The History of Armand Trousseau and Cancer-Associated Thrombosis

Multifaceted Heparin: Diverse Applications beyond Anticoagulant Therapy

Heparin, a naturally occurring polysaccharide, has fascinated researchers and clinicians for nearly a century due to its versatile biological properties and has been used for various therapeutic purposes. Discovered in the early 20th century, heparin has been a key therapeutic anticoagulant ever since, and its use is now implemented as a life-saving pharmacological intervention in the management of thrombotic disorders and beyond. In addition to its known anticoagulant properties, heparin has been found to exhibit anti-inflammatory, antiviral, and anti-tumorigenic activities, which may lead to its widespread use in the future as an essential drug against infectious diseases such as COVID-19 and in various medical treatments. Furthermore, recent advancements in nanotechnology, including nano-drug delivery systems and nanomaterials, have significantly enhanced the intrinsic biofunctionalities of heparin. These breakthroughs have paved the way for innovative applications in medicine and therapy, expanding the potential of heparin research. Therefore, this review aims to provide a creation profile of heparin, space for its utilities in therapeutic complications, and future characteristics such as bioengineering and nanotechnology. It also discusses the challenges and opportunities in realizing the full potential of heparin to improve patient outcomes and elevate therapeutic interventions.

Analysis of thromboembolism and prognosis in metastatic pancreatic cancer from the Tokushukai REAl‑world data project

Cancer-associated thromboembolism (CAT), including venous thromboembolism (VTE) and arterial thromboembolism (ATE), is a frequent complication of advanced pancreatic cancer. However, reports on its incidence and clinical outcomes, especially on ATE, are limited. The present study aimed to investigate the incidence of CAT and its effects on overall survival in patients with metastatic pancreatic cancer. As part of the Tokushukai REAl-world data project in Japan, 846 eligible patients with metastatic pancreatic cancer treated with first-line chemotherapy were identified between April 2010 and March 2020. Using diagnosis procedure combination data from these patients, the present study investigated the incidence of VTE, ATE and cerebral and gastrointestinal bleeding requiring hospitalization. Blood laboratory data were collected within 14 days of the start of first-line treatment, and Khorana scores were calculated. The associations between CAT complications and comorbidities, concomitant medications and prognosis were examined. Among the 846 patients, 21 (2.5) and 70 (8.3%) had VTE and ATE, respectively (including five with overlapping VTE and ATE). CAT-positive patients had a significantly higher rate of gastrointestinal bleeding events compared with CAT-negative patients [13 of 86 (15.2%) vs. 46 of 760 (6.1%); P=0.01]. CAT-positive patients had a poorer prognosis [hazard ratio (HR), 1.28; 95% confidence interval (CI), 1.01-1.62] compared with CAT-negative patients, even after adjusting for background factors (HR, 1.20; 95% CI, 0.95-1.52). Cox regression analyses showed that higher Khorana scores were associated with significantly worse prognosis. This real-world data demonstrated that the incidence rate of CAT in patients with metastatic pancreatic cancer was 10.2%, and no statistically significant differences were observed, although there was a trend toward an adverse prognosis. The Khorana score may also be useful for predicting prognosis, even in the absence of CAT. This study was registered in the UMIN Clinical Trial Registry (http://www.umin.ac.jp/ctr/index.htm; clinical trial no. UMIN000050590).

Trousseau's Syndrome: A Paraneoplastic Complication

Trousseau syndrome, also known as thrombophlebitis migrans or migratory superficial thrombophlebitis, is a rare but significant paraneoplastic manifestation associated with various cancers. This syndrome is characterized by the occurrence of recurrent deep or superficial venous thrombosis in patients with malignancies. Patients with cancer have a greatly increased risk of venous thrombosis, especially in the first few months after diagnosis and in the presence of distant metastases. This article describes the case of a 72-year-old female patient who suffered a deep vein thrombosis in the right lower limb, which led to Trousseau syndrome secondary to non-Hodgkin's lymphoma.

Platelet Contributions to the (Pre)metastatic Tumor Microenvironment

Alongside their conventional roles in thrombosis and hemostasis, platelets have long been associated with nonhemostatic pathologies, including tumor cell metastasis. Numerous mechanistic studies have since demonstrated that the direct binding of platelets to intravascular tumor cells promotes key hallmarks of metastasis, including survival in circulation and tumor cell arrest at secondary sites. However, platelets also interact with nonmalignant cells that make up the stromal and immune compartments within both primary and metastatic tumors. This review will first provide a brief historical perspective on platelet contributions to metastatic disease before discussing the emerging roles that platelets play in creating microenvironments that likely support successful tumor cell metastasis.

