Managing thrombosis in cancer patients

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.

Primary prevention of cancer-associated venous thrombosis: Rationale and challenges in clinical practice

Cancer-associated venous thrombosis (CAT) is a common, multifactor event known to complicate the course of cancer and jeopardize a patient's prognosis. The current guidelines regarding the prevention of CAT are sometimes considered insufficiently precise about specific situations, or are poorly applied. The expected benefits of thromboprophylaxis are balanced by the risk of major bleeding induced by anticoagulation, which implies a need to accurately identify ambulatory patients at high risk of thrombosis or hemorrhage. The Khorana score is commonly used for this, but is limited by the non-reproducibility of predicted performance across cancer types, and by the fact that antitumor treatment and cardiovascular risks are not included. The COMPASS-CAT score, which includes those two aspects, was found to be a more accurate predictor of venous thromboembolism in patients with lung cancer, and to better distinguish between patients at low or high risk of thrombosis. The frailty of patients with cancer is also a major issue, and should be taken into account when thromboprophylaxis is considered. According to current guidelines, CAT prophylaxis should be considered for hospitalized patients, those for whom surgery is scheduled, or those with pancreatic cancers. In ambulatory patients, decisions should be made according to patient, cancer and antitumoral treatment characteristics. Low molecular weight heparin is the gold standard of CAT prophylaxis. Despite increased risks of bleeding or drug-drug interactions in cancer patients, direct oral anticoagulants could be alternate options for high-risk ambulatory patients that should be accompanied by a careful global analysis of benefits, harms, and patient preferences.

Kinase Inhibitors and Atrial Fibrillation

Recent advances have significantly expanded the options of available therapeutics for cancer treatment, including novel targeted cancer therapies. Within this broad category of targeted therapies is the class of kinase inhibitors (KIs), which target kinases that have undergone aberrant activation in cancerous cells. Although KIs have shown a benefit in treating various forms of malignancy, they have also been shown to cause a wide array of cardiovascular toxicities, with cardiac arrhythmias, in particular atrial fibrillation (AF), being 1 of the predominant side effects. The occurrence of AF in patients undergoing cancer treatment can complicate the treatment approach and poses unique clinical challenges. The association of KIs and AF has led to new research aimed at trying to elucidate the underlying mechanisms. Furthermore, there are unique considerations to treating KI-induced AF because of the anticoagulant properties of some KIs as well as drug-drug interactions with KIs and some cardiovascular medications. Here, we review the current literature pertaining to KI-induced AF.

[Prophylaxis and management of cancer-associated thrombosis: Practical issues about anticoagulant use]

Cancer-associated thrombosis (CAT) is a common complication resulting from various vascular mechanisms related to cancer, antitumoral therapy and patient status, and is associated with a poor prognosis. Anticoagulants recommended for CAT treatment or prevention mainly include low molecular weight heparin (LMWH) and direct oral anticoagulants (DOACs). Regarding thromboprophylaxis, a situation for which LMWH is a preferred option due to a lower risk of hemorrhage especially in patients with unresected gastro-intestinal and genito-urinary malignancies, the identification of patients at risk is a major issue. For patients with established CAT, the main issue is the choice of the most appropriate anticoagulant therapy. Because of the convenience of oral formulation, DOACs are an attractive option, and their efficacy has been shown in randomized trials. However, such studies are limited by selection biases, which make the analyzed population not representative of the real-life setting, as for instance cancers associated with a high risk of hemorrhage, or antitumoral therapies (e.g., tyrosine kinase inhibitors) known to interact with DOACs and then modifying their bioavailability. Caution associated with DOAC use is highlighted by most updated guidelines that recommend a case-by-case-based approach. The aim of the present paper is to help the oncologists make the most appropriate decision regarding the choice of anticoagulant therapy in a context of thromboprophylaxis or established CAT management in a patient with a solid tumor. The main issues are addressed through key practical questions, the answers of which are based on the current guidelines and additional published data or expert opinions.

