Anticancer treatment and thrombosis

Underlying Mechanisms of Thrombosis Associated with Cancer and Anticancer Therapies

OPINION STATEMENT

Cancer-associated thrombosis (CAT) has been identified as the second most prevalent cause of death after cancer itself. Moreover, the risk of thrombotic events in cancer patients increases due to anticancer drugs, such as tyrosine kinase inhibitors (TKIs). Venous thromboembolism (VTE) as well as arterial thromboembolic (ATE) events are present in CAT. Although VTE occurs more frequently, ATE events are very significant and in some cases are more dangerous than VTE. Guidelines for preventing thrombosis refer mainly VTE as well as the contribution of ATE events. Several factors are involved in thrombosis related to cancer, but the whole pathomechanism of thrombosis is not clear and may differ between patients. The activation of the coagulation system and the interaction of cancer cells with other cells including platelets, endothelial cells, monocytes, and neutrophils are promoted by a hypercoagulable state caused by cancer. We present an update on the pathomechanisms of CAT and the effect of anticancer drugs, mainly targeted therapies with a focus on TKIs. Considering the risk of bleeding associated with anticoagulation in each cancer patient, the anticoagulation strategy may involve the use of FXIa inhibitors, direct oral anticoagulants, and low-molecular-weight heparin. Further research would be valuable in developing strategies for reducing CAT.

Incidence of thromboembolic events in non-small cell lung cancer patients treated with immune checkpoint inhibitors: A systematic review and meta-analysis

ABSTRACT

The incidence of thromboembolic events (TEs) in non-small cell lung cancer (NSCLC) patients treated with immune checkpoint inhibitors (ICIs) has rarely been reported. The MEDLINE, EMBASE, and the Cochrane Library databases were searched. The primary outcome was the incidence of TEs, and the secondary outcome was the relationship between TEs and overall survival (OS) following ICI therapy. A subgroup analysis of TE incidents was performed according to the TE type and combination regimens. The I2 statistic was used to determine the heterogeneity, and funnel plots and Egger's test were used to assess publication bias. A total of 16,602 patients with NSCLC in 63 experimental arms were included in the analysis. The rate of TEs ranged from 0.1% to 13.8%, and the pooled overall incidence of all-grade TEs was 3% (95% confidence interval [CI], 2%-4%). The pooled rate of high-grade TEs was 1% (95% CI, 1%-2%). The venous and arterial TE rates were 3% (95% CI, 2%-4%) and 1% (95% CI, 1%-2%), respectively. Patients who received immunotherapy + chemoradiotherapy had the highest incidence of TEs (7%). The TE pooled rate was higher in patients treated with combined ICIs than in those treated with mono ICIs (4% vs. 2%). The OS was lower in patients with TEs than in those without TEs (hazard ratio, 1.4; 95% CI, 1.02%-1.92%). The incidence of TEs in NSCLC patients treated with ICIs was reasonable. Nonetheless, clinicians must be aware of potential thrombotic complications and treat them promptly.

Late venous thromboembolism in survivors of adolescent and young adult cancer: A population-based study in California

INTRODUCTION

Venous thromboembolism (VTE), a common complication in cancer patients, occurs more often during the initial phase of treatment. However, information on VTE beyond the first two years after diagnosis ('late VTE') is scarce, particularly in young survivors.

METHODS

We examined the risk of, and factors associated with, late VTE among adolescents and young adults (AYA, 15-39 years) diagnosed with cancer (2006-2018) who survived ≥2 years. Data were obtained from the California Cancer Registry linked to hospitalization, emergency department and ambulatory surgery data. We used non-parametric models and Cox proportional hazard regression for analyses.

RESULTS

Among 59,343 survivors, the 10-year cumulative incidence of VTE was 1.93 % (CI 1.80-2.07). The hazard of VTE was higher among those who had active cancer, including progression from lower stages to metastatic disease (Hazard Ratio (HR) = 10.41, 95 % confidence interval (CI): 8.86-12.22), second primary cancer (HR = 2.58, CI:2.01-3.31), or metastatic disease at diagnosis (HR = 2.38, CI:1.84-3.09). The hazard of late VTE was increased among survivors who underwent hematopoietic cell transplantation, those who received radiotherapy, had a VTE history, public insurance (vs private) or non-Hispanic Black/African American race/ethnicity (vs non-Hispanic White). Patients with leukemias, lymphomas, sarcoma, melanoma, colorectal, breast, and cervical cancers had a higher VTE risk than those with thyroid cancer.

CONCLUSIONS

VTE risk remained elevated ≥2 years following cancer diagnosis in AYA survivors. Active cancer is a significant risk factor for VTE. Future studies might determine if late VTE should prompt evaluation for recurrence or second malignancy, if not already known.

