Search Results (104)

Background: HER2-low breast cancer (HER2 immunohistochemical [IHC] score 1+, or IHC 2+ without HER2 gene amplification) is distinct from HER2-positive and HER2-0 breast cancer (IHC 0), with a differing prognosis and specific therapeutic options. The DESTINY-Breast04 trial demonstrated notable efficacy of the HER2 antibody–drug conjugate trastuzumab deruxtecan over standard chemotherapy in patients with metastatic breast cancer (MBC) defined as HER2-low. More recently, the DESTINY-Breast06 trial confirmed this benefit in hormone receptor-positive and HER2-ultralow (less than 1+, but with ≤10% of infiltrating cancer cells showing incomplete and faint/weak membrane staining) cases, prompting re-evaluation of HER2 diagnostic thresholds and treatment strategies. Methods: Eligible patients were women with HER2-low or HER2-0 MBC evaluated at MD Anderson between January 2006 and January 2019. HER2-low was defined as either (1) IHC 1+ or (2) IHC 2+ and negative on fluorescence in situ hybridization. Multivariate logistic regression was used to evaluate distinct clinicopathologic features of patients with HER2-low status. Overall survival (OS) was estimated by the Kaplan–Meier method. Multivariate Cox proportional hazards regression was applied to assess the effects of covariates of interest on OS across different HER2 groups. Results: We included 3834 women: 2637 (69%) with recurrent and 1197 (31%) with de novo MBC; HER2-low disease was present in 1575 (60%) and 712 (59%), respectively. In de novo cases, higher nuclear grade was associated with HER2-low status (grade 2 vs. 1, OR = 2.02, p = 0.007; grade 3 vs. 1, OR = 1.87, p = 0.015), while recurrent cases were associated with ER-positivity (OR = 1.96, p < 0.001) and prior adjuvant radiotherapy (OR = 0.79, p = 0.007). Median OS was 3.2 years (95% CI 3.0–3.5). In de novo disease, Black race (HR = 1.48), metaplastic (HR = 3.15) or other non-ductal/lobular histologies (HR = 2.36), and grade 3 (HR = 1.67) predicted worse OS, whereas Hispanic ethnicity (HR = 0.74) and Other races (HR = 0.57), higher ER (HR = 0.48–0.41) and PR (HR = 0.72–0.53), and HER2-low status (HR = 0.77) conferred improved outcomes. In recurrent disease, Black race predicted worse OS (HR = 1.21, 95% CI 1.05–1.39), while Other race (HR = 0.78, 95% CI 0.62–0.97), higher ER (HR = 0.69–0.44) and PR (HR = 0.73–0.73), and HER2-low (HR = 0.89) were protective. HER2 discordance between primary and metastatic sites occurred in 38.8% of recurrent and 13.1% of de novo cases. Conclusions: HER2-low status was significantly associated with longer OS compared to HER2-0 status in both recurrent and de novo MBC cases. These real-world data help establish the prevalence of HER2-low status and its distinct outcomes. The discrepancy in HER2-low status between the primary tumor and metastatic sites highlights the potential for changes in HER2 expression over time, exploring the interaction between HER2-low breast cancer and the tumor microenvironment and emphasizing the importance of monitoring and reassessing HER2 status at various stages to guide treatment decisions effectively and the need for more quantitative and reproducible HER assays. Full article

