Platelets and Cancer-Associated Thrombosis

Thrombotic events associated with immune checkpoint inhibitors and novel antithrombotic strategies to mitigate bleeding risk

Although immunotherapy is expanding treatment options for cancer patients, the prognosis of advanced cancer remains poor, and these patients must contend with both cancers and cancer-related thrombotic events. In particular, immune checkpoint inhibitors are associated with an increased risk of atherosclerotic thrombotic events. Given the fundamental role of platelets in atherothrombosis, co-administration of antiplatelet agents is always indicated. Platelets are also involved in all steps of cancer progression. Classical antithrombotic drugs can cause inevitable hemorrhagic side effects due to blocking integrin β3 bidirectional signaling, which regulates simultaneously thrombosis and hemostasis. Meanwhile, many promising new targets are emerging with minimal bleeding risk and desirable anti-tumor effects. This review will focus on the issue of thrombosis during immune checkpoint inhibitor treatment and the role of platelet activation in cancer progression as well as explore the mechanisms by which novel antiplatelet therapies may exert both antithrombotic and antitumor effects without excessive bleeding risk.

Cancer progression and tumor hypercoagulability: a platelet perspective

Venous thromboembolism, which is common in cancer patients and accompanies or even precedes malignant tumors, is known as cancer-related thrombosis and is an important cause of cancer- associated death. At present, the exact etiology of the elevated incidence of venous thrombosis in cancer patients remains elusive. Platelets play a crucial role in blood coagulation, which is intimately linked to the development of arterial thrombosis. Additionally, platelets contribute to tumor progression and facilitate immune evasion by tumors. Tumor cells can interact with the coagulation system through various mechanisms, such as producing hemostatic proteins, activating platelets, and directly adhering to normal cells. The relationship between platelets and malignant tumors is also significant. In this review article, we will explore these connections.

Cancer-Associated Stroke: Thrombosis Mechanism, Diagnosis, Outcome, and Therapeutic Strategies

Cancer can induce hypercoagulability, which may lead to stroke. This occurs when tumor cells activate platelets as part of their growth and metastasis. Tumor cells activate platelets by generating thrombin and expressing tissue factor, resulting in tumor cell-induced platelet aggregation. Histopathological studies of thrombi obtained during endovascular thrombectomy in patients with acute stroke and active cancer have shown a high proportion of platelets and thrombin. This underscores the crucial roles of platelets and thrombin in cancer-associated thrombosis. Cancer-associated stroke typically occurs in patients with active cancer and is characterized by distinctive features. These features include multiple infarctions across multiple vascular territories, markedly elevated blood D-dimer levels, and metastasis. The presence of cardiac vegetations on echocardiography is a robust indicator of cancer-associated stroke. Suspicion of cancer-associated stroke during endovascular thrombectomy arises when white thrombi are detected, particularly in patients with active cancer. Cancer-associated stroke is almost certain when histopathological examination of thrombi shows a very high platelet and a very low erythrocyte composition. Patients with cancer-associated stroke have high risks of mortality and recurrent stroke. However, limited data are available on the optimal treatment regimen for stroke prevention in these patients. Thrombosis mechanism in cancer is well understood, and distinct therapeutic targets involving thrombin and platelets have been identified. Therefore, direct thrombin inhibitors and/or antiplatelet agents may effectively prevent stroke recurrence. Additionally, this strategy has potential benefits in cancer treatment as accumulating evidence suggests that aspirin use reduces cancer progression, metastasis, and cancer-related mortality. However, clinical trials are necessary to assess the efficacy of this strategy involving the use of direct thrombin inhibitors and/or antiplatelet therapies.

The pathogenesis of cancer-associated thrombosis

Patients with cancer have a higher risk of venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), compared to the general population. Cancer-associated thrombosis (CAT) is a thrombotic event that occurs as a complication of cancer or cancer therapy. Major factors determining VTE risk in cancer patients include not only treatment history and patient characteristics, but also cancer type and site. Cancer types can be broadly divided into three groups based on VTE risk: high risk (pancreatic, ovarian, brain, stomach, gynecologic, and hematologic), intermediate risk (colon and lung), and low risk (breast and prostate). This implies that the mechanism of VTE differs between cancer types and that specific VTE pathways may exist for different cancer types. This review summarizes the specific pathways that contribute to VTE in cancer patients, with a particular focus on leukocytosis, neutrophil extracellular traps (NETs), tissue factor (TF), thrombocytosis, podoplanin (PDPN), plasminogen activator inhibitor-1 (PAI-1), the intrinsic coagulation pathway, and von Willebrand factor (VWF).

Venous Thromboembolism in Peritoneal Mesothelioma: Uncovering the Hidden Risk

INTRODUCTION

Venous thromboembolism (VTE) is a common complication in patients with abdominal malignancies. Despite known associations between pleural mesothelioma and increased VTE risk, the characteristics of VTE in patients with peritoneal mesothelioma (PeM) remain undescribed.

METHODS

Patients treated for PeM were retrospectively identified from our institutional database. The frequency of VTE was assessed and logistic regression modeling was employed to assess VTE risk factors. The association between VTE and overall survival was also ascertained. Recommended thromboprophylaxis for patients who underwent surgery at our institution comprised a single preoperative dose of prophylactic anticoagulation, followed by daily dosing for four weeks postoperatively.

RESULTS

Among 120 PeM patients, 26 (21.7%) experienced VTE, including 19/91 (20.9%) surgical patients, 4/23 (17.4%) patients who received systemic therapy, and 3/6 (50%) patients who underwent observation (p = 0.21). Most events were symptomatic (n = 16, 62%) and were attributable to pulmonary emboli (n = 16, 62%). The 90-day postoperative VTE rate was 4.4% (4/91), including 1 of 60 patients who underwent index surgical intervention at our institution and 3 patients with surgery elsewhere. A low serum albumin concentration was associated with VTE in non-surgical patients (odds ratio 0.12, confidence interval [CI] 0.02-0.72; p = 0.03). No significant difference in overall survival was observed between patients with and without VTE (median 46.0 months [CI 24.9-67.0] vs. 55.0 months [CI 27.5-82.5]; hazard ratio 0.98 [CI 0.54-1.81], p = 0.98).

CONCLUSIONS

A high risk of VTE was observed in PeM patients, warranting suspicion throughout the disease trajectory. Postoperative VTE rates were within acceptable limits with 4-week thromboprophylaxis.

Platelet Parameters as Biomarkers for Thrombosis Risk in Cancer: A Systematic Review and Meta-analysis

Cancer-associated thrombosis (CAT) is a major cause of both morbidity and mortality in cancer patients. Platelet count has been investigated as a predictor of CAT in various settings while knowledge on platelet activation parameters is sparse. This report provides a systematic review and meta-analysis on available literature on associations between platelet count and/or function and arterial and venous thrombosis in adult cancer patients. The review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. PubMed and Embase were searched up to March 2022. The National Heart, Lung, and Blood Institute's tools were used for quality assessment. In total, 100 studies were included which investigated the association between CAT and platelet count (n = 90), platelet indices (n = 19), and platelet function/activation markers (n = 13) in patients with solid cancers (n = 61), hematological cancers (n = 17), or mixed cancer types (n = 22). Eighty-one studies had venous thrombosis as their outcome measure, while 4 had arterial thrombosis and 15 studies had both. We found significantly elevated odds ratio of 1.50 (95% confidence interval: 1.19-1.88) for thrombosis with higher platelet counts. We saw a tendency toward an association between markers of platelet activation in forms of mean platelet volume and soluble P selectin and both arterial and venous thrombosis. Only one study investigated dynamic platelet function using flow cytometry. In conclusion, platelet count is associated with CAT across different cancer types and settings. Platelet function or activation marker analysis may be valuable in assisting thrombosis risk assessment in cancer patients but is sparsely investigated so far.

