Venous thrombosis and cancer: from mouse models to clinical trials

Anti-Thrombin, Anti-Adhesive, Anti-Migratory, and Anti-Proliferative Activities of Sulfated Galactans from the Tropical Green Seaweed, Udotea flabellum

In this study, sulfated polysaccharide-rich extracts were isolated from 22 tropical seaweeds (4 red, 11 brown, and 7 green) found in northeastern Brazil, and evaluated for the role of anticoagulant agents. Fifteen of the extracts showed anticoagulant activity, including all the extracts from green seaweeds. Udoteaflabellum (a green seaweed) extract was the most potent, requiring an amount of only 3 µg to double the plasma coagulation time in the activated partial thromboplastin time test. A similar result was obtained with 1 µg of heparin. Two sulfated homogalactans with anticoagulant activity, F-I (130 kDa) and F-II (75 kDa), were isolated from this extract using several bio-guided purification steps. Their anticoagulant activity, as well as properties related to antitumor activity (anti-proliferative, anti-adhesive, and anti-migratory), were accessed. Their anticoagulant activities were close to that of heparin. We found that F-I and F-II (0.5–10 μg/mL) were not able to directly inhibit thrombin. In the presence of anti-thrombin, F-I (0.5 μg/mL) was more effective than heparin (0.5 μg/mL) in inhibiting thrombin, while F-II showed similar effects as heparin. F-I and F-II also inhibited B16-F10 (murine melanoma cells) adhesion, migration, and proliferation on a fibronectin-coated surface, but not on laminin- or collagen I-coated surfaces. Except for the antiproliferative activity, the other effects of F-I and F-II were eliminated upon their desulfation (~50%), indicating that the degree of sulfation is not as important for F-I and F-II anti-proliferative activity as the sulfation position. Taken together, the results provide strong evidence for the potential utility of sulfated galactans from U.flabellum, making these compounds an interesting option for future investigations that aim to design new anticoagulant/antitumor agents.

Behçet's syndrome as a tool to dissect the mechanisms of thrombo-inflammation: clinical and pathogenetic aspects

Behçet's syndrome (BS) is a complex disease with different organ involvement. The vascular one is the most intriguing, considering the existence of a specific group of patients suffering from recurrent vascular events involving the venous and, more rarely, the arterial vessels. Several clinical clues suggest the inflammatory nature of thrombosis in BS, especially of the venous involvement, thus BS is considered a model of inflammation-induced thrombosis. Unique among other inflammatory conditions, venous involvement (together with the arterial one) is currently treated with immunosuppressants, rather than with anti-coagulants. Although many in-vitro studies have suggested the different roles of the multiple players involved in clot formation, in-vivo models are crucial to study this process in a physiological context. At present, no clear mechanisms describing the pathophysiology of thrombo-inflammation in BS exist. Recently, we focused our attention on BS patients as a human in-vivo model of inflammation-induced thrombosis to investigate a new mechanism of clot formation. Indeed, fibrinogen displays a critical role not only in inflammatory processes, but also in clot formation, both in the fibrin network and in platelet aggregation. Reactive oxygen species (ROS)-derived modifications represent the main post-translational fibrinogen alterations responsible for structural and functional changes. Recent data have revealed that neutrophils (pivotal in the pathogenetic mechanisms leading to BS damage) promote fibrinogen oxidation and thrombus formation in BS. Altogether, these new findings may help understand the pathogenetic bases of inflammation-induced thrombosis and, more importantly, may suggest potential targets for innovative therapeutic approaches.

Biomarkers and potential pathogenesis of colorectal cancer-related ischemic stroke

AIM

To investigate the specific biomarkers and potential pathogenesis of colorectal cancer-related ischemic stroke (CRCIS).

METHODS

A retrospective study was conducted on CRCIS patients (colorectal cancer patients with ischemic stroke without conventional stroke risk factors) registered at seven centers between January 2007 and December 2017. Clinical data and laboratory and imaging findings were compared with age- and sex- matched patients with colorectal cancer (CRC) without ischemic stroke that were admitted to the same hospital during the same period. Univariate and multivariate analyses were performed to analyze the independent risk factors for CRCIS. A receiver operator characteristic curve was configured to calculate the optimal cut-off value of the products of the independent risk factors for CRCIS.

RESULTS

A total of 114 CRCIS patients and 114 CRC patients were included. Multiple lesions in multiple vascular territories were common in CRCIS patients (71, 62.28%). The levels of plasma D-dimer, carcinoembryonic antigen (CEA), cancer antigen 125, and neutrophil count were significantly higher in CRCIS patients than in CRC patients. Multiple logistic regression analysis revealed that plasma D-dimer levels [odds ratio (OR) = 1.002, 95% confidence interval (CI): 1.001-1.003, P < 0.001], CEA levels (OR = 1.011, 95%CI: 1.006-1.015, P < 0.001), and neutrophil count levels (OR = 1.626, 95%CI: 1.268-2.087, P < 0.001) were independent risk factors for CRCIS. In addition, receiver operator characteristic curve revealed that the area under curve for the products of plasma D-dimer, CEA, and neutrophil count was 0.889 ± 0.022 (95%CI: 0.847-0.932, P < 0.001), and the optimal cut-off value for the product was 252.06, which was called the CRCIS Index, with a sensitivity of 86.0% and specificity of 79.8%.

CONCLUSION

Hypercoagulability induced by elevated CEA and neutrophils may be an important cause of CRCIS. The CRCIS index, which serves as a biomarker of CRCIS, needs further study.

Analysis of peripheral central venous access ports at the forearm: An observational study

The aim of this study was to analyse the characteristics of central venous catheters with brachial-implanted reservoirs and the complications associated with their use over a 4-years period. This observational study was carried out in an onco-haematological day hospital in Spain. Information was collected about 125 catheters inserted in patients requiring intravenous chemotherapy. There were more catheters implanted in women than men and the mean age was 58.6 years. Seventy of the implanted catheters were made of polyurethane and 55 of silicone. Left laterality prevailed with a mean catheter dwell-time of 347.1 days. A total of 164 complications were registered, 124 of them came from blood draws, where the most frequent complication was "inability to withdraw, ability to infuse". Forty complications were associated with the administration of treatments. Furthermore, there were 21 catheter removals, caused by several other complications different from those mentioned before. Statistically significant differences were found when associating types of catheters, laterality, blood draws and administration of treatments. Results showed how silicone ports would be more appropriate for patients who carry these types or ports than polyurethane because they reduce the number of complications causes by thrombosis.