Alterations in the tumor extracellular environment and matrix stiffness promote tumor progression. Furthermore, correlational studies have identified enrichment of extracellular matrix (ECM) proteins (glycoproteins, collagens) in breast tumors. Despite these findings, there has yet to be an interdisciplinary analysis of both ECM composition and structural architecture in rare breast tumors, such as metaplastic breast cancer. Here, we explored changes in ECM protein expression and architecture in a triple-negative breast cancer (TNBC) metaplastic tumor through SEM, proteomics, and RNA sequencing. SEM revealed that the tumor pore size was larger compared to the control adipose tissue. Oscillating rheometry demonstrated increased ECM stiffness in the tumor compared to the control adipose breast adipose. Proteomic analysis of the metaplastic TNBC tumor showed significant enrichment for ECM proteins, notably glycoproteins compared to the control adipose. Interestingly, these samples showed no observed changes in expression for major fibrillar collagens COL1A1 and COL1A2, and a reduced expression of COL3A1. To determine the impact of less characterized ECMs in metaplastic TNBC, we overexpressed MFAP2 in primary metaplastic breast cancer cells and performed RNA sequencing. MFAP2 overexpression was associated with upregulation of epithelial-to-mesenchymal transition-related genes. Overall, our results establish an extracellular signature and onco-architecture for the metaplastic triple-negative tumor type. Full article

Background/objectives: Metaplastic breast carcinoma (MpBC) is a rare, poorly differentiated breast cancer defined by the presence of ductal carcinoma along with areas of matrix-producing, spindle-cell, sarcomatous, or squamous differentiation. It does not express hormone receptors and has a poor overall prognosis. The Hippo molecular pathway was recently related to cancer progression and adjuvant therapy resistance. The objective of this study was to evaluate the expression of Hippo pathway transducers, YAP/TAZ, CCND1, and CTGF, in MpBC and their relation to the clinicopathological characteristics of the disease. Methods: Specimens from patients with MpBC treated at our department from 2003 to 2021 were analyzed utilizing immunohistochemistry and real-time PCR. Results: Forty-four female patients (62.6 ± 14.7 years old) met inclusion criteria and were included in this study. Strong nuclear YAP/TAZ expression was found in 61.4% of patients, while the expressions of CCND1 and CTGF were 3.9% and 12.5%, respectively. Patients presenting at an advanced stage had a statistically worse prognosis compared to the ones diagnosed with stage IA disease. Adjuvant chemotherapy was associated with better overall survival, while disease recurrence was significantly associated with a worse prognosis. Conclusions: Advanced stage at diagnosis and disease recurrence were significantly associated with worse prognosis in MpBC. However, adjuvant chemotherapy significantly led to better overall survival. The Hippo pathway is frequently deregulated (nuclear YAP/TAZ in 61.4% of patients), suggesting it is a compelling novel therapeutic target for this aggressive disease. Full article

A long-standing question in stress physiology is when and how the adaptive stress response can become maladaptive. In this narrative review primarily focusing on experimental studies in (male) animals, we argue that this is not merely a semantic matter but that—within limits—the organism’s response to an acute or chronic stressor and the interpretation thereof as adaptive or maladaptive very much depends on the context and the circumstances under which the response is studied, including the task configuration and the state of the organism, in relation to its recent and past stress history. We substantiate this by providing examples at the behavioral level. The behavioral findings can be understood from neurophysiological studies, which show that the recent and distant (stress) history of an organism shapes its brain function and plasticity. Consequently, renewed exposure to a challenging situation evokes a different cellular and circuit response than it would without this history, pointing to metaplastic changes. Overall, we argue that many of the stress-induced effects that are currently interpreted as maladaptive are, in fact, adaptive as long as the environment aligns with the circumstances predicted by the individual’s experience. Adaptation to novel circumstances will require (behavioral) flexibility. Understanding the relationship between metaplastic or state-dependent cellular responses on the one hand and flexible behavioral outcomes that foster adaptation on the other hand may contribute to developing interventions or preventing stress-related mental disorders. Full article