KRAS-mutant colorectal cancer cell lines cause a prothrombotic state through the upregulation of thrombin: experimental study

Background

The KRAS genotype status is strongly associated with a prothrombotic state in colorectal cancer, and hypercoagulability and cancer-related thrombosis are among the significant events leading to poor prognosis. However, this correlation has not been confirmed at the cellular level. This study aimed to assess the maximum platelet aggregation rate and thrombin expression induced by colorectal cancer cells under different KRAS genotypes.

Materials and methods

Platelet aggregation rate assay and western blotting analysis were used to detect platelet aggregation and thrombin expression induced by four colorectal cancer cells with different KRAS genotypes, including RKO, HCT116, SW480, and SW620. FVIIa/tissue factor and thrombin inhibitors were added to explore changes in platelet aggregation rates induced by colorectal cancer cells and the association between KRAS genotype status and hypercoagulable state.

Results

KRAS-mutant cells were more likely to increase maximal platelet aggregation, with RKO, HCT116, SW480, and SW620 inducing 34.7%, 55.4%, 44.4%, and 63.8% of platelet aggregation, respectively. The maximum platelet aggregation rate was higher in the metastatic rectal cancer tumour strain SW620 than in the primary rectal cancer strain SW480. RKO cells had lower thrombin expression than the other three cells. Furthermore, the addition of thrombin inhibitors caused a more significant decrease in the platelet aggregation rate in KRAS-mutant cell lines compared to KRAS wild-type cell lines.

Conclusion

Compared to KRAS wild-type colorectal cancer cells, KRAS-mutant colorectal cancer cell lines were more likely to be hypercoagulable through the upregulation of thrombin expression, which was mainly achieved through the TF-thrombin pathway.

The combined detection of hematological indicators is used for the differential diagnosis of colorectal cancer and benign-colorectal lesions

OBJECTIVE

This article aims to investigate the clinical value of hemoglobin/red cell distribution width ratio (Hb/RDW), C-reactive protein/albumin ratio (CAR) and plateletcrit (PCT) combined with carcinoembryonic antigen (CEA) in colorectal cancer (CRC) auxiliary diagnosis.

METHODS

We retrospectively analyzed in 718 subjects (212 with CRC, 209 with benign colorectal lesions (BCL), 111 with other cancers, and 186 healthy controls).

RESULTS

The CAR, PCT, and CEA in the CRC group were higher than those in the BCL, other cancers, and the healthy control group. However, Hb/RDW in the CRC group was lower than the other three groups. Moreover, there were significant differences in Hb/RDW and CEA among different T-N-M stages (all P< 0.05). Multivariate logistic regression showed that low level of Hb/RDW and high level of CAR, CEA, PCT were risk factors for CRC, and are correlated with CRC stage. Additionally, the area under the receiver operating characteristic curve (AUC) of Hb/RDW+CEA (AUC: 0.735), CAR+CEA (AUC: 0.748), PCT+CEA (AUC: 0.807) was larger than that of Hb/RDW (AUC: 0.503), CAR (AUC: 0.614), or PCT (AUC: 0.713) alone (all P< 0.001) in distinguishing CRC from BCL.

CONCLUSIONS

Hb/RDW, CAR, PCT, and CEA are independent risk factors for CRC. Hb/RDW, CAR, and PCT combined with CEA have significant value for auxiliary differential diagnosis of CRC and BCL.

The Role of Injectables in the Treatment and Prevention of Cancer-Associated Thrombosis

Cancer-associated thrombosis (CAT) is a leading cause of death among patients with cancer. CAT can manifest itself as venous thromboembolism (VTE), in the form of deep vein thrombosis or pulmonary embolism, or arterial thromboembolism. The pathophysiology of CAT is complex and depends on cancer-, patient-, treatment- and biomarkers-related factors. Treatment of VTE in patients with cancer is complex and includes three major classes of anticoagulant agents: heparin and its derivatives, e.g., low molecular weight heparins, direct oral anticoagulants (DOACs), and vitamin K inhibitors. Given the tremendous heterogeneity of clinical situations in patients with cancer and the challenges of CAT, there is no single universal treatment option for patients suffering from or at risk of CAT. Initial studies suggested that patients seemed to prefer an anticoagulant that would not interfere with their cancer treatment, suggesting the primacy of cancer over VTE, and favoring efficacy and safety over convenience of route of administration. Recent studies show that when the efficacy and safety aspects are similar, patients prefer the oral route of administration. Despite this, injectables are a valid option for many patients with cancer.

Platelets as a prognostic factor for patients with adenocarcinoma of the gastroesophageal junction

OBJECTIVE

The aim of this study was to investigate the prognostic role of plasma platelet count (PLT), mean platelet volume (MPV), and the combined COP-MPV score in patients with resectable adenocarcinomas of the gastroesophageal junction.

BACKGROUND

Platelet activation, quantified by PLT and elevated MPV, plays an essential part in the biological process of carcinogenesis and metastasis. An increased preoperative COP-MPV is associated with poor survival in various tumor entities.

METHODS

Data of 265 patients undergoing surgical resection for adenocarcinoma of the gastroesophageal junction were abstracted. COP-MPV score was defined for each patient. Utilizing univariate and multivariate Cox proportional hazard analyses, survival was determined.

RESULTS

In univariate analysis, elevated PLT (HR 3.58, 95% CI 2.61-4.80, p<0.001) and increased COP-MPV (HR 0.27, 95% CI 0.17-0.42, p<0.001 and HR 0.42, 95% CI 0.29-0.60, p<0.001) significantly correlated with shorter patients' overall and disease-free survival, for all 256 patients, as well as in the subgroups of neoadjuvantly treated (p<0.001) and primarily resected patients (p<0.001). COP-MPV remained a significant prognostic factor in multivariate analysis for OS. However, PLT alone showed significant diminished OS and DFS in all subgroups (p<0.001) in univariate and multivariate analysis.

CONCLUSION

PLT is a potent independent prognostic biomarker for survival in a large prospective cohort of patients with resectable adenocarcinoma of the gastroesophageal junction. Additionally, we confirm that the COP-MPV score is significantly associated with worse outcome in these patients, but has no benefit in comparison to PLT.

Establishment and Validation of a Postoperative VTE Prediction Model in Patients with Colorectal Cancer Undergoing Radical Resection: CRSPOT Nomogram

Venous thromboembolism (VTE) is a life-threatening postoperative complication of malignant tumors. We identified risk factors for postoperative VTE in patients undergoing radical resection of colorectal cancer (CRC) and constructed and validated a clinical prediction model. Clinical data of 982 patients undergoing radical resection of CRC from September 1, 2020, to March 31, 2022, in Ningxia Medical University General Hospital were analyzed retrospectively. Patients were randomly divided into training (n = 617) and validation groups (n = 264). Data included baseline characteristics, preoperative complications, examination results, and intraoperative and postoperative indicators. Logistic regression analysis was used to determine risk factors, build a predictive model, and draw a predictive nomogram (CRSPOT). Receiver operating characteristics (ROC) curve was used to calculate the area under the curve (AUC) for evaluating the model's predictive ability. Independent risk factors for postoperative VTE were as follows: postoperative hemoglobin of <10 g/L (odds ratio [OR] 0.413, 95% confidence interval [CI] 0.220-0.777), postoperative D-dimer of ≥3.5μg/mL (OR 2.156, 95% CI 1.145-4.061), BMI of ≥25 kg/m2 (OR 2.313, 95% CI 1.225-4.369), operation time of ≥4 h (OR 2.292, 95% CI 1.232-4.262), lower extremity varicose veins (OR 4.499, 95% CI 1.764-11.476), postoperative ileus (OR 5.760, 95% CI 2.031-16.337), and postoperative hypoxemia (OR 9.230, 95% CI 4.562-18.672). The nomogram's AUC was 0.826, demonstrating a reliable predictive ability. The CRSPOT nomogram reliably predicts postoperative VTE in patients undergoing radical resection of CRC, identifying high-risk patients early, allowing early implementation of antithrombotic strategies, and helping to reduce the incidence and mortality of postoperative VTE.