Pulmonary embolism management in the emergency department: part 2

Pulmonary embolism (PE) can present with a range of severity. Prognostic risk stratification is important for efficacious and safe management. This second of two review articles discusses the management of high-, intermediate- and low-risk PE. We discuss strategies to identify patients suitable for urgent outpatient care in addition to identification of patients who would benefit from thrombolysis. We discuss specific subgroups of patients where optimal treatment differs from the usual approach and identify emerging management paradigms exploring new therapies and subgroups.

Case Report: A Mysterious Giant Thrombus in the Right Atrium in a Patient With Dilated Cardiomyopathy

An isolated right atrial thrombus is a life-threatening entity that is extremely rare in patients with dilated cardiomyopathy (DCM), which is characterized by a reduced left ventricular function and consequent left ventricular thrombosis. Here, we present the case of a mysterious isolated giant right atrial thrombus in a male patient with DCM. The presence of deep vein thrombosis prompted us to investigate for other underlying diseases for his right atrial thrombus. Interestingly, the elevation of two tumor markers indicated the likelihood of cancer-associated thrombosis. Further, the computed tomography demonstrated a spiculated mass in the lower right lung that was confirmed by an endobronchial biopsy as lung squamous cell carcinoma. Consequently, the giant thrombus in the right atrium should be attributed principally to lung squamous cell carcinoma on the background of DCM. After 3 weeks of enoxaparin, the echocardiogram indicated partial resolution of the thrombus. However, the patient suffered sudden death due to pulmonary embolism.

Risk of venous thromboembolism in men with prostate cancer compared with men in the general population: a nationwide population-based cohort study in Sweden

OBJECTIVE

To estimate the additional risk of venous thromboembolism (VTE) in men with prostate cancer compared with men without prostate cancer in Sweden.

DESIGN

Nationwide cohort study following 92 105 men with prostate cancer and 466 241 men without prostate cancer (comparison cohort) matched 5:1 by birth year and residential region.

SETTING

The male general population of Sweden (using the Nationwide Prostate Cancer data Base Sweden).

PRIMARY AND SECONDARY OUTCOME MEASURES

Crude incidence proportion ratios (IPRs) comparing the incidence of VTE in men with prostate cancer and men in the comparison cohort. Cox regression was used to calculate HRs for VTE adjusted for confounders.

RESULTS

2955 men with prostate cancer and 9774 men in the comparison cohort experienced a first VTE during a median of 4.5 years' follow-up. Deep vein thrombosis (DVT) accounted for 52% of VTE cases in both cohorts. Median time from start of follow-up to VTE was 2.5 years (IQR 0.9-4.7) in the prostate cancer cohort and 2.9 years (IQR 1.3-5.0) in the comparison cohort. Crude incidence rates of VTE per 1000 person-years were 6.54 (95% CI 6.31 to 6.78) in the prostate cancer cohort (n=2955 events) and 4.27 (95% CI 4.18 to 4.35) in the comparison cohort (n=9774 events). The IPR decreased from 2.53 (95% CI 2.26 to 2.83) at 6 months to 1.59 (95% CI 1.52 to 1.67) at 5 years' follow-up. Adjusted HRs were 1.48 (95% CI 1.39 to 1.57) for DVT and 1.47 (95% CI 1.39 to 1.56) for pulmonary embolism after adjustment for patient characteristics.

CONCLUSIONS

Swedish men with prostate cancer had a mean 50% increased risk of VTE during the 5 years following their cancer diagnosis compared with matched men free of prostate cancer. Physicians should be mindful of this marked increase in VTE risk in men with prostate cancer to help ensure timely diagnosis.

