New insights into cancer-associated thrombosis

Malignancy-associated ischemic stroke: Implications for diagnostic and therapeutic workup

BACKGROUND

Patients with malignancies have an increased risk of suffering ischemic stroke via several mechanisms such as coagulation dysfunction and other malignancy-related effects as well as iatrogenic causes. Moreover, stroke can be the first sign of an occult malignancy, termed as malignancy-associated ischemic stroke (MAS). Therefore, timely diagnostic assessment and targeted management of this complex clinical situation are critical.

FINDINGS

Patients with both stroke and malignancy have atypical ages, risk factors, and often exhibit malignancy-related symptoms and multiple lesions on neuroimaging. New biomarkers such as eicosapentaenoic acid and blood mRNA profiles may help in distinguishing MAS from other strokes. In terms of treatment, malignancy should not be considered a contraindication, given comparable rates of recanalization and complications between stroke patients with or without malignancies.

CONCLUSION

In this review, we summarize the latest developments in diagnosing and managing MAS, especially stroke with occult malignancies, and provide new recommendations from recently emerged clinical evidence for diagnostic and therapeutic workup strategies.

Prognostic Effect of Incidental Pulmonary Embolism on Long-Term Mortality in Cancer Patients

BACKGROUND

The effect of incidental pulmonary embolism (PE) on long-term prognosis in cancer patients is unclear. This study assessed the characteristics of cancer and venous thromboembolism (VTE) and the effect of incidental PE identified by oncologists on long-term survival of patients with cancer.Methods and Results:This single-center, retrospective, cohort study used hospital-based cancer registry data from the Osaka International Cancer Institute linked with electronic medical records and administrative data from Japan's Diagnosis Procedure Combination Per-diem Payment System. Overall, 15,689 cancer patients underwent contrast-enhanced thoracic computed tomography during 2010-2018. After excluding patients with missing data, symptomatic patients, or patients with suspected PE, 174 with incidental PE (PE+ group) and 13,197 with no PE (PE- group) were identified. The total incidence of incidental PE was 1.3%. No deaths from thrombotic events were identified in the PE+ group. Both groups were adjusted for cancer- and VTE-related characteristics using inverse probability weighting. After adjusting for immortal time bias in the PE+ group, Kaplan-Meier analysis revealed that all-cause mortality was higher in the PE+ group (hazard ratio, 2.26; 95% confidence interval, 1.53-3.33). A Cox proportional hazard model revealed that metastatic cancer and a history of curative treatment were significant prognostic factors, whereas central PE and residual proximal deep vein thrombosis were not.

CONCLUSIONS

Incidental PE in cancer patients indicates poorer prognosis. Cancer-related but not thrombosis-related factors determine prognosis.

Analysis of thromboembolic events in patients with non-small cell lung cancer who received adjuvant chemotherapy: single-center real-world data

Thromboembolic events (TEEs) are common in cancer patients, with increased risk of TEE by chemotherapy in patients with lung cancer. However, TEEs in patients with non-small cell lung cancer (NSCLC) who received adjuvant chemotherapy have rarely been reported. This study retrospectively analyzed real-world data of 275 patients with NSCLC treated with adjuvant chemotherapy after surgery from October, 2005 to June, 2020, in a single institution. The incidence of TEEs during or within one year of completion of adjuvant chemotherapy was investigated, and factors related to TEEs were analyzed. TEEs were confirmed in nine patients (3.3%), without fatal event related to TEEs. None of the factors, including Khorana score, was significantly associated with the occurrence of TEEs. All patients with TEEs had pathologic stage IIB or higher and a history of smoking, except for one patient. In conclusion, TEEs occurred in a smaller proportion of patients with NSCLC treated with adjuvant chemotherapy in the real world compared with those treated with palliative chemotherapy in previous reports. Furthermore, prophylactic anticoagulation in patients with NSCLC receiving adjuvant chemotherapy may not be needed except for high-risk patients, although those patients should be informed about the possible risk of TEEs.

Development and Validation of a Risk Prediction Model for Venous Thromboembolism in Lung Cancer Patients Using Machine Learning

Background

There is currently a lack of model for predicting the occurrence of venous thromboembolism (VTE) in patients with lung cancer. Machine learning (ML) techniques are being increasingly adapted for use in the medical field because of their capabilities of intelligent analysis and scalability. This study aimed to develop and validate ML models to predict the incidence of VTE among lung cancer patients.

Methods

Data of lung cancer patients from a Grade 3A cancer hospital in China with and without VTE were included. Patient characteristics and clinical predictors related to VTE were collected. The primary endpoint was the diagnosis of VTE during index hospitalization. We calculated and compared the area under the receiver operating characteristic curve (AUROC) using the selected best-performed model (Random Forest model) through multiple model comparison, as well as investigated feature contributions during the training process with both permutation importance scores and the impurity-based feature importance scores in random forest model.

Results

In total, 3,398 patients were included in our study, 125 of whom experienced VTE during their hospital stay. The ROC curve and precision–recall curve (PRC) for Random Forest Model showed an AUROC of 0.91 (95% CI: 0.893–0.926) and an AUPRC of 0.43 (95% CI: 0.363–0.500). For the simplified model, five most relevant features were selected: Karnofsky Performance Status (KPS), a history of VTE, recombinant human endostatin, EGFR-TKI, and platelet count. We re-trained a random forest classifier with results of the AUROC of 0.87 (95% CI: 0.802–0.917) and AUPRC of 0.30 (95% CI: 0.265–0.358), respectively.

Conclusion

According to the study results, there was no conspicuous decrease in the model’s performance when use fewer features to predict, we concluded that our simplified model would be more applicable in real-life clinical settings. The developed model using ML algorithms in our study has the potential to improve the early detection and prediction of the incidence of VTE in patients with lung cancer.