Trends and Risk Factors for Venous Thromboembolism Among Hospitalized Medical Patients

IMPORTANCE

While hospital-associated venous thromboembolism (HA-VTE) is a known complication of hospitalization, contemporary incidence and outcomes data are scarce and methodologically contested.

OBJECTIVE

To define and validate an automated electronic health record (EHR)-based algorithm for retrospective detection of HA-VTE and examine contemporary HA-VTE incidence, previously reported risk factors, and outcomes.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study was conducted using hospital admissions between January 1, 2013, and June 30, 2021, with follow-up until December 31, 2021. All medical (non-intensive care unit) admissions at an integrated health care delivery system with 21 hospitals in Northern California during the study period were included. Data were analyzed from January to June 2022.

EXPOSURES

Previously reported risk factors associated with HA-VTE and administration of pharmacological prophylaxis were evaluated as factors associated with HA-VTE.

MAIN OUTCOMES AND MEASURES

Yearly incidence rates and timing of HA-VTE events overall and by subtype (deep vein thrombosis, pulmonary embolism, both, or unknown), as well as readmissions and mortality rates.

RESULTS

Among 1 112 014 hospitalizations involving 529 492 patients (268 797 [50.8%] women; 75 238 Asian [14.2%], 52 697 Black [10.0%], 79 398 Hispanic [15.0%], and 307 439 non-Hispanic White [58.1%]; median [IQR] age, 67.0 [54.0-79.0] years), there were 13 843 HA-VTE events (1.2% of admissions) occurring in 10 410 patients (2.0%). HA-VTE events increased from 307 of 29 095 hospitalizations (1.1%) in the first quarter of 2013 to 551 of 33 729 hospitalizations (1.6%) in the first quarter of 2021. Among all HA-VTE events, 10 746 events (77.6%) were first noted after discharge. In multivariable analyses, several factors were associated with increased odds of HA-VTE, including active cancer (adjusted odds ratio [aOR], 1.96; 95% CI, 1.85-2.08), prior VTE (aOR, 1.71; 95% CI, 1.63-1.79), and reduced mobility (aOR, 1.63; 95% CI, 1.50-1.77). Factors associated with decreased likelihood of HA-VTE included Asian race (vs non-Hispanic White: aOR, 0.65; 95% CI, 0.61-0.69), current admission for suspected stroke (aOR, 0.73; 95% CI, 0.65-0.81), and Hispanic ethnicity (vs non-Hispanic White: aOR, 0.81; 95% CI, 0.77-0.86). HA-VTE events were associated with increased risk of readmission (hazard ratio [HR], 3.33; 95% CI, 3.25-3.41) and mortality (HR, 1.63; 95% CI, 1.57-1.70).

CONCLUSIONS AND RELEVANCE

This study found that HA-VTE events occurred in 1.2% of medical admissions, increased over time, and were associated with increased adverse outcomes. These findings suggest that approaches designed to mitigate occurrence and outcomes associated with HA-VTE may remain needed.

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.

Venous Thromboembolism and Cancer: A Comprehensive Review from Pathophysiology to Novel Treatment

Acute thrombotic events can unveil occult cancer, as they are its first manifestation in about 20 to 30% of all cases. Malignancy interacts in an intricate way with the hemostatic system, promoting both thrombosis and bleeding. The main pathway involved in these reactions involves the activation of tumor-associated procoagulant factors, which eventually results in clot formation. The clinical manifestation of cancer-related thrombotic events mainly involves the venous side, and manifests in a broad spectrum of conditions, including unusual sites of venous thrombosis. The selection of patients who have a balanced risk–benefit profile for management of anticoagulation is complex, given individual patient goals and preferences, different prognosis of specific cancers, common comorbidities, potential drug–drug interactions, underweight states, and the competing risks of morbidity and mortality. Anticoagulant treatment in cancer settings is broadly debated, considering the potential application of direct oral anticoagulants in both thromboprophylaxis and secondary prevention, having demonstrated its efficacy and safety compared to conventional treatment. This review aims to provide a brief overview of the pathophysiology and management of cancer-related thrombosis, summarizing the results obtained in recent clinical trials.

Prognostic Significance of Platelet (PLT) and Platelet to Mean Platelet Volume (PLT/MPV) Ratio During Apatinib Second-Line or Late-Line Treatment in Advanced Esophageal Squamous Cell Carcinoma Patients

Background: Apatinib has a certain efficacy for advanced esophageal squamous cell carcinoma (ESCC). This study aimed to investigate the prognostic significance of platelet (PLT) and platelet to mean platelet volume (PLT/MPV) ratio for advanced ESCC patients with apatinib second-line or late-line treatment. Methods: A retrospective study included 80 patients with advanced ESCC who received Apatinib ≥ 2 lines targeted therapy. We collected baseline clinical characteristics and blood parameters from the patients. Kaplan-Meier plots and univariate and multivariate analysis were used to find the factors related to progression-free survival (PFS). Results: The optimal cut-off values of PLT and PLT/MPV ratio were determined by X-tile software. Kaplan-Meier analysis demonstrated that patients in the high PLT group had better PFS than those in the low PLT group (156 d vs 80 d, P <.001), and patients in the high PLT/MPV ratio group had better PFS than those in low PLT/MPV ratio group (157 d vs 85 d, P <.001). Univariate analysis revealed pretreatment PLT and PLT/MPV ratio were significantly correlated with PFS. Multivariate analysis revealed high levels of pretreatment PLT/MPV ratio was an independent predictor of longer PFS (HR: 0.257, 95% CI: 0.089-0.743, P = .012). Conclusion: High levels of baseline PLT and PLT/MPV may indicate a better prognosis in apatinib ≥ 2 lines treatment for advanced ESCC patients.

Arterial Thrombosis in Cancer Patients: An Update

Cancer is associated with an increased incidence of both venous thromboembolism (VTE) and arterial thrombosis (cardiovascular events and ischemic stroke). Cancer-associated arterial thrombotic events are less well studied than VTE, but increasingly recognized, particularly in specific malignancies and in association with specific anticancer therapies. The pathogenesis of arterial thrombotic events in cancer is complex and involves generation of tumor-associated procoagulant factors and a variety of alterations in platelet function as well as in the coagulation and fibrinolytic systems, and endothelial injury and dysfunction, that combine to produce hypercoagulability. The multifactorial interaction between this prothrombotic state, the individual cardiovascular risk, advanced age and presence of comorbidities, and the specific neoplasm characteristics and therapy, may induce the vascular events. Recent studies based on population databases and prospective or retrospective analyses with prolonged follow-up highlight that cancer patients experience an increased (approximately 1.5-2-fold) risk of both cerebrovascular and cardiovascular events compared with noncancer individuals, which peaks in the time period of the diagnosis of cancer but may persist for years. Beyond the type of cancer, the risk reflects the tumor burden, being higher in advanced stages and metastatic cancers. The occurrence of arterial thromboembolic events is also associated with increased overall mortality. We here present an update of the pathophysiology, risk factors, clinical evidence, and treatment considerations on cancer-associated arterial thrombosis, in the light of the need for specific multidisciplinary prevention and surveillance strategies in this setting, in the frame of cardio-oncology approaches.

