D-dimer testing: A narrative review.

D-dimer containing species are soluble fibrin degradation products derived from plasmin-mediated degradation of cross-linked fibrin, i.e., 'D-dimer'. D-dimer can hence be considered a biomarker of in vivo activation of both coagulation and fibrinolysis, the leading clinical application in daily practice of which is ruling out venous thromboembolism (VTE). D-dimer has been further evaluated for assessing the risk of VTE recurrence and helping define optimal duration of anticoagulation treatment in VTE, for diagnosing disseminated intravascular coagulation (DIC), and for screening those at enhanced risk of VTE. D-dimer assays should however be performed as intended by regulatory agencies, as their use outside these indications might make them a laboratory-developed test (LDT). This narrative review is aimed at: (1) reviewing the definition of D-dimer, (2) discussing preanalytical variables affecting D-dimer measurement, (3) reviewing and comparing the assays performance and some postanalytical variables (e.g., different units and age-adjusted cutoffs), and (4) discussing the interest of D-dimer measurement across different clinical settings, including pregnancy, cancer, and coronavirus disease 2019 (COVID-19).

High fibrinogen levels are associated with poor survival in patients with liposarcoma.

The aim of this study was to evaluate whether (preoperative) plasma levels of fibrinogen, an essential clotting and acute phase protein, are associated with the prognosis of patients with a liposarcoma, a subtype of sarcoma derived from adipose tissue. We performed a retrospective cohort study of 158 patients with liposarcoma treated at the Department of Orthopaedics of the Medical University of Vienna in Austria from May 1994 to October 2021. Kaplan-Meier curves as well as uni- and multivariable Cox proportional hazard models were performed to evaluate the association between fibrinogen levels and overall survival. Elevated fibrinogen was associated with adverse overall survival in cause specific hazards analysis of mortality (hazard ratio [HR] per 10 mg/dL increase: 1.04; 95% CI 1.02-1.06; p < 0.001). This association prevailed in multivariable analysis after adjustment for AJCC tumor stage (HR 1.03; 95% CI 1.01-1.05; p = 0.013). Increasing levels of fibrinogen, a routinely available and inexpensive parameter, predicts the risk of mortality in patients with liposarcoma.

Venous thromboembolism in cancer patients: a population-based cohort study.

The incidence of venous thromboembolism (VTE) in cancer patients may have changed in the past decade, possibly due to novel cancer therapies, improved survival, and high-resolution imaging. Danish medical registries were used to identify 499 092 patients with a first-time cancer diagnosis between 1997 and 2017, who were matched to 1 497 276 comparison individuals without cancer from the general population. We computed cumulative incidences of VTE 6 and 12 months after the diagnosis/index date. Hazard ratios (HRs) were calculated using Cox regression. Risk factors were examined by computing subdistribution hazard ratios (SHRs) in a competing-risk analysis. Cumulative incidence of VTE 12 months after the cancer diagnosis/index date was 2.3% (95% confidence interval [CI], 2.2% to 2.3%) in the cancer cohort and 0.35% (95% CI, 0.34% to 0.36%) in the comparison cohort (HR, 8.5; 95% CI, 8.2-8.8). Important risk factors for cancer patients were prior VTE (SHR, 7.6; 95% CI, 7.2-8.0), distant metastasis (SHR, 3.2; 95% CI, 2.9-3.4), and use of chemotherapy (SHR, 3.4; 95% CI, 3.1-3.7), protein kinase inhibitors (SHR, 4.1; 95% CI, 3.4-4.9), antiangiogenic therapy (SHR, 4.4; 95% CI, 3.8-5.2), and immunotherapy (SHR, 3.6; 2.8-4.6). Twelve-month incidence in the cancer cohort increased from 1.0% (95% CI, 0.9% to 1.2%) in 1997 to 3.4% (95% CI, 2.9% to 4.0%) in 2017, which was paralleled by improved 12-month survival and increased use of computed tomography scans, chemotherapy, and targeted therapies. In conclusion, the risk of VTE in cancer patients is increasing steadily and is ninefold higher than in the general population.

Treatment of cancer-associated venous thromboembolism in the age of direct oral anticoagulants.