Oral Squamous Cell Carcinoma Is Associated with a Low Thrombosis Risk Due to Storage Pool Deficiency in Platelets

Venous thrombo-embolism (VTE) disease is the second most common cause of mortality in cancer patients, and evaluation and prevention of thrombosis risk is essential. VTE-associated risk varies according to the type of tumor disease. Oral cancer is the most frequent type of head and neck cancer, and it represents approximately 2.1% of all cancers worldwide. Most tumors are squamous cell carcinomas and are mainly due to tobacco and alcohol abuse. VTE risk associated with oral squamous cell carcinoma (OSCC) is low. However, many studies have shown that OSCC has the following biological features of cancers associated with a high thrombosis risk: modified thrombosis and fibrinolysis mechanisms; strong expression of procoagulant proteins; secretion of procoagulant microparticles; and production of procoagulant cytokines. Using an original mouse model of tongue squamous cell carcinoma, our study aimed to clarify this paradoxical situation. First, we showed that OSCC tumors have a pro-aggregatory phenotype and a high local thrombosis risk. Second, we found that tongue tumor mice do not have an elevated systemic thrombosis risk (the risk of an "at distance" thrombosis event such as lower extremity deep venous thrombosis or pulmonary embolism) and even show a reduction in risk. Third, we demonstrated that tongue tumor mice show a reduction in platelet reactivity, which explains the low systemic thrombosis risk. Finally, we found that tongue tumor mice present granule pool deficiency, thereby explaining the reduction in platelet reactivity and systemic thrombosis risk.

An update on the efficacy and safety of novel anticoagulants for cancer associated thrombosis

Introduction: Cancer-associated thrombosis (CAT) refers to the most common thromboembolic complication of cancer which is venous thromboembolism (VTE). CAT primary prophylaxis, treatment, and secondary prevention are challenging for the complexity of cancer patients, who exhibit hypercoagulability with concomitant-heightened bleeding risk.Areas covered: In this review, the author examines the role of low molecular weight heparins (LMWH), which have been the standard of care for CAT treatment for many years. Direct oral anticoagulants (DOACS) have practical advantages over subcutaneous LMWH, especially for long-term therapy. The author then discusses the results of two RCTs which separately compared the direct oral factor Xa inhibitors, apixaban or rivaroxaban, with placebo for CAT prophylaxis in ambulatory high-risk cancer patients and found that DOACS reduced VTE but increased bleeding. Finally, the author discusses four RCTS separately comparing an oral direct factor Xa inhibitor (edoxaban, rivaroxaban, or apixaban) with LMWH for CAT treatment. DOACS showed non-inferior efficacy, although rivaroxaban and edoxaban showed higher bleeding rates, especially in gastrointestinal cancers.Expert opinion: DOACS have a convenient route of administration and do not require laboratory monitoring, although choice of anticoagulants for CAT depends on factors such as tumor type, bleeding risk, concomitant drugs, and comorbidities.

microRNAs and Markers of Neutrophil Activation as Predictors of Early Incidental Post-Surgical Pulmonary Embolism in Patients with Intracranial Tumors

Venous thromboembolism (VTE) is a common complication of cancer that severely increases morbidity and mortality. Patients with intracranial tumors are more likely to develop VTE than patients with cancers at other sites. Conversely, limited tools exist to identify patients with high thrombotic risk. Upon activation, neutrophils release their content through different mechanisms triggering thrombosis. We explored the ability of microRNAs (miRNAs) and plasma markers of neutrophil activation measured before surgery to predict the risk of early post-surgical pulmonary embolism (PE) in glioma and meningioma patients. We recruited and prospectively followed 50 patients with glioma and 50 with meningioma, 34% of whom in each group developed an early objectively-diagnosed post-surgical PE. We measured miRNA expression and neutrophil markers (cell-free DNA, nucleosomes, calprotectin and myeloperoxidase) before surgery. In glioma patients, we adjusted and validated a predictive model for post-surgical PE with 6 miRNAs: miR-363-3p, miR-93-3p, miR-22-5p, miR-451a, miR-222-3p and miR-140-3p (AUC = 0.78; 95% Confidence Interval (CI) [0.63, 0.94]) and another with cfDNA and myeloperoxidase as predictors (AUC = 0.71; 95% CI [0.52, 0.90]). Furthermore, we combined both types of markers and obtained a model with myeloperoxidase and miR-140-3p as predictors (AUC = 0.79; 95% CI [0.64, 0.94]). In meningioma patients we fitted and validated a predictive model with 6 miRNAs: miR-29a-3p, miR-660-5p, miR-331-3p, miR-126-5p, miR-23a-3p and miR-23b-3p (AUC = 0.69; 95% CI [0.52, 0.87]). All our models outperformed the Khorana score. This is the first study that analyzes the capability of plasma miRNAs and neutrophil activation markers to predict early post-surgical PE in glioma and meningioma patients. The estimation of the thrombotic risk before surgery may promote a tailored thromboprophylaxis in a selected group of high-risk patients, in order to minimize the incidence of PE and avoid bleedings.

Cancer-Related Stroke: An Emerging Subtype of Ischemic Stroke with Unique Pathomechanisms

Systemic cancer and ischemic stroke are common conditions and two of the most frequent causes of death among the elderly. The association between cancer and stroke has been reported worldwide. Stroke causes severe disability for cancer patients, while cancer increases the risk of stroke. Moreover, cancer-related stroke is expected to increase due to advances in cancer treatment and an aging population worldwide. Because cancer and stroke share risk factors (such as smoking and obesity) and treatment of cancer can increase the risk of stroke (e.g., accelerated atherosclerosis after radiation therapy), cancer may accelerate conventional stroke mechanisms (i.e., atherosclerosis, small vessel disease, and cardiac thrombus). In addition, active cancer and chemotherapy may enhance thrombin generation causing stroke related to coagulopathy. Patients with stroke due to cancer-related coagulopathy showed the characteristics findings of etiologic work ups, D-dimer levels, and infarct patterns. In this review, we summarized the frequency of cancer-related stroke among patients with ischemic stroke, mechanisms of stroke with in cancer patients, and evaluation and treatment of cancer-related stroke. We discussed the possibility of cancer-related stroke as a stroke subtype, and presented the most recent discoveries in the pathomechanisms and treatment of stroke due to cancer-related coagulopathy.