Background/Objectives: Autoimmune metaplastic atrophic gastritis (AMAG) is a chronic, autoimmune-mediated condition associated with increased risk of malignancy and nutritional deficiencies, yet diagnostic and follow-up processes remain inconsistent and unclear. This study investigates follow-up testing performance in patients with AMAG and neuroendocrine tumors (NET), as well as the correlation between endoscopic impressions and histologic findings. Methods: We retrospectively analyzed 65 gastric biopsies with final diagnoses or comments mentioning the possibility of AMAG, 12 of which included well-differentiated WHO grade 1 NET arising in AMAG. H&E slides were reviewed to assess atrophy severity, the presence or absence of enterochromaffin-like (ECL) cell hyperplasia, and Helicobacter organisms. The final diagnostic line or comments made were scored from 1 to 5, based on the strength of the language used to alert the treating clinician to the likelihood of AMAG. Corresponding endoscopy reports were scored from 1 to 5 based on the likelihood of the reports documenting AMAG features. Data regarding follow-up laboratory testing relevant to AMAG and biopsy performance were collected from the electronic medical records. Results: Endoscopy scores showed no significant associations with the histology comment score or atrophy grade. The histology comment score was positively associated with performing at least a total of three laboratory tests (p = 0.03). No association was found between the presence or absence of follow-up biopsy and histology comment score (p = 0.60). Follow-up biopsy was more common in patients with NET than those with AMAG without NET (p < 0.001). Conclusions: Poor endoscopic–histologic correlation with variable follow-up practices highlights the need for standardized protocols in AMAG management. Enhanced adherence to biopsy guidelines, standardized pathology reporting, and consistent surveillance, particularly for patients with AMAG without NET, are imperative to improve diagnosis and outcomes. Future research should focus on optimizing endoscopic techniques, standardizing serological tests, and establishing evidence-based surveillance protocols for AMAG patients. Full article

Background and Objectives: Low-grade triple-negative breast carcinomas (LG-TNBCs) represent a rare subset of breast cancers that deviate from the aggressive clinical course typically associated with triple-negative tumors. This narrative review aims to consolidate current knowledge on LG-TNBCs, highlighting their diagnostic features, molecular characteristics, and clinical implications to guide appropriate patient management and prevent overtreatment. Materials and Methods: We conducted a comprehensive narrative review using PubMed/MEDLINE, Embase, and Scopus databases up to September 2025. Search terms included combinations of “triple-negative breast carcinoma”, “low-grade”, “adenoid cystic carcinoma”, “secretory carcinoma”, “acinic cell carcinoma”, “tall cell carcinoma with reversed polarity”, “low-grade adenosquamous carcinoma”, and “fibromatosis-like metaplastic carcinoma.” Studies reporting clinicopathologic, immunohistochemical, or molecular data were included. Results: LG-TNBCs include seven distinct entities: adenoid cystic carcinoma, secretory carcinoma, acinic cell carcinoma, tall cell carcinoma with reversed polarity, low-grade adenosquamous carcinoma, fibromatosis-like metaplastic carcinoma, and mucoepidermoid carcinoma. These neoplasms are characterized by distinct morphologic patterns, specific immunohistochemical profiles, and recurrent molecular alterations such as ETV6-NTRK3 fusions and MYB rearrangements. Despite their triple-negative immunoprofile, they demonstrate indolent clinical behavior with excellent prognosis and low metastatic potential, although local recurrence is reported in variants exhibiting infiltrative, locally aggressive behavior. Conclusions: Recognition of LG-TNBCs is essential to prevent overtreatment and guide personalized patient management. Molecular characterization provides diagnostic confirmation and therapeutic opportunities, particularly for NTRK-fusion-positive tumors treatable with targeted inhibitors, highlighting the importance of precision medicine in rare breast tumors. Full article