Anticoagulation for cancer-associated venous thromboembolism (VTE) can be challenging due to complications-including bleeding and potential drug-drug interactions with chemotherapy-associated with vitamin K antagonists and inconvenience of low-molecular-weight heparin (LMWH). Direct oral anticoagulants (DOACs) could partially overcome these issues, but until recently there were no large clinical trials assessing their efficacy and safety in cancer patients. This review summarizes clinical treatment guidelines, prior clinical and real-world evidence for anticoagulant choice, recent clinical trials assessing DOACs for cancer-associated VTE (i.e. Hokusai-VTE Cancer, SELECT-D, CARAVAGGIO, and ADAM VTE), and special considerations for DOAC use. Based on established data, clinical guidelines recommend patients with cancer-associated VTE receive LMWH treatment of at least 3-6 months. Nevertheless, LMWH is underused and associated with poor compliance and persistence in these patients relative to oral anticoagulants. Clinical data supporting DOAC use in cancer patients are becoming available. In Hokusai-VTE Cancer, edoxaban was noninferior to dalteparin for the composite of recurrent VTE and major bleeding (12.8% versus 13.5%), with numerically lower recurrent VTE (7.9% versus 11.3%) and significantly higher major bleeding (6.9% versus 4.0%); only patients with gastrointestinal cancer had significantly higher risk of bleeding with edoxaban. In SELECT-D, rivaroxaban had numerically lower VTE recurrence (4% versus 11%), comparable major bleeding (6% versus 4%), and numerically higher clinically relevant nonmajor bleeding (13% versus 4%) versus dalteparin. Most bleeding events were gastrointestinal or urologic; patients with esophageal/gastroesophageal cancer had higher rates of major bleeding with rivaroxaban (36% versus 11%). For comparison of apixaban versus dalteparin, CARAVAGGIO is ongoing, and preliminary results from ADAM VTE are favorable. This review concludes that DOACs appear to be reasonable alternatives to LMWH for treatment of cancer-associated VTE. In patients with gastrointestinal cancer, DOAC use should be considered on a case-by-case basis with consideration of the relative risks and benefits.

Combination of isocitrate dehydrogenase 1 (IDH1) mutation and podoplanin expression in brain tumors identifies patients at high or low risk of venous thromboembolism.

Essentials Risk stratification for venous thromboembolism (VTE) in patients with brain tumors is challenging. Patients with IDH1 wildtype and high podoplanin expression have a 6-month VTE risk of 18.2%. Patients with IDH1 mutation and no podoplanin expression have a 6-month VTE risk of 0%. IDH1 mutation and podoplanin overexpression in primary brain tumors appear to be exclusive. SUMMARY: Background Venous thromboembolism (VTE) is a frequent complication in primary brain tumor patients. Independent studies revealed that podoplanin expression in brain tumors is associated with increased VTE risk, whereas the isocitrate dehydrogenase 1 (IDH1) mutation is associated with very low VTE risk. Objectives To investigate the interrelation between intratumoral podoplanin expression and IDH1 mutation, and their mutual impact on VTE development. Patients/Methods In a prospective cohort study, intratumoral IDH1 R132H mutation and podoplanin were determined in brain tumor specimens (mainly glioma) by immunohistochemistry. The primary endpoint of the study was symptomatic VTE during a 2-year follow-up. Results All brain tumors that expressed podoplanin to a medium-high extent showed also an IDH1 wild-type status. A score based on IDH1 status and podoplanin expression levels allowed prediction of the risk of VTE. Patients with wild-type IDH1 brain tumors and high podoplanin expression had a significantly increased VTE risk compared with those with mutant IDH1 tumors and no podoplanin expression (6-month risk 18.2% vs. 0%). Conclusions IDH1 mutation and podoplanin overexpression seem to be exclusive. Although brain tumor patients with IDH1 mutation are at very low risk of VTE, the risk of VTE in patients with IDH1 wild-type tumors is strongly linked to podoplanin expression levels.

Citrullinated histone H3, a biomarker of neutrophil extracellular trap formation, predicts the risk of venous thromboembolism in cancer patients.