Circulating DNAs, a Marker of Neutrophil Extracellular Traposis and Cancer-Related Stroke: The OASIS-Cancer Study

Background and Purpose- The role of circulating neutrophil extracellular traps (NETs) in cancer-related stroke is unknown. Methods- We conducted a prospective cohort study to test whether NETs are increased in cancer-related stroke and whether elevated NETs levels are associated with coagulopathy, assessed using D-dimer levels (≥2 μg/mL). Plasma DNA and nucleosome were assessed as NET-specific biomarkers. Results- In total, 138 patients were recruited; 38 patients had cancer-related stroke (active cancer and acute cryptogenic embolic stroke), 33 patients were healthy-controls, 27 patients were cancer-controls (active cancer but no stroke), and 40 patients were stroke-controls (acute ischemic stroke but no cancer). Plasma DNA and nucleosome levels were significantly elevated in cancer-related stroke patients than in healthy-controls (P<0.05). These levels were correlated with the D-dimer levels (P<0.01). In multiple regression analyses, increased plasma DNA levels were associated with cancer-related stroke (odds ratio=11.65 for highest quartile; 95% CI, 3.199-42.46) and D-dimer levels of ≥2 μg/mL (odds ratio=19.09 for highest quartile; 95% CI, 4.143-87.95) after adjusting for possible confounders. Conclusions- Increased circulating DNA levels were associated with cancer-related stroke, suggesting that NETosis is one of the molecular mechanisms of cancer-related stroke. Further long-term follow-up studies in large cohorts are needed to confirm the role of NET-specific biomarkers.

Predicting VTE in Cancer Patients: Candidate Biomarkers and Risk Assessment Models

Risk prediction of chemotherapy-associated venous thromboembolism (VTE) is a compelling challenge in contemporary oncology, as VTE may result in treatment delays, impaired quality of life, and increased mortality. Current guidelines do not recommend thromboprophylaxis for primary prevention, but assessment of the patient's individual risk of VTE prior to chemotherapy is generally advocated. In recent years, efforts have been devoted to building accurate predictive tools for VTE risk assessment in cancer patients. This review focuses on candidate biomarkers and prediction models currently under investigation, considering their advantages and disadvantages, and discussing their diagnostic performance and potential pitfalls.

Thromboembolic events in patients with advanced stage non-small cell lung cancer treated with platinum-based chemotherapy: a prospective observational study

Objectives

Cancer is frequently complicated by thromboembolic events (TEs). We aimed to determine the incidence of TEs in lung cancer patients treated with platinum-based chemotherapy and study patients’ baseline and treatment attributes correlating with its onset.

Materials and methods

Advanced lung cancer patients started on platinum-based chemotherapy were evaluated at baseline and during routine visits for the development of TEs. The duration of follow-up was 4 weeks from the last chemotherapy. A TE occurring between the first dose of chemotherapy and 4 weeks after the last dose was considered to be chemotherapy associated.

Results

Of the 165 patients on platinum chemotherapy who completed follow-up, TEs occurred in 4.8% (8 out of 165) patients. Among these, three patients had developed venous pulmonary thromboembolism and five patients had developed cerebral infarction, out of which four had arterial cerebral infarction and one patient had a superior sagittal sinus thrombosis. The majority of events (7 out of 8) occurred within 100 days of starting platinum chemotherapy. Overall, the median time until occurrence of TE was 48 days (range, 10–130 days). None of the presumed risk factors were found be associated with the occurrence of TEs on univariate analysis.

Conclusions

Advanced lung cancer patients on platinum chemotherapy are predisposed to thromboembolism due to many factors. Despite its lower incidence in our study, exclusion of patients with prior thrombosis suggests the incidence of de novo thrombosis, and hence raises a valid question of the need of thromboprophylaxis in a selected group of patients.

Protease-activated receptor 1 activation enhances doxorubicin-induced cardiotoxicity

OBJECTIVE

The anti-cancer anthracycline drug Doxorubicin (Dox) causes cardiotoxicity. We investigated the role of protease-activated receptor 1 (PAR-1) in Dox-induced cardiotoxicity.

METHODS AND RESULTS

In vitro experiments revealed that PAR-1 enhanced Dox-induced mitochondrial dysfunction, reactive oxygen species and cell death of cardiac myocytes and cardiac fibroblasts. The contribution of PAR-1 to Dox-induced cardiotoxicity was investigated by subjecting PAR-1^-/- mice and PAR-1^+/+ mice to acute and chronic exposure to Dox. Heart function was measured by echocardiography. PAR-1^-/- mice exhibited significant less cardiac injury and dysfunction compared to PAR-1^+/+ mice after acute and chronic Dox administration. PAR-1^-/- mice had reduced levels of nitrotyrosine, apoptosis and inflammation in their heart compared to PAR-1^+/+ mice. Furthermore, inhibition of PAR-1 in wild-type mice with vorapaxar significantly reduced the acute Dox-induced cardiotoxicity.

CONCLUSION

Our results indicate that activation of PAR-1 contributes to Dox-induced cardiotoxicity. Inhibition of PAR-1 may be a new approach to reduce Dox-induced cardiotoxicity in cancer patients.

Pretreatment platelet count as a prognostic factor in patients with pancreatic cancer: a systematic review and meta-analysis

Background

The relationship between platelet counts and pancreatic cancer as a prognostic factor has been reported in many studies. We aimed to evaluate the prognostic value of platelet counts in predicting the prognosis of pancreatic cancer patients.

Methods

We searched PubMed, Medline, EMBASE, and Google Scholar for eligible studies up to May 2017. Information about the characteristics of the study and relevant outcomes was extracted. A meta-analysis was performed to analyze the prognostic value of platelet counts using the hazard ratio (HR) and 95% confidence intervals (CIs).

Results

A total of 1,756 patients in 13 retrospective studies were included. The pooled HR of 1.51 (95% CI: 1.20–1.90, P<0.001) showed that patients with elevated platelet counts were expected to have poor overall survival after treatment. Subgroup analysis showed that prognostic value of platelet levels was stronger in patients who received surgical resection (HR =1.60, 95% CI: 1.09–2.34, P=0.02), followed by patients who received palliative therapy (HR =1.46, 95% CI: 1.03–2.06, P=0.03).

Conclusion

Platelet counts could be a useful prognostic marker for pancreatic cancer. Patients with high platelet counts are expected to have poor survival.