Coagulation and inflammation in cancer: Limitations and prospects for treatment

The development of so-called immune checkpoint inhibitors (ICIs), which target specific molecular processes of tumour growth, has had a transformative effect on cancer treatment. Widespread use of antibody-based medicines to inhibit tumour cell immune evasion by modulating T cell responses is becoming more common. Despite this, response rates are still low, and secondary resistance is an issue that arises often. In addition, a wide range of serious adverse effects is triggered by enhancing the immunological response. As a result of an increased mortality rate, a higher prevalence of thrombotic complications is connected with an increased incidence of immunological reactions, complement activation, and skin toxicity. This suggests that the tumour microenvironment's interaction between coagulation and inflammation is important at every stage of the tumour's life cycle. The coagulation system's function in tumour formation is the topic of this review. By better understanding the molecular mechanisms in which tumour cells circulate, plasmatic coagulation and immune system cells are engaged, new therapy options for cancer sufferers may be discovered.

Population-based study of long-term anticoagulation for treatment and secondary prophylaxis of venous thromboembolism in men with prostate cancer in Sweden

Background

Epidemiological data on anticoagulation for venous thromboembolism (VTE) in prostate cancer are sparse. We aimed to investigate associations between anticoagulation duration and risks of VTE recurrence after treatment cessation and major on-treatment bleeding in men with prostate cancer in Sweden.

Methods

Using nationwide prostate cancer registry and prescribing data, we followed 1413 men with VTE and an outpatient anticoagulant prescription following prostate cancer diagnosis. Men were followed to identify cases of recurrent VTE, and hospitalized major bleeding. We calculated adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) to quantify the association between anticoagulation duration (reference ≤ 3 months) and recurrent VTE using Cox regression. We estimated 1-year cumulative incidences of major bleedings from anticoagulation initiation.

Results

The outpatient anticoagulation prescribed was parenteral (64%), direct oral anticoagulant (31%), and vitamin K antagonist (20%). Median duration of anticoagulation was 7 months. Adjusted HRs (95% CI) for off-treatment recurrent pulmonary embolism (PE) were 0.32 (0.09–1.15) for > 3–6 months’ duration, 0.21 (0.06–0.69) for > 6–9 months and 0.16 (0.05–0.55) for > 9 months; corresponding HRs for deep vein thrombosis (DVT) were 0.67 (0.27–1.66), 0.80 (0.31–2.07), and 1.19 (0.47–3.02). One-year cumulative incidences of intracranial, gastrointestinal and urogenital bleeding were 0.9%, 1.7%, 3.0% during treatment, and 1.2%, 0.9%, 1.6% after treatment cessation.

Conclusion

The greatest possible benefit in reducing recurrent VTE risk occurred with > 9 months anticoagulation for PE and > 3–6 months for DVT, but larger studies are needed to confirm this. Risks of major bleeding were low overall.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12894-022-00967-z.

Non-bacterial thrombotic endocarditis in pancreatic cancer and other high-risk malignancies: the case for prophylactic treatment

Non-bacterial thrombotic endocarditis (NBTE) typically affects patients with underlying adenocarcinoma, often of pancreatic origin. If untreated, it can lead to serious morbidity and mortality, including recurrent ischaemic stroke. NBTE is frequently missed or confused with infective endocarditis, leading to inappropriate management. We present the case of a 54-year-old male with newly diagnosed pancreatic malignancy (CA19–9 >120 000) who suffered recurrent deep-vein-thromboses and multiple ischaemic strokes despite full anticoagulation therapy. Transoesophageal echocardiography was correctly performed, but only after a second stroke was NBTE considered. We recommend early clinical suspicion and investigation for NBTE in patients with known or suspected malignancy presenting with neurological symptoms consistent with stroke. Initial calculations indicate this could also be cost-effective. Further, the patient’s significantly elevated tumour-markers and NBTE-severity raise the possibility of a link; if further research established a reliable relationship, routine surveillance of high-risk malignancies could identify patients who might benefit from earlier echocardiography and anticoagulation management.

Antithrombotic Therapy for VTE Disease: Second Update of the CHEST Guideline and Expert Panel Report - Executive Summary

BACKGROUND

This is the second update to the 9^th edition of these guidelines. We provide recommendations on 17 PICO (Patients, Interventions, Comparators, Outcomes) questions, four of which have not been addressed previously.