Oncogenes and cancer associated thrombosis: what can we learn from single cell genomics about risks and mechanisms?

Single cell analysis of cancer cell transcriptome may shed a completely new light on cancer-associated thrombosis (CAT). CAT causes morbid, and sometimes lethal complications in certain human cancers known to be associated with high risk of venous thromboembolism (VTE), pulmonary embolism (PE) or arterial thromboembolism (ATE), all of which worsen patients' prognosis. How active cancers drive these processes has long evaded scrutiny. While "unspecific" microenvironmental effects and consequences of patient care (e.g., chemotherapy) have been implicated in pathogenesis of CAT, it has also been suggested that oncogenic pathways driven by either genetic (mutations), or epigenetic (methylation) events may influence the coagulant phenotype of cancer cells and stroma, and thereby modulate the VTE/PE risk. Consequently, the spectrum of driver events and their downstream effector mechanisms may, to some extent, explain the heterogeneity of CAT manifestations between cancer types, molecular subtypes, and individual cases, with thrombosis-promoting, or -protective mutations. Understanding this molecular causation is important if rationally designed countermeasures were to be deployed to mitigate the clinical impact of CAT in individual cancer patients. In this regard, multi-omic analysis of human cancers, especially at a single cell level, has brought a new meaning to concepts of cellular heterogeneity, plasticity, and multicellular complexity of the tumour microenvironment, with profound and still relatively unexplored implications for the pathogenesis of CAT. Indeed, cancers may contain molecularly distinct cellular subpopulations, or dynamic epigenetic states associated with different profiles of coagulant activity. In this article we discuss some of the relevant lessons from the single cell "omics" and how they could unlock new potential mechanisms through which cancer driving oncogenic lesions may modulate CAT, with possible consequences for patient stratification, care, and outcomes.

Macrophages and platelets in liver fibrosis and hepatocellular carcinoma

During fibrosis, (myo)fibroblasts deposit large amounts of extracellular matrix proteins, thereby replacing healthy functional tissue. In liver fibrosis, this leads to the loss of hepatocyte function, portal hypertension, variceal bleeding, and increased susceptibility to infection. At an early stage, liver fibrosis is a dynamic and reversible process, however, from the cirrhotic stage, there is significant progression to hepatocellular carcinoma. Both liver-resident macrophages (Kupffer cells) and monocyte-derived macrophages are important drivers of fibrosis progression, but can also induce its regression once triggers of chronic inflammation are eliminated. In liver cancer, they are attracted to the tumor site to become tumor-associated macrophages (TAMs) polarized towards a M2- anti-inflammatory/tumor-promoting phenotype. Besides their role in thrombosis and hemostasis, platelets can also stimulate fibrosis and tumor development by secreting profibrogenic factors and regulating the innate immune response, e.g., by interacting with monocytes and macrophages. Here, we review recent literature on the role of macrophages and platelets and their interplay in liver fibrosis and hepatocellular carcinoma.

Decoding the role of platelets in tumour metastasis: enigmatic accomplices and intricate targets for anticancer treatments

The canonical role of platelets as central players in cardiovascular disease by way of their fundamental role in mediating thrombosis and haemostasis is well appreciated. However, there is now a large body of experimental evidence demonstrating that platelets are also pivotal in various physiological and pathophysiological processes other than maintaining haemostasis. Foremost amongst these is the emerging data highlighting the key role of platelets in driving cancer growth, metastasis and modulating the tumour microenvironment. As such, there is significant interest in targeting platelets therapeutically for the treatment of cancer. Therefore, the purpose of this review is to provide an overview of how platelets contribute to the cancer landscape and why platelets present as valuable targets for the development of novel cancer diagnosis tools and therapeutics.

[Thromboembolic disease and cancer: Attitude and practice of general practitioners. A qualitative study]

INTRODUCTION

Cancer is a major public health problem in France. Idiopathic venous thromboembolic disease may be one of the modes of discovery. Few studies have been performed on this subject in primary care. The general practitioner plays a key role in the diagnosis for which a more codified approach seems desirable. The aim was to study how general practitioners conceive the search for cancer in patients with idiopathic venous thromboembolic disease in primary care.