Leukocytes as a reservoir of circulating oncogenic DNA and regulatory targets of tumor-derived extracellular vesicles

Essentials Tumor-bearing mice were employed to follow oncogenic HRAS sequences in plasma, and blood cells. Cancer DNA accumulated in leukocytes above levels detected in exosomes, platelets and plasma. Extracellular vesicles and nucleosomes are required for uptake of tumor DNA by leukocytes. Uptake of tumor-derived extracellular vesicles by leukocytes triggers coagulant phenotype.

SUMMARY

Background Tumor-derived extracellular vesicles (EVs) and free nucleosomes (NSs) carry into the circulation a wealth of cancer-specific, bioactive and poorly understood molecular cargoes, including genomic DNA (gDNA). Objective Here we investigated the distribution of extracellular oncogenic gDNA sequences (HRAS and HER2) in the circulation of tumor-bearing mice. Methods and Results Surprisingly, circulating leukocytes (WBCs), especially neutrophils, contained the highest levels of mutant gDNA, which exceeded the amount of this material recovered from soluble fractions of plasma, circulating EVs, platelets, red blood cells (RBCs) and peripheral organs, as quantified by digital droplet PCR (ddPCR). Tumor excision resulted in disappearance of the WBC-associated gDNA signal within 2-9 days, which is in line with the expected half-life of these cells. EVs and nucleosomes were essential for the uptake of tumor-derived extracellular DNA by neutrophil-like cells and impacted their phenotype. Indeed, the exposure of granulocytic HL-60 cells to EVs from HRAS-driven cancer cells resulted in a selective increase in tissue factor (TF) procoagulant activity and interleukin 8 (IL-8) production. The levels of circulating thrombin-antithrombin complexes (TAT) were markedly elevated in mice harboring HRAS-driven xenografts. Conclusions Myeloid cells may represent a hitherto unrecognized reservoir of cancer-derived, EV/NS-associated oncogenic gDNA in the circulation, and a possible novel platform for liquid biopsy in cancer. In addition, uptake of this material alters the phenotype of myeloid cells, induces procoagulant and proinflammatory activity and may contribute to systemic effects associated with cancer.

Molecular Dynamics Simulations on Nucleic Acid Binding Polymers Designed To Arrest Thrombosis

Cancer-associated thrombosis is managed by the administration of anticoagulants and antithrombotic agents that have a high risk of inducing hemorrhagic complications. To develop safer strategies for antithrombotic therapy, in vivo activators of the intrinsic pathway, namely, cell-free nucleic acids (DNA and RNA) have been targeted with cationic, polyamine-based polymers. The cytotoxicity of the highly cationic polymers is a major drawback for their practical use, and biocompatible alternatives are in high demand. In this study, we carried out all-atom molecular dynamics simulations to systematically examine the DNA binding of polyamine-poly(ethylene glycol) (PEG) diblock polymers designed from biocompatible building blocks to inhibit the procoagulant activity of DNA. The differences in cationic charge, PEG chain length, and initial conformations of the polymers resulted in marked differences in their binding to DNA. We found that having an exposed cationic polyamine group is essential to polymer-DNA binding and a certain level of electrostatic interactions is necessary to maintain the bound state. Intrachain associations between the polyamine groups and PEG chains in some cases have led to a collapsed state of the polymer that precludes binding to DNA. This self-association is mainly due to a strong hydrogen bond between polymer polyamine and PEG groups and partly due to a partially charged semibranched polyamine group architecture. As polymer "masking" of DNA is thought to arrest DNA's prothrombotic activity, our findings highlight the desired structural features of the polymers for stronger DNA binding and provide insights into the design of novel antithrombotic agents.

Lysophospholipid Signaling in the Epithelial Ovarian Cancer Tumor Microenvironment

As one of the important cancer hallmarks, metabolism reprogramming, including lipid metabolism alterations, occurs in tumor cells and the tumor microenvironment (TME). It plays an important role in tumorigenesis, progression, and metastasis. Lipids, and several lysophospholipids in particular, are elevated in the blood, ascites, and/or epithelial ovarian cancer (EOC) tissues, making them not only useful biomarkers, but also potential therapeutic targets. While the roles and signaling of these lipids in tumor cells are extensively studied, there is a significant gap in our understanding of their regulations and functions in the context of the microenvironment. This review focuses on the recent study development in several oncolipids, including lysophosphatidic acid and sphingosine-1-phosphate, with emphasis on TME in ovarian cancer.

Biomarkers for the risk of thrombosis in pancreatic adenocarcinoma are related to cancer process

Background

Venous thrombo-embolic events (VTE) frequently occur in patients with pancreatic ductal adenocarcinoma (PDAC) and contribute to high morbidity and mortality.

Objectives

To determine whether VTE biomarkers are related to cancer, inflammation or precancerous states and to assess their relevance to predict VTE in PDAC.

Patients and Methods

We compared VTE biomarkers in patients with PDAC (n = 42), intraductal papillary mucinous neoplasm of the pancreas (IPMN, n = 48) or chronic pancreatitis (n = 50). PDAC patients were followed-up for 6 months.

Results

Factor VIII, D-dimers, von Willebrand factor, free tissue factor pathway inhibitor and microvesicle-tissue factor (MV-TF) activity were higher in PDAC patients compared to patients with IPMN or chronic pancreatitis. PDAC patients with metastasis presented higher D-dimers and MV-TF activity compared to patients with localized lesions, but elevation of D-dimers was dependent on tumor size. In multivariate analysis, elevated D-dimers (≥2.16 µg/mL) or MV-TF activity (≥2.37 pg/mL) were significant risk factors for VTE in PDAC patients, after adjustment for age and sex (HR 4.9 [1.0-23.1] or HR 10.5 [1.5-72.4], mean [interquartile range], respectively). Cumulative probability of VTE at 6 months was higher in patients with elevated D-dimers (56.3% vs 15.6%, p = 0.009) and in patients with high MV-TF activity (74.3% vs 21.7%, p = 0.01).

Conclusions

VTE biomarkers including D-dimers and MV-TF activity are not related to inflammation but rather to cancer process and dissemination. D-dimers and MV-TF activity are associated to future VTE in PDAC patients and could help identify patients who could benefit from thromboprophylaxis.

Association between oncogenic status and risk of venous thromboembolism in patients with non-small cell lung cancer

Background

Preclinical data suggest that oncogene (EGFR and KRAS) events regulate tumor procoagulant activity. However, few studies have prospectively investigated the clinical relevance between the presence of EGFR or KRAS mutations and occurrence of venous thromboembolism(VTE) in patients with non-small cell lung cancer (NSCLC).