Essentials Neutrophil extracellular traps (NETs) might play a role in cancer-related coagulopathy. We determined NET biomarkers and followed cancer patients for venous thromboembolism (VTE). We found a constant association with VTE for citrullinated histone H3. Biomarkers of NET formation could reflect a novel pathomechanism of cancer-related VTE. SUMMARY: Background Neutrophil extracellular traps (NETs) are decondensed chromatin fibers that might play a role in the prothrombotic state of cancer patients. Objectives To investigate whether the levels of citrullinated histone H3 (H3Cit), a biomarker for NET formation, cell-free DNA (cfDNA) and nucleosomes predict venous thromboembolism (VTE) in cancer patients. Patients/Methods Nine-hundred and forty-six patients with newly diagnosed cancer or progression after remission were enrolled in this prospective observational cohort study. H3Cit, cfDNA and nucleosome levels were determined at study inclusion, and patients were followed for 2 years. VTE occurred in 89 patients; the cumulative 3-month, 6-month, 12-month and 24-month incidence rates of VTE were 3.7%, 6.0%, 8.1%, and 10.0%, respectively. Results Patients with elevated H3Cit levels (> 75th percentile of its distribution, n = 236) experienced a higher cumulative incidence of VTE (2-year risk of 14.5%) than patients with levels below this cut-off (2-year risk of 8.5%, n = 710). In a competing-risk regression analysis, a 100 ng mL-1 increase in H3Cit level was associated with a 13% relative increase in VTE risk (subdistribution hazard ratio [SHR] 1.13, 95% confidence interval [CI] 1.04-1.22). This association remained after adjustment for high VTE risk and very high VTE risk tumor sites, D-dimer level, and soluble P-selectin level (SHR 1.13, 95% CI 1.04-1.22). The association of elevated nucleosome and cfDNA levels with VTE risk was time-dependent, with associations with a higher risk of VTE only during the first 3-6 months. Conclusion These data suggest that biomarkers of NET formation are associated with the occurrence of VTE in cancer patients, indicating a role of NETs in the pathogenesis of cancer-associated thrombosis.

Von Willebrand factor indicates bacterial translocation, inflammation, and procoagulant imbalance and predicts complications independently of portal hypertension severity.

BACKGROUND: Elevated plasma von Willebrand factor antigen (vWF) has been shown to indicate the presence of clinically significant portal hypertension, and thus, predicts the development of clinical events in patients with cirrhosis. AIM: To investigate the impact of bacterial translocation and inflammation on vWF, as well as the association between vWF and procoagulant imbalance. Moreover, we assessed whether vWF predicts complications of cirrhosis, independent of the severity of portal hypertension. METHODS: Our study population comprised 225 patients with hepatic venous pressure gradient (HVPG) ≥ 10 mm Hg without active bacterial infections or hepatocellular carcinoma. RESULTS: vWF correlated with markers of bacterial translocation (lipopolysaccharide-binding protein [LBP; ρ = 0.201; P = 0.021]), inflammation (interleukin 6 [IL-6; ρ = 0.426; P < 0.001] and C-reactive protein [CRP; ρ = 0.249; P < 0.001]), and procoagulant imbalance (factor VIII/protein C ratio; ρ = 0.507; P < 0.001). Importantly, the associations between vWF and these parameters were independent of HVPG. Moreover, vWF (per 10%) independently predicted variceal bleeding (hazard ratio [HR]: 1.08 [95% confidence interval (95% CI): 1.01-1.16]; P = 0.023), requirement of paracentesis (HR: 1.05 [95% CI: 1.01-1.1]; P = 0.023) and bacterial infections (HR: 1.04 [95% CI: 1-1.09]; P = 0.04) including spontaneous bacterial peritonitis (HR: 1.09 [95% CI: 0.999-1.18]; P = 0.053) on a trend-wise level. After backward elimination, vWF (HR: 1.05 [95% CI: 1.02-1.08]; P = 0.003) and CRP (per 10 mg/L; HR: 1.53 [95% CI: 1.14-2.05]; P = 0.005) remained in the final model for transplant-free mortality. Finally, the independent prognostic value of vWF/CRP groups for mortality was confirmed by competing risk analysis. CONCLUSION: Our results demonstrate that vWF is not only a marker of portal hypertension but also independently linked to bacterial translocation, inflammation and procoagulant imbalance, which might explain its HVPG-independent association with most clinical events. Prognostic groups based on vWF/CRP efficiently discriminate between patients with a poor 5-year survival and patients with a favourable prognosis.