Although information theory is widely used in neuroscience, its application has primarily been limited to the analysis of neural activity, with much less emphasis on behavioral data. This is despite the fact that the discrete nature of behavioral variables in many experimental settings—such as choice and reward outcomes—makes them particularly well-suited to information-theoretic analysis. In this study, we provide a framework for how behavioral metrics based on conditional entropy and mutual information can be used to infer an agent’s decision-making and learning strategies under uncertainty. Using simulated reinforcement-learning models as ground truth, we illustrate how information-theoretic metrics can reveal the underlying learning and choice mechanisms. Specifically, we show that these metrics can uncover (1) a positivity bias, reflected in higher learning rates for rewarded compared to unrewarded outcomes; (2) gradual, history-dependent changes in the learning rates indicative of metaplasticity; (3) adjustments in choice strategies driven by reward harvest rate; and (4) the presence of alternative learning strategies and their interaction. Overall, our study highlights how information theory can leverage the discrete, trial-by-trial structure of many cognitive tasks, with the added advantage of being parameter-free as opposed to more traditional methods such as logistic regression. Information theory thus offers a versatile framework for investigating neural and computational mechanisms of learning and choice under uncertainty—with potential for further extension. Full article

This research delves into the complex relationship between progenitor cells and the differentiated cell types that make up the stomach. It highlights the need for further investigation into the mechanisms governing stomach development and how these mechanisms relate to the maintenance of the stomach in a healthy state. The transition from normal gastric mucosa to metaplasia involves significant alterations in the phenotype and function of gastric epithelial cells, including stem cells, mucous neck cells, chief cells, and parietal cells. The presented literature review provides an in-depth analysis of pyloric and pseudopyloric metaplasia, along with spasmolytic polypeptide-expressing metaplasia, focusing on their biological significance, underlying pathogenesis, diagnostic features, and prognostic implications. It explores the role of various gastric epithelial cell types in the pathogenesis of metaplasia, highlighting recent advances in cellular plasticity, molecular pathways, and the implications for gastric carcinogenesis. Full article

This study aims to develop and validate a multisequence MRI-based radiomics approach for distinguishing metaplastic breast cancer (MBC) from non-metaplastic triple-negative breast cancer (TNBC) at the initial diagnosis, which could facilitate optimal treatment selection. In this retrospective study, we analyzed 105 patients (27 MBC, 78 non-metaplastic TNBC) who underwent standardized breast magnetic resonance imaging (MRI), which included T1-weighted contrast-enhanced (T1W-CE) and short-tau inversion recovery (STIR) sequences. Two radiologists performed ground truth lesion segmentation, verified by a senior radiologist. We extracted 214 radiomic features (using PyRadiomics) and used least absolute shrinkage and selection operator (LASSO) regression for feature selection. Seven machine learning classifiers were thoroughly evaluated using five-fold cross-validation, with performance assessed through ROC analysis and accuracy metrics. The combined T1W-CE and STIR analysis demonstrated superior diagnostic performance for distinguishing MBC from non-metaplastic TNBC (AUC = 0.845; accuracy = 81%) compared with either sequence alone (T1W only AUC = 0.805; accuracy = 80%; STIR only AUC:0.768; accuracy = 77%). Multisequence MRI radiomics can reliably distinguish between MBC and TNBC at the time of initial diagnosis. This could potentially facilitate the selection of more appropriate treatments and help avoid ineffective chemotherapy for MBC patients. Full article

The stomach epithelium is a highly dynamic tissue that undergoes continuous self-renewal and responds robustly to injury through tightly regulated repair processes. Organoids have emerged as powerful tools for modelling gastrointestinal biology. This review focuses on the capacity of gastric organoids to model epithelial homeostasis, injury and repair in the stomach. We examine how organoid systems recapitulate key features of in vivo gastric architecture and stem cell dynamics, enabling detailed interrogation of lineage specification, proliferative hierarchies and regional identity. Gastric organoids have proven particularly useful for studying how environmental factors, such as Helicobacter pylori infection or inflammatory cytokines, disrupt epithelial equilibrium and drive metaplastic transformation. Furthermore, we discuss the emerging use of injury-mimicking conditions, co-cultures and bioengineered platforms to model regeneration and inflammatory responses in vitro. While organoids offer unparalleled accessibility and experimental manipulation, they remain limited by the absence of critical niche components such as immune, stromal and neural elements. Nevertheless, advances in multi-cellular and spatially resolved organoid models are closing this gap, making them increasingly relevant for disease modelling and regenerative medicine. Overall, gastric organoids represent a transformative approach to dissecting the cellular and molecular underpinnings of stomach homeostasis and repair. Full article