High incidence of venous thromboembolism despite electronic alerts for thromboprophylaxis in hospitalised cancer patients

Many cancer patients are at high risk of venous thromboembolism (VTE) during hospitalisation; nevertheless, thromboprophylaxis is frequently underused. Electronic alerts (e-alerts) have been associated with improvement in thromboprophylaxis use and a reduction of the incidence of VTE, both during hospitalisation and after discharge, particularly in the medical setting. However, there are no data regarding the benefit of this tool in cancer patients. Our aim was to evaluate the impact of a computer-alert system for VTE prevention in patients with cancer, particularly in those admitted to the Oncology/Haematology ward, comparing the results with the rest of inpatients at a university teaching hospital. The study included 32,167 adult patients hospitalised during the first semesters of years 2006 to 2010, 9,265 (28.8%) with an active malignancy. Appropriate prophylaxis in medical patients, significantly increased over time (from 40% in 2006 to 57% in 2010) and was maintained over 80% in surgical patients. However, while e-alerts were associated with a reduction of the incidence of VTE during hospitalisation in patients without cancer (odds ratio [OR] 0.31; 95% confidence interval [CI], 0.15–0.64), the impact was modest in cancer patients (OR 0.89; 95% CI, 0.42–1.86) and no benefit was observed in patients admitted to the Oncology/Haematology Departments (OR 1.11; 95% CI, 0.45–2.73). Interestingly, 60% of VTE episodes in cancer patients during recent years developed despite appropriate prophylaxis. Contrary to the impact on hospitalised patients without cancer, implementation of e-alerts for VTE risk did not prevent VTE effectively among those with malignancies.

Platelet × CRP Multiplier Value as an Indicator of Poor Prognosis in Patients With Resectable Pancreatic Cancer

OBJECTIVE

Thrombocytosis in patients with various cancers has been considered a parameter for poor prognosis; however, its contribution to pancreatic cancer remains controversial.

METHODS

Potential preoperative prognostic parameters (platelets, neutrophils, lymphocytes, the platelet-lymphocyte ratio, the neutrophil-lymphocyte ratio, the serum C-reactive protein [CRP], and carbohydrate antigen 19-9) were retrospectively analyzed in 95 patients with pancreatic cancer. Cutoff values were defined according to receiver operating characteristic curve analysis, and median survival times (MSTs) were compared.

RESULTS

Median survival times (days) significantly differed according to platelet count (high [552] vs low [735], P = 0.017), CRP (high [471] vs low [750], P = 0.001), and carbohydrate antigen 19-9 level (high [639] vs low [765], P = 0.021), whereas there was no difference in the platelet-lymphocyte ratio and the neutrophil-lymphocyte ratio. Multivariate analysis identified thrombocytosis (hazard ratio, 2.015) and CRP level (hazard ratio, 1.771) as independent prognostic factors. The combinatory effects of platelets and the inflammatory response using a platelet × CRP multiplier value could effectively distinguished the MSTs (days) of patients with pancreatic cancer (high [482] vs low [812], P < 0.001).

CONCLUSIONS

Thrombocytosis and CRP influenced pancreatic cancer patient prognosis. Platelet × CRP multiplier is assumed as a useful parameter that reflects the contribution of activated platelets to cancer progression.

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.

Risk Assessment for Venous Thromboembolism in Chemotherapy-Treated Ambulatory Cancer Patients

OBJECTIVE

To design a precision medicine approach aimed at exploiting significant patterns in data, in order to produce venous thromboembolism (VTE) risk predictors for cancer outpatients that might be of advantage over the currently recommended model (Khorana score).

DESIGN

Multiple kernel learning (MKL) based on support vector machines and random optimization (RO) models were used to produce VTE risk predictors (referred to as machine learning [ML]-RO) yielding the best classification performance over a training (3-fold cross-validation) and testing set.

RESULTS

Attributes of the patient data set ( n = 1179) were clustered into 9 groups according to clinical significance. Our analysis produced 6 ML-RO models in the training set, which yielded better likelihood ratios (LRs) than baseline models. Of interest, the most significant LRs were observed in 2 ML-RO approaches not including the Khorana score (ML-RO-2: positive likelihood ratio [+LR] = 1.68, negative likelihood ratio [-LR] = 0.24; ML-RO-3: +LR = 1.64, -LR = 0.37). The enhanced performance of ML-RO approaches over the Khorana score was further confirmed by the analysis of the areas under the Precision-Recall curve (AUCPR), and the approaches were superior in the ML-RO approaches (best performances: ML-RO-2: AUCPR = 0.212; ML-RO-3-K: AUCPR = 0.146) compared with the Khorana score (AUCPR = 0.096). Of interest, the best-fitting model was ML-RO-2, in which blood lipids and body mass index/performance status retained the strongest weights, with a weaker association with tumor site/stage and drugs.

CONCLUSIONS

Although the monocentric validation of the presented predictors might represent a limitation, these results demonstrate that a model based on MKL and RO may represent a novel methodological approach to derive VTE risk classifiers. Moreover, this study highlights the advantages of optimizing the relative importance of groups of clinical attributes in the selection of VTE risk predictors.

Cancer Cell-Derived Extracellular Vesicles Are Associated with Coagulopathy Causing Ischemic Stroke via Tissue Factor-Independent Way: The OASIS-CANCER Study

Background

Cancer and stroke, which are known to be associated with one another, are the most common causes of death in the elderly. However, the pathomechanisms that lead to stroke in cancer patients are not well known. Circulating extracellular vesicles (EVs) play a role in cancer-associated thrombosis and tumor progression. Therefore, we hypothesized that cancer cell-derived EVs cause cancer-related coagulopathy resulting in ischemic stroke.

Methods

Serum levels of D-dimer and EVs expressing markers for cancer cells (epithelial cell adhesion molecule [CD326]), tissue factor (TF [CD142]), endothelial cells (CD31+CD42b-), and platelets (CD62P) were measured using flow cytometry in (a) 155 patients with ischemic stroke and active cancer (116 − cancer-related, 39 − conventional stroke mechanisms), (b) 25 patients with ischemic stroke without cancer, (c) 32 cancer patients without stroke, and (d) 101 healthy subjects.

Results

The levels of cancer cell-derived EVs correlated with the levels of D-dimer and TF+ EVs. The levels of cancer cell-derived EVs (CD326+ and CD326+CD142+) were higher in cancer-related stroke than in other groups (P<0.05 in all the cases). Path analysis showed that cancer cell-derived EVs are related to stroke via coagulopathy as measured by D-dimer levels. Poor correlation was observed between TF+ EV and D-dimer, and path analysis demonstrated that cancer cell-derived EVs may cause cancer-related coagulopathy independent of the levels of TF+ EVs.

Conclusions

Our findings suggest that cancer cell-derived EVs mediate coagulopathy resulting in ischemic stroke via TF-independent mechanisms.