Cardiac metastasis causes paradoxical malignant embolism

Background

Embolic events play an important role in clinical everyday practice. Malignant arterial embolism is a rare nevertheless often fatal entity for cardiac, cerebral or systemic ischemia, requiring immediate diagnosis and treatment.

Case

This is a case report of a 65 years‐old female, suffering from pulmonal adenocarcinoma, who was hospitalized due to neurological deficits caused by an acute ischemic stroke, followed by anterior myocardial infarction within 3 days. Diagnostic work‐up revealed metastasis of the pulmonal adenocarcinoma in the right atrium and a patent foramen ovale. Histopathological examination of the coronary embolus verified paradoxical arterial embolism of the pulmonal adenocarcinoma into a coronary vessel and consequently cerebral arteries.

Conclusion

The present case underlines the need for (i), consideration of malignant embolism, (ii) histopathological examination of the embolus to determine its etiology, and (iii) interdisciplinary discussion of individual therapeutic and prevention strategies in cancer patients with cerebral, cardiac or systemic embolic events.

The Value of Detecting Pathological Changes During Clot Formation in Early Disease Treatment-Naïve Breast Cancer Patients

Breast cancer (BC) is one of the most prevalent forms of cancer in women worldwide. Clinical research indicates that BC patients are at an increased risk for thrombotic events, drastically decreasing their quality-of-life and treatment outcomes. There is ample evidence of this in the literature, but it is mainly focused on metastatic BC. Therefore, coagulopathies of nonmetastatic BC are understudied and require in-depth investigation. In this study, clot kinetics and ultrastructure were used to investigate treatment-naïve, nonmetastatic BC patients using scanning electron microscopy, Thromboelastography®, and confocal laser scanning microscopy. It was demonstrated that nonmetastatic BC patients exhibit minimal ultrastructural alterations of the clot components and no changes in the clot kinetics. However, BC patients presented changes to fibrinogen protein structure, compared to matched controls, using an amyloid-selective stain. Together, these findings suggest that coagulation dysfunction(s) in BC patients with early disease manifest at the microlevel, rather than the macrolevel. This study presents novel insights to a method that are more sensitive to coagulation changes in this specific patient group, emphasizing that the coagulation system may react in different forms to the disease, depending on the progression of the disease itself.

Roles of microRNA-186 and vascular endothelial growth factor in hepatocellular carcinoma complicated with portal vein tumor thrombus

The present study aims to investigate the role and underlying mechanism of microRNA (miR)-186 in patients with hepatocellular carcinoma (HCC) complicated with portal vein tumor thrombus. Blood samples from 29 HCC patients with portal vein tumor thrombus were collected between January 2014 and September 2015 in Huai'an First People's Hospital, while blood from 36 HCC patients without vein tumor thrombus was also collected in the same period. In addition, tumor thrombus specimens were collected from the HCC patients with portal vein tumor thrombus, and peritumoral tissues of the tumor thrombus were used as the control. Reverse transcription-quantitative polymerase chain reaction, ELISA and western blot analyses were applied to detect vascular endothelial growth factor (VEGF) expression at the mRNA and protein levels. Bioinformatics prediction was used to predict the target of miR-186, and then miR-186 expression was detected. Furthermore, dual-luciferase reporter assay was used to validate whether miR-186 directly targeted VEGF. Following transfection with agomiR-186, the expression levels of miR-186 and VEGF were detected, while MTT assay was used to detect EA.hy926 cell proliferation subsequent to small interfering RNA (siRNA) silencing. The results identified that VEGF was significantly increased in the tumor thrombus and blood samples of HCC patients with vein tumor thrombus at the mRNA and protein levels, while miR-186 expression was significantly decreased (P<0.05). Following silencing VEGF by siRNA transfection, the proliferation of EA.hy926 cells was inhibited. In addition, VEGF expression was significantly decreased and cell proliferation was reduced when upregulating miR-186. Dual-luciferase reporter assay demonstrated that miR-186 regulated VEGF expression through complementary binding to 3'-untranslated region. In conclusion, VEGF was significantly increased in tumor thrombus and blood samples from HCC patients with vein tumor thrombus, which may be associated with the downregulation of miR-186. Thus, miR-186 may promote the development and progression of vein tumor thrombus in HCC.

Molecular Requirements for the Expression of Antiplatelet Effects by Synthetic Structural Optimized Analogues of the Anticancer Drugs Imatinib and Nilotinib

Background

Platelets play important roles in cancer progression and metastasis, as well as in cancer-associated thrombosis (CAT). Tyrosine kinases are implicated in several intracellular signaling pathways involved in tumor biology, thus tyrosine kinase inhibitors (TKIs) represent an important class of anticancer drugs, based on the concept of targeted therapy.

Purpose

The objective of this study is the design and synthesis of analogues of the TKIs imatinib and nilotinib in order to develop tyrosine kinase inhibitors, by investigating their molecular requirements, which would express antiplatelet properties.

Methods

Based on a recently described by us improved approach in the preparation of imatinib and/or nilotinib analogues, we designed and synthesized in five-step reaction sequences, 8 analogues of imatinib (I-IV), nilotinib (V, VI) and imatinib/nilotinib (VII, VIII). Their inhibitory effects on platelet aggregation and P-selectin membrane expression induced by arachidonic acid (AA), adenosine diphosphate (ADP) and thrombin receptor activating peptide-6 (TRAP-6), in vitro, were studied. Molecular docking studies and calculations were also performed.

Results

The novel analogues V-VIII were well established with the aid of spectroscopic methods. Imatinib and nilotinib inhibited AA-induced platelet aggregation, exhibiting IC₅₀ values of 13.30 μΜ and 3.91 μΜ, respectively. Analogues I and II exhibited an improved inhibitory activity compared with imatinib. Among the nilotinib analogues, V exhibited a 9-fold higher activity than nilotinib. All compounds were less efficient in inhibiting platelet aggregation towards ADP and TRAP-6. Similar results were obtained for the membrane expression of P-selectin. Molecular docking studies showed that the improved antiplatelet activity of nilotinib analogue V is primarily attributed to the number and the strength of hydrogen bonds.

Conclusion

Our results show that there is considerable potential to develop synthetic analogues of imatinib and nilotinib, as TKIs with antiplatelet properties and therefore being suitable to target cancer progression and metastasis, as well as CAT by inhibiting platelet activation.

Risk factors of catheter-related thrombosis in early-stage breast cancer patients: a single-center retrospective study

Purpose

Totally implantable venous access devices (TIVADs) are widely used in cancer patients. The main purpose of our study is to observe the incidence and identified risk factors of catheter-related thrombosis (CRT) in breast cancer patients with TIVAD.

Patients and methods

We performed a retrospective cohort study of consecutive breast cancer patients who received the ultrasound-guided TIVAD implantation for the administration of chemotherapy from 2013 to 2016. The primary outcome was CRT (both symptomatic and asymptomatic detected by ultrasound). Univariable and multivariable logistic regression analyses were used to identify the risk factors for breast cancer TIVAD-related CRT.