Risk factors and clinical impact of thrombosis during induction chemotherapy for pediatric acute lymphoblastic leukemia: A report from CYP-C

Thromboembolism (TE) is associated with reduced survival in pediatric acute lymphoblastic leukemia (ALL). It has been hypothesized that TE might signal leukemic aggressiveness. The objective was to determine risk factors for TE during ALL induction (TEind ) therapy and whether TEind is associated with treatment refractoriness. This retrospective cohort study using the population-based Cancer in Young People Canada (CYP-C) registry included children <15 years of age diagnosed with ALL (2000-2019) and treated at one of 12 Canadian pediatric centers outside of Ontario. Univariate and multivariable logistic regression models were used to determine risk factors for TEind and whether TEind predicted induction failure and ALL treatment intensification. The impact of TEind on overall and event-free survival was estimated using Cox proportional hazard regression models. The study included 2589 children, of which 45 (1.7%) developed a TEind . Age (<1 year and ≥10 years vs. 1-<10 years), T-cell phenotype, high-risk ALL, and central nervous system involvement were all associated with TEind in univariate analysis. Age and T-cell phenotype remained independent predictors of TEind in multivariable analysis. Induction failure occurred in 53 patients (2.1%). TEind was not associated with induction failure (OR: not estimable) or treatment intensification (adjusted OR [95% CI]: 0.66 [0.26-1.69]). TEind was independently associated with overall survival (adjusted HR [95% CI]: 2.54 [1.20-5.03]) but not event-free survival (adjusted HR [95% CI] 1.86 [0.98-3.51]). In this population-based study of children treated with contemporary chemotherapy protocols, TEind was associated with age and T-cell phenotype and mortality but did not predict induction failure.

Interpretable machine learning models for predicting venous thromboembolism in the intensive care unit: an analysis based on data from 207 centers

BACKGROUND

Venous thromboembolism (VTE) is a severe complication in critically ill patients, often resulting in death and long-term disability and is one of the major contributors to the global burden of disease. This study aimed to construct an interpretable machine learning (ML) model for predicting VTE in critically ill patients based on clinical features and laboratory indicators.

METHODS

Data for this study were extracted from the eICU Collaborative Research Database (version 2.0). A stepwise logistic regression model was used to select the predictors that were eventually included in the model. The random forest, extreme gradient boosting (XGBoost) and support vector machine algorithms were used to construct the model using fivefold cross-validation. The area under curve (AUC), accuracy, no information rate, balanced accuracy, kappa, sensitivity, specificity, precision, and F1 score were used to assess the model's performance. In addition, the DALEX package was used to improve the interpretability of the final model.

RESULTS

This study ultimately included 109,044 patients, of which 1647 (1.5%) had VTE during ICU hospitalization. Among the three models, the Random Forest model (AUC: 0.9378; Accuracy: 0.9958; Kappa: 0.8371; Precision: 0.9095; F1 score: 0.8393; Sensitivity: 0.7791; Specificity: 0.9989) performed the best.

CONCLUSION

ML models can be a reliable tool for predicting VTE in critically ill patients. Among all the models we had constructed, the random forest model was the most effective model that helps the user identify patients at high risk of VTE early so that early intervention can be implemented to reduce the burden of VTE on the patients.

Cardiogenic shock among cancer patients

Sophisticated cancer treatments, cardiovascular risk factors, and aging trigger acute cardiovascular diseases in an increasing number of cancer patients. Among acute cardiovascular diseases, cancer treatment, as well as the cancer disease itself, may induce a cardiogenic shock. Although increasing, these cardiogenic shocks are still relatively limited, and their management is a matter of debate in cancer patients. Etiologies that cause cardiogenic shock are slightly different from those of non-cancer patients, and management has some specific features always requiring a multidisciplinary approach. Recent guidelines and extensive data from the scientific literature can provide useful guidance for the management of these critical patients. Even if no etiologic therapy is available, maximal intensive supportive measures can often be justified, as most of these cardiogenic shocks are potentially reversible. In this review, we address the major etiologies that can lead to cardiogenic shock in cancer patients and discuss issues related to its management.

EHA Guidelines on Management of Antithrombotic Treatments in Thrombocytopenic Patients With Cancer

In cancer patients, thrombocytopenia can result from bone marrow infiltration or from anticancer medications and represents an important limitation for the use of antithrombotic treatments, including anticoagulant, antiplatelet, and fibrinolytic agents. These drugs are often required for prevention or treatment of cancer-associated thrombosis or for cardioembolic prevention in atrial fibrillation in an increasingly older cancer population. Data indicate that cancer remains an independent risk factor for thrombosis even in case of thrombocytopenia, since mild-to-moderate thrombocytopenia does not protect against arterial or venous thrombosis. In addition, cancer patients are at increased risk of antithrombotic drug-associated bleeding, further complicated by thrombocytopenia and acquired hemostatic defects. Furthermore, some anticancer treatments are associated with increased thrombotic risk and may generate interactions affecting the effectiveness or safety of antithrombotic drugs. In this complex scenario, the European Hematology Association in collaboration with the European Society of Cardiology has produced this scientific document to provide a clinical practice guideline to help clinicians in the management of patients with cancer and thrombocytopenia. The Guidelines focus on adult patients with active cancer and a clear indication for anticoagulation, single or dual antiplatelet therapy, their combination, or reperfusion therapy, who have concurrent thrombocytopenia because of either malignancy or anticancer medications. The level of evidence and the strength of the recommendations were discussed according to a Delphi procedure and graded according to the Oxford Centre for Evidence-Based Medicine.