Methods

A total of 605 Chinese patients with newly diagnosed NSCLC were included and were followed for a maximum period of 4.5 years. EGFR and KRAS mutations were determined by amplification refractory mutation system polymerase chain reaction method at inclusion. The main outcome was objectively confirmed VTE.

Results

Of the 605 patients, 40.3% (244) had EGFR mutations and 10.2% (62) of patients had KRAS mutations. In multivariable analysis including age, sex, tumor histology, tumor stage, performance status, EGFR and KRAS status, EGFR wild-type (sub-distribution hazard ratio 1.81, 95% confidence interval 1.07–3.07) were associated with the increased risk of VTE. In competing risk analysis, the probability of developing VTE was 8.3% in those with and 13.2% in those without EGFR mutations after 1 year; after 2 years, the corresponding risks were 9.7 and 15.5% (Gray test P = 0.047).

Conclusions

EGFR mutations have a negative association with the risk of VTE in Chinese patients with NSCLC.

Risk Stratification for Bleeding Complications in Patients With Venous Thromboembolism: Application of the HAS-BLED Bleeding Score During the First 6 Months of Anticoagulant Treatment

BACKGROUND

The Hypertension, Abnormal renal/liver function, Stroke, Bleeding, Labile International Normalized Ratio (INR), Elderly, Drugs or alcohol use (HAS-BLED) score has strong predictive validity for major bleeding complications, but limited validation has been conducted in venous thromboembolism (VTE). This study evaluates the HAS-BLED score in a large cohort of VTE patients.

METHODS AND RESULTS

A retrospective cohort of adults ≥18 years with primary diagnosis of VTE between January 1, 2010 and November 31, 2013 were identified in an insurance claims database. Patients were tracked until death, any bleed event, or end of study period. HAS-BLED score and components were evaluated via proportional hazard models. Cumulative incidence functions were reported at 30, 60, 90, and 180 days. N=132 280 patients with a VTE were identified, with 73.8% having HAS-BLED scores of 0 to 2, 3.6% score ≥4, and 4789 bleeding events (3.6% all patients). A 1-point HAS-BLED score increase was associated with 20% to 30% bleeding rate increase overall, but in a cancer cohort only the increase from 3- to 4-points was significant for all bleeds (csHR=1.41, 95% CI: 1.17-1.69; sdHR=1.40, 95% CI: 1.17-1.69) and major bleeds (csHR=1.66, 95% CI: 1.26-2.20; sdHR=1.66, 95% CI: 1.25-2.19). Adding cancer to the model as an independent covariate provided the strongest association among all covariates, with csHR=2.25 (95% CI: 1.98-2.56) and sdHR=2.11 (95% CI: 1.85-2.41) in the model for major bleeds.

CONCLUSIONS

The HAS-BLED score has good predictive validity for bleeding risks in patients with VTE. The addition of cancer as an independent bleeding risk factor merits consideration, possibly as part of the "B" criterion ("bleeding tendency or predisposition").

A Case of Left Atrial Myxoma Whose Initial Symptom Was Finger Ischemic Symptom

We experienced a 45-year-old Japanese man who was transferred to our hospital complaining of acute onset of pain and pallor in the right lower limb. Two years earlier, he had complained of repetitive pain at rest and pallor in the left third and fourth fingers. The physical exam and angiography demonstrated occlusion of finger arteries, however we could not reach final diagnosis. Acute arterial occlusive disease in the right lower limb was suspected. Transthoracic echocardiography demonstrated a gross tumor in the left atrium, which suggested left atrial myxoma. An emergency tumorectomy was successfully conducted. Pathologically, the fragile tumor and resultant thrombosis could have caused the patient's peripheral circulatory failure at least two years prior to this episode. A rigorous systemic survey is important even when the ischemic symptom is localized in peripheral circulation.

Tissue factor-bearing microparticles and inflammation: a potential mechanism for the development of venous thromboembolism in cancer

Cancer is associated with an increased risk of venous thromboembolism (VTE); the exact mechanisms for the induction of VTE remain to be fully elucidated, but it is widely acknowledged that tissue factor (TF)-bearing microparticles (TF-MPs) may play a significant role. However, TF-MPs have yet to be accepted as a genuine biomarker for cancer-associated VTE, as the presence of elevated TF-MP levels is not always accompanied by thrombosis; interestingly, in certain cases, particularly in pancreatic cancer, VTE seems to be more likely in the context of acute inflammation. Although several potential mechanisms for the development of VTE in cancer have been postulated, this review explores the homeostatic disruption of TF-MPs, as the main reservoir of bloodborne TF, in the context of cancer and inflammation, and considers the abrogated responses of the activated endothelium and mononuclear phagocyte system in mediating this disruption.

Cancer and Thrombotic Risk: The Platelet Paradigm

Hematologic malignancies and solid tumors increase the risk of venous and arterial thrombosis and contribute greatly to patient morbidity and mortality. Thrombosis occurs when the intricate balance of circulating antithrombotic and prothrombotic blood elements are disrupted. In recent years, the interplay between paraneoplastic cells and platelets has become apparent, with a change in platelet phenotype causing dysregulated platelet activity. This review discusses mechanism of thrombosis in cancer, evidence for using drug therapy, and exciting research efforts to understand and hopefully control aberrant thrombotic events in patients with cancer.

Fibrin-bearing microparticles: marker of thrombo-embolic events in pancreatic and colorectal cancers

Background

Microparticles (MPs) are plasma membrane-derived extracellular vesicles present in the bloodstream. We have described a specific signature of MPs, called microparticulosome, in colorectal (CRC) and pancreatic (PC) cancers. We observed that levels of fibrin-bearing MPs were significantly increased in patients suffering from PC and CRC in comparison with control groups. Here, we hypothesised that fibrin-MPs may constitute a relevant biomarker of thrombosis associated with cancer. The objective was to compare the microparticulosome signature between patients presenting with thrombo-embolic event and those without.

Methods

Patients with CRC and PC were prospectively included and divided in those with thrombo-embolic events (Group A) and those without (Group B).

MPs were analyzed by flow cytometer, combining the analysis of Annexin V-positive with characterization of their origin and determination of their procoagulant activities. D-dimer levels were measured in the same samples.