Results

A total of 209 breast cancer patients with a newly implanted TIVAD for chemotherapy were included in this study. The average time of port duration was 7 months. Of the enrolled 209 patients, 33 patients (15.8%) had CRT, 2 of the 33 cases were symptomatic (1 pulmonary embolism, 1 deep-venous thrombosis [DVT]), the other 31 cases were asymptomatic detected by routine ultrasound examination of the catheter-associated vein before TIVAD removal with all cycles of chemotherapy completed. In total, 19 (57.6%) of CRT patients underwent directly TIVAD removal without any further treatments, 14 patients received anticoagulation treatments for 3–30 days followed by TIVAD removal. No DVT event was observed within at least 1.5 years of follow-up. In the multiple-variable analysis, tumor size >2 cm (OR 2.735, 95% CI 1.042–7.177; P=0.032), positive HbsAg (OR 2.803 95% CI 1.027–7.856; P=0.047) and low-density lipoprotein (LDL) >3.6 mmol/L (OR 2.360, 95% CI 1.059–5.351; P=0.040) were the significant independent risk factors of breast cancer TIVAD-related CRT.

Conclusion

CRT is a common complication in breast cancer patients with TIVAD for chemotherapy. Tumor size, HbsAg status and LDL level were independent predictors of breast cancer for TIVAD-related CRT. Removal of the port without anticoagulation treatments might be a feasible choice for asymptomatic TIVAD-related CRT.

Influence of Tumor Thrombus on Occurrence of Distant Venous Thromboembolism and Survival in Patients With Renal Cell Carcinoma After Surgery

Tumor thrombus is a unique characteristic of renal cell carcinoma (RCC). However, only a few studies have reported its clinical influence on the occurrence of venous thromboembolism (VTE). This study aimed to clarify the influence of tumor thrombus and other risk factors for VTE and to elucidate the impact of tumor thrombus on survival outcomes. We retrospectively reviewed data from patients with RCC who underwent radical or partial nephrectomy from September 1999 to August 2015 at Seoul National University Hospital. A total of 2762 patients were enrolled. The 1- and 5-year cumulative incidences of VTE were 0.5% ± 0.1% and 1.5% ± 0.3%, respectively. During a median follow-up of 39.0 months (95% confidence interval [CI], 37.1-41.0 months), deep vein thrombosis occurred in 13 patients and pulmonary embolism in 15 patients. Patients with tumor thrombus (diagnosed by surgical pathology findings) had a significantly higher incidence of VTE than those without thrombus (odds radio 8.160, 95% CI, 1.480-45.004). Older age (≥60 years) and higher preoperative C-reactive protein (>0.5 mg/dL) were also significant risk factors for VTE. Additionally, tumor thrombus was independently associated with worse progression-free survival (PFS) but not with overall survival (OS) in multivariable analysis (hazard ratio [HR] 1.916, 95% CI, 1.295-2.834 for PFS; HR 1.164, 95% CI, 0.755-1.793 for OS). In conclusion, the incidence of VTE was relatively low in patients who underwent surgery for RCC. Nevertheless, patients with tumor thrombus had an increased risk of VTE and should be closely monitored for VTE.

Hematological Malignancies and Arterial Thromboembolism

Established guidelines exist for prevention and treatment of venous thromboembolism in hematological malignancies, but none for arterial thromboembolism. However, arterial and venous thromboembolism share the same provoking features—including altered procoagulant factors and defective fibrinolytic system. The morbidity for arterial thromboembolism is increasing in hematological malignancies, with the advent of immunomodulatory and targeted therapy. However, survival rate for hematological malignancy is improving. Consequently, as patients with hematological malignancies live longer, comorbidities including diabetes, hypertension and dyslipidemia, may accentuate arterial thrombosis. Thus far, the scientific literature on prophylaxis and treatment for arterial thromboembolism in hematological malignancies is limited. This review highlights the pathogenesis, incidence and clinical features of arterial thromboembolism in hematological malignancies.

Biomarkers of Cancer-Associated Thromboembolism

Venous thromboembolism is known to be associated with an increase in morbidity and mortality in patients with malignancy. Predictive laboratory biomarkers of venous thromboembolism (VTE) have long been sought after to improve outcomes and help guide clinical decision making. Previously studied biomarkers include C reactive protein (CRP), tissue factor expressing microparticles (TF MP), D-dimer, soluble P-selectin (sP-selectin), plasminogen activator inhibitor 1 (PAI-1), factor VIII, platelet count, and leukocyte counts. This chapter will focus on these possible biomarkers for cancer-associated thrombosis (CAT) with particular emphasis on the pathophysiology behind thrombosis formation as well as data from clinical studies in patients with malignancy. The incorporation of the above biomarkers into risk assessment tools to predict CAT will also be reviewed, as will risk factors for recurrent VTE in patients with malignancy. Further studies are ongoing to develop readily available biomarkers that can be incorporated into future risk assessment models with the goal of reducing morbidity and mortality due to cancer-associated thrombosis.

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).

The role of coagulation and platelets in colon cancer-associated thrombosis

Cancer-associated thrombosis is a common first presenting sign of malignancy and is currently the second leading cause of death in cancer patients after their malignancy. However, the molecular mechanisms underlying cancer-associated thrombosis remain undefined. In this study, we aimed to develop a better understanding of how cancer cells affect the coagulation cascade and platelet activation to induce a prothrombotic phenotype. Our results show that colon cancer cells trigger platelet activation in a manner dependent on cancer cell tissue factor (TF) expression, thrombin generation, activation of the protease-activated receptor 4 (PAR4) on platelets and consequent release of ADP and thromboxane A2. Platelet-colon cancer cell interactions potentiated the release of platelet-derived extracellular vesicles (EVs) rather than cancer cell-derived EVs. Our data show that single colon cancer cells were capable of recruiting and activating platelets and generating fibrin in plasma under shear flow. Finally, in a retrospective analysis of colon cancer patients, we found that the number of venous thromboembolism events was 4.5 times higher in colon cancer patients than in a control population. In conclusion, our data suggest that platelet-cancer cell interactions and perhaps platelet procoagulant EVs may contribute to the prothrombotic phenotype of colon cancer patients. Our work may provide rationale for targeting platelet-cancer cell interactions with PAR4 antagonists together with aspirin and/or ADP receptor antagonists as a potential intervention to limit cancer-associated thrombosis, balancing safety with efficacy.

Arterial thrombosis and cancer

Cancer-associated arterial thrombotic events (ATEs) are increasingly recognized in specific malignancies and in association with the expanding armamentarium of novel chemotherapeutic agents. The improved cancer survival led to cardiovascular complications becoming clinically relevant many years after cancer diagnosis. The pathobiology of ATEs in cancer is complex and the individual patient risk for an ATE entails a multifactorial interaction between the traditional cardiovascular risk factors and comorbidities, the specific malignancy and selected therapy. Treatment with several specific chemotherapeutic agents, immunomodulatory drugs, vascular endothelial growth factor pathway inhibitors, tyrosine kinase inhibitors, and radiotherapy, impart increased risk for ATEs that result from specific therapy-related mechanisms, often involving endothelial injury. Cancer cell-specific prothrombotic properties are important players in the pathogenesis of cancer-associated hypercoagulability. There are distinct biological and molecular processes preferentially activated in specific cancer cells which can trigger ATEs, including platelet activation, increased expression of procoagulants and suppression of fibrinolytic activity. ATEs portend adverse prognosis in cancer patients. Prevention and treatment of cancer-associated ATEs may be improved by greater awareness and careful monitoring for vascular toxicity, aggressive effort to optimize conventional cardiovascular risk factors, and use of antiplatelet and antithrombotic agents in selected patients. These issues are targets for future studies aimed to reduce ATEs in patients with cancer.