METHOD

A qualitative study, inspired by the grounded theory approach, was carried out using semi-structured interviews with 12 established general practitioners. It was conducted from May to July 2022. The interview guide was developed based on data from the literature.

RESULTS

Idiopathic venous thromboembolic disease as a mode of cancer discovery in primary care was a well-known topic among general practitioners but remained a difficult exercise in practice. Our study revealed similarities in their practices: a complete anamnesis, clinical examination, verification of screening tests, and finally a TAP scan. They emphasized the importance of collaboration with angiologists and asked for a more codified management.

DISCUSSION

The question of etiology of cancer remains unanswered. General practioners would like to be made aware of a common, codified attitude. This raises the question of the applicability of the recommendations. The aim is to avoid misdiagnosing a cancer or delaying a diagnosis, while at the same time, not unnecessarily exposing certain patients to excessive investigations when these are not needed. So, it is time to think about better dissemination of recommendations, tools to help GPs easily finding what they need among the multitude of existing recommendations and tools, to establish better collaboration between general practice and hospital medicine, and between general practice and specialist medicine in order to improve cancer diagnosis as early as possible.

Antiphospholipid syndrome in cardiovascular disease and cancer

Antiphospholipid syndrome is an autoimmune disorder which is characterized by the presence of heterogeneous antiphospholipid antibodies. There is an evidence on antiphospholipid (aPL) antibodies related to thromboembolic events in cancer patients. In fact, the thrombotic complications in patients with malignancy occur at a rather high frequency, compared to other risk factors. In parallel with standard therapies available, there is need of case-by-case monitoring of each patient and the introduction of new therapies and need for more clinical trials which will address many questions for the optimal management of patients. This paper presents a basic review of the literature on the aPL antibodies associated with cardiovascular disease and cancer, as well as its complications, which are reported so far in the bibliography.

Live-imaging studies reveal how microclots and the associated inflammatory response enhance cancer cell extravasation

Previous clinical studies and work in mouse models have indicated that platelets and microclots might enable the recruitment of immune cells to the pre-metastatic cancer niche, leading to efficacious extravasation of cancer cells through the vessel wall. Here, we investigated the interaction between platelets, endothelial cells, inflammatory cells, and engrafted human and zebrafish cancer cells by live-imaging studies in translucent zebrafish larvae, and show how clotting (and clot resolution) act as foci and as triggers for extravasation. Fluorescent tagging in each lineage revealed their dynamic behaviour and potential roles in these events, and we tested function by genetic and drug knockdown of the contributing players. Morpholino knockdown of fibrinogen subunit α (fga) and warfarin treatment to inhibit clotting both abrogated extravasation of cancer cells. The inflammatory phenotype appeared fundamental, and we show that forcing a pro-inflammatory, tnfa-positive phenotype is inhibitory to extravasation of cancer cells.

Thromboxane biosynthesis in cancer patients and its inhibition by aspirin: a sub-study of the Add-Aspirin trial

BACKGROUND

Pre-clinical models demonstrate that platelet activation is involved in the spread of malignancy. Ongoing clinical trials are assessing whether aspirin, which inhibits platelet activation, can prevent or delay metastases.

METHODS

Urinary 11-dehydro-thromboxane B2 (U-TXM), a biomarker of in vivo platelet activation, was measured after radical cancer therapy and correlated with patient demographics, tumour type, recent treatment, and aspirin use (100 mg, 300 mg or placebo daily) using multivariable linear regression models with log-transformed values.

RESULTS

In total, 716 patients (breast 260, colorectal 192, gastro-oesophageal 53, prostate 211) median age 61 years, 50% male were studied. Baseline median U-TXM were breast 782; colorectal 1060; gastro-oesophageal 1675 and prostate 826 pg/mg creatinine; higher than healthy individuals (~500 pg/mg creatinine). Higher levels were associated with raised body mass index, inflammatory markers, and in the colorectal and gastro-oesophageal participants compared to breast participants (P < 0.001) independent of other baseline characteristics. Aspirin 100 mg daily decreased U-TXM similarly across all tumour types (median reductions: 77-82%). Aspirin 300 mg daily provided no additional suppression of U-TXM compared with 100 mg.