Results

We included 118 patients, divided in 19 patients with thrombo embolic event and 99 patients without. Fibrin-bearing MPs levels were significantly higher in presence of thrombo-embolic events, contrary to D-dimers levels. Fibrin-bearing MPs were more frequently produced by erythrocytes, endothelial cells or Ep-CAM+cells than platelets or leukocytes. Overall survival was shorter in case of thrombo-embolic events than without. The most frequent genes expressed by MPs derived from PC or CRC were implicated in metastatic diffusion of tumor cells, drug resistance, coagulation and inflammation.

Conclusion

Circulating MPs, particularly fibrin-bearing MPs, could be used as a new biomarker to predict cancer-associated thrombo-embolic events and poor survival.

Circulating tumor cell count and thrombosis in metastatic breast cancer

Essentials Tumor cells circulating in blood (CTC) may favor thrombotic events in cancer patients. We assessed the impact of CTC on the risk of thrombosis in metastatic breast cancer. Baseline CTC detection was the only independent factor associated with the risk of thrombosis. CTC detection under therapy may be the hidden link between tumor progression & thrombosis.

SUMMARY

Background Circulating tumor cell (CTC) count is a major prognostic factor in metastatic breast cancer (MBC) and has been reported to be associated with thrombosis in short-term studies on MBC patients. Objective To assess whether CTC detection (CellSearch® ) before first-line chemotherapy impacts the risk of thrombosis throughout the course of MBC. Patients/Methods Among patients included before first-line chemotherapy for MBC in the prospective IC2006-04 CTC detection study (NCT00898014), the electronic medical files of those patients treated at Institut Curie (Paris, France) were searched in silico and manually checked for incident venous or arterial thrombotic events (TE) in the course of MBC. Univariate and multivariate analyses were performed using Cox and Fine-Gray models, adjusted for age and Khorana score. Results/Conclusions With a median follow-up of 64 months (25-81 months), among the 142 patients included, 34 (24%) experienced a TE (incidence rate, 8 TE/100 patient-years). The TE incidence rate was 13 TE/100 patient-years for the 80 patients with ≥ 1 CTC/7.5 mL of blood before initiating first-line chemotherapy, vs. only 4 TE/100 patient-years for the 62 CTC-negative patients. Fine-Gray multivariate analysis (with death as competing event) included age, Khorana score and baseline lactate dehydrogenase and CTC levels: detectable CTC was the only factor significantly associated with an increased risk of TE (sub-distribution hazard ratio [SHR] for patients with [1-4] CTC = 3.1, 95% CI [1.1; 8.6], SHR for patients with ≥ 5 CTC = 1.4, 95% CI [0.5; 4.6]). This study shows that CTC detection before starting first-line chemotherapy is an independent risk factor for TE in MBC patients.

Statin use and venous thromboembolism in cancer: A large, active comparator, propensity score matched cohort study

BACKGROUND

Statins have been shown to have a protective effect for venous thromboembolism (VTE) in the general population. This study sought to assess the association between statins and the risk for cancer-associated deep vein thrombosis (DVT) and pulmonary embolism (PE).

METHODS

Patients with newly diagnosed cancer were followed for up to one year in a healthcare claims database (2010-2013). Three treatment groups included statin users, non-statin cholesterol lowering medication users, and an untreated group with pre-existing indications for statin therapy (hyperlipidemia, diabetes, or heart disease). Propensity score matched groups were compared using competing risks survival models for DVT and PE outcomes reporting the hazard ratios (HR) between the treatment groups. Sensitivity analyses assessed the influence of age and individual medications.

RESULTS

The total cohort included 170,459 patients, which, after matching, were similar on baseline characteristics. The overall model showed a statistically significant protective effect for statins compared to no treatment attributed only to leukemia for DVT (HR=0.77, 95% CI 0.61-0.99) and colorectal cancers for PE (HR=0.80, 95% CI 0.64-0.99) in stratified analyses. There were generally no differences in outcomes between statins and non-statins and no individual statin use showed results different from the class effect.

CONCLUSIONS

In this propensity score matched sample of patients with cancer, statins were shown to have a small protective effect in some cancers for DVT or PE compared to no treatment and little difference compared to an active control group. The lack of effect was consistent across statins and was also not found for any of the sensitivity analyses included.

Tumor-Derived Exosomes Induce the Formation of Neutrophil Extracellular Traps: Implications For The Establishment of Cancer-Associated Thrombosis

Cancer patients are at an increased risk of developing thromboembolic complications. Several mechanisms have been proposed to explain cancer-associated thrombosis including the release of tumor-derived extracellular vesicles and the activation of host vascular cells. It was proposed that neutrophil extracellular traps (NETs) contribute to the prothrombotic phenotype in cancer. In this study, we evaluated the possible cooperation between tumor-derived exosomes and NETs in cancer-associated thrombosis. Female BALB/c mice were orthotopically injected with 4T1 breast cancer cells. The tumor-bearing animals exhibited increased levels of plasma DNA and myeloperoxidase in addition to significantly increased numbers of circulating neutrophils. Mice were subjected to either Rose Bengal/laser-induced venous thrombosis or ferric chloride-induced arterial thrombosis models. The tumor-bearing mice exhibited accelerated thrombus formation in both models compared to tumor-free animals. Treatment with recombinant human DNase 1 reversed the prothrombotic phenotype of tumor-bearing mice in both models. Remarkably, 4T1-derived exosomes induced NET formation in neutrophils from mice treated with granulocyte colony-stimulating factor (G-CSF). In addition, tumor-derived exosomes interacted with NETs under static conditions. Accordingly, the intravenous administration of 4T1-derived exosomes into G-CSF-treated mice significantly accelerated venous thrombosis in vivo. Taken together, our observations suggest that tumor-derived exosomes and neutrophils may act cooperatively in the establishment of cancer-associated thrombosis.