Cancer-associated venous thromboembolism

Cancer-associated thrombosis (including venous thromboembolism (VTE) and arterial events) is highly consequential for patients with cancer and is associated with worsened survival. Despite substantial improvements in cancer treatment, the risk of VTE has increased in recent years; VTE rates additionally depend on the type of cancer (with pancreas, stomach and primary brain tumours having the highest risk) as well as on individual patient's and cancer treatment factors. Multiple cancer-specific mechanisms of VTE have been identified and can be classified as mechanisms in which the tumour expresses proteins that alter host systems, such as levels of platelets and leukocytes, and in which the tumour expresses procoagulant proteins released into the circulation that directly activate the coagulation cascade or platelets, such as tissue factor and podoplanin, respectively. As signs and symptoms of VTE may be non-specific, diagnosis requires clinical assessment, evaluation of pre-test probability, and objective diagnostic testing with ultrasonography or CT. Risk assessment tools have been validated to identify patients at risk of VTE. Primary prevention of VTE (thromboprophylaxis) has long been recommended in the inpatient and post-surgical settings, and is now an option in the outpatient setting for individuals with high-risk cancer. Anticoagulant therapy is the cornerstone of therapy, with low molecular weight heparin or newer options such as direct oral anticoagulants. Personalized treatment incorporating risk of bleeding and patient preferences is essential, especially as a diagnosis of VTE is often considered by patients even more distressing than their cancer diagnosis, and can severely affect the quality of life. Future research should focus on current knowledge gaps including optimizing risk assessment tools, biomarker discovery, next-generation anticoagulant development and implementation science.

Thrombosis is associated with worse survival in children with acute lymphoblastic leukemia: A report from CYP-C

There are conflicting data about whether the development of cancer-associated thrombo-embolism (TE) negatively impacts survival in children. The objective was to determine whether TE during treatment was associated with overall survival (OS) and event-free survival (EFS) in children with acute lymphoblastic leukemia (ALL). We performed a population-based retrospective cohort study using the Cancer in Young People-Canada registry. Children <15 years of age were diagnosed with de novo ALL (2000-2016). The primary exposure variable was radiologically-confirmed thrombo-embolism requiring medical intervention. Multivariable Cox regression models were used to determine the impact of thrombo-embolism on survival, where TE was time-dependent. We included 2006 children (median age: 4 years, 88.5% precursor B-cell ALL). Thrombo-embolism occurred in 113 patients (5.6%), at a median time of 107 days (interquartile range: 35-184 days) after ALL diagnosis. Among standard/low-risk patients, 41/1165 (3.5%) developed TE while among high/very high-risk patients, 72/841 (8.6%) developed TE. Patients with TE had a significantly worse OS (adjusted HR [aHR] of death: 2.61, 95% CI: 1.62-4.22, p < 0.001) and EFS (aHR of an event [death, relapse, second malignancy]: 2.03, 95% CI: 1.35-3.05, p = 0.001), compared with patients without TE. No statistically significant difference was seen in standard/low risk ALL for OS and EFS, but TE was associated with a significantly lower OS and EFS in children with high/very high-risk ALL (aHR of death: 2.90, 95% CI: 1.79-4.72, p < 0.001; aHR of an event: 2.02, 95% CI: 1.30-3.12, p = 0.002). Thus, TE led to a statistically significant reduction in OS and EFS in children with high risk/very high-risk leukemia.

Incidence of venous thromboembolic events in cancer patients receiving immunotherapy: a single-institution experience

BACKGROUND

Cancer and cancer therapies have been associated with an increased incidence of venous thromboembolic events (VTE). However, the incidence of VTE in patients on immunotherapy has not been well characterized. The aim of this study was to assess the incidence of VTE in cancer patients receiving immunotherapy and ascertain its prognostic utility.

MATERIALS AND METHODS

We conducted a single-institution retrospective study, including all cancer patients treated with anti-Programmed cell Death 1 (PD-1), anti-Programmed cell Death Ligand-1 (PD-L1), anti-Cytotoxic T-Lymphocyte-Associated Protein 4 (CTLA4), a combination of anti-PD-1/anti-PD-L1 and anti-CTLA4 or a combination including any of these drugs with chemotherapy, antiangiogenic agents or both between June 2013 and April 2019 at La Paz University Hospital, Madrid (Spain).

RESULTS

We selected 229 patients. VTE occurred in 16 of 229 patients (7%). VTE occurred more frequently in patients with lung cancer followed by melanoma. Female sex and melanoma were independently associated with an increased risk of VTE. 12 of 16 VTE (75%) were symptomatic. Progressive disease to immunotherapy [HR 31.60 (95% CI 11.44-87.22), p = 0.00], lung cancer [HR 2.55 (95% CI 1.34-4.86), p = 0.00] and melanoma [HR 2.42 (1.20-4.86), p = 0.01] were independently associated with shorter OS. VTE occurrence was not independently associated with shorter OS [HR 1.33 (95% CI 0.63-2.80), p = 0.44].