Impact of Transfusion on Cancer Growth and Outcome

For many years, transfusion of allogeneic red blood cells, platelet concentrates, and plasma units has been part of the standard therapeutic arsenal used along the surgical and nonsurgical treatment of patients with malignancies. Although the benefits of these blood products are not a matter of debate in specific pathological conditions associated with life-threatening low blood cell counts or bleeding, increasing clinical evidence is nevertheless suggesting that deliberate transfusion of these blood components may actually lead to negative clinical outcomes by affecting patient’s immune defense, stimulating tumor growth, tethering, and dissemination. Rigorous preclinical and clinical studies are needed to dimension the clinical relevance, benefits, and risks of transfusion of blood components in cancer patients and understand the amplitude of problems. There is also a need to consider validating preparation methods of blood components for so far ignored biological markers, such as microparticles and biological response modifiers. Meanwhile, blood component transfusions should be regarded as a personalized medicine, taking into careful consideration the status and specificities of the patient, rather than as a routine hospital procedure.

Tick salivary gland as potential natural source for the discovery of promising antitumor drug candidates

Nowadays, the relationship between cancer blood coagulation is well established. Regarding biodiversity and bioprospection, the tick biology has become quite attractive natural source for coagulation inhibitors, since its saliva has a very rich variety of bioactive molecules. For instance, a Kunitz-type FXa inhibitor, named Amblyomin-X, was found through transcriptome of the salivary gland of the Amblyomma cajennense. tick. This TFPI-like inhibitor, after obtained as recombinant protein, has presented anticoagulant, antigionenic, and antitumor properties. Although its effects on blood coagulation could be relevant for antitumor effect, Amblyomin-X acts by non-hemostatic mechanisms, such as proteasome inhibition and autophagy inhibition. Notably, cytotoxicity was not observed on non-tumor cells treated with this protein, suggesting some selectivity for tumor cells. Considering the current efforts in order to develop effective anticancer therapies, the findings presented in this review strongly suggest Amblyomin-X as a promising novel antitumor drug candidate.

Cyclophosphamide, epirubicin and fluorouracil chemotherapy-induced alteration of haemostasis markers in breast cancer patients

The occurrence of chemotherapy-induced alterations in markers of haemostasis during chemotherapy has been reported previously. However, the change of the haemostasis markers in the cyclophosphamide, epirubicin and fluorouracil (CEF) regimen remains unclear. The aim of the present study was to identify the change of the haemostasis markers during systemic chemotherapy (600 mg/m² cyclophosphamide, 80 mg/m² epirubicin and 500 mg/m² fluorouracil; four courses over 21 days) to investigate its influence on the haemostasis markers of breast cancer patients and to discuss the requirement of anticoagulation therapy. D-dimer, activated partial thromboplastin time (APTT), prothrombin time (PT) and fibrinogen (FIB) values were obtained before chemotherapy and on days 1, 4, 7 and 21. The results show that PT, D-dimer and FIB were not prolonged prior to chemotherapy compared to that under the control. APTT was prolonged until day 4. The levels of D-dimer and APTT were significantly higher compared to those of the breast cancer patients before receiving chemotherapy and controls on days 1, 4, 7 and 21 after chemotherapy. Alteration of the haemostasis markers occurred in the breast cancer patients under the CEF chemotherapy regimen. As there is an increased risk of deep vein thrombosis and pool prognosis of cancer patients, anticoagulant therapy should be considered.

Venous thromboembolism and lung cancer: a review

Venous thromboembolism (VTE) is a common complication of malignancies and epidemiological studies suggest that lung cancer belonged to the group of malignancies with the highest incidence rates of VTE. Risk factors for VTE in lung cancer patients are adenocarcinoma, NSCLC in comparison with SCLC, advanced disease, pneumonectomy, chemotherapy including antiangiogenic therapy. Other risk factors are pretreatment platelet counts and increased release of TF-positive microparticles. Elevated D-dimer levels do not necessarily indicate an increased risk of VTE but have been shown to be predictive for a worse clinical outcome in lung cancer patients. Mechanisms responsible for the increase in venous thrombosis in patients with lung cancer are not understood.

Currently no biomarker is recognized as a predictor for VTE in lung cancer patients.

Although several clinical trials have reported the efficacy of antithrombotic prophylaxis in patients with lung cancer who are receiving chemotherapy, further trials are needed to assess the clinical benefit since these patients are at an increased risk of developing a thromboembolism.

High-Dose Vitamin C Injection to Cancer Patients May Promote Thrombosis Through Procoagulant Activation of Erythrocytes

Potential risk of high-dose vitamin C consumption is often ignored. Recently, gram-dose vitamin C is being intravenously injected for the treatment of cancer, which can expose circulating blood cells to extremely high concentrations of vitamin C. As well as platelets, red blood cells (RBCs) can actively participate in thrombosis through procoagulant activation. Here, we examined the procoagulant and prothrombotic risks associated with the intravenous injection of gram-dose vitamin C. Vitamin C (0.5-5 mM) increased procoagulant activity of freshly isolated human RBCs via the externalization of phosphatidylserine (PS) to outer cellular membrane and the formation of PS-bearing microvesicles. PS exposure was induced by the dysregulation of key enzymes for the maintenance of membrane phospholipid asymmetry, which was from vitamin C-induced oxidative stress, and resultant disruption of calcium and thiol homeostasis. Indeed, the intravenous injection of vitamin C (0.5-1.0 g/kg) in rats in vivo significantly increased thrombosis. Notably, the prothrombotic effects of vitamin C were more prominent in RBCs isolated from cancer patients, who are at increased risks of thrombotic events. Vitamin C-induced procoagulant and prothrombotic activation of RBCs, and increased thrombosis in vivo. RBCs from cancer patients exhibited increased sensitivity to the prothrombotic effects of vitamin C, reflecting that intravenous gram-dose vitamin C therapy needs to be carefully revisited.

Pre-operative thrombotic complications of neoadjuvant chemotherapy for breast cancer: Implications for immediate breast reconstruction

Thrombotic complications arising during the treatment of breast cancer can impact the breast reconstruction pathway. We set out to review the details of cases of thromboembolism occurring during neoadjuvant chemotherapy and peri-operatively to study the impact of the event and its management on subsequent breast reconstruction.

METHODS

We retrospectively reviewed the medical records of seven patients who had experienced a thrombotic event during their treatment of breast cancer between 2008 and 2012, who then proceeded to breast reconstruction. We recorded size and grade of tumour, neoadjuvant chemotherapeutic regimen, details of port insertion, planned reconstruction, thrombotic event and its management and the surgery performed and outcome.

RESULTS

All patients received chemotherapy via central venous access and went on to present with local symptomatic thrombosis. They were managed with anticoagulant regimens at the time of mastectomy and reconstruction, which were unique for each patient. The results revealed delays to surgery and modifications to planned reconstruction.