Pathological expression of tissue factor confers promising antitumor response to a novel therapeutic antibody SC1 in triple negative breast cancer and pancreatic adenocarcinoma

The pathological presence of tissue factor (TF) in cancer cells promotes tumor-initiated thrombosis and cancer metastasis. We found that TF is aberrantly present in large percentage of aggressive triple negative breast cancer (TNBC) and pancreatic adenocarcinoma (PaC), two most lethal forms of malignancy that urgently need effective treatment. TF expression in TNBC clustered with higher levels of vimentin, basal-type keratins KRT5/14 and caveolin-1 but lower levels of luminal-type biomarkers. We developed a novel and specific anti-TF therapeutic antibody SC1, which displayed an exceedingly high potency against TF extracellular domain (EC₅₀: 0.019 nM), TF-positive TNBC- or PaC cells (EC₅₀: 2.5 nM), intracellular protease activated receptor 2 (PAR2) signaling (IC₅₀: 2-3 nM) and tumor-initiated coagulation (IC₅₀: <10 nM). Depletion of TF or SC1-treatment in TNBC or PaC cells inhibited TF-induced cell migration, lung metastasis and tumor growth in vivo, accompanied by diminished levels of tumor angiogenesis and stromal fibrosis. We further propose TF as a promising target for antibody-drug conjugate (ADC) development based on its rapid and efficient internalization of SC1-drug conjugate. Both SC1-DM1 and SC1-MMAE elicited exquisite cytotoxicity in TF-positive TNBC and PaC cells (IC₅₀: 0.02-0.1 nM) but not in TF-negative cells (>100 nM) achieving >5000 fold target selectivity. Following a weekly intravenous administration, SC1-MMAE and its humanized hSC1-MMAE inhibited TNBC- and PaC tumor growth achieving MED of 0.3-1 mg/kg and were both well tolerated. Thus, the prevalent TF expression in TNBC and PaC renders these challenging tumors highly susceptible to TF-targeted treatment and may offer new opportunity in cancer patients.

Chemotherapy administration to breast cancer patients affects extracellular vesicles thrombogenicity and function

Breast cancer (BC) is the most prevalent type of malignancy in women. Extracellular vesicles (EVs) are subcellular membrane blebs that include exosomes and microparticles.

The platelet-to-lymphocyte ratio as a predictor of patient outcomes in ovarian cancer: a meta-analysis

OBJECTIVES

The platelet-to-lymphocyte ratio (PLR) is a predictive clinical biomarker for different cancers. However, the results of several studies investigating the association between the PLR and the prognosis of ovarian cancer have been inconclusive. Therefore, there is a need to conduct a meta-analysis to estimate the prognostic value of the PLR in ovarian cancer.

METHODS

We searched the EMBASE, Medline, PubMed, and Web of Science databases to identify clinical studies that had evaluated the association between the PLR and ovarian cancer prognosis. Outcomes evaluated included overall survival (OS) and progression-free survival (PFS). We also analyzed PLR differences between malignant ovarian masses and the controls.

RESULTS

Twelve relevant studies that comprised 2340 patients were selected for the meta-analysis. The results revealed that elevated PLR was significantly associated with poor OS (hazard ratio (HR) 1.63, 95% confidence interval (CI) 1.05-2.56, p < 0.01) and PFS (HR 1.61, 95% CI 1.03-2.51, p < 0.01). The PLRs in malignant cases were higher than in controls (mean difference = 63.57, 95% CI 39.47-87.66, p < 0.00001).

CONCLUSION

An elevated PLR is associated with poor prognosis in patients with ovarian cancer. The PLR could be employed as a prognostic marker in patients with ovarian cancer.

Potential Coagulation Factor-Driven Pro-Inflammatory Responses in Ovarian Cancer Tissues Associated with Insufficient O₂ and Plasma Supply

Tissue factor (TF) is a cell surface receptor for coagulation factor VII (fVII). The TF-activated fVII (fVIIa) complex is an essential initiator of the extrinsic blood coagulation process. Interactions between cancer cells and immune cells via coagulation factors and adhesion molecules can promote progression of cancer, including epithelial ovarian cancer (EOC). This process is not necessarily advantageous, as tumor tissues generally undergo hypoxia due to aberrant vasculature, followed by reduced access to plasma components such as coagulation factors. However, hypoxia can activate TF expression. Expression of fVII, intercellular adhesion molecule-1 (ICAM-1), and multiple pro-inflammatory cytokines can be synergistically induced in EOC cells in response to hypoxia along with serum deprivation. Thus, pro-inflammatory responses associated with the TF-fVIIa-ICAM-1 interaction are expected within hypoxic tissues. Tumor tissue consists of multiple components such as stromal cells, interstitial fluid, albumin, and other micro-factors such as proton and metal ions. These factors, together with metabolism reprogramming in response to hypoxia and followed by functional modification of TF, may contribute to coagulation factor-driven inflammatory responses in EOC tissues. The aim of this review was to describe potential coagulation factor-driven inflammatory responses in hypoxic EOC tissues. Arguments were extended to clinical issues targeting this characteristic tumor environment.

Performance of Khorana Risk Score for Prediction of Venous Thromboembolism in Patients With Hepatocellular Carcinoma

Cancer-associated venous thromboembolism (VTE) is one of the leading causes of mortality and morbidity among patients with malignancy. The Khorana risk score (KRS) is currently the best validated risk assessment model to stratify risks of VTE development in ambulatory patients with cancer. In the current study, we assessed the performance of KRS in patients with hepatocellular carcinoma (HCC). We retrospectively analyzed patients with diagnosis of HCC (screened by International Classification of Diseases [ ICD-9] and ICD-10 code, confirmed with radiographic examination and/or histopathology) at a large public hospital over 15 years (January 2000 through July 2015). Cases with VTE were identified through radiographic examination and blindly adjudicated. Khorana risk score was calculated for each patient, and its association with VTE development and mortality was assessed. Among 270 patients with HCC, 16 (5.9%) cases of VTE were identified, including 7 (43.8%) pulmonary embolism, 4 (25%) peripheral deep vein thrombosis, and 6 (37.5%) intra-abdominal thrombosis. One hundred eighty-four (68.1%) patients had a KRS of 0 and 86 (31.9%) patients had a KRS >0. Most of the thrombotic (n = 9, 56%) events occurred in the low-risk group. In univariate analysis, only prechemotherapy leukocyte count equal to or greater than 11 000/μL was statistically significant in the prediction of VTE incidence. After adjusting for confounding factors in multivariate analysis, KRS >0 was not predictive of VTE (hazard ratio [HR] = 1.83, 95% confidence interval [CI] = 0.81-4.15, P = .15) or mortality (HR = 1.61, 95% CI = 0.92-2.81, P = .09). Khorana risk score did not predict VTE development or mortality in patients with HCC. Design of HCC-specific risk assessment model for VTE development is necessary.