CONCLUSIONS

The incidence of VTE in cancer patients receiving immunotherapy in our study appeared to be similar to the incidence previously reported in other series of cancer patients treated with systemic therapies. VTE occurrence did not correlate with the prognosis. Further and prospective studies are needed to derive definitive conclusions.

Elevated Microparticles, Thrombin-antithrombin and VEGF Levels in Colorectal Cancer Patients Undergoing Chemotherapy

Hypercoagulable state and neoangiogenesis are common phenomena associated with malignancy. Cancer patients have increased levels of circulating endothelium-derived microparticles (EMPs), which have been hypothesized to be involved in numerous pathophysiological processes. Hemostasis and angiogenesis are also activated in colorectal cancer (CRC) patients. The study aimed to investigate potential influence of chemotherapy on EMPs, thrombin anti-thrombin complex (TAT) and vascular endothelial growth factor (VEGF) levels in CRC patients undergoing chemotherapy. The study group consisted of 18 CRC patients: 8 stage III colon cancer (CC) and 10 stage IV rectal cancer (RC) patients. EMPs, TAT and VEGF levels were assessed before chemotherapy and after the third course. Results were compared with 10 healthy subjects. EMP concentration was measured by flow cytometry, while TAT and VEGF concentrations were assayed employing ELISA. Compared to the control group, CC and RC patients had significantly higher levels of tissue factor (TF)-bearing and non-TF-bearing EMPs before and after three courses of chemotherapy. VEGF concentrations in CRC patients were higher than in the control groups and increased following chemotherapy. TAT levels were elevated in CRC patients before chemotherapy compared to healthy subjects and significantly increased after the third course of chemotherapy. No significant correlation was found either between EMP and TAT levels, or between EMP concentrations and VEGF levels in the study group. CRC patients have increased EMPs, and TAT as well as VEGF levels tend to increase during chemotherapy.

[Lung involvement in hematologic systemic diseases]

Pulmonary diseases can occur across the entire disease spectrum of malignant hematologic systemic diseases. Although infectious processes of the lungs are common in these immunosuppressed patient collectives, noninfectious causes account for up to half of the pulmonary manifestations found in hematologic malignancies. Besides the frequent infections including opportunistic pathogens, a broad differential diagnosis including drug-induced lung injury by cytostatic substances, cytokines, and innovative immunotherapeutic agents, rarer transfusion of blood products and intrathoracic manifestations of the hematologic malignancy itself, have to be kept in mind. Finally, vascular complications can also lead to pulmonary reactions. Early and consistent diagnostics and treatment of the bronchopulmonary, intrathoracic and vascular complications within the framwework of hematologic systemic diseases can be essential for the patient's prognosis.

Aortic Mural Thrombus in the Non-atherosclerotic Aorta of Patients with Multiple Hypercoagulable Factors

An aortic mural thrombus (AMT) on a non-atherosclerotic wall is a rare but important cause of arterial thromboembolism. We herein report two cases of AMT in the thoracic aorta. Both showed multiple hypercoagulable factors (case 1: protein S deficiency and positive finding of anti-cardiolipin antibody; case 2: protein C deficiency, gastric cancer, and cisplatin-based chemotherapy) and were successfully treated with anticoagulation. Hypercoagulable states, including malignancy, can influence the formation of AMT; therefore, the accurate assessment of a hypercoagulable condition is necessary when we encounter patients with AMT.

Pathophysiology 1. Mechanisms of Thrombosis in Cancer Patients

Thrombosis is a major cause of morbidity and mortality in cancer patients. The pathogenesis of blood coagulation activation in oncological patients is complex and involves both clinical and biological factors. Abnormalities in one or more coagulation test are common in cancer patients, even without thrombotic manifestations, indicating an ongoing hypercoagulable condition. Moreover, venous thromboembolism (VTE) can be the first symptom of an occult malignancy in an otherwise healthy individual. The levels of laboratory markers of activation of blood coagulation parallel the development of malignancy, being the coagulant mechanisms important for both thrombogenesis and tumor progression. Besides general clinical risk factors for VTE, also disease-specific clinical factors, i.e., type and stage of the tumor, and anticancer therapies increase the thrombotic risk in these patients. Furthermore, biological factors, including the cancer cell-specific prothrombotic properties together with the host cell inflammatory response to the tumor, are relevant as well as unique players in the pathogenesis of the cancer-associated hypercoagulability. Cancer cells produce and release procoagulant and fibrinolytic proteins, inflammatory cytokines, and procoagulant microparticles. They also express adhesion molecules binding to the receptors of host vascular cells (i.e., endothelial cells, platelets, and leukocytes), thereby stimulating the prothrombotic properties of these normal cells, including the shed of cell-specific microparticles and neutrophil extracellular traps. Of interest, several genes responsible for the cellular neoplastic transformation drive the programs of hemostatic properties expressed by cancer tissues. A better understanding of such mechanisms will help the development of novel strategies to prevent and treat the Trousseau's syndrome (i.e., cancer-associated thrombosis).