CONCLUSIONS

Persistently increased thromboxane biosynthesis was detected after radical cancer therapy, particularly in colorectal and gastro-oesophageal patients. Thromboxane biosynthesis should be explored further as a biomarker of active malignancy and may identify patients likely to benefit from aspirin.

Management of Thromboembolic Disease in Patients with Primary and Metastatic Brain Tumors

OPINION STATEMENT

Patients with primary brain tumors are at a substantially elevated risk of venous thromboembolism (VTE) compared to other disease states or other forms of malignancy. Deep venous thrombosis (DVT) and pulmonary embolism (PE), often complicate the care of patients with primary brain tumors, and treatment may pose specific unique risks and considerations for management. This paper critically reviews the relevant literature and the most common treatment options in addition to a discussion regarding the relative risk considerations for neurooncology patients facing thromboembolic disease.

Extracellular vesicles and particles as mediators of long-range communication in cancer: connecting biological function to clinical applications

Over the past decade, extracellular vesicles and particles (EVPs) have emerged as critical mediators of intercellular communication, participating in numerous physiological and pathological processes. In the context of cancer, EVPs exert local effects, such as increased invasiveness, motility, and reprogramming of tumor stroma, as well as systemic effects, including pre-metastatic niche formation, determining organotropism, promoting metastasis and altering the homeostasis of various organs and systems, such as the liver, muscle, and circulatory system. This review provides an overview of the critical advances in EVP research during the past decade, highlighting the heterogeneity of EVPs, their roles in intercellular communication, cancer progression, and metastasis. Moreover, the clinical potential of systemic EVPs as useful cancer biomarkers and therapeutic agents is explored. Last but not least, the progress in EVP analysis technologies that have facilitated these discoveries is discussed, which may further propel EVP research in the future.

Pro-Tumorigenic and Thrombotic Activities of Platelets in Lung Cancer

Aside from their key protective roles in hemostasis and innate immunity, platelets are now recognized as having multifaceted, adverse roles in the pathogenesis, progression and outcome of many types of human malignancy. The most consistent and compelling evidence in this context has been derived from the notable association of elevated circulating platelet counts with the onset and prognosis of various human malignancies, particularly lung cancer, which represents the primary focus of the current review. Key topics include an overview of the association of lung cancer with the circulating platelet count, as well as the mechanisms of platelet-mediated, pro-tumorigenic immunosuppression, particularly the role of transforming growth factor beta 1. These issues are followed by a discussion regarding the pro-tumorigenic role of platelet-derived microparticles (PMPs), the most abundant type of microparticles (MPs) in human blood. In this context, the presence of increased levels of PMPs in the blood of lung cancer patients has been associated with tumor growth, invasion, angiogenesis and metastasis, which correlate with disease progression and decreased survival times. The final section of the review addresses, firstly, the role of cancer-related platelet activation and thrombosis in the pathogenesis of secondary cardiovascular disorders and the associated mortality, particularly in lung cancer, which is second only to disease progression; secondly, the review addresses the potential role of antiplatelet agents in the adjunctive therapy of cancer.

Unraveling the Role of Hydrogen Bonds in Thrombin via Two Machine Learning Methods

Hydrogen bonds play a critical role in the folding and stability of proteins, such as proteins and nucleic acids, by providing strong and directional interactions. They help to maintain the secondary and 3D structure of proteins, and structural changes in these molecules often result from the formation or breaking of hydrogen bonds. To gain insights into these hydrogen bonding networks, we applied two machine learning models - a logistic regression model and a decision tree model - to study four variants of thrombin: wild-type, ΔK9, E8K, and R4A. Our results showed that both models have their unique advantages. The logistic regression model highlighted potential key residues (GLU295) in thrombin's allosteric pathways, while the decision tree model identified important hydrogen bonding motifs. This information can aid in understanding the mechanisms of folding in proteins and has potential applications in drug design and other therapies. The use of these two models highlights their usefulness in studying hydrogen bonding networks in proteins.

NETworking with cancer: The bidirectional interplay between cancer and neutrophil extracellular traps

Neutrophils are major effectors and regulators of the immune system. They play critical roles not only in the eradication of pathogens but also in cancer initiation and progression. Conversely, the presence of cancer affects neutrophil activity, maturation, and lifespan. By promoting or repressing key neutrophil functions, cancer cells co-opt neutrophil biology to their advantage. This co-opting includes hijacking one of neutrophils' most striking pathogen defense mechanisms: the formation of neutrophil extracellular traps (NETs). NETs are web-like filamentous extracellular structures of DNA, histones, and cytotoxic granule-derived proteins. Here, we discuss the bidirectional interplay by which cancer stimulates NET formation, and NETs in turn support disease progression. We review how vascular dysfunction and thrombosis caused by neutrophils and NETs underlie an elevated risk of death from cardiovascular events in cancer patients. Finally, we propose therapeutic strategies that may be effective in targeting NETs in the clinical setting.