Much More than Trousseau Syndrome. The Broad Spectrum of the Pancreatic Paraneoplastic Syndromes

When 150 years ago Armand Trousseau proposed that some thrombotic events might be the first sign of concealed visceral malignancies, these findings seemed to be just of anecdotal interest. Since then, however, we have learned that adenocarcinomas, including pancreatic cancers could be associated with a wide spectrum of paraneoplastic syndromes. They may precede the detection of the tumor, may occur simultaneously or may develop during its progression. Due to various hematologic, endocrine, cutaneous, articular, neuromuscular, renal or even psychiatric syndromes, their correct interpretation is intriguing, and because their early signs are not necessarily recognized first by oncologists, the paraneoplastic syndromes pose a diagnostic challenge. Unfortunately, we cannot generalize about their mechanisms, because the molecular backgrounds are far-reaching. In most of the cases, the pancreatic cancer cells release various factors into the bloodstream triggering the coagulation cascade. These patients frequently present with venous thromboembolism, and sometimes they are resistant to anticoagulation. The simultaneous thrombotic and bleeding evens do reflect the abnormal hemostasis. In other instances autoantibodies are formed against cutaneous, renal, neuromuscular or nervous tissues, but the mechanism of some syndromes remains unclear. Clinicians should be aware that pancreatic carcinoma may be associated with not just the Trousseau-syndrome.

Microparticles and cancer thrombosis in animal models

Cancer-associated venous thromboembolism (VTE) constitutes the second cause of death after cancer. Many risk factors for cancer-associated VTE have been identified, among them soluble tissue factor and microparticles (MPs). Few data are available about the implication of MPs in cancer associated-VTE through animal model of cancer. The objective of the present review was to report the state of the current literature about MPs and cancer-associated VTE in animal model of cancer. Fourteen series have reported the role of MPs in cancer-associated VTE, through three main mouse models: ectopic or orthotopic tumor induction, experimental metastasis by intravenous injection of tumor cells into the lateral tail vein of the mouse. Pancreatic cancer is the most used animal model, due to its high rate of cancer-associated VTE. All the series reported that tumor cell-derived MPs can promote thrombus formation in TF-dependent manner. Some authors reported also the implication of phosphatidylserine and PSGL1 in the generation of thrombin. Moreover, MPs seem to be implicated in cancer progression through a coagulation-dependent mechanism secondary to thrombocytosis, or a mechanism implicating the regulation of the immune response. For these reasons, few authors have reported that antiplatelet and anticoagulant treatments may prevent tumor progression and the formation of metastases in addition of coagulopathy.

Cancer and Thrombosis: The Platelet Perspective

Platelets are critical to hemostatic and immunological function, and are key players in cancer progression, metastasis, and cancer-related thrombosis. Platelets interact with immune cells to stimulate anti-tumor responses and can be activated by immune cells and tumor cells. Platelet activation can lead to complex interactions between platelets and tumor cells. Platelets facilitate cancer progression and metastasis by: (1) forming aggregates with tumor cells; (2) inducing tumor growth, epithelial-mesenchymal transition, and invasion; (3) shielding circulating tumor cells from immune surveillance and killing; (4) facilitating tethering and arrest of circulating tumor cells; and (5) promoting angiogenesis and tumor cell establishment at distant sites. Tumor cell-activated platelets also predispose cancer patients to thrombotic events. Tumor cells and tumor-derived microparticles lead to thrombosis by secreting procoagulant factors, resulting in platelet activation and clotting. Platelets play a critical role in cancer progression and thrombosis, and markers of platelet-tumor cell interaction are candidates as biomarkers for cancer progression and thrombosis risk.

Hypercoagulation and complement: Connected players in tumor development and metastases

Hypercoagulation is a common feature of several tumors to the extent that individuals with coagulation defects often present with occult visceral cancers. Recent evidence has shown that hypercoagulation is not just a mere secondary effect due to the presence of the tumor, rather it actively contributes to tumor development and dissemination. Among the numerous mechanisms that can contribute to cancer-associated hypercoagulation, the ones involving immune-mediated processes are gaining increasing attention. In particular, complement cascade and hypercoagulation are one inducing the other in a vicious circle that involves neutrophil extracellular traps (NETs) formation. Together, in this feedback loop, they can promote the protumorigenic phenotype of immune cells and the protection of tumor cells from immune attack, ultimately favouring tumor development, progression and metastases formation. In this review, we summarize the role of these processes in cancer development and highlight new possible intervention strategies based on anticoagulants that can arrest this vicious circle.

Is forgoing chemical venous thromboembolism prophylaxis for women undergoing breast-conserving surgery for breast cancer safe?

BACKGROUND

Cancer patients have a 4 to 7 fold increased risk of venous thromboembolism (VTE) vs the normal population. Chest guidelines recommend no chemical VTE prophylaxis for women with a <1.5% risk for VTE. Although the risk of VTE among women undergoing breast-conserving therapy is reported to be low overall, the rate without chemical prophylaxis has not been defined. The objective of the study was to establish the VTE risk among women undergoing breast-conserving surgery (BCS) who did not receive chemical VTE prophylaxis.

METHODS

From a prospective breast cancer database, 1,000 consecutive patients who underwent BCS without chemical VTE prophylaxis and with mechanical prophylaxis (support hose and intermittent pneumatic compression devices) were analyzed for VTE occurrence within 30 days postoperatively. Institutional review board approval was obtained.

RESULTS

The mean age was 65.4 ± 11.7 years, and mean body mass index was 27.3 ± 5.7. About 81.9% of the patients were postmenopausal. Median tumor size was 1.1 cm, and 24.7% of patients had lymph node metastases. The 30-day rate of clinically significant VTE was 0% (95% CI 0% to .37%). Hematomas requiring surgical intervention occurred among .6% of patients.

CONCLUSIONS

This cohort demonstrates that breast cancer patients undergoing BCS may be safely managed without chemical VTE prophylaxis because the risk with only mechanical prophylaxis is acceptable.

14-3-3ζ regulates the mitochondrial respiratory reserve linked to platelet phosphatidylserine exposure and procoagulant function

The 14-3-3 family of adaptor proteins regulate diverse cellular functions including cell proliferation, metabolism, adhesion and apoptosis. Platelets express numerous 14-3-3 isoforms, including 14-3-3ζ, which has previously been implicated in regulating GPIbα function. Here we show an important role for 14-3-3ζ in regulating arterial thrombosis. Interestingly, this thrombosis defect is not related to alterations in von Willebrand factor (VWF)–GPIb adhesive function or platelet activation, but instead associated with reduced platelet phosphatidylserine (PS) exposure and procoagulant function. Decreased PS exposure in 14-3-3ζ-deficient platelets is associated with more sustained levels of metabolic ATP and increased mitochondrial respiratory reserve, independent of alterations in cytosolic calcium flux. Reduced platelet PS exposure in 14-3-3ζ-deficient mice does not increase bleeding risk, but results in decreased thrombin generation and protection from pulmonary embolism, leading to prolonged survival. Our studies define an important role for 14-3-3ζ in regulating platelet bioenergetics, leading to decreased platelet PS exposure and procoagulant function.