Updated clinical models for VTE prediction in hospitalized medical patients

Venous thromboembolism (VTE) occurring in hospitalized medical patients is associated with increased length of hospitalization, high rate of acute care hospital transfer, longer inpatient rehabilitation and multiplication of health-care costs. Identification of acutely ill hospitalized medical patients eligible for thromboprophylaxis is a sophisticated process. Global VTE risk stems from the combination of predictors related with the acute medical illness, comorbidities, associated treatments and patients' intrinsic risk factors. Emerging clinical risk factors related to underlying pathologies should be considered when VTE risk is assessed. The Padua Prediction Score (PPS), the International Medical Prevention Registry on Venous Thromboembolism (IMPROVE-RAM) and the Geneva Risk Score are three robust risk assessment models (RAM) which underwent extensive external validation in cohorts of acutely ill hospitalized medical patients. The development of the IMPROVE bleeding risk assessment model and the identification of D-Dimer increase as a biomarker-predictor of VTE are some steps forward for personalized thromboprophylaxis. The beneficial impact of the RAMs in VTE prevention is already seen by the decrease of in-hospital VTE rates when RAMs are incorporated in electronic alert systems.

Incidence of venous thromboembolism and use of anticoagulation in hematological malignancies: Critical review of the literature

Venous Thromboembolism (VTE) frequently complicates the course of hematologic malignancies (HM) and its incidence is similar to that observed in high-risk solid tumors. Despite that, pharmacologic prophylaxis and treatment of VTE in patients with HM is challenging, mainly because a severe thrombocytopenia frequently complicates the course of treatments or may be present since diagnosis, thus increasing the risk of bleeding. Therefore, in this setting, safe and effective methods of VTE prophylaxis and treatment have not been well defined and hematologists generally refer to guidelines produced for cancer patients that give indications on anticoagulation in patients with thrombocytopenia. In this review, besides to summarize the incidence and the available data on prophylaxis and treatment of VTE in HM, we give some advices on how to use antithrombotic drugs in patients with HM according to platelets count.

Outcomes of low-molecular-weight heparin treatment for venous thromboembolism in patients with primary and metastatic brain tumours

Venous thromboembolism (VTE) is one of the most common complications in patients with brain tumours. There is limited data available in the literature on VTE treatment in these patients. We conducted a matched retrospective cohort study of patients with primary or metastatic brain cancer who were diagnosed with cancer-associated VTE. Patients were selected after a retrospective chart review of consecutive patients who were diagnosed with cancer-associated VTE between January 2010 and January 2014 at the Juravinski Thrombosis Clinic, Hamilton, Canada. Controls were age- and gender-matched patients with cancer-associated VTE from the same cohort, but without known brain tumours. A total of 364 patients with cancer-associated VTE were included (182 with primary or metastatic brain tumours and 182 controls). The median follow-up duration was 6.7 (interquartile range 2.5–15.8) months. The incidence rate of recurrent VTE was 11.0 per 100 patient-years (95 % CI; 6.7–17.9) in patients with brain tumours and 13.5 per 100 patient-years (95 % CI; 9.3–19.7) in non-brain tumour group. The incidence of major bleeding was 8.6 per 100 (95 % CI; 4.8–14.7) patient-years in patients with brain tumours versus 5.0 per 100 patient-years (95 % CI; 2.8–9.2) in controls. Rate of intracranial bleeding was higher in brain tumour patients (4.4 % vs 0 %, p-value=0.004). In summary, rates of recurrent VTE and major bleeding were not significantly different in patients with cancer-associated VTE in the setting of primary or metastatic brain tumours compared those without known brain tumours. However, greater numbers of intracranial bleeds were observed in patients with brain tumours.

Thrombin inhibition and cisplatin block tumor progression in ovarian cancer by alleviating the immunosuppressive microenvironment

Cancer is often associated with an increased risk of thrombotic complications which can be aggravated by treatment with chemotherapeutics such as cisplatin. Multiple lines of evidence suggest that thrombin activity promotes tumor growth and metastasis. We examined the effect of co-treatment with dabigatran etexilate, a direct thrombin inhibitor, and cisplatin using the murine ID8 ovarian cancer model. Mice receiving co-treatment with both dabigatran etexilate and low dose cisplatin had significantly smaller tumors, developed less ascites and had lower levels of circulating activated platelets and tissue factor (TF) positive microparticles than those treated with dabigatran etexilate or cisplatin alone. Co-treatment with dabigatran etexilate and cisplatin significantly decreased the number of Gr1+/CD11b+ myeloid derived suppresser cells and CD11b+/CD11c+ dendritic cells in the ascites of ID8 tumor-bearing mice. Co-treatment also significantly reduced levels of pro-tumorigenic cytokines including TGF-β, VEGF, IL-6, IL-10, and MCP-1 in the ascites while increasing IFN-γ production by CD8+ effector T cells in the tumor ascites. These results demonstrate that co-treatment with dabigatran etexilate significantly augments the anti-tumor activity of cisplatin in ovarian tumor progression by alleviating the immunosuppressive microenvironment, suggesting that thrombin may be a potential therapeutic target for treatment of ovarian cancer.