Cancer and stroke: What do we know and where do we go?

Cancer is an increasingly recognized cause for ischemic stroke, with recent acknowledgement of cancer-related stroke as an emerging stroke subtype with unique pathophysiologic mechanisms. In addition, cancer-related stroke may differ from stroke in the general population as cancer patients may not receive guideline-recommended stroke care, and the occurrence of stroke may also preclude patients from receiving optimal cancer treatments. Due to the high degree of morbidity and mortality associated with both conditions, understanding the relationship between stroke and cancer is crucial. In this narrative review, we discuss the association between cancer and stroke, the unique pathophysiologic mechanisms underlying this phenomenon, treatment options including acute reperfusion therapies and secondary prevention strategies, compare outcomes between cancer-related stroke and stroke in the general population, and review new and emerging evidence in this field.

Platelets in the NETworks interweaving inflammation and thrombosis

Platelets are well characterized for their indispensable role in primary hemostasis to control hemorrhage. Research over the past years has provided a substantial body of evidence demonstrating that platelets also participate in host innate immunity. The surface expression of pattern recognition receptors, such as TLR2 and TLR4, provides platelets with the ability to sense bacterial products in their environment. Platelet α-granules contain microbicidal proteins, chemokines and growth factors, which upon release may directly engage pathogens and/or contribute to inflammatory signaling. Additionally, platelet interactions with neutrophils enhance neutrophil activation and are often crucial to induce a sufficient immune response. In particular, platelets can activate neutrophils to form neutrophil extracellular traps (NETs). This specific neutrophil effector function is characterized by neutrophils expelling chromatin fibres decorated with histones and antimicrobial proteins into the extracellular space where they serve to trap and kill pathogens. Until now, the mechanisms and signaling pathways between platelets and neutrophils inducing NET formation are still not fully characterized. NETs were also detected in thrombotic lesions in several disease backgrounds, pointing towards a role as an interface between neutrophils, platelets and thrombosis, also known as immunothrombosis. The negatively charged DNA within NETs provides a procoagulant surface, and in particular NET-derived proteins may directly activate platelets. In light of the current COVID-19 pandemic, the topic of immunothrombosis has become more relevant than ever, as a majority of COVID-19 patients display thrombi in the lung capillaries and other vascular beds. Furthermore, NETs can be found in the lung and other tissues and are associated with an increased mortality. Here, virus infiltration may lead to a cytokine storm that potently activates neutrophils and leads to massive neutrophil infiltration into the lung and NET formation. The resulting NETs presumably activate platelets and coagulation factors, further contributing to the subsequent emergence of microthrombi in pulmonary capillaries. In this review, we will discuss the interplay between platelets and NETs and the potential of this alliance to influence the course of inflammatory diseases. A better understanding of the underlying molecular mechanisms and the identification of treatment targets is of utmost importance to increase patients’ survival and improve the clinical outcome.

Old is new again: emergence of thromboembolic complications in cancer patients on immunotherapy

Cancer immunotherapy has emerged as one of the most important new treatments for cancer in many years, moving rapidly to front-line therapy for several cancers. Cancer immunotherapy is based on treatment with immune checkpoint inhibitors (ICI), which are monoclonal antibodies directed toward immunoregulatory proteins including PD-1, PD-L1 and CTLA-4. ICI inhibit interactions between these proteins and their ligands, disabling physiologic immune regulatory networks and enhancing anti-tumor immunity. However, since the immune response cannot be directed specifically to the tumor, ICI are associated with immune-related adverse events (irAEs) resulting from immune-mediated attack of normal tissues. We and others have reported a high incidence of thrombosis in patients treated with ICI, which may approach 20%. Given the rapidly increasing use of ICIs, it is clear that ICI-Associated Thrombosis (IAT) is a major emerging clinical problem. However, there is a remarkable knowledge gap concerning mechanisms of IAT. IAT may be a composite irAE resulting from activation of blood and vascular cells, leading to thromboinflammation. Cancer itself is an inflammatory disorder, and inducing further inflammation through ICI administration may stimulate procoagulant activity by multiple cell types. Moreover, some blood and vascular cells express ICI target proteins. Here, we review the results of several studies describing the clinical manifestations of IAT, as well as our recent studies demonstrating that elevated levels of myeloid derived suppressor cells and inflammatory cytokines may serve as biomarkers of IAT. It is hoped that the concepts reviewed here may stimulate further research into this important clinical problem.