Human pancreatic tumors grown in mice release tissue factor-positive microvesicles that increase venous clot size.

Essentials Tumor-bearing mice have larger venous clots than controls. Human tissue factor is present in clots in tumor-bearing mice. Inhibition of human tissue factor reduces clot size in tumor-bearing mice. This new mouse model may be useful to study mechanisms of cancer-associated thrombosis. SUMMARY: Background Pancreatic cancer patients have a high rate of venous thromboembolism. Human pancreatic tumors and cell lines express high levels of tissue factor (TF), and release TF-positive microvesicles (TF+ MVs). In pancreatic cancer patients, tumor-derived TF+ MVs are present in the blood, and increased levels are associated with venous thromboembolism and decreased survival. Previous studies have shown that mice with orthotopic human or murine pancreatic tumors have circulating tumor-derived TF+ MVs, an activated clotting system, and increased incidence and mean clot weight in an inferior vena cava stenosis model. These results suggest that TF+ MVs contribute to thrombosis. However, the specific role of tumor-derived TF+ MVs in venous thrombosis in mice has not been determined. Objectives To test the hypothesis that tumor-derived TF+ MVs enhance thrombosis in mice. Methods We determined the contribution of TF+ MVs derived from human pancreatic tumors grown orthotopically in nude mice to venous clot formation by using an anti-human TF mAb. We used an inferior vena cava stasis model of venous thrombosis. Results Tumor-bearing mice had significantly larger clots than control mice. Clots from tumor-bearing mice contained human TF, suggesting the incorporation of tumor-derived MVs. Importantly, administration of an anti-human TF mAb reduced clot size in tumor-bearing mice but did not affect clot size in control mice. Conclusions Our results indicate that TF+ MVs released from orthotopic pancreatic tumors increase venous thrombosis in mice. This new model may be useful for evaluating the roles of different factors in cancer-associated thrombosis.

Myeloid but not epithelial tissue factor exerts protective anti-inflammatory effects in acid aspiration-induced acute lung injury.

Essentials Tissue factor (TF) represents a central link between hemostasis and inflammation. We studied the roles of myeloid and airway epithelial TF in acid-caused acute lung injury (ALI). TF on myeloid cells displays a non-coagulatory role regulating the inflammatory response in ALI. Airway epithelial TF contributes to hemostatic functions, but is dispensable in ALI pathogenesis. SUMMARY: Introduction Acute lung injury (ALI) is a life-threatening condition characterized by damaged alveolar-capillary structures and activation of inflammatory and hemostatic processes. Tissue factor (TF) represents a crucial link between inflammation and coagulation, as inflammatory mediators induce myeloid TF expression, and TF initiates extrinsic coagulation. Objective As pulmonary inflammation stimulates TF expression and TF modulates immune responses, we aimed to elucidate its impact on ALI. In particular, we wanted to distinguish the contributions of TF expressed on airway epithelial cells and TF expressed on myeloid cells. Methods Mice with different cell type-specific TF deficiency and wild-type littermates were intratracheally treated with hydrochloric acid, and leukocyte recruitment, cytokine levels, thrombin-antithrombin (TAT) complexes and pulmonary protein-rich infiltrates were analyzed. Results Our data demonstrate that a lack of epithelial TF did not influence acute responses, as bronchoalveolar neutrophil accumulation 8 h after ALI induction was unaltered. However, it led to mild, prolonged inflammation, as pulmonary leukocyte and erythrocyte numbers were still increased after 24 h, whereas those in wild-type mice had returned to basal levels. In contrast, myeloid TF was primarily involved in regulating the acute phase of ALI without affecting local coagulation, as indicated by increased bronchoalveolar neutrophil infiltration, pulmonary interleukin-6 levels, and edema formation, but equal TAT complex formation, 8 h after ALI induction. This augmented inflammatory response associated with myeloid TF deficiency was confirmed in vitro, as lipopolysaccharide-stimulated TF-deficient alveolar macrophages released increased levels of chemokine (C-X-C motif) ligand 1 and tumor necrosis factor-α as compared with wild-type macrophages. Conclusion We conclude that myeloid TF dampens inflammation in acid-induced ALI.

OC-16 - Neutrophil extracellular traps and tissue factor-bearing microvesicles: a liaison dangereuse causing overt DIC in cancer patients?