Thrombin inhibition and cyclophosphamide synergistically block tumor progression and metastasis

Cancer is often associated with an increased risk of thrombotic events which are exacerbated by treatment with chemotherapeutics such as cyclosphosphamide (CP). Evidence suggests that thrombin can stimulate tumor progression via formation of fibrin and activation of protease-activated receptors (PARs) and platelets. We examined the effect of co-treatment with CP and dabigatran etexilate, a direct inhibitor of thrombin, using the murine orthotopic 4T1 tumor model. Mice receiving co-treatment with both low dose CP and dabigatran etexilate had significantly smaller mammary tumors and fewer lung metastases than mice treated with CP or dabigratran etexilate alone. Co-treatment with dabigatran etexilate and low dose CP also significantly decreased the number of arginase(+)Gr-1(+)CD11b(+) myeloid derived suppressor cells as well as levels of TGF-β in spleens from tumor bearing mice. 4T1 tumors express procoagulant tissue factor (TF) and spontaneously release TF(+) microparticles which are potent procoagulant factors that promote thrombin generation. Treatment with dabigatran etexilate alone prevented tumor-induced increases in circulating TF(+) microparticles and also decreased the numbers of tumor-induced activated platelets by 40%. These results show that co-treatment with dabigatran etexilate and CP synergistically inhibits growth and metastasis of mammary tumors, suggesting that oral administration of the thrombin inhibitor dabigatran etexilate may be beneficial in not only preventing thrombotic events in cancer patients but also in treating malignant tumors themselves.

Perioperative Deep Vein Thrombosis Risk Stratification: A Comparative Analysis of Free and Pedicled Flap Patients

Patients with head and neck cancer who undergo reconstructive surgery are at risk for deep venous thrombosis (DVT), but the risk profile for patients undergoing major flap reconstruction is highly variable. Herein, we report our findings from a retrospective analysis of head and neck cancer patients (n = 517) who underwent free (n = 384) or pedicled (n = 133) flap reconstructive operations at a major tertiary care center from 2011 to 2014. DVTs developed perioperatively in 9 (1.7%) patients. Compared with pedicled flap patients, free flap patients had a longer mean operative time (421.4 ± 4.4 vs 332.7 ± 10.7 min, P < .0001), but the DVT incidence did not differ significantly between free and pedicled flap patients (1.6% vs 2.2%, respectively, P = .28). These data suggest that perioperative DVT risk in head and neck oncology patients may be largely similar regardless of the reconstructive strategy pursued.

Longitudinal analysis of hemostasis biomarkers in cancer patients during antitumor treatment

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.

Perioperative Considerations in Metastatic Renal Cell Carcinoma

Patients with metastatic renal cell carcinoma are complex, with the potential for significant complications, and require extensive pre-, peri-, and postoperative management. This article discusses, in depth, the necessary considerations in the treatment of these patients.

Management of chemotherapy-induced thromboembolism in breast cancer

Thromboembolic events are common in cancer patients and, apart from contributing to significant morbidity, are regarded as the second leading cause of death in this population. Breast cancer patients are considered low risk for venous thromboembolism; however, the presence of advanced disease and use of chemotherapy and/or other adjunct treatments significantly raises this risk by altering the balance of pro- and anti-coagulant proteins. Low molecular weight heparin is central to the management of venous thromboembolism in this context, whether for prophylaxis, acute management or prevention of recurrences. Risk stratification models need to be incorporated to guide decision making where available.

The prothrombotic activity of cancer cells in the circulation

The hemostatic system is often subverted in patients with cancer, resulting in life-threatening venous thrombotic events. Despite the multifactorial and complex etiology of cancer-associated thrombosis, changes in the expression and activity of cancer-derived tissue factor (TF) - the principle initiator of the coagulation cascade - are considered key to malignant hypercoagulopathy and to the pathophysiology of thrombosis. However, many of the molecular and cellular mechanisms coupling the hemostatic degeneration to malignancy remain largely uncharacterized. In this review we discuss some of the tumor-intrinsic and tumor-extrinsic mechanisms that may contribute to the prothrombotic state of cancer, and we bring into focus the potential for circulating tumor cells (CTCs) in advancing our understanding of the field. We also summarize the current status of anti-coagulant therapy for the treatment of thrombosis in patients with cancer.

Tissue factor expressed by circulating cancer cell-derived microparticles drastically increases the incidence of deep vein thrombosis in mice

BACKGROUND

The risk of thrombotic complications such as deep vein thrombosis (DVT) during tumor development is well known. Tumors release into the circulation procoagulant microparticles (MPs) that can participate in thrombus formation following vessel injury. The importance of this MP tissue factor (TF) in the initiation of cancer-associated DVT remains uncertain.