Platelet and Cancer-Cell Interactions Modulate Cancer-Associated Thrombosis Risk in Different Cancer Types

The first cause of death in cancer patients, after tumoral progression itself, is thrombo-embolic disease. This cancer-associated hypercoagulability state is known as Trousseau's syndrome, and the risk for developing thrombotic events differs according to cancer type and stage, as well as within patients. Massive platelet activation by tumor cells is the key mediator of thrombus formation in Trousseau's syndrome. In this literature review, we aimed to compare the interactions between cancer cells and platelets in three different cancer types, with low, medium and high thrombotic risk. We chose oral squamous cell carcinoma for the low-thrombotic-risk, colorectal adenocarcinoma for the medium-thrombotic-risk, and pancreatic carcinoma for the high-thrombotic-risk cancer type. We showcase that understanding these interactions is of the highest importance to find new biomarkers and therapeutic targets for cancer-associated thrombosis.

The memory for words: Armand Trousseau on aphasia

Of all the nineteenth-century physicians whose names still resonate today, Armand Trousseau is perhaps the one most familiar, for his description of carpal spasm as a sign of hypocalcemia (Trousseau's sign) and his description of the hypercoagulable state associated with cancer (Trousseau's syndrome). In the last three years of his life, Trousseau turned his attention to aphasia, which he included in his 1864 and 1865 lectures given at Hôtel-Dieu Hospital in Paris and which he discussed in an address to the Imperial Academy of Medicine in 1865. Trousseau preceded Wernicke in describing aphasia as a symptom complex, in which he included Broca's aphemia, receptive aphasia, the inability to read with and without the inability to write (alexia with and without agraphia), the inability to name common objects (amnesic aphasia or anomia) and to recognize numbers (acalculia), and the inability to draw. Trousseau concluded that such a varied symptomatology could not arise from a single area, and he proposed that lesions of the posterior inferior frontal convolution identified by Broca, of the insula and corpus striatum and of the temporal and parietal lobes, could give rise to aphasia. The role of the posterior temporal lobe in receptive aphasia was confirmed by Wernicke in 1874, and the role of the inferior parietal lobule in agraphia and alexia was confirmed by Dejerine in 1891. Trousseau thought that aphasia resulted from the loss of the memory for words and for the synergistic actions of the movements of articulations learned in early childhood. Trousseau added inattention, lack of comprehension, and cognitive decline to amnesia as contributing factors to the verbal and nonverbal expression of thought. Trousseau constructed a comprehensive theory of aphasia that unified its semiology, localization, and pathophysiology. This construct had the virtue of being predictive and falsifiable by the clinico-pathological method. Through insight born of observation, Trousseau identified the issues that dominated aphasiology into the twenty-first century.

Interactions of platelets with circulating tumor cells contribute to cancer metastasis

Recent studies have suggested that platelets have a crucial role in enhancing the survival of circulating tumor cells in the bloodstream and aggravating cancer metastasis. The main function of platelets is to bind to the sites of the damaged vessels to stop bleeding. However, in cancer patients, activated platelets adhere to circulating tumor cells and exacerbate metastatic spreading. Several hypotheses have been proposed about the platelet-cancer cell interactions, but the underlying mechanisms of these interactions are not completely understood yet. In this work, we quantitatively investigated the interactions between circulating tumor cells, red blood cells, platelets, plasma flow and microvessel walls via computational modelling at the cellular scale. Our highly detailed computational model allowed us to understand and quantitatively explain the role of platelets in deformation, adhesion and survival of tumor cells in their active arrest to the endothelium.

New prophylaxis strategies to reduce the risk of thromboembolism in cancer

INTRODUCTION

: Patients with cancer are at risk of thrombotic events, mainly deep vein thrombosis and/or pulmonary embolism. The thrombosis risk is generally 4-6 times higher than in a healthy population and depends on factors related to patient characteristics, tumor factors, and treatment-related factors. The decision-making for prophylactic anticoagulation is individualized according to the relative risks and benefits. The VTE risk has been quantified using different assessment scores. In recent years, an effort has been made to establish "risk assessment models" specifically for patients undergoing chemotherapy.