METHODS

We generate strong and weak recommendations based on high, moderate, and low-certainty evidence, using GRADE methodology.

RESULTS

The panel generated 29 guidance statements, 13 of which are graded as strong recommendations, covering aspects of antithrombotic management of venous thromboembolism from initial management through secondary prevention and risk reduction of post-thrombotic syndrome. Four new guidance statements are added that did not appear in the 9^th edition (2012) or first update (2016). Eight statements have been substantially modified from the first update.

CONCLUSION

New evidence has emerged since 2016 which further informs the standard of care for patients with venous thromboembolism. Substantial uncertainty remains regarding important management questions, particularly in limited disease and special patient populations.

Primary Thromboprophylaxis in Patients with Malignancies: Daily Practice Recommendations by the Hemostasis Working Party of the German Society of Hematology and Medical Oncology (DGHO), the Society of Thrombosis and Hemostasis Research (GTH), and the Austrian Society of Hematology and Oncology (ÖGHO)

Patients with cancer, both hematologic and solid malignancies, are at increased risk for thrombosis and thromboembolism. In addition to general risk factors such as immobility and major surgery, shared by non-cancer patients, cancer patients are exposed to specific thrombotic risk factors. These include, among other factors, cancer-induced hypercoagulation, and chemotherapy-mediated endothelial dysfunction as well as tumor-cell-derived microparticles. After an episode of thrombosis in a cancer patient, secondary thromboprophylaxis to prevent recurrent thromboembolism has long been established and is typically continued as long as the cancer is active or actively treated. On the other hand, primary prophylaxis, even though firmly established in hospitalized cancer patients, has only recently been studied in ambulatory patients. This recent change is mostly due to the emergence of direct oral anticoagulants (DOACs). DOACs have a shorter half-life than vitamin K antagonists (VKA), and they overcome the need for parenteral application, the latter of which is associated with low-molecular-weight heparins (LMWH) and can be difficult for the patient to endure in the long term. Here, first, we discuss the clinical trials of primary thromboprophylaxis in the population of cancer patients in general, including the use of VKA, LMWH, and DOACs, and the potential drug interactions with pre-existing medications that need to be taken into account. Second, we focus on special situations in cancer patients where primary prophylactic anticoagulation should be considered, including myeloma, major surgery, indwelling catheters, or immobilization, concomitant diseases such as renal insufficiency, liver disease, or thrombophilia, as well as situations with a high bleeding risk, particularly thrombocytopenia, and specific drugs that may require primary thromboprophylaxis. We provide a novel algorithm intended to aid specialists but also family practitioners and nurses who care for cancer patients in the decision process of primary thromboprophylaxis in the individual patient.

Assessing the risk of venous thromboembolism (VTE) in ambulatory patients with cancer: Rationale and implementation of a pharmacist-led VTE risk assessment program in an ambulatory cancer centre

Objectives

The objectives of this paper were to identify and compare clinical prediction models used to assess the risk of venous thromboembolism (VTE) in ambulatory patients with cancer, as well as review the rationale and implementation of a pharmacist-led VTE screening program using the Khorana Risk Score model in an ambulatory oncology centre in Sault Ste. Marie, Ontario, Canada.

Data Sources

PubMed was used to identify clinical practice guidelines and review articles discussing risk prediction models used to assess VTE risk in ambulatory patients with cancer.

Data Summary

Three commonly used VTE risk prediction models in ambulatory patients with cancer: the Khorana Risk Score, Vienna Cancer and Thrombosis Study (CATS) and Protecht Score, were identified via literature review. After considering guideline recommendations, site-specific factors (i.e. laboratory costs, time pharmacists spent calculating VTE risk) and evidence from the CASSINI and AVERT trials, a novel pharmacist-led VTE risk assessment program using the Khorana Risk Score was developed during a fourth-year PharmD clinical rotation at the Algoma District Cancer Program (ADCP) [ambulatory cancer care centre]. ADCP patients with a Khorana Risk Score of ≥2 were referred to the hematologist for a full VTE workup. Considering limitations, inclusion and exclusion criteria of the CASSINI and AVERT trials, the hematologist and pharmacy team decided on appropriate initiation of thromboprophylaxis with a direct oral anticoagulant (DOAC).

