small, early-phase cohorts. We then discuss key biological and translational challenges that currently limit OV impact in PDAC, such as systemic delivery in the context of pre-existing antiviral immunity and rapid clearance, penetration through the fibrotic stroma, and rational selection of encoded transgenes to reshape myeloid cell-driven, pro-tumoral inflammation and enhance T-cell recruitment. Finally, we outline future directions for the field, including carrier-cell–based systemic delivery, stroma-targeting or cytokine-armed constructs, and combinatorial strategies with chemotherapy and immune checkpoint blockade, arguing that design refinement, innovative combinations and mechanism-driven trial designs will be essential to unlock the full therapeutic potential of oncolytic virotherapy in PDAC. Full article

Background/Objectives: Tumor–stroma ratio (TSR) and tumor-infiltrating lymphocytes (TILs) were suggested as prognostic markers in oral squamous cell carcinoma (OSCC). Identification of markers assessable in preoperative biopsies that could guide treatment planning is of great importance. This study aimed to evaluate the concordance and prognostic impact of TSR and TILs in preoperative biopsies and matched resection specimens of OSCC. Methods: This study included 100 patients with OSCC. TSR and stromal TILs were evaluated on hematoxylin and eosin-stained slides of biopsies and paired resection specimens and categorized (into low TSR and high TSR; high TILs and low TILs). The agreement between resections and biopsies, and the prognostic significance and clinicopathological correlations of TSR and TILs, were investigated. Results: For TSR, substantial agreement between preoperative biopsies and surgical specimens (kappa correlation coefficient 0.713) was demonstrated. The assessment of TILs showed poor concordance between biopsies and resections (kappa correlation coefficient 0.372). For both biopsies and resections, Cox regression showed an independent negative prognostic impact of low TSR on disease-free, disease-specific, and overall survival. Independent prognostic value of TILs evaluated in biopsies was not found, and the negative prognostic impact of low TILs on disease-free and overall survival was observed only in the main resection specimens. Conclusions: TSR evaluated in preoperative biopsies was highly concordant with results in main resection specimens and may provide significant information for OSCC prognostication, risk stratification, and treatment decisions. In contrast, TILs evaluated in biopsies showed poor concordance with main resection specimens and failed to demonstrate prognostic significance. Full article

Background: While the prognostic and predictive value of tumor cell–derived features such as grade, estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) status, and Ki67 index is well established in breast cancer, less is known about the prognostic role of tumor stroma. This study aimed to evaluate stromal parameters in HER2-positive breast cancer patients treated with adjuvant trastuzumab. Material and methods: The study included 224 patients (T ≥ 1, N ≥ 0, M0) who underwent radical treatment followed by adjuvant chemotherapy, hormone therapy (if ER/PR-positive), and trastuzumab. The following histological and immunohistochemical parameters were analyzed: stroma type, tumor-infiltrating lymphocytes (TILs), eosinophils, neutrophils, central area of fibrosis, necrosis, and programmed cell death protein ligand 1 (PD-L1) expression in tumor and stromal cells. Results: Low TILs percentage (≤50%) was associated with lower tumor grade (G2) (p = 0.013) and ER/PR positivity (p = 0.001). Tumors lacking PD-L1 expression had a lower percentage of TILs (p < 0.001), less frequently exhibited tumor-associated neutrophilia (p = 0.019), and more often presented with desmoplastic stroma (p < 0.001). The following parameters were associated with prognosis: TILs percentage, stroma type, and PD-L1 expression. High TILs percentage (>50%) was an independent positive prognostic factor. Conclusions: In patients with HER2-positive breast cancer treated with adjuvant trastuzumab, the percentage of TILs, stroma type, and PD-L1 expression are prognostically relevant. Specifically, a TILs percentage >50% independently predicts favorable outcomes. Routine evaluation of stromal features may provide additional prognostic information and support treatment planning. Full article