AREAS COVERED

This article reviews current data and ongoing research on predictive factors involved in cancer-related thrombosis and it is highlighted the currently suggested strategies for prophylaxis. Several trials that compared the two treatment options, direct factor Xa inhibitor or LMWH, with placebo and not each other are discussed. In this article, was analyzed the safety and efficacy features that led several international organizations such as ASCO, NCCN, and others, to issue guidelines for the prophylaxis and treatment of patients at high risk of thrombosis by using LMWH, fondaparinux and DOACs.

EXPERT OPINION

ASCO, NCCN, and other international organizations recommend thromboprophylaxis in high risk patients. However, further investigation is needed to define better biomarkers for more accurate identification of cancer patients that will benefit from anticoagulant treatment.

Coagulation Signaling through PAR1 as a Therapeutic Target in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly fatal disease with a 5-year survival rate of less than 10% following diagnosis. The aggressive and invasive properties of pancreatic cancer tumors coupled with poor diagnostic options contribute to the high mortality rate since most patients present with late-stage disease. Accordingly, PDAC is linked to the highest rate of cancer-associated venous thromboembolic disease of all solid tumor malignancies. However, in addition to promoting clot formation, recent studies suggest that the coagulation system in PDAC mediates a reciprocal relationship, whereby coagulation proteases and receptors promote PDAC tumor progression and dissemination. Here, upregulation of tissue factor (TF) by tumor cells can drive local generation of the central coagulation protease thrombin that promotes cell signaling activity through protease-activated receptors (PARs) expressed by both tumor cells and multiple stromal cell subsets. Moreover, the TF-thrombin-PAR1 signaling axis appears to be a major mechanism of cancer progression in general and PDAC in particular. Here, we summarize the current literature regarding the role of PAR1 in PDAC and review possibilities for pharmacologically targeting PAR1 as a PDAC therapeutic approach.

The Role of Platelet Cell Surface P-Selectin for the Direct Platelet-Tumor Cell Contact During Metastasis Formation in Human Tumors

Mammalian platelets, devoid of nuclei, are the smallest cells in the blood stream. They are essential for hemostasis, but also transmit cell signals that are necessary for regenerative and generative processes such as inflammation, immunity and tissue repair. In particular, in malignancies they are also associated with cell proliferation, angiogenesis, and epithelial-mesenchymal transition. Platelets promote metastasis and resistance to anti-tumor treatment. However, fundamental principles of the interaction between them and target cells within tumors are complex and still quite obscure. When injected into animals or circulating in the blood of cancer patients, cancer cells ligate platelets in a timely manner closely related to platelet activation either by direct contact or by cell-derived substances or microvesicles. In this context, a large number of different surface molecules and transduction mechanisms have been identified, although the results are sometimes species-specific and not always valid to humans. In this mini-review, we briefly summarize the current knowledge on the role of the direct and indirect platelet-tumor interaction for single steps of the metastatic cascade and specifically focus on the functional role of P-selectin.

Neurologic complications of venous thromboembolism

Patients with neurologic disease are at high risk of venous thromboembolism (VTE). The converse risk of neurological complications in concert or following peripheral VTE is rarely considered. The major neurologic complication following pulmonary embolism or peripheral VTE is intracranial hemorrhage that occurs following anticoagulation therapy for VTE. Ischemic stroke may occur concomitantly with VTE. VT occurrence may also be a marker for a future increased risk of stroke. Peripheral neuropathy may occur or neuropathic pain may occur as a result of thrombophlebitis following deep venous thrombosis. Other sequelae of VTE are somewhat theoretical including the discovery of central nervous system malignancies after incident VTE.