OBJECTIVE

To investigate how pancreatic cancer MPs promote DVT in vivo.

METHODS

We combined a DVT mouse model in which thrombosis is induced by flow restriction in the inferior vena cava with one of subcutaneous pancreatic cancer in C57BL/6J mice. We infused high-TF and low-TF tumor MPs to determine the importance of TF in experimental cancer-associated DVT.

RESULTS

Both tumor-bearing mice and mice infused with tumor MPs subjected to 3 h of partial flow restriction developed an occlusive thrombus; fewer than one-third of the control mice did. We observed that MPs adhered to neutrophil extracellular traps (NETs), which are functionally important players during DVT, whereas neither P-selectin nor glycoprotein Ib were required for MP recruitment in DVT. The thrombotic phenotype induced by MP infusion was suppressed by hirudin, suggesting the importance of thrombin generation. TF carried by tumor MPs was essential to promote DVT, as mice infused with low-TF tumor MPs had less thrombosis than mice infused with high-TF tumor MPs.

CONCLUSIONS

TF expressed on tumor MPs contributes to the increased incidence of cancer-associated venous thrombosis in mice in vivo. These MPs may adhere to NETs formed at the site of thrombosis.

Risk of venous thromboembolism among hospitalizations of adults with selected autoimmune diseases

Previous research has suggested autoimmune diseases are risk factors for developing venous thromboembolism (VTE). We assessed whether having diagnoses of selected autoimmune diseases associated with antiphospholipid antibodies--autoimmune hemolytic anemia (AIHA), immune thrombocytopenic purpura (ITP), rheumatoid arthritis (RA), and systemic lupus erythematosus (SLE)--were associated with having a VTE diagnosis among US adult hospitalizations. A cross-sectional study was conducted using the 2010 Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality. VTE and autoimmune diseases were identified using International Classification of Diseases, Ninth Revision, Clinical Modification coded diagnoses information. The percentages of hospitalizations with a VTE diagnosis among all non-maternal adult hospitalizations without any of the four autoimmune diseases of interest and among those with AIHA, ITP, RA, and SLE diagnoses were 2.28, 4.46, 3.35, 2.65 and 2.77%, respectively. The adjusted odds ratios (OR) for having a diagnosis of VTE among non-maternal adult hospitalizations with diagnoses of AIHA, ITP, RA, and SLE were 1.25 [95% confidence interval (CI) 1.05-1.49], 1.20 (95% CI 1.07-1.34), 1.17 (95% CI 1.13-1.21), and 1.23 (95% CI 1.15-1.32), respectively, when compared to those without the corresponding conditions. The adjusted OR for a diagnosis of VTE associated with a diagnosis of any of the four autoimmune diseases was 1.20 (95% CI 1.16-1.24). The presence of a diagnosis of AIHA, ITP, RA, and SLE was associated with an increased likelihood of having a VTE diagnosis among the group of all non-maternal adult hospitalizations.

Elevated risk of venous but not arterial thrombosis in Waldenström macroglobulinemia/lymphoplasmacytic lymphoma

BACKGROUND

Many malignancies, including multiple myeloma and its precursor, monoclonal gammopathy of unknown significant, are associated with an elevated risk of thromboembolism. There is limited information on the risk of thrombosis in patients with Waldenström macroglobulinemia (WM) and lymphoplasmacytic lymphoma (LPL).

OBJECTIVES

To assess the risk of venous and arterial thrombosis in WM/LPL patients in a large population-based cohort study in Sweden.

PATIENTS/METHODS

A total of 2190 patients with WM/LPL and 8086 matched controls were identified through Swedish registers between 1987 and 2005. Information on occurrence of venous and arterial thrombosis after the diagnosis of WM/LPL was obtained through the centralized Swedish Patient Register, with follow-up to 2006. Cox regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Patients with WM/LPL had a significantly increased risk of venous thrombosis and the highest risk was observed during the first year following diagnosis (HR = 4.0, 95% CI 2.5-6.4). The risk was significantly elevated 5 (HR = 2.3, 95% CI 1.7-3.0) and 10 years after diagnosis (HR = 2.0, 95% CI 1.6-2.5). There was no increased risk of arterial thrombosis during any period of follow-up time (10-year HR = 1.0, 95% CI 0.9-1.1).

CONCLUSIONS

Venous thrombosis is a significant cause of morbidity in patients with WM/LPL. The potential role of thromboprophylaxis in WM/LPL, especially during the first year after diagnosis and in patients treated with thrombogenic agents, needs to be assessed to further improve outcome in WM/LPL patients.