Elevated extracellular potassium (K⁺) in the tumor microenvironment (TME) of breast and other cancers is increasingly recognized as a critical factor influencing tumor progression and immune suppression. Current methods for noninvasive mapping of the potassium distribution in tumors are limited. Here, we employed photoacoustic chemical imaging (PACI) with a solvatochromic dye-based, potassium-sensitive nanoprobe (SDKNP) to quantitatively visualize extracellular potassium levels in an orthotopic metaplastic breast cancer mouse model, Ccn6-KO. Tumors of three distinct sizes (5 mm, 10 mm, and 20 mm) were imaged using multi-wavelength photoacoustic imaging at five laser wavelengths (560, 576, 584, 605, and 625 nm). Potassium concentration maps derived from spectral unmixing of the photoacoustic images at the five laser wavelengths revealed significantly increased potassium levels in larger tumors, confirmed independently by inductively coupled plasma mass spectrometry (ICP-MS). The PACI results matched ICP-MS measurements, validating PACI as a robust, noninvasive imaging modality for potassium mapping in tumors in vivo. This work establishes PACI as a promising tool for studying the chemical properties of the TME and provides a foundation for future studies evaluating the immunotherapy response through ionic biomarker imaging. Full article

Barrett’s esophagus (BE), a metaplastic transformation of an esophageal squamous epithelium into an intestinal-type columnar epithelium, is the primary precursor to esophageal adenocarcinoma (EAC). Traditional management strategies have relied heavily on selective screening, tailored surveillance intervals, and early dysplasia detection and treatment algorithms. However, the heterogeneity in progression risk among BE patients necessitates a more nuanced, personalized approach involving precision care, tailoring decisions to individual patient characteristics, promises to enhance outcomes in BE through more targeted screening, personalized surveillance intervals, and risk-based therapeutic strategies. This review explores the current landscape and emerging trends in precision medicine for Barrett’s esophagus, highlighting genomic markers, digital pathology, and AI-driven models as tools to transform how we approach this complex disease and prevent progression to EAC. Full article

Exposure to high-linear energy transfer (LET) heavy ions, such as ²⁸Si, poses a significant cancer risk for astronauts. While previous studies have linked high-LET radiation exposure to persistent oxidative stress and dysregulated stress responses in intestinal crypt cells with an increased risk of tumorigenesis, the relationship between IR-induced oxidative DNA damage and intestinal cancer risk remains incompletely understood. Here, we investigated the time-dependent effects of ²⁸Si-ion radiation on intestinal tumorigenesis and oxidative DNA damage in Apc^1638N/+ mice, a model for human intestinal cancer predisposition. Male Apc^1638N/+ mice were exposed to 10 cGy of either γ-rays (low-LET) or ²⁸Si-ions (high-LET), and intestinal tumor burden was assessed at 60 and 150 days post-irradiation. While both radiation groups showed modest, non-significant tumor increases at 60 days, ²⁸Si-irradiated mice exhibited an approximately 2.5-fold increase in tumor incidence by 150 days, with a higher incidence of invasive carcinomas compared to γ and sham groups. Serum 8-OxodG levels, a marker of systemic oxidative stress, were significantly elevated in the ²⁸Si-ion group, correlating with increased intestinal 8-OxodG staining. Additionally, assessment of the proliferation marker Cyclin D1 and metaplasia marker Guanylyl Cyclase C (GUCY2C) also revealed significant crypt cell hyperproliferation accompanied by increased metaplasia in ²⁸Si-exposed mouse intestines. Positive correlations between serum 8-OxodG and tumor-associated endpoints provide compelling evidence that exposure to ²⁸Si-ions induces progressive intestinal tumorigenesis through sustained oxidative DNA damage, crypt cell hyperproliferation, and metaplastic transformation. This study provides evidence in support of the radiation quality-dependent progressive increase in systemic and intestinal levels of 8-OxodG during intestinal carcinogenesis. Moreover, the progressive increase in oxidative DNA damage and simultaneous increase in oncogenic events after ²⁸Si exposure also suggest that non-targeted effects might be a significant player in space radiation-induced intestinal cancer development. The correlation between serum 8-OxodG and oncogenic endpoints supports its potential utility as a predictive biomarker of high-LET IR-induced intestinal carcinogenesis, with implications for astronaut health risk monitoring during long-duration space missions. Full article