Platelets express negatively charged phosphatidylserine (PS) on their plasma membrane when propagating coagulation within a developing thrombus. Here the authors show that an adaptor protein 14-3-3 regulates mitochondrial function and PS exposure and thus platelet procoagulant activity, promising a new therapy to reduce thrombosis.

The Khorana Score in Predicting Venous Thromboembolism for Patients With Metastatic Urothelial Carcinoma and Variant Histology Treated With Chemotherapy

BACKGROUND

The Khorana score is a predictive risk model for venous thromboembolism (VTE) in patients with cancer planning to receive chemotherapy. Urothelial carcinoma and variant histologies (UC/VH) were underrepresented in the model. We sought to evaluate whether the Khorana score predicts for VTE in a retrospective multinational data set of patients with metastatic UC/VH.

METHODS

Patients diagnosed with metastatic UC/VH who received chemotherapy were eligible. Those with incomplete or miscoded data were excluded. Khorana scores were calculated based on the pretreatment data and categorized into high (≥3) or intermediate (1-2) VTE risk. Other patient-, tumor-, and therapy-related factors were also analyzed. The χ² and logistic regression analyses were used to assess differences in VTE rates based on the clinical characteristics. Subgroup analyses were performed to evaluate the Khorana score and associated variables for early (<3 months) and late (>3 months) VTE.

RESULTS

A total of 943 patients were eligible for analysis. The cumulative VTE rate was 9.9%. There was no statistical difference in overall VTE rate between Khorana high- and intermediate-risk groups ( P = .16). In the multivariate analysis, nonurothelial histology (odds ratio [OR] = 2.56; P = .002) and the presence of cardiovascular disease (CVD) or CVD risk factors (OR = 2.14; P = .002) were associated with increased VTE risk. In the first 3 months from initiation of chemotherapy, Khorana high risk (OR = 2.08; P = .04) was associated with higher VTE rates. White blood cell (WBC) count (OR = 1.05; P = .04) was the only significant Khorana variable for early VTE.

CONCLUSIONS

The Khorana score stratifies early but not overall VTE risk in patients with metastatic UC/VH. The WBC count drives the increased early VTE risk seen with the Khorana score.

Routine Hemostasis and Hemogram Parameters: Valuable Assessments for Coagulation Disorder and Chemotherapy in Cancer Patients

Background:

The clotting system abnormalities are the common complication in cancer patients. The aim of this retrospective study was to evaluate the coagulation state, clinical features, and treatment in cancer patients by routine tests.

Methods:

A total of 2328 patients with different types of cancer were classified as the positive group (n = 1419, including 53 patients with thrombosis) and the negative group (n = 909) based on D-dimer (DD) value. Of the 2328 cases, 354 were admitted for chemotherapy. Hemostasis test and complete blood count (CBC) were performed during treatment or following-up.

Results:

This study showed that the hypercoagulable state was affected not only by clinical staging (P < 0.0001) but also by metastasis site (P < 0.0001 for bone vs. lung). Compared to negative DD group, the higher fibrinogen level, the extended activated partial thromboplastin time, and prothrombin time interacted markedly with disease clinical stage (P < 0.05) in the positive group. Between positive DD groups with and without thrombus, the significantly statistic difference in white blood cell (WBC) and DD (P < 0.05) rather than in red blood cell (RBC) and platelet count was observed. However, the higher DD level was not correlated with WBC, RBC, and platelet count in the positive DD group. Furthermore, the hypercoagulable plasma profile in cancer patients was moderated 2–3 weeks after chemotherapy (P < 0.05 for first six cycles).

Conclusions:

The routine hemostatic parameters and CBC are valuable to assessment for thrombosis and chemotherapy even for disease prognosis.

Lipid profile of platelets and platelet-derived microparticles in ovarian cancer

Background

Ovarian cancer patients have a high risk of developing venous thrombosis. The membrane lipid bilayer of platelets and platelet-derived microparticles (PMP) provides a platform for assembly of coagulation proteins and generation of blood clots.

Methods

We compared the lipid composition of platelets and PMPs in patients with ovarian cancer to those in healthy subjects. We used shotgun lipidomics to quantify 12 classes and 177 species of lipids.

Results

We found a significant change in 2 classes of lipids in platelets and PMPs isolated from ovarian cancer patients: higher phosphatidylinositol and lower lyso-phosphatidylcholine. The level of 28 species of lipids was also significantly altered in the direction of an increase in the pro-coagulant and a reduction in the anticoagulant lipids. We found that cancer platelets expressed less lipid phosphate phosphatase 1 (LPP1), a key enzyme in phospholipid biosynthesis pathways, than normal platelets. The reduction in LPP1 might contribute to the changes in the lipid profile of cancer platelets.

Conclusion

Our results support a procoagulant lipid profile of platelets in ovarian cancer patients that can play a role in the increased risk of venous thrombosis in these patients.

General significance

As far as we are aware, our study is the first study on platelet lipidomics in ovarian cancer. The importance of our findings for the future studies are: 1) a similar change in lipid profile of platelets and PMP may be responsible for hypercoagulability in other cancers, and 2) plasma level of high-risk lipids for venous thrombosis may be useful biomarkers.

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Lipid composition of platelet and PMP is altered in ovarian cancer.

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The change in lipid composition of platelet and PMP is in a procoagulant direction.

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LPP1 enzyme is reduced in cancer platelets.

Fibrin degradation by rtPA enhances the delivery of nanotherapeutics to A549 tumors in nude mice

Effective drug delivery to a tumor depends on favorable blood perfusion within the tumor. As an important component of tumor extracellular matrix, fibrin is abundant near tumor vessels. Inspired by the distinct distribution pattern and vessel-dependent production of fibrin, we hypothesized that fibrin depletion in tumors decompresses tumor vessels to improve tumor blood perfusion and accordingly enhance drug delivery to tumors rich in vessels. In the present study, we attempted to employ a clinically used thrombolytic drug, recombinant tissue plasminogen activator (rtPA), to modulate fibrin deposition in tumors. We then combined this drug with a nanoparticle drug delivery system for tumor therapy. RtPA treatment (25 mg/kg/d i. p. administration for two weeks) successfully depleted fibrin deposition and enhanced blood perfusion within A549 tumor xenografts. Furthermore, rtPA treatment also improved the in vivo delivery of 115-nm nanoparticles to tumor tissues. Finally, rtPA combined with therapeutic agent-loaded nanoparticles resulted in the most effective shrinkage of A549 tumor xenografts compared with the control groups. Overall, the present study provides a new strategy to enhance the delivery of nanotherapeutics to tumors rich in vessels.