INTRODUCTION: Overt disseminated intravascular coagulation (DIC) is a systemic process characterized by excessive coagulation activation and fibrinolysis that may occur in cancer patients. The underlying pathomechanisms are still poorly understood. Recent experimental studies found an important role for the interaction between procoagulant neutrophil extracellular traps (NETs) and tissue factor (TF) in the pathogenesis of thrombosis. AIM: To investigate whether NETs and TF-bearing microvesicles (MVs) play a central role in cancer-related overt DIC. MATERIALS AND METHODS: Twenty-eight cancer patients with overt DIC (ISTH score ≥5, 14 females, median age: 62 years [range: 21-80], 13 with solid tumors, 15 with acute leukemia) and 28 matched healthy controls were included. NET formation parameters (plasma DNA and nucleosomes), MVassociated TF activity, and routine coagulation parameters were determined at study inclusion. In 11 patients with acute myeloid leukemia (AML), follow-up measurements were also performed. RESULTS: Plasma DNA, nucleosomes, and MV-TF activity were highly elevated in patients with cancer-related DIC compared to healthy individuals (all p-values<0.001). Strong correlations were found between plasma DNA and nucleosomes (Spearman correlation-coefficient: r=0.68), nucleosomes and MV-TF activity (r=0.62), and DNA and MV-TF activity (r=0.57). In multivariate regression, altered routine coagulation parameters were highly associated with NET parameters and MV-TF activity. In detail, a doubling in plasma DNA was associated with a 7.6% decrease in fibrinogen (p=0.012), a 15.3% decrease in platelet count (p=0.002), a 3.9% decrease in prothrombin time (p=0.014), and a 41.0% increase in D-dimer (p<0.001). A 10% increase in nucleosomes was associated with a 3.1% decrease in fibrinogen (p<0.001), a 5.0% decrease in platelet count (p<0.001), a 1.0% decrease in prothrombin time (p<0.009), and a 112.7% increase in D-dimer (p<0.001). A 10% increase in MV-TF activity was associated with a 4.9% decrease in fibrinogen (p<0.001), a 7.1% decrease in platelet count (p<0.001), a 1.3% decrease in prothrombin time (p<0.001), and a 15.5% increase in D-dimer (p<0.001). After initiation of chemotherapy in AML patients, NET parameters and MV-TF activity decreased significantly (nucleosomes: 3.3-fold decrease and normalization after 1 week; DNA: 1.2-fold decrease after 1 week and 1.5-fold decrease after 1 month; MV-TF activity: 10-fold decease after 1 week and normalization after 1 month) (Figure 1), and routine coagulation parameters improved. CONCLUSIONS: Our results add to experimental studies that have investigated the interaction between NETs and TF. Taken together, evidence indicates the presence of a liaison dangereuse between NETs and TF-bearing MVs, which could be the underlying cause of cancer-related overt DIC.

PO-01 - Congestive heart failure is an independent risk factor for venous thromboembolism and mortality in cancer patients.

INTRODUCTION: Prediction of venous thromboembolism (VTE) occurrence in cancer patients using individual risk factors may contribute to preventing the burden of disease associated with VTE. Congestive heart failure in patients with cancer may increase the risk of VTE and worsen the prognosis. AIM: We sought to investigate the association of congestive heart failure and occurrence of VTE in cancer patients, specifically with consideration for the poor prognosis in patients with heart failure and cancer. MATERIALS AND METHODS: Hospitalized and ambulatory cancer patients were included in the prospective Vienna Cancer and Thrombosis Study (CATS) in search of risk factors for occurrence of VTE. Cancer entities and comorbidities were recorded at baseline and verified using medical documentation including a diagnosis of congestive heart failure. The occurrence of VTE events was compiled via mail and telephone follow-ups for two years. Risk of VTE occurrence was calculated in the competing risk regression model, considering death as a competing event during follow-up. RESULTS: In the current analysis 1,433 patients (632 women, 44.1%) with a median age of 61 years (25th-75th percentile: 52-75) were included. During the observation period, 108 (7.5%) VTE events and 522 (36.4%) deaths occurred. The median observation time was 729 days (233-731), and 34 patients (2.3%) had diagnosed congestive heart failure at the time of study inclusion, 12 of which had NYHA II-IV and 22 unspecified congestive heart failure. In the group of heart failure patients, 6 had VTE events and 23 died. In univariate competing risk analysis, the risk of VTE occurrence was increased 2.6-fold in patients with heart failure compared to those without a diagnosis of heart failure (SHR 2.58, 95% CI 1.13-5.92, p=0.025). After multivariable adjustment for age, BMI, gender, diabetes, history of myocardial infarction or stroke, use of antiplatelet drugs, cancer site, hypertension, D-Dimer level and peripheral arterial disease, the risk of VTE in heart failure patients was 3-times the risk of patients without heart failure (HR 3.07, 95% CI 1.15-8.19, p=0.025). Further, congestive heart failure was a strong predictor of mortality (HR 1.70, 95% CI 1.10-2.65, p=0.018). CONCLUSIONS: Congestive heart failure is not only a risk factor for mortality in cancer patients, but also an independent predictor of VTE occurrence. In order to prevent VTE and the associated burden, patients with cancer and congestive heart failure may benefit from thromboprophylaxis.