Coagulation and cancer: biological and clinical aspects

Malignancy affects the hemostatic system and the hemostatic system affects malignancy. In cancer patients there are a number of coagulation abnormalities which provide the background for an increased tendency of these patients to both thrombosis and hemorrhage. The causes of this coagulation impairment rely on general risk factors which are common to other categories of patients, and other factors which are specific to cancer, such as tumor type and disease stage. In addition, data from basic research indicate that the hemostatic components and the cancer biology are interconnected in multiple ways. Notably, while cancer cells are able to activate the coagulation system, the hemostatic factors play a role in tumor progression. This opens the way to the development of bifunctional therapeutic approaches that are both capable of attacking the malignant process and resolving the coagulation impairment. On the other hand, the management of thrombosis and hemorrhages in cancer patients can be different. To approach these problems, some guidelines have been released by prominent international scientific societies. Also actively investigated is the issue of identifying new biomarkers to classify the subjects at a higher risk, thus improving the prevention of thrombohemorrhagic events in these patients. Finally, novel prophylactic and therapeutic approaches are currently under development. This review provides an overview of the hemostatic complications in cancer, together with new insights into the interaction between hemostasis and cancer biology. We also review the assessment of the risk of thrombohemorrhagic events in cancer patients, and the prophylaxis and treatment of such manifestations.

Clinical manifestation of cancer related stroke: retrospective case-control study

Cancer related stroke may have different phenotypes from non-cancer stroke, especially in terms of stroke progression and recurrence. We performed a case-control study to identify their incidences and risk factors in cancer related stroke. Between January 2001 and December 2009, we conducted a retrospective review of acute ischemic stroke patients with cancer who were admitted to Seoul National University Hospital, Seoul, Korea. The stroke patients without cancer served as control. We collected demographic variables, vascular risk factors, stroke phenotype, clinical course, and cancer information including diagnosis, stage, and treatment status. Among cancer stroke patients, the potential risk factor of stroke recurrence was evaluated. The mean age of the 102 cancer patients was 66.4 ± 10.8 years, and 64.7 % were men. The mean time interval from cancer diagnosis to stroke onset was 39.7 ± 60.9 months. The principal lesion pattern of cancer stroke was multiple dots extending single vascular territory (39.2 %), and they were associated with low hemoglobin and high fibrinogen levels. Stroke progression and recurrence were noted in 9.8 and 27.5 % of cancer stroke patients, and in 9.3 and 12.7 % of control patients, respectively. The stroke subtype was independently associated with recurrence of cancer stroke after multiple logistic regression (odds ratio = 3.165, 95 % confidence interval = 1.080-9.277, p = 0.036). Cancer related stroke has a distinct phenotype in terms of infarction pattern and laboratory findings. Stroke recurrence is frequently observed among cancer stroke patients, and its risk is related with stroke subtype.

Tumour and microparticle tissue factor expression and cancer thrombosis

Cancer is frequently complicated by venous thromboembolic events (VTE), which pose a significant health burden due to the associated high morbidity and mortality rates, yet the exact details of the pathophysiological mechanisms underlying their development are yet to be fully elucidated. Tissue factor (TF), the primary initiator of coagulation, is often overexpressed in malignancy and as such is a prime candidate in predicting the hypercoagulable state. Further exploration of this potential role has identified increases in the number of TF-expressing microparticles (MP) in the circulation of cancer patients, in particular in those known to have high incidences of thromboembolic complications. The risk of VTE in cancer is found to be further elevated by chemotherapy. Chemotherapy may, in eliciting cancer cell apoptosis, result in an increase in release of circulating procoagulant MP. We discuss a potential role of elevated tumour TF expression and increased circulating TF-positive MP in predicting VTE risk.

Soluble endothelial protein C receptor (sEPCR) is likely a biomarker of cancer-associated hypercoagulability in human hematologic malignancies

Elevated plasma level of soluble endothelial protein C receptor (sEPCR) may be an indicator of thrombotic risk. The present study aims to correlate leukemia-associated hypercoagulability to high level plasma sEPCR and proposes its measurement in routine clinical practice. EPCR expressions in leukemic cell lines were determined by flow cytometry, immunocytochemistry, and reverse transcription polymerase chain reaction (RT-PCR). EPCR gene sequence of a candidate cell line HL-60 was also determined. Plasma samples (n = 76) and bone marrow aspirates (n = 72) from 148 patients with hematologic malignancies and 101 healthy volunteers were analyzed by enzyme-linked immunosorbent assay (ELISA) via a retrospective study for sEPCR and D-dimer. All leukemic cell lines were found to express EPCR. Also, HL-60 EPCR gene sequence showed extensive similarities with the endothelial reference gene. All single nucleotide polymorphisms (SNPs) originally described and some new SNPs were revealed in the promoter and intronic regions. Among these patients 67% had plasma sEPCR level higher than the controls (100 ± 28 ng/mL), wherein 16.3% patients had experienced a previous thrombotic event. These patients were divided into: group-1 (n = 45) with amount of plasmatic sEPCR below 100 ng/mL, group-2 (n = 45) where the concentration of sEPCR was between 100 and 200, and group-3 (n = 20) higher than 200 ng/mL. The numbers of thrombotic incidence recorded in each group were four, six, and eight, respectively. These results reveal that EPCR is expressed not only by a wide range of human malignant hematological cells but also the detection of plasma sEPCR levels provides a powerful insight into thrombotic risk assessment in cancer patients, especially when it surpasses 200 ng/mL.