The role of Mean Platelet Volume/platelet count Ratio and Neutrophil to Lymphocyte Ratio on the risk of Febrile Seizure

Systemic inflammatory response has been implicated as a contributor to the onset of febrile seizures (FS). The four novel indices of the inflammatory response such as, neutrophil-to-lymphocyte ratio (NLR), mean platelet volume (MPV), platelet count (PLT) ratio and red blood cell distribution width (RDW) have been investigated in FS susceptibility and FS types (simple febrile seizure and complex febrile seizure). However, the potential role of these inflammatory markers and MPV/PLT ratio (MPR) in Chinese children with FS has yet to be fully determined. This study investigated the relevance of NLR, MPV, PLT, MPR and RDW in febrile children with and without seizures. 249 children with FS and 249 age matched controls were included in this study. NLR and MPR were calculated from complete blood cell counts prior to therapy. Differences in age, gender and these inflammatory markers between the FS group and the control group were evaluated using the chi-square test, t-test or logistic regression analysis. Receiver Operating Characteristic (ROC) curve was used to determine the optimal cut-off value of NLR and MPR for FS risk. Interactions between NLR and MPR on the additive scale were calculated by using the relative excess risk due to interaction (RERI), the proportion attributable to interaction (AP), and the synergy index (S). It has been shown that the elevated NLR and MPR levels were associated with increased risk of FS. The optimal cut-off values of NLR and MPR for FS risk were 1.13 and 0.0335 with an area under the curve (AUC) of 0.768 and 0.689, respectively. Additionally, a significant synergistic interaction between NLR and MPR was found on an additive scale. The mean levels of MPV were lower and NLR levels were higher in complex febrile seizure (CFS) than simple febrile seizure (SFS), and the differences were statistically significant. ROC analysis showed that the optimal cut-off value for NLR was 2.549 with 65.9% sensitivity and 57.5% specificity. However, no statistically significant differences were found regarding average values of MPR and RDW between CFS and SFS. In conclusion, elevated NLR and MPR add evidence to the implication of white cells subsets in FS risk, and our results confirmed that NLR is an independent, albeit limited, predictor in differentiating between CFS and SFS. Moreover, NLR and MPR may have a synergistic effect that can influence the occurrence of FS.

Mean platelet volume as a predictive marker for venous thromboembolism in patients treated for Hodgkin lymphoma

Mean platelet volume (MPV) is reported to be associated with the risk of venous thromboembolism (VTE) and mortality in patients with cancer. We sought to determine the association of MPV with symptomatic VTE occurrence in patients treated for newly diagnosed Hodgkin lymphoma (HL) and their outcomes. We retrospectively studied 167 consecutive adult patients treated with HL. During first-line treatment 12 (7.2%) patients developed VTE and 14 (8%) died within the observation period. The pre-chemotherapy values of MPV were significantly lower in VTE patients than those without (p=0.0343). Patients with MPV≤25^th percentile (6.8 fl) had an increased risk of VTE occurrence (p=0.0244). In multivariate analysis, MPV≤25^th percentile (OR 2.21; 95%CI 1.07-4.57, p=0.033), advanced stage (OR 2.08; 95%CI 1.06-4.07, p=0.033) and bulky disease (OR 2.23; 95%CI 1.16-4.31, p=0.016) were significant factors for developing VTE. Only the impact of MPV≤25^th percentile on VTE-free survival rates was found. VTE occurred in 43% (n=3) of the high-risk patients of the Thrombosis Lymphoma (ThroLy) score and in 17% (n=2) of the high-risk of the Khorana Risk Score (KRS). Neither the KRS nor the ThroLy score could identify patients at a high risk of VTE with a high degree of accuracy. We expanded the ThroLy score with the addition of the MPV≤25^th percentile to more accurately identify HL patients with a higher risk of VTE. Our study indicates that the pre-chemotherapy MPV value, while of no use as an overall prognosis predictor, may still represent a useful prognostic marker for a significant VTE risk especially when incorporated into VTE-risk assessment models.

Induction of Apoptosis in Cancer Cells of pre-B ALL Patients after Exposure to Platelets, Platelet-Derived Microparticles and Soluble CD40 Ligand

Objective

The in vitro treatment of tumor cells with platelet (Plt) causes inhibition of tumor cell growth, although mechanism of this effect is not clear yet. Induction of apoptosis has been proposed as a mechanism of Plt effects on tumor cells. The purpose of this study was to clarify the role of Plts and Plt-derived components in the induction of apoptosis in the blood mononuclear cells of patients with leukemia.

Materials and Methods

In this experimental study, peripheral blood mononuclear cells (PBMCs) were isolated from whole blood of five patients with childhood B-precursor acute lymphoblastic leukemia (pre-B ALL) and encountered with Plts, Plt-derived microparticles (Plt-MPs) as well as purified soluble CD40L (sCD40L). After 48 hours of co-culture, the anti-cancer activity of the aforementioned factors was surveyed using examination of apoptosis markers of the cells including active caspase-3 and CD95 using ELISA and flow cytometer techniques, respectively. Additionally, staining of the cells with 7-Aminoactinomycin D (7-AAD) was evaluated by flow cytometer technique. Trypan blue exclusion test and WST-1 method were also used to compare the death/survival status of the cells.

Results

Levels of CD95 and caspase-3 were significantly increased in the all treated groups (P<0.05). On the other hand, trypan blue, 7-AAD and WST-1 methods showed significantly lower number of the live cells in the treated groups (P<0.05).

Conclusion

This study can show the ability of Plts, Plt-MPs and sCD40L for the induction of apoptosis in PBMCs of pre-B-ALL patients. Further studies are necessary to elucidate the different effects of platelets on cancer cells in vitro and in vivo.

Meta-analysis of individual patient safety data from six randomized, placebo-controlled trials with the antiangiogenic VEGFR2-binding monoclonal antibody ramucirumab

BACKGROUND

Ramucirumab, the human immunoglobulin G1 monoclonal antibody receptor antagonist of vascular endothelial growth factor receptor 2, has been approved for treating gastric/gastroesophageal junction, non-small-cell lung, and metastatic colorectal cancers. With the completion of six global, randomized, double-blind, placebo-controlled, phase III trials across multiple tumor types, an opportunity now exists to further establish the safety parameters of ramucirumab across a large patient population.

MATERIALS AND METHODS

An individual patient meta-analysis across the six completed phase III trials was conducted and the relative risk (RR) and associated 95% confidence intervals (CIs) were derived using fixed-effects or mixed-effects models for all-grade and high-grade adverse events (AEs) possibly related to vascular endothelial growth factor pathway inhibition. The number needed to harm was also calculable due to the placebo-controlled nature of all six registration standard trials.

RESULTS

A total of 4996 treated patients (N = 2748 in the ramucirumab arm and N = 2248 in the control, placebo arm) were included in this meta-analysis. Arterial thromboembolic events [ATE; all-grade, RR: 0.8, 95% CI 0.5-1.3; high-grade (grade ≥3), RR: 0.9, 95% CI 0.5-1.7], venous thromboembolic events (VTE; all-grade, RR: 0.7, 95% CI 0.5-1.1; high-grade, RR: 0.7, 95% CI 0.4-1.2), high-grade bleeding (RR: 1.1, 95% CI 0.8-1.5), and high-grade gastrointestinal (GI) bleeding (RR: 1.1, 95% CI 0.7-1.7) did not demonstrate a definite increased risk with ramucirumab. A higher percentage of hypertension, proteinuria, low-grade (grade 1-2) bleeding, GI perforation, infusion-related reaction, and wound-healing complications were observed in the ramucirumab arm compared with the control arm.