Conclusions

The Khorana Risk Score was the chosen model used for the pharmacist-led VTE risk assessment program due to its user-friendly scoring algorithm, evidence from validation studies and clinical trials, as well as ease of integration into pharmacy workflow. More research is needed to determine if pharmacist-led VTE risk assessment programs will impact patient outcomes, such as morbidity and mortality, secondary to cancer-associated thrombosis.

Clinical controversies in the treatment of cancer-associated venous thromboembolism

Cancer-associated venous thromboembolism (VTE) is a common complication of malignancy. Patients with cancer exhibit risk factors for both recurrent VTE and major or minor bleeding. Direct oral anticoagulants (DOACs) are an attractive treatment option; however, there is a lack of consensus among national guidelines for choice between DOACs and LMWH, agent selection, dosing strategy, and duration of anticoagulation. Characteristics of the thrombotic event, the malignancy, the patient, and the anticoagulant must be considered. A systematic search of online databases was performed to identify literature on the management of cancer-associated VTE. Multiple controversies remain surrounding the optimal treatment of cancer-associated VTE.

Direct oral anticoagulants for the treatment and prevention of venous thromboembolism in patients with cancer: current evidence

Venous thromboembolic disease (VTED) is a common and clinically important complication in patients with cancer, contributing to its mortality and morbidity. Direct oral anticoagulant agents (DOACs), including direct thrombin inhibitors and direct factor Xa inhibitors, are as effective as vitamin K antagonists for the treatment of VTED and are associated with less frequent and severe bleeding. They have advantages over low-molecular-weight heparin, but comparative long-term efficacy and safety data are lacking for these compounds. Recent randomized clinical trials suggest a role for DOACs in the treatment of VTED in patients with cancer. This review will discuss the existing evidence and future perspectives on the role of DOACs in the treatment of VTE based on the current evidence about their overall efficacy and safety and the limited information in patients with cancer; in addition, we will briefly review their pharmacokinetic properties with special reference to potential interactions.

Mechanisms and biomarkers of cancer-associated thrombosis

Cancer-associated thrombosis is a leading cause of non-cancer death in cancer patients and is comprised of both arterial and venous thromboembolism (VTE). There are multiple risk factors for developing VTE, including cancer type, stage, treatment, and other medical comorbidities, which suggests that the etiology of thrombosis is multifactorial. While cancer-associated thrombosis can be treated with anticoagulation, benefits of therapy must be balanced with the increased bleeding risks seen in patients with cancer. Although risk models exist for primary and recurrent VTE, additional predictors are needed to improve model performance and discrimination of high-risk patients. This review will outline the diverse mechanisms driving thrombosis in cancer patients, as well as provide an overview of biomarkers studied in thrombosis risk and important considerations when selecting candidate biomarkers.

Meta-Analysis of VTE Risk: Ovarian Cancer Patients by Stage, Histology, Cytoreduction, and Ascites at Diagnosis