Endometrial carcinosarcoma (ECS) is a rare and aggressive histological subtype of endometrial cancer that is associated with a dismal prognosis. It is a biphasic metaplastic carcinoma with a monoclonal origin comprising epithelial and mesenchymal components. The ECS originates from the epithelial components of the tumor, which undergoes an epithelial-to-mesenchymal transition. Approximately half of patients are diagnosed at the early stage of the disease, whereas the other half are diagnosed at the advanced stage. More than one-third of women present with metastatic lymph nodes, and approximately 10% will have distant metastases. Therefore, ECS is the deadliest type of endometrial cancer compared to other high-grade endometrial carcinomas. Surgical resection with adjuvant therapy remains the standard of care in most cases. The rarity of this disease hinders conducting prospective clinical trials to establish the optimal treatment regimens and increase overall survival. There are no specific guidelines for managing these rare and aggressive tumors despite the increasing interest in ECS in the gynecologic oncology community. The present review focuses on all new insights into ECS regarding its epidemiology, pathology, prognosis, and treatment. Furthermore, the molecular characteristics and new treatment regimens for primary (early and advanced stages) and recurrent ECS are discussed in detail. Full article

Despite its significance, hysteresis remains underrepresented in mainstream models of plasticity. In this work, we propose a novel framework that explicitly models hysteresis in simple one- and two-neuron models. Our models capture key feedback-dependent phenomena such as bistability, multistability, periodicity, quasi-periodicity, and chaos, offering a more accurate and general representation of neural adaptation. This opens the door to new insights in computational neuroscience and neuromorphic system design. Synaptic weights change in several contexts or mechanisms including, Bienenstock–Cooper–Munro (BCM) synaptic modification, where synaptic changes depend on the level of post-synaptic activity; homeostatic plasticity, where all of a neuron synapses simultaneously scale up or down to maintain stability; metaplasticity, or plasticity of plasticity; neuromodulation, where neurotransmitters influence synaptic weights; developmental processes, where synaptic connections are actively formed, pruned and refined; disease or injury; for example, neurological conditions can induce maladaptive synaptic changes; spike-time dependent plasticity (STDP), where changes depend on the precise timing of pre- and postsynaptic spikes; and structural plasticity, where changes in dendritic spines and axonal boutons can alter synaptic strength. The ability of synapses and neurons to change in response to activity is fundamental to learning, memory formation, and cognitive adaptation. This paper presents simple continuous and discrete neuro-modules with adapting feedback synapses which in turn are subject to feedback. The dynamics of continuous periodically driven Hopfield neural networks with adapting synapses have been investigated since the 1990s in terms of periodicity and chaotic behaviors. For the first time, one- and two-neuron models are considered as parameters are varied using a feedback mechanism which more accurately represents real-world simulation, as explained earlier. It is shown that these models are history dependent. A simple discrete two-neuron model with adapting feedback synapses is analyzed in terms of stability and bifurcation diagrams are plotted as parameters are increased and decreased. This work has the potential to improve learning algorithms, increase understanding of neural memory formation, and inform neuromorphic engineering research. Full article