Light Chain Mutation Effects on the Dynamics of Thrombin

Thrombin plays an important role in the process of hemostasis and blood coagulation. Studies in thrombin can help us find ways to treat cancer because thrombin is able to reduce the characteristic hypercoagulability of cancer. Thrombin is composed of two chains, the light chain and the heavy chain. The function of the heavy chain has been largely explored, while the function of the light chain was obscured until several disease-associated mutations in the light chain come to light. In this study, we want to explore the dynamic and conformation effects of mutations on the light chain further to determine possible associations between mutation, conformational changes, and disease. The study, which is a follow-up for our studies on apo thrombin and the mutant, ΔK9, mainly focuses on the mutants E8K and R4A. E8K is a disease-associated mutation, and R4A is used to study the role of Arg4, which is suggested experimentally to play a critical role for thrombin's catalytic activities. We performed five all-atom one microsecond-scale molecular dynamics (MD) simulations for both E8K and R4A, and quantified the changes in the conformational ensemble of the mutants. From the root-mean-square fluctuations (RMSF) for the α-carbons, we find that the atomic fluctuations change in the mutants in the 60s loop and γ loop. The correlation coefficients for the α-carbons indicate that the correlation relation for atom-pairs in the protein is also impacted. The clustering analysis and the principal component analysis (PCA) consistently tell us that the catalytic pocket and the regulatory loops are destabilized by the mutations. We also find that there are two binding modes for Na+ by clustering the vector difference between the Na+ ions and the 220s loop. After further analysis, we find that there is a relation between the Na+ binding and the rigidification of the γ loop, which may shed light on the mysterious role of the γ loop in thrombin.

The aegis: platelets as biomarkers of tumor progression

There is increasing awareness that platelets play a significant role in creating a hypercoagulable environment that mediates tumor progression, beyond their classical hemostatic function. Platelets have heterogenic responses to agonists, and differential release and uptake of bioactive molecules may be manipulated via reciprocal cross-talk with cells of the tumor microenvironment. Platelets thus promote tumor progression by enhancing tumor growth, promoting the development of tumor-associated vasculature and encouraging invasion. In the metastatic process, platelets form the shield that protects tumor cells from high-velocity forces and immunosurveillance, while ensuring the establishment of the pre-metastatic niche. This review presents the complexity of these concepts, considering platelets as biomarkers for diagnosis, prognosis and potentially as therapeutic targets in cancer.

Venous thromboembolic complications in lymphoma patients

Lymphomas represent a heterogeneous group of malignant hematological diseases with high risk for development of venous thromboembolic complications (VTE). Consequently, VTE significantly impacts morbidity and mortality in these patients. Another concern is the financial burden of the healthcare system caused by diagnostic and therapeutic procedures of cancer-associated thrombosis (CAT). The complex biology of lymphoma, in conjunction with patient and treatment related risk factors for the development of VTE, results in a procoagulant hemostatic dysregulation. Considering the incidence of VTE in patients with lymphoma, there is an emerging demand for both reliable risks assessment model (RAM) for prediction of VTE, as well as for effective VTE prophylaxis and treatment. The clinical course of patients with malignant diseases is accompanied by a wide range of potential treatment complications, making the task of prevention and treatment of VTE even more challenging. In recent years, great progress has been achieved in understanding the pathophysiological mechanisms of thrombotic complications, while the significant number of randomized controlled trials (RCT) have provided standards of prophylaxis and treatment of VTE complications in patients with malignancy. In comparison to previous recommendations and guidelines for CAT, the use of direct oral anticoagulants (DOAC) has been gradually approaching low molecular weight heparins (LMWH) in terms of efficacy and safety profile in these indications. This systematic review is focused on the latest pathophysiological advances, risk factors assessment, prophylactic and therapeutic recommendations and guidelines concerning VTE in patients with lymphoma.

Novel Aspects of Extracellular Vesicles as Mediators of Cancer-Associated Thrombosis

The establishment of prothrombotic states during cancer progression is well reported but the precise mechanisms underlying this process remain elusive. A number of studies have implicated the presence of the clotting initiator protein, tissue factor (TF), in circulating tumor-derived extracellular vesicles (EVs) with thrombotic manifestations in certain cancer types. Tumor cells, as well as tumor-derived EVs, may activate and promote platelet aggregation by TF-dependent and independent pathways. Cancer cells and their secreted EVs may also facilitate the formation of neutrophil extracellular traps (NETs), which may contribute to thrombus development. Alternatively, the presence of polyphosphate (polyP) in tumor-derived EVs may promote thrombosis through a TF-independent route. We conclude that the contribution of EVs to cancer coagulopathy is quite complex, in which one or more mechanisms may take place in a certain cancer type. In this context, strategies that could attenuate the crosstalk between the proposed pro-hemostatic routes could potentially reduce cancer-associated thrombosis.