Venous thromboembolisms (VTEs) have been a leading secondary cause of death among ovarian cancer patients, prompting multiple studies of risk factors. The objective of this meta-analysis is to quantify the associations between VTE and the most commonly reported risk factors among ovarian cancer patients. PubMed, Embase, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) were used to identify observational studies. Two reviewers independently abstracted data and assessed quality via the Newcastle–Ottawa tool. A random effects model was used to calculate the pooled odds ratios for VTE with each of the following exposures: advanced cancer stage, clear cell histology, serous histology, ascites at diagnosis, and complete cytoreduction. The I² and Q tests were used to evaluate heterogeneity. Twenty cohort studies with 6,324 total ovarian cancer patients, 769 of whom experienced a VTE, were included. The odds of VTE in ovarian cancer patients were higher among patients with cancer stage III/IV (versus cancer stage I/II, pooled odds ratio (OR) 2.73; 95% CI 1.84–4.06; I²= 64%), clear cell (versus nonclear cell) histology (OR 2.11; 95% CI 1.55–2.89; I² = 6%), and ascites (versus no ascites) at diagnosis (OR 2.12; 95% CI 1.51–2.96; I² = 32%). Serous (versus nonserous) histology (OR 1.26; 95% CI 0.91–1.75; I² = 42%) and complete (versus incomplete) cytoreduction (OR 1.05; 95% CI 0.27–4.11; I² = 88%) were not associated with VTE. This meta-analysis quantifies the significantly elevated odds of VTE in ovarian cancer patients with advanced stage at diagnosis, clear cell histology, and ascites at diagnosis. Further studies are needed to account for confounders and inform clinical decision-making tools.

A systematic review on the efficacy and safety of low molecular weight heparin as an anticancer therapeutic in preclinical animal models

OBJECTIVE

The therapeutic effects of low molecular weight heparins (LMWH) may extend past thrombosis prevention, with preclinical evidence demonstrating anti-metastatic properties. Clinical evidence on the topic, however, remains controversial. A systematic review of preclinical evidence may help elucidate reasons for this contradictory evidence. The objective of our systematic review is to assess the anti-metastatic properties of LMWHs in solid tumour animal models.

METHODS

MEDLINE, Embase, Web of Science and PubMed were searched from inception to May 12th, 2020. All articles were screened independently and in duplicate. Studies that compared LMWH to a placebo or no treatment arm in solid tumour animal models were included. The primary outcome was the burden of metastasis. Secondary outcomes included primary tumour growth and mortality. The risk of bias was assessed in duplicate using a modified Cochrane Risk of Bias tool.

RESULTS

Forty-two studies were included in the review. Administration of a LMWH was associated with a significant decrease in the burden of metastasis (SMD -2.18; 95% CI -2.66 to -1.70). Additionally, the administration of a LMWH was also associated with a significant reduction in primary tumour growth (SMD -1.95; 95% CI -2.56 to -1.34) and risk of death (RR 0.39; 95% CI 0.16-0.97). All included studies were deemed to be at an unclear risk of bias for at least one methodological criterion.

CONCLUSIONS

Our results demonstrate that LMWH can effectively reduce metastatic burden and reduce tumour growth in preclinical animal models of solid tumour malignancies. Reasons for the contradiction with clinical evidence require further exploration.

Potential Drug Interactions between Recombinant Interleukin-2 and Direct Oral Anticoagulants: Indirect Evidence from In Vivo Animal Studies

Recombinant interleukin-2 (rIL-2) is indicated for metastatic renal cell carcinoma and melanoma. Over recent years low-dose rIL-2 has been studied for the treatment of autoimmune diseases and acute coronary syndrome because of its ability to expand and activate T regulatory (T_reg) cells. However, several medical conditions potentially benefiting from rIL-2 administrations are characterized by an intrinsic prothrombotic risk, thus requiring concurrent anticoagulation. In our systematic review of the literature, we investigated the potential for drug interactions between oral anticoagulants and rIL-2 by assessing the influence of rIL-2 administration on transporters and cytochromes determining the pharmacokinetics of (direct) oral anticoagulants. We extracted data from 12 studies, consisting of 11 animal studies and one study in humans. Eight studies investigated the pharmacokinetics of P-glycoprotein (P-gp) substrates and reported that the intraperitoneal rIL-2 administration may inhibit intestinal P-gp. Four studies on hepatic cytochrome P450 yielded conflicting results. The only human study included in this systematic review concluded that rIL-2 suppresses the hepatic cytochrome P450, but only if given at higher doses. Based on the results from animal studies, the co-administration of rIL-2 and dabigatran etexilate, a substrate of intestinal P-gp, may lead to higher dabigatran plasma concentrations and bioavailability. Human studies should confirm whether this potential interaction is clinically relevant.