DISCUSSION

The majority of patients developing thrombotic complications go on to achieve successful reconstruction. There is significant variation in the anticoagulation management in this patient group. Identification of optimal anticoagulant regimes and the possibilities for prophylaxis may prove key in informing surgeons when planning the reconstructive process.

CONCLUSION

An awareness of the effects of thrombotic events in this patient group is important in terms of developing an understanding of its impact on the performance of reconstruction, on the management of anticoagulation peri-operatively and on monitoring for post-operative complications.

Risk Characteristics of Venous Thromboembolism in Chinese Patients

BACKGROUND AND OBJECTIVE

There is little report concerning risk characteristics of Chinese patients with venous thromboembolism (VTE). The present study was designed to investigate the risk characteristics in Chinese patients with VTE through a retrospective study.

METHODS

A total of 1048 registry patients with VTE in the recent 10 years were analyzed retrospectively with respect to underlying diseases or predisposing factors.

RESULTS

The incidence of VTE in both male and female has been increasing in the recent 10 years. A total of 885 patients were aged more than 50 years, and the mean age of the patients at diagnosis was 58.8 ± 15.7 years. Main risk factors were a prolonged immobilization and malignant tumors, which were different from Western patients.

CONCLUSIONS

This registry demonstrated the different risk characteristics in Chinese patients compared to Western patients. Our results will be available for establishing the prevention of VTE in China.

Thrombosis as a complication of central venous access in pediatric patients with malignancies: a 5-year single-center experience

Background

Reliable central venous access (CVC) is essential for hematology–oncology patients since frequent puncture of peripheral veins—e.g., for chemotherapy, antibiotic administration, repeated blood sampling, and monitoring—can cause unacceptable pain and psychological trauma, as well as severe side effects in cases of extravasation of chemotherapy drugs. However, CVC lines still carry major risk factors, including thrombosis, infection (e.g., entry site, tunnel, and luminal infections), and catheter dislocation, leakage, or breakage.

Methods

Here we performed a retrospective database analysis to determine the incidence of CVC-associated thrombosis in a single-center cohort of 448 pediatric oncologic patients, and to analyze whether any subgroup of patients was at increased risk and thus might benefit from prophylactic anticoagulation.

Results

Of the 448 patients, 269 consecutive patients received a CVC, and 55 of these 269 patients (20%) also had a thrombosis. Of these 55 patients, 43 had at least one CVC-associated thrombosis (total number of CVC-associated thrombosis: n = 52). Among all patients, the median duration of CVC exposure was 464 days. Regarding exposure time, no significant difference was found between patients with and without CVC-associated thrombosis. Subclavia catheters and advanced tumor stages seem to be the main risk factors for the development of CVC-associated thrombosis, whereas pharmacologic prophylaxis did not seem to have a relevant impact on the rate of thrombosis.

Conclusions

We conclude that pediatric surgeons and oncologists should pay close attention to ensuring optimal and accurate CVC placement, as this appears the most effective tool to minimize CVC-associated complications.

A retrospective analysis of plasma D-dimer dynamic variation in terminal stage cancer patients: implications for disease progression

Elevated D-dimer is frequently found among cancer patients especially for advanced stage patients. Activation of the coagulation system and the fibrinolytic cascade are supposed to be associated with higher risk of invasion, metastases and worse outcome. The purpose of this study is to investigate the dynamic variation of plasma D-dimer and its relationship with other markers of the coagulation system including platelet counts, fibrinogen levels, prothrombin time (PT), activated partial thromboplastin time (APTT) and thrombin time (TT) in terminal stage cancer patients. We designed a self-controlled study to compare plasma D-dimer dynamic variation from 0-4 weeks to 4-8 weeks before patients' death. The plasma D-dimer levels pointed an elevated tendency and revealed statistically significant difference as patients gradually near death. Prolonged PT, APTT and TT were found. D-dimer levels were positively correlated with PT, APTT and TT but showed negative correlation with platelet counts and fibrinogen levels. Plasma D-dimer levels gradually increased as terminal stage cancer patients approaching to death. Increasing D-dimer levels may predict worse outcome.

Overview and assessment of risk factors for pulmonary embolism

Pulmonary embolism is one of the most common undiagnosed conditions affecting hospitalized patients. There are a plethora of risk factors for venous thromboembolism and pulmonary emboli. These factors are grouped under the broad triad of hypercoagulability, stasis and injury to provide a framework for understanding. Important risk factors include inherited thrombophilia, age, malignancy and estrogens. These risk factors are reviewed in detail and several risk assessment models are reviewed. These risk assessment models help identify those at risk for disease and therefore candidates for thromboprophylaxis. Diagnosis can be difficult and is aided by clinical decision rules that incorporate clinical scores that define the likelihood of pulmonary embolism. These are important considerations, not only for diagnostic purposes, but also to minimize excessive use of imaging, which increases exposure to and risks associated with radiation. A healthy index of suspicion is often the key to diagnosis.

The platelet-cancer loop

The relationship between cancer and thrombosis has been established since 1865 when Armand Trousseau described superficial thrombophlebitis as forewarning sign of occult visceral malignancy. Platelets are the primary hemostatic tool and play a primordial role in cancer-induced thrombosis. Tumor-induced numerical and functional platelet abnormalities have been described in conjunction to changes in coagulation. Such changes are reported even in the absence of clinically detectable thrombosis and correlate with tumor progression and metastasis. Reciprocally, platelets seem to interplay with the tumors and the immune system, both directly and indirectly favoring tumor progressions, tethering and distant spread. A number of growth factors supporting tumor growth, angiogenesis and metastasis are released from the platelets. A reciprocating loop of tumor-induced platelet activation/platelet-induced tumor growth and dissemination is initiated, acting as a thrombosis trigger/tumor amplifier. Recent studies have demonstrated that the use of anti-platelet agents can break this loop resulting in a reduction of short-term risk for incident cancer, cancer mortality and metastasis. The beneficial effect in reduction in cancer-induced thrombosis remains to be established. The current review aims at shedding the light on the intimate reciprocal cross-talk between platelets and cancer and on exploring the potential beneficial effect of anti-platelet agents in breaking the deadly loop of tumor amplification.