Targeting clotting proteins in cancer therapy - progress and challenges

Cancer-associated thrombosis remains a significant complication in the clinical management of cancer and interactions of the hemostatic system with cancer biology continue to be elucidated. Here, we review recent progress in our understanding of tissue factor (TF) regulation and procoagulant activation, TF signaling in cancer and immune cells, and the expanding roles of the coagulation system in stem cell niches and the tumor microenvironment. The extravascular functions of coagulant and anti-coagulant pathways have significant implications not only for tumor progression, but also for the selection of appropriate target specific anticoagulants in the therapy of cancer patients.

Microvesicle-associated tissue factor procoagulant activity for the preoperative diagnosis of ovarian cancer

BACKGROUND

Tissue factor (TF) is involved in tumor growth and metastasis and contributes to venous thromboembolism (VTE) in cancer, including gynecological malignancies. The diagnostic value of microvesicle-associated TF procoagulant activity (MV TF PCA) in women with suspected ovarian cancer, however, has not been studied.

OBJECTIVE

To evaluate MV TF PCA as a diagnostic tool in women with an ovarian mass of unknown etiology and as a predictive biomarker for perioperative VTE.

METHODS

Plasma MVs were isolated by high-speed centrifugation and analyzed for TF-specific PCA by single-stage clotting assay. In addition, plasma TF antigen and soluble P-selectin (sCD62P) were measured by ELISA.

RESULTS

D-Dimer, MV TF PCA, and sCD62P, but not the tumor marker, CA-125, significantly differentiated patients with malignant (n=40) from those with benign tumors (n=15) and healthy controls (n=34). In cancer patients, only D-Dimer and CA-125 correlated with the FIGO stage. An abnormal D-dimer had the highest sensitivity for the diagnosis of cancer, while MV TF PCA above the ROC curve-derived cut-off value of 182U/mL had the highest specificity. By multivariate logistic regression analysis, addition of MV TF PCA conferred diagnostic benefit to the single variables, CA-125 (p=0.052) and D-dimer (p=0.019). Perioperative VTE occurred in 16% of cancer patients and was associated with an advanced FIGO stage, but not MV TF PCA. There was no difference in plasma TF antigen levels between study groups.

CONCLUSIONS

MV TF PCA, but not plasma TF antigen, may provide valuable additional information for the diagnostic work-up of women with suspected ovarian cancer.

Measurement of microparticle tissue factor activity in clinical samples: A summary of two tissue factor-dependent FXa generation assays

Thrombosis is a leading cause of morbidity and mortality. Detection of a prothrombotic state using biomarkers would be of great benefit to identify patients at risk of thrombosis that would benefit from thromboprophylaxis. Tissue factor (TF) is a highly procoagulant protein that under normal conditions is not present in the blood. However, increased levels of TF in the blood in the form of microparticles (MPs) (also called extracellular vesicles) are observed under various pathological conditions. In this review, we will discuss studies that have measured MP-TF activity in a variety of diseases using two similar FXa generation assay. One of the most robust signals for MP-TF activity (16-26 fold higher than healthy controls) is observed in pancreatic cancer patients with venous thromboembolism. In this case, the TF+ MPs appear to be derived from the cancer cells. Surprisingly, cirrhosis and acute liver injury are associated with 17-fold and 38-fold increases in MP-TF activity, respectively. Based on mouse models, we speculate that the TF+ MPs are derived from hepatocytes. More modest increases are observed in patients with urinary tract infections (6-fold) and in a human endotoxemia model (9-fold) where monocytes are the likely source of the TF+ MPs. Finally, there is no increase in MP-TF activity in the majority of cardiovascular disease patients. These studies indicate that MP-TF activity may be a useful biomarker to identify patients with particular diseases that have an increased risk of thrombosis.

Tissue factor-positive tumor microvesicles activate platelets and enhance thrombosis in mice

ESSENTIALS: Cancer patients have a high rate of venous thrombosis (VT) but the underlying mechanisms are unknown. Tumor-derived, tissue factor-positive microvesicles in platelet activation in vitro and in vivo were studied. Tumor-derived, tissue factor-positive microvesicles enhanced VT in mice. Platelets may contribute to VT in some cancer patients, and this could be prevented with antiplatelet drugs.

BACKGROUND

Cancer patients have an approximately 4-fold increased risk of venous thromboembolism (VTE) compared with the general population, and cancer patients with VTE have reduced survival. Tumor cells constitutively release small membrane vesicles called microvesicles (MVs) that may contribute to thrombosis in cancer patients. Clinical studies have shown that levels of circulating tumor-derived, tissue factor-positive (TF(+) ) MVs in pancreatic cancer patients are associated with VTE. Objectives We tested the hypothesis that TF(+) tumor-derived MVs (TMVs) activate platelets in vitro and in mice.

MATERIALS AND METHODS

We selected two human pancreatic adenocarcinoma cell lines expressing high (BxPc-3) and low (L3.6pl) levels of TF as models to study the effect of TF(+) TMVs on platelets and thrombosis.

RESULTS AND CONCLUSIONS

We found that both types of TF(+) TMVs activated human platelets and induced aggregation in vitro in a TF and thrombin-dependent manner. Further, injection of BxPc-3 TF(+) TMVs triggered platelet activation in vivo and enhanced thrombosis in two mouse models of venous thrombosis in a TF-dependent manner. Importantly, BxPc-3 TF(+) TMV-enhanced thrombosis was reduced in Par4-deficient mice and in wild-type mice treated with clopidogrel, suggesting that platelet activation was required for enhanced thrombosis. These studies suggest that TF(+) TMV-induced platelet activation contributes to thrombosis in cancer patients.

Diagnosis and therapy in cancer-associated thromboembolism – what about guideline recommendations?

Oncogenic transformation is closely linked to coagulation activation and cancer-associated venous thromboembolism (VTE) is a common problem. Guidelines recommend thromboprophylaxis with a low molecular weight heparin for hospitalized cancer patients. However, thromboprophylaxis is not customarily advised for ambulatory cancer patients. Cancer patients with VTE are usually treated with a low molecular weight heparin for 3–6 months. Vitamin K antagonists have a higher bleeding risk and there are not sufficient data to recommend any of the new oral anticoagulants. All physicians taking care of cancer patients should be aware of the current guideline recommendations. Oncology professionals should educate patients about the signs of VTE.