Venous Thromboembolism Treatment and Prevention in Cancer Patients: Can We Use Pills Yet?

OPINION STATEMENT

Cancer increases a patient's risk for developing a venous thromboembolism (VTE) and is a relatively common finding in this population. Traditionally, anticoagulants used to treat VTE have included low molecular weight heparin (LMWH) or vitamin K antagonists (VKA). However, within the last several years, a newer class of anticoagulant, the direct oral anticoagulants (DOACs), has emerged as a potential option for pharmacologic thromboprophylaxis and for treatment of VTE in patients with cancer. While data is still limited and evolving, DOACs offer several benefits that are worth considering, including ease of administration and similar efficacy compared to LMWH in preventing recurrent VTE. However, some studies have reported a notable risk of increased bleeding associated with the use of DOACs. Additional studies are underway to evaluate the role of DOACs compared to LMWH in the setting of cancer. In our practice, based on existing data, we have been using DOACs for the chronic treatment of acute VTE and prevention of recurrent VTE in patients who do not have contraindications to anticoagulation and do not have severe renal insufficiency (creatinine clearance < 30 mL/min). For cancer patients admitted to the hospital with an acute medical illness, we use LMWH for primary prevention of VTE. In the perioperative setting, for patients undergoing major surgery with an active cancer, we prefer pharmacologic thromboprophylaxis with LMWH, although there is some emerging evidence that DOACs may be safe in this setting.

Expanding Access to Lung Cancer Clinical Trials by Reducing the Use of Restrictive Exclusion Criteria: Perspectives of a Multistakeholder Working Group

Low rates of adult patient participation have been a persistent problem in cancer clinical trials and have continued to be a barrier to efficient drug development. The routine use of significant exclusion criteria has contributed to this problem by limiting participation in studies and creating significant clinical differences between the study cohorts and the real-world cancer patient populations. These routine exclusions also unnecessarily restrict opportunities for many patients to access potentially promising new therapies during clinical development. Multiple efforts are underway to broaden eligibility criteria, allowing more patients to enroll in studies and generating more robust data regarding the effect of novel therapies in the population at large. Focusing specifically on lung cancer as an example, a multistakeholder working group empaneled by the LUNGevity Foundation identified 14 restrictive and potentially outdated exclusion criteria that appear frequently in lung cancer clinical trials. As a part of the project, the group evaluated data from multiple recent lung cancer studies to ascertain the extent to which these 14 criteria appeared in study protocols and played a role in excluding patients (screen failures). The present report describes the working group's efforts to limit the use of these routine exclusions and presents clinical justifications for reducing the use of 14 criteria as routine exclusions in lung cancer studies, potentially expanding trial eligibility and improving the generalizability of the results from lung cancer trials.

Evaluation of direct oral anticoagulants for the treatment of cancer-associated thrombosis: an update

Cancer is associated with an increased risk of venous thromboembolism of four to sixfold. Cancer-related interventions such as chemotherapy, hormonal therapy and indwelling central venous catheters also increase the risk of venous thromboembolism. Low molecular weight heparin for at least 3-6 months is the current standard of care for the treatment of cancer associated venous thromboembolism. Anticoagulation should be continued as long as the cancer is active. Over the past few years, direct oral anticoagulants have emerged, including one direct thrombin inhibitor (dabigatran etexilate) and three factor Xa inhibitors (apixaban, edoxaban and rivaroxaban). In the randomized controlled trials comparing direct oral anticoagulants with vitamin K antagonists, the direct oral anticoagulants all provide non-inferior in prevention of thromboembolic events in patients with atrial fibrillation, for the prevention and treatment of venous thromboembolism and in acute coronary syndrome. In people with cancer, these drugs have emerged as attractive alternatives for the treatment of venous thromboembolism with the potential to overcome the limitations of low molecular weight heparin. Randomized controlled studies comparing direct oral anticoagulants to low molecular weight heparin in cancer patients are still limited and direct oral anticoagulants are not recommended for the treatment of cancer associated venous thromboembolism yet. However, new emerging data are supporting the use of direct oral anticoagulants in cancer-associated thrombosis. Here, we review recent data on the evidence related to the efficacy and safety of direct oral anticoagulants for the treatment of venous thromboembolism in patients with cancer.