The skin and hypercoagulable states

Hypercoagulable states (HS) are inherited or acquired conditions that predispose an individual to venous and/or arterial thrombosis. The dermatologist can play a vital role in diagnosing a patient's HS by recognizing the associated cutaneous manifestations, such as purpura, purpura fulminans, livedo reticularis, livedo vasculopathy (atrophie blanche), anetoderma, chronic venous ulcers, and superficial venous thrombosis. The cutaneous manifestations of HS are generally nonspecific, but identification of an abnormal finding can warrant a further workup for an underlying thrombophilic disorder. This review will focus on the basic science of hemostasis, the evaluation of HS, the skin manifestations associated with hypercoagulability, and the use of antiplatelet and anticoagulant therapy in dermatology.

Impact of chemotherapy on activated protein C-dependent thrombin generation--association with VTE occurrence

Chemotherapy has been associated with an increased risk of venous thromboembolism (VTE). However, the prevalence of coagulation abnormalities or VTE occurrence as a consequence of different anti-cancer agents or treatment schemes is largely uncharacterized. Thus, this study was aimed at analyzing the impact of different anticancer drugs on the prothrombotic status of cancer out-patients scheduled for chemotherapy. To this purpose, a mono-institutional study was prospectively conducted to monitor serial changes of activated protein C (APC) function in 505 consecutive cancer out-patients with primary or relapsing solid cancer at the start of a new chemotherapy regimen. The results obtained showed that age >65 years (p = 0.01), ECOG performance status (p = 0.01), platinum-based (p = 0.035) and fluoropyrimidine-based regimens (p = 0.008) were independent predictors of an acquired APC resistance during the first chemotherapy cycle. Multivariate model of Cox proportional hazards survival analysis demonstrated that a decline in APC functionality (HR = 2.4; p = 0.013) and platinum-based regimens (HR = 2.2; p = 0.042) were both capable of predicting the occurrence of a first VTE episode during chemotherapy. Indeed, 14% of patients with platinum-associated APC impairment had VTE over a 1-year follow-up, compared to 3% of patients treated with other regimens and in whom APC functionality remained stable (HR = 1.5; p = 0.003). We may, thus, conclude that use of platinum-based regimens is responsible for induction of an acquired thrombophilic condition and represents a predictor for VTE even after adjustment for other risk factors.

A Kunitz-type FXa inhibitor affects tumor progression, hypercoagulable state and triggers apoptosis

Cancer is linked to hypercoagulability, and many studies have shown that anticoagulant drugs affect tumor progression. In this study was demonstrated that the Amblyomin-X (which is a recombinant protein that exerts similarity to the Kunitz-type inhibitors and shows pro-apoptotic effects in different tumor cell lines) and heparin (a classic anticoagulant) have similar effects on cancer progression and on normalization of the hypercoagulable state. However, Amblyomin-X showed a distinct mechanism in triggering its effects in vitro, because it exerted a cytotoxic effect in cancer cells by inducing apoptosis and promoting cell cycle arrest.

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.

Association between increased tumor necrosis factor alpha levels and acquired activated protein C resistance in patients with metastatic colorectal cancer

PURPOSE

The purpose of this study was to investigate the possible association between tumor necrosis factor-α (TNF-α) levels and defects in the activated protein C (APC) system as a determinant of venous thromboembolism (VTE) in metastatic colorectal cancer patients (mCRC) undergoing chemotherapy.

METHODS

TNF-α levels (measured by immunoassay) and abnormalities in the APC system [evaluated by an APC-dependent thrombin generation assay (ThromboPath-ThP)] were evaluated in 45 mCRC patients undergoing chemotherapy. VTE events were recorded during follow-up.

RESULTS

TNF-α levels were increased (p < 0.01), and APC functionality was decreased (p < 0.0001) in mCRC patients compared to age- and sex-matched controls. An inverse correlation was observed between TNF-α and APC impairment in mCRC (p < 0.0001). TNF-α was confirmed as an independent predictor (p = 0.007) for APC abnormalities at multivariate regression analysis. Nine (20 %) of 45 mCRC patients experienced VTE during chemotherapy. Bayesian analysis of combined ThP/TNF-α showed a positive predictive value of 0.67 in predicting VTE (p = 0.01). Cox proportional hazards survival analysis confirmed the predictive value of combined ThP/TNF-α determination in VTE risk assessment of mCRC patients (either negative vs. both positive: HR = 0.02; p = 0.001), and Kaplan-Meier analysis demonstrated that mCRC patients with either negative TNF-α or ThP values prior to chemotherapy were less likely to experience VTE (13 %) than patients with abnormalities of both markers (67 %, p = 0.002).

CONCLUSIONS

These results suggest that the host inflammatory response to cancer cells and/or tumor-derived cytokines could be responsible for an impairment of the APC system and a switch toward a pro-thrombotic state, which might predispose to the occurrence of VTE in mCRC patients undergoing chemotherapy.

Breast cancer as an acquired thrombophilic state

Cancer is an acquired thrombophilic condition manifested by increased incidence of venous and arterial thromboembolic complications. Despite progress that has been achieved in treatments over the recent years, thromboembolism remains a major complication in patients with breast cancer; it is accompanied by significant morbidity and mortality. Approximately, 1% of breast cancer patients develop venous thromboembolism within 2 years with the highest incidence occurring in the 6 months post diagnosis. Metastatic disease and their comorbidities are the strongest predictors of the development of thrombotic event. The diagnosis of venous thromboembolism is associated with a higher risk of death within 2 years of diagnosis. Thromboembolic events in cancer patients range from abnormal laboratory coagulation tests without specific symptoms to massive thomboembolism and disseminated intravascular coagulation. The underlying pathophysiology is complex and includes the prothrombotic properties of cancer cells, which can be enhanced by anticancer treatment modalities, such as surgery, hormonal agents, and chemotherapy. Primary thromboprophylaxis in cancer patients should be individualized according to risk. For secondary prevention, several clinical studies have shown that low molecular weight heparin has improved patients' compliance, cancer outcomes and overall survival. This review summarizes the available data on the pathogenesis and clinical approach of hemostatic changes in breast cancer.

Novel high-sensitive D-dimer determination predicts chemotherapy-associated venous thromboembolism in intermediate risk lung cancer patients

INTRODUCTION

We hypothesized that the use of a novel high sensitivity (HS) assay for D-dimer determination might ameliorate venous thromboembolism (VTE) risk prediction in intermediate risk lung cancer patients in whom chemotherapy could act as a trigger for VTE onset.