CONCLUSIONS

Ramucirumab may be distinct among antiangiogenic agents in terms of ATE, VTE, high-grade bleeding, or high-grade GI bleeding by showing no clear evidence for an increased risk of these AEs in this meta-analysis of a large and diverse patient population. Ramucirumab is consistent with other angiogenic inhibitors in the risk of developing certain AEs. Clinical Trial Numbers: NCT00917384 (REGARD), NCT01170663 (RAINBOW), NCT01168973 (REVEL), NCT01183780 (RAISE), NCT01140347 (REACH), and NCT00703326 (ROSE).

Count of platelet and mean platelet volume score: serologic prognostic factor in patients with oral squamous cell carcinoma

Objectives

TNM staging, especially for lymph node metastasis, is the scoring system most widely used among prognostic factors for cancer survival. Several biomarkers have been studied as serologic markers, but their specificity is low and clinical applications are difficult. This study aimed to establish a scoring system for patients with oral squamous cell carcinoma (OSCC) using platelet (PLT) and mean platelet volume (MPV) levels measured postoperatively and to evaluate their significance as prognostic factors.

Materials and Methods

We studied 40 patients admitted to the Department of Oral and Maxillofacial Surgery of Dankook University Hospital who were diagnosed with primary OSCC histopathologically between May 2006 and May 2012. Clinical pathological information obtained from the medical records of each patient included age, sex, height, weight, tumor location, degree of differentiation, tumor diameter, lymph node metastasis, TNM stage, and other test values including white blood cell, MPV, PLT, C-reactive protein (CRP), and albumin obtained through a test conducted within 7 days before surgery. Count of platelet (COP)-MPV Score: Patients with both PLT and MPV values below the cut-off values were defined as score 0 (group A). Patients with at least one of the two higher than the cut-off value were defined as score 1 (group B).

Results

Univariate analyses showed N-metastasis, COP-MPV (A vs B), PLT, platelet-lymphocyte ratio, and CRP were statistically significant prognostic factors. A multivariate Cox proportional hazards model showed N-metastasis (hazard ratio [HR] 6.227, P=0.016) and COP-MPV (A vs B) (HR 18.992, P=0.013) were independent prognostic factors with a significant effect on survival.

Conclusion

COP-MPV score is a simple and cost-effective test method and is considered a more effective prognostic factor than other considered factors in predicting the prognosis of OSCC patients.

Cancer-associated pathways and biomarkers of venous thrombosis

Cancer patients have an increased risk of venous thromboembolism (VTE). In this review, we summarize common and cancer type-specific pathways of VTE in cancer patients. Increased levels of leukocytes, platelets, and tissue factor-positive (TF⁺) microvesicles (MVs) are all potential factors that alone or in combination increase cancer-associated thrombosis. Patients with lung or colorectal cancer often exhibit leukocytosis. Neutrophils could increase VTE in cancer patients by releasing neutrophil extracellular traps whereas monocytes may express TF. Thrombocytosis is often observed in gastrointestinal, lung, breast, and ovarian cancer and this could decrease the threshold required for VTE. Soluble P-selectin has been identified as a biomarker of cancer-associated thrombosis in a general cancer population and may reflect activation of the endothelium. P-selectin expression by the endothelium may enhance VTE by increasing the recruitment of leukocytes. Studies in patients with pancreatic or brain cancer suggest that elevated levels of PAI-1 may contribute to VTE. Although elevated levels of TF⁺ MVs have been observed in patients with different types of cancer, an association between TF⁺ MVs and VTE has been observed only in pancreatic cancer. Podoplanin expression is associated with VTE in patients with brain cancer and may activate platelets. Future studies should measure multiple biomarkers in each cancer type to determine whether combinations of biomarkers can be used as predictors of VTE. A better understanding of the pathways that increase VTE in cancer patients may lead to the development of new therapies to reduce the morbidity and mortality associated with thrombosis.

Targeting Platelets for the Treatment of Cancer

The majority of cancer-associated mortality results from the ability of tumour cells to metastasise leading to multifunctional organ failure and death. Disseminated tumour cells in the blood circulation are faced with major challenges such as rheological shear stresses and cell-mediated cytotoxicity mediated by natural killer cells. Nevertheless, circulating tumour cells with metastatic ability appear equipped to exploit host cells to aid their survival. Despite the long interest in targeting tumour-associated host cells such as platelets for cancer treatment, the clinical benefit of this strategy is still under question. In this review, we provide a summary of the latest mechanistic and clinical evidence to evaluate the validity of targeting platelets in cancer.

Anticoagulation in combination with antiangiogenesis and chemotherapy for cancer patients: evidence and hypothesis

Hypercoagulable state and disorganized angiogenesis are two conspicuous characteristics during tumor progression. There are a considerable number of clinical trials focusing on the effects of anticoagulant and antiangiogenic drugs on the survival of cancer patients. Favorable outcomes have been observed. Excessive blood coagulation not only causes cancer-associated thrombosis, which is a common complication and is the second leading cause of death in patients, but also decreases intratumoral perfusion rates and drug delivery by reducing the effective cross-sectional area of blood vessels. Meanwhile, structural and functional abnormalities of the tumor microvasculature also compromise convective drug transport and create a hypoxic and acidic microenvironment. Vascular normalization strategy can temporarily recover the abnormal state of tumor vasculature by improving blood density, dilation, and leakiness, resulting in enhanced penetration of chemotherapies and oxygen within a short time window. In this article, we first review the evidence to support the opinion that anticoagulant and antiangiogenic therapy can improve cancer survival through several underlying mechanisms. Next, we speculate on the feasibility and value of the combined strategy and discuss whether such a combination has a synergistic antineoplastic effect in cancer patients by way of increasing blood vessel perfusion and drug distribution.

Combination of platelet count and mean platelet volume (COP-MPV) predicts postoperative prognosis in both resectable early and advanced stage esophageal squamous cell cancer patients

The aim of this study is to search the most powerful prognostic factor from routine blood test for esophageal squamous cell cancer (ESCC) patients. Multiple laboratory tests were evaluated including those reflecting red blood cell parameters (hemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), and red blood cell distribution width (RDW)), platelet morphological parameters (mean platelet volume (MPV) and platelet count (PLT)), blood coagulation status (D-dimer), and tumor biomarker (CA19-9). Known inflammatory indices (NLR and PLR) were also calculated. A total of 468 patients who were diagnosed with ESCC between December 2005 and December 2008 were retrospectively analyzed in this study. By utilizing univariate and multivariate Cox proportional hazard analyses, we found that PLT and MPV were significantly associated with overall survival (OS) and disease-free survival (DFS) of ESCC patients, with optimal cutoff values of 212 and 10.6, respectively. Moreover, the combination of the preoperative PLT and MPV (COP-MPV) was calculated as follows: patients with both PLT (≥212 × 10(9) L(-1)) and MPV (≥10.6 fL) elevation were assigned a score of 2, and patients with one or neither were assigned a score of 1 and 0. The COP-MPV was an independent prognostic factor for OS (hazard ratio (HR) 0.378, 95 % confidence interval (CI) 0.241 to 0.593, P < 0.001, 0/2) and DFS (HR 0.341, 95 % CI 0.218 to 0.534, P < 0.001, 0/2) in multivariate analyses. In subgroup analyses for early (stages I and II) and locally (stage III) advanced stage patients, COP-MPV was found significantly associated with OS and DFS in each group (P = 0.025 and P = 0.018 for OS and P = 0.029 and P = 0.002 for DFS). In conclusion, we considered that COP-MPV is a promising predictor for postoperative survival in ESCC patients.