PO-63 - Exhausted platelets in cancer patients with high risk of venous thromboembolism and poor prognosis.

INTRODUCTION: Platelets play a crucial role in cancer development, progression and metastatic spread of malignancy. In vitro data show that cancer cells have the ability to activate platelets, and clinical studies found increased levels of platelet activation markers in cancer patients. Moreover, platelets are thought to be involved in the development of venous thromboembolism (VTE) in cancer patients, a frequent complication of malignant disease associated with high morbidity and mortality. AIM: In this study, we aimed to examine the activation status of platelets in cancer patients and investigate the association with risk of future venous thromboembolism (VTE) and mortality. MATERIALS AND METHODS: In a prospective observational cohort study of cancer patients we measured pre-chemotherapy platelet P-selectin and glycoprotein (GP) IIb/IIIa expression and monocyte-platelet aggregates (MPA) in vivo and in response to ex vivo stimulation of the platelet activation receptors protease-activated receptor (PAR) -1, -4, and GPVI by whole blood flow cytometry. Primary and secondary endpoints of the study were occurrence of objectively confirmed VTE and death during 2-year follow-up, respectively. RESULTS: Out of 62 patients (median age [interquartile range, IQR]: 63 [54-70] years, 48% female) with cancers of the pancreas (n=19), lung (n=18), brain (n=14), colon (n=8) and stomach (n=3), 9 (14.5%) developed VTE and 32 (51.6%) died. P-selectin, activated GPIIb/IIIa expression and MPA formation did not significantly differ between tumor sites (Kruskal Wallis test). Reduced platelet responsiveness to PAR-1 and GPVI stimulation was associated with a higher risk of VTE (hazard ratio [HR] per decile increase in %P-selectin positive platelets: 0.73 [95% confidence interval: 0.56-0.92, p=0.007] and 0.77 [0.59-0.98, p=0.034], respectively; Table 1). Further, lower platelet P-selectin and activated GPIIb/IIIa expression in vivo and in response to PAR-1, -4 and GPVI stimulation, but not MPA formation, were associated with a higher risk of death (Table 1). CONCLUSIONS: Cancer patients with a poor prognosis had degranulated platelets, presumably as a consequence of previous activation. Our data suggest that platelets' continuous activation and thus exhaustion is involved in cancer-associated VTE and cancer mortality.

Decrease in microvesicle-associated tissue factor activity in morbidly obese patients after bariatric surgery.

BACKGROUND: Tissue factor (TF) is the main in vivo initiator of the blood coagulation cascade. Active circulating TF was detected on small, negatively charged membrane vesicles, the so-called microvesicles (MVs), which are released upon cell activation and apoptosis from a variety of cells. Increased coagulation activation was found in morbidly obese patients, and elevated levels of TF-bearing MVs may contribute to the prothrombotic state in these patients. AIM: To determine MV-associated TF activity levels in morbidly obese patients before and after weight loss due to bariatric surgery. METHODS: MV-TF activity was measured with a factor Xa generation assay in morbidly obese patients before and 2 years after bariatric surgery. In addition, clinical parameters were determined. RESULTS: Seventy-four morbidly obese patients (mean age: 42 (±11) years; 61 females) were included in this study. After bariatric surgery, the body mass index decreased from (median, 25-75th percentile) 45.5 (42.3-50.2) to 30.5 (28.0-34.4 kg m(-2); P<0.001), and a significant improvement in metabolic parameters was observed. Preoperative MV-TF activity correlated with C-reactive protein levels (r=0.3; P=0.02). Postoperatively, the mean MV-TF activity decreased significantly from 0.20 pg ml(-1) (0.18-0.47) to 0.02 (0.00-0.28; P<0.01). CONCLUSION: We could demonstrate a significant decrease in MV-TF activity after weight loss in morbidly obese patients. Decreased MV-TF activity might contribute to an improved coagulation profile in these patients after weight loss.