PATIENTS AND METHODS

Pretreatment HS D-dimer levels were retrospectively evaluated in 108 lung cancer outpatients using a novel automated latex enhanced turbidimetric immunoassay. All patients were at the start of a new platinum-based chemotherapy regimen and were classified as intermediate risk according to Khorana's assessment model. Patients were followed-up for a median period of 6.9 months.

RESULTS

Receiver operating characteristic (ROC) curves and corresponding Bayesian analysis showed that the best performance was obtained at a cutoff level of 1500 ng/mL, which resulted in a sensitivity of 81%, a specificity of 69%, a positive predictive value (PPV) of 31%, a negative predictive value (NPV) of 96%, and an accuracy of 70%. Patients with HS D-dimer levels above the cutoff had a worse VTE-free survival (60%) compared with those with levels below the cutoff (95%; P = .0001). Multivariate Cox proportional hazards survival analysis confirmed that pretreatment HS D-dimer levels were able to significantly predict VTE with a hazard ratio of 11 (95% confidence interval, 2.62-46.2; P = .001), independently of classic VTE risk factors.

CONCLUSIONS

The use of HS D-dimer determination prior to chemotherapy might allow for VTE risk stratification of intermediate risk cancer patients, helping in identifying those individuals who could benefit from thromboprophylaxis.

Venous thromboembolism in the cancer population: pathology, risk, and prevention

Patients with cancer have an increased risk of developing venous thromboembolism (VTE) and the incidence of these events has been increasing over the past decade. Venous thromboembolic events include both deep venous thrombosis and pulmonary embolism. These events contribute to higher morbidity and mortality rates. Understanding the complex pathogenesis of and risk factors for cancer-associated VTE will help guide advanced practitioners to improve outcomes with prophylaxis. The American Society of Clinical Oncology, the National Comprehensive Cancer Network, and the European Society of Medical Oncology have utilized this information and developed evidence-based guidelines for prophylactic management for those who are at highest risk of developing cancer-associated VTE. This review will discuss the impact of cancer-associated VTE as well as its underlying pathogenesis, risk factors, and current recommendations for prophylaxis.

Tissue factor over-expression by human pancreatic cancer cells BXPC3 is related to higher prothrombotic potential as compared to breast cancer cells MCF7

Cancer histology influences the risk of venous thromboembolism and tissue factor (TF) is the key molecule in cancer-induced hypercoagulability. We investigated the relation between TF expression by pancreatic and breast cancer cells (BXPC3 and MCF7 respectively) and their capacity to trigger in vitro thrombin generation in normal human plasma. Flow cytometry and Western blot analysis for TF expression were performed using murine IgG1 monoclonal antibody against human TF. Real-time PCR for TFmRNA was also performed. Activity of TF expressed by cancer cells was measured with a specific chromogenic assay. Thrombin generation in PPP was assessed using calibrated automated thrombogram. Cancer cells were added to platelet poor plasma from healthy volunteers. In separate experiments cells were incubated with the anti-TF antibody at concentration that completely neutralized the activity of recombinant human TF on thrombin generation. BXPC3 cells expressed significantly higher amounts of functional TF as compared to MCF7 cells. Incubation of BXPC3 and MCF7 cells with PPP resulted in acceleration of the initiation phase of thrombin generation. BXPC3 cells manifested higher procoagulant potential than MCF7 cells. The incubation of BXPC3 or MCF7 cells with the anti-TF monoclonal antibody which resulted in reversal of their effect on thrombin generation. The present study establishes a link between the amount of TF expressed by cancer cells with their procoagulant activity. Both studied types of cancer cells trigger thrombin generation but they have different procoagulant potential. The procoagulant activity of BXPC3 and MCF7 cells is related to the amount of TF expressed. Kinetic parameters of thrombogram are the most relevant for the detection of the TF-dependent procoagulant activity of cancer cells. TF expression is one of the mechanisms by which cancer cells manifest their procoagulant potential but it is not the unique one. The present experimental model will allow the characterization the procoagulant fingerprint of cell lines from the same or different histological types of cancer.

Doxorubicin-induced platelet procoagulant activities: an important clue for chemotherapy-associated thrombosis

Thrombotic risk associated with chemotherapy including doxorubicin (DOX) has been frequently reported; yet, the exact mechanism is not fully understood. Here, we report that DOX can induce procoagulant activity in platelets, an important contributor to thrombus formation. In human platelets, DOX increased phosphatidylserine (PS) exposure and PS-bearing microparticle (MP) generation. Consistently, DOX-treated platelets and generated MPs induced thrombin generation, a representative marker for procoagulant activity. DOX-induced PS exposure appeared to be from intracellular Ca²⁺ increase and ATP depletion, which resulted in the activation of scramblase and inhibition of flippase. Along with this, apoptosis was induced by DOX as determined by the dissipation of mitochondrial membrane potential (Δψ), cytochrome c release, Bax translocation, and caspase-3 activation. A Ca²⁺ chelator ethylene glycol tetraacetic acid, caspase inhibitor Q-VD-OPh, and antioxidants (vitamin C and trolox) can attenuate DOX-induced PS exposure and procoagulant activity significantly, suggesting that Ca²⁺, apoptosis, and reactive oxygen species (ROS) were involved in DOX-enhanced procoagulant activity. Importantly, rat in vivo thrombosis model demonstrated that DOX could manifest prothrombotic effects through the mediation of platelet procoagulant activity, which was accompanied by increased PS exposure and Δψ dissipation in platelets.

The engagement of selectins and their ligands in colorectal cancer liver metastases

The colonization of the liver by colorectal cancer (CRC) cells is a complicated process which includes many stages, until macrometastases occur. The entrapment of malignant cells within the hepatic sinusoids and their interactions with resident non-parenchymal cells are considered very important for the whole metastatic sequence. In the sinusoids, cell connection and signalling is mediated by multiple cell adhesion molecules, such as the selectins. The three members of the selectin family, E-, P- and L-selectin, in conjunction with sialylated Lewis ligands and CD44 variants, regulate colorectal cell communication and adhesion with platelets, leucocytes, sinusoidal endothelial cells and stellate cells. Their role in CRC liver metastases has been investigated in animal models and human tissue, in vivo and in vitro, in static and shear flow conditions, and their key-function in several molecular pathways has been displayed. Therefore, trials have already commenced aiming to exploit selectins and their ligands in the treatment of benign and malignant diseases. Multiple pharmacological agents have been developed that are being tested for potential therapeutic applications.