NETosis promotes cancer-associated arterial microthrombosis presenting as ischemic stroke with troponin elevation

INTRODUCTION

Large elevations of high sensitive Troponin T (hsTnT) in ischemic stroke patients is associated with a poor outcome. In a pilot study we found a high prevalence of malignancies among these patients. Since neutrophil extracellular traps (NETs) have been linked to cancer-associated thrombosis, we hypothesized that the concomitant cerebral and myocardial ischemia could be the result of a NET-induced hypercoagulable state.

MATERIALS AND METHODS

Clinical assessments, plasma analyses and autopsies with histopathology (in cases of in-hospital mortality) were performed on ischemic stroke patients with high elevations of hsTnT (N=12) and normal hsTnT (N=19).

RESULTS

Patients with hsTnT elevation had an unexpectedly higher prevalence of cancer (p=0.002), half of which were diagnosed post-mortem. Autopsies of these patients revealed widespread myocardial, cerebral and pulmonary microthrombosis with H3Cit in thrombi. A pro-coagulant state and an increase of the NET specific marker citrullinated histone H3 (H3Cit) was found in plasma of patients with elevated hsTnT compared to patients with normal levels (p<0.001). Plasma analyses in cancer patients showed even higher H3Cit levels (p<0.001), and an increase in granulocyte colony-stimulating factor, known to prime neutrophils towards NETosis. H3Cit correlated positively with thrombin-antithrombin complex (p=0.004) and soluble P-selectin (p<0.001), further linking NETosis to the pro-thrombotic state.

CONCLUSIONS

The high prevalence of known or occult cancer in our study suggests that cancer-associated arterial microthrombosis may be underestimated. By linking the thrombosis to NETs, we suggest markers of NETosis that could aid in revealing cancer in arterial microthrombosis as well as arterial microthrombosis in cancer.

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

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS AND CONCLUSIONS

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

Venous thrombosis and cancer: from mouse models to clinical trials

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

Venous thromboembolism, interleukin-6 and survival outcomes in patients with advanced ovarian clear cell carcinoma

BACKGROUND

We compared survival outcomes and risk of venous thromboembolism (VTE) among patients with advanced and early-stage ovarian clear cell carcinoma (OCCC) and serous ovarian carcinoma (SOC), as well as potential links with interleukin-6 (IL-6) levels.

METHODS

A multicenter case-control study was conducted in 370 patients with OCCC and 938 with SOC. In a subset of 200 cases, pretreatment plasma IL-6 levels were examined.

FINDINGS

Patients with advanced OCCC had the highest 2-year cumulative VTE rates (advanced OCCC 43.1%, advanced SOC 16.2%, early-stage OCCC 11.9% and early-stage SOC 6.4%, P<0.0001) and the highest median levels of IL-6 (advanced OCCC 17.8 pg/mL, advanced SOC 9.0 pg/mL, early-stage OCCC 4.2 pg/mL and early-stage SOC 5.0 pg/mL, P=0.006). Advanced OCCC (hazard ratio [HR] 3.38, P<0.0001), thrombocytosis (HR 1.42, P=0.032) and elevated IL-6 (HR 8.90, P=0.046) were independent predictors of VTE. In multivariate analysis, patients with advanced OCCC had significantly poorer 5-year progression-free and overall survival rates than those with advanced SOC (P<0.01), and thrombocytosis was an independent predictor of decreased survival outcomes (P<0.01). Elevated IL-6 levels led to poorer 2-year progression-free survival rates in patients with OCCC (50% versus 87.5%, HR 4.89, P=0.016) than in those with SOC (24.9% versus 40.8%, HR 1.40, P=0.07).

INTERPRETATION

Advanced OCCC is associated with an increased incidence of VTE and decreased survival outcomes, which has major implications for clinical management of OCCC.

Venous thrombosis

Venous thromboembolism (VTE) encompasses deep-vein thrombosis (DVT) and pulmonary embolism. VTE is the leading cause of lost disability-adjusted life years and the third leading cause of cardiovascular death in the world. DVT leads to post-thrombotic syndrome, whereas pulmonary embolism can cause chronic pulmonary hypertension, both of which reduce quality of life. Genetic and acquired risk factors for thrombosis include non-O blood groups, factor V Leiden mutation, oral contraceptive use, hormone replacement therapy, advanced age, surgery, hospitalization and long-haul travel. A combination of blood stasis, plasma hypercoagulability and endothelial dysfunction is thought to trigger thrombosis, which starts most often in the valve pockets of large veins. Animal studies have revealed pathogenic roles for leukocytes, platelets, tissue factor-positive microvesicles, neutrophil extracellular traps and factors XI and XII. Diagnosis of VTE requires testing and exclusion of other pathologies, and typically involves laboratory measures (such as D-dimer) and diagnostic imaging. VTE is treated with anticoagulants and occasionally with thrombolytics to prevent thrombus extension and to reduce thrombus size. Anticoagulants are also used to reduce recurrence. New therapies with improved safety profiles are needed to prevent and treat venous thrombosis. For an illustrated summary of this Primer, visit: http://go.nature.com/8ZyCuY.

Risk factors for embolism in cardiac myxoma: a retrospective analysis

BACKGROUND

Myxomas are the most common primary heart tumors and are closely associated with embolic events. Cardiac myxomas typically arise from the interatrial septum at the border of the fossa ovalis in the left atrium. Any other location is considered atypical. Embolism, one of the complications of myxoma, is associated with high morbidity and mortality. The aim of this study was to investigate the risk factors for embolism in patients with cardiac myxoma.

MATERIAL AND METHODS

In this retrospective study, a cohort of 162 patients with cardiac myxomas was surgically treated between January 1998 and June 2014 at 3 cardiac centers in China. Preoperative data, including platelet count, sex, age, and the tumor (size, location, surface, and attachment), were compared between embolic and non-embolic groups of patients.

RESULTS

No significant differences in vascular risk factors were seen between the 2 groups. However, the percentage of higher platelet count (>300 × 10(9)/L) and mean platelet volume in the embolic group were significantly higher than in the non-embolic group (P=0.0356, and 0.0113, respectively). Irregular surface and atypical location of the myxomas were also independently associated with increased risk of embolic complications.

CONCLUSIONS

Tumor location, macroscopic appearance, mean platelet volume, and high platelet count are strong risk factors for embolic events in patients with cardiac myxomas.

Thromboembolic Events in Malignant Pleural Mesothelioma

AIM

Malignant pleural mesothelioma (MPM) increases the risk of thromboembolic events (TEEs). In this retrospective study, we aimed to determine the rate of TEEs in MPM and investigate its relationship with the presence of thrombocytosis, the disease stage, and the tumor histopathology.

METHODS

The study included 178 patients who were histopathologically diagnosed as MPM between the years January 2008 and June 2014.

RESULTS

The mean age was 58.7 ± 11.8 years, and the median follow-up time was 8 months. Seventy-one patients (39.9%) had thrombocytosis (>350 × 10(3)/mL). In total, 14 (7.9%) TEEs were identified: 6 (3.4%) pulmonary thromboembolism, 6 (3.4%) deep venous thrombosis, and 2 (1.1%) myocardial infarctions. Although 5 (2.8%) of the TEEs preceded the diagnosis of MPM, 1 (0.6%) occurred simultaneously with the diagnosis of MPM and 8 (4.5%) followed the diagnosis of MPM. Thromboembolic event rates were not statistically different based on the presence of thrombocytosis (P = .51), disease stage (P = .14), and histopathology (P = .38).

CONCLUSION

The rate of TEEs was 7.9%. Presence of thrombocytosis, disease stage, and histopathology did not affect the incidence of TEEs.