Longitudinal analysis of hemostasis biomarkers in cancer patients during antitumor treatment.

UNLABELLED: ESSENTIALS: Hemostasis biomarkers impact thrombosis occurrence and survival in cancer patients. We performed a longitudinal analysis of hemostatic parameters in 112 cancer patients. Hemostatic parameters are associated with disease state, patients' prognosis, and the risk of VTE. The procoagulant state exists not only at diagnosis, but also during the course of disease. BACKGROUND: Hemostasis biomarkers are known to have an impact on venous thromboembolism (VTE) occurrence and survival in cancer patients. OBJECTIVES: As there are almost no data on longitudinal changes, we aimed to evaluate those in the present prospective observational study during chemotherapy and the course of disease. PATIENTS/METHODS: Patients with cancer of the brain (n = 39), lung (n = 41), colon (n = 15) or pancreas (n = 17) were included before initiation of antitumor therapy. Blood samples for determination of factor VIII, thrombin peak height, D-dimer, F1 + 2 , fibrinogen and soluble P-selectin (sP-selectin) were drawn on a monthly basis. The study endpoints were death, VTE occurrence, or completion of the study period. RESULTS: Overall, 546 blood samples of 112 patients were analyzed. D-dimer and sP-selectin levels were significantly higher in patients with distant metastasis than in those without. Patients with complete remission had significantly lower levels of F1 + 2 , D-dimer and fibrinogen. Peak height thrombin levels showed a decrease over time in all tumor types. Levels of biomarkers behaved differently in the various tumor types. Patients who developed VTE (n = 14) showed increasing levels of FVIII, sP-selectin, and D-dimer. At the last blood sampling time-point before VTE occurrence, in 13 patients the D-dimer level was above the median, and in seven of these patients it was even above the 75th percentile; however, the individual course was highly variable. Regarding survival, steadily increased FVIII, sP-selectin and D-dimer levels were associated with higher mortality. CONCLUSIONS: Hemostatic parameters show an association with disease state, prognosis, and the risk of VTE, not only at diagnosis, but also during the course of antineoplastic treatment.

Venous thrombosis and cancer: from mouse models to clinical trials.

Cancer patients have a ~4 fold increased risk of venous thromboembolism (VTE) compared with the general population and this is associated with significant morbidity and mortality. This review summarizes our current knowledge of VTE and cancer, from mouse models to clinical studies. Notably, the risk of VTE varies depending on the type and stage of cancer. For instance, pancreatic and brain cancer patients have a higher risk of VTE than breast and prostate cancer patients. Moreover, patients with metastatic disease have a higher risk than those with localized tumors. Tumor-derived procoagulant factors and growth factors may directly and indirectly enhance VTE. For example, increased levels of circulating tumor-derived, tissue factor-positive microvesicles may trigger VTE. In a mouse model of ovarian cancer, tumor-derived IL-6 and hepatic thrombopoietin have been linked to increased platelet production and thrombosis. In addition, mouse models of mammary and lung cancer showed that tumor-derived granulocyte colony-stimulating factor causes neutrophilia and activation of neutrophils. Activated neutrophils can release neutrophil extracellular traps (NETs) that enhance thrombosis. Cell-free DNA in the blood derived from cancer cells, NETs and treatment with cytotoxic drugs can activate the clotting cascade. These studies suggest that there are multiple mechanisms for VTE in patients with different types of cancer. Preventing and treating VTE in cancer patients is challenging; the current recommendations are to use low-molecular-weight heparin. Understanding the underlying mechanisms may allow the development of new therapies to safely prevent VTE in cancer patients.