Right Ventricular Thrombus in Transit: Raising the Stakes in the Management of Pulmonary Embolism

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Right heart thrombi are rare and associated with significant mortality.

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RV thrombus was complicated by recurrent pulmonary emboli and managed surgically.

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Recurrent pulmonary emboli in anticoagulated patients may suggest malignancy.

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The optimal treatment for right heart thrombi remains uncertain.

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Surgical thrombectomy is an option, but treatment should be individualized.

Direct oral anticoagulants for treatment and prevention of venous thromboembolism in cancer patients

Venous thromboembolism (VTE) is a common cause of morbidity and mortality in patients with cancer. Compared with the general population, cancer patients with VTE have higher rates of both VTE recurrence and bleeding. While low molecular weight heparin (LMWH) has been the mainstay of treatment for cancer-associated VTE for over a decade, direct oral anticoagulants (DOACs) have recently emerged as a new therapeutic option due to their ease of administration and because they do not require laboratory monitoring. Several large randomized clinical trials have been performed or are ongoing at the time of writing, comparing DOACs with LMWH in this population. Three of these trials have thus far been published and suggest that DOACs are a reasonable alternative to LMWH for management of cancer-associated VTE. Despite the advantages offered by DOACs, these agents may not be appropriate for certain patient groups owing to increased risk of bleeding, organ compromise, extremes of weight, and other issues. Finally, data are emerging suggesting that DOACs may be useful for primary thromboprophylaxis in cancer patients in conjunction with validated risk assessment scores. In this evidence-based review, data for the use of DOACs to treat cancer-associated VTE will be examined, focusing on efficacy, safety, and timing of treatment. Guidance on choosing the optimal anticoagulant for a given patient is also offered.

Management of venous thromboembolism in patients with cancer

Current guidelines for anticoagulant therapy do not so far suggest any form of differentiated approach to cancer patients with venous thromboembolism (VTE). This review article provides an overview of the published literature in cancer patients with VTE, mostly using data from the RIETE registry. Our findings provide some insights into what factors may be used to guide physicians in adapting recommended anticoagulant regimens to the individual patient, as oncologists are increasingly doing with cancer treatments. For instance, patients presenting with deep vein thrombosis (DVT) alone might benefit from curtailing treatment intensity as anticoagulant therapy progresses. The site of cancer also needs to be considered. In patients with incidental PE or splanchnic vein thrombosis, we should be more cautious before prescribing anticoagulant therapy. The optimal duration of anticoagulant therapy is unknown.

Cancer-Associated Thrombosis: An Overview of Mechanisms, Risk Factors, and Treatment

Cancer-associated thrombosis is a major cause of mortality in cancer patients, the most common type being venous thromboembolism (VTE). Several risk factors for developing VTE also coexist with cancer patients, such as chemotherapy and immobilisation, contributing to the increased risk cancer patients have of developing VTE compared with non-cancer patients. Cancer cells are capable of activating the coagulation cascade and other prothrombotic properties of host cells, and many anticancer treatments themselves are being described as additional mechanisms for promoting VTE. This review will give an overview of the main thrombotic complications in cancer patients and outline the risk factors for cancer patients developing cancer-associated thrombosis, focusing on VTE as it is the most common complication observed in cancer patients. The multiple mechanisms involved in cancer-associated thrombosis, including the role of anticancer drugs, and a brief outline of the current treatment for cancer-associated thrombosis will also be discussed.