Primary prophylaxis for venous thromboembolism in ambulatory cancer patients receiving chemotherapy

Cost-effectiveness analysis of direct oral anticoagulants versus low-molecular-weight heparin and no thromboprophylaxis in primary prevention of cancer-associated venous thromboembolism in China

Background and objective

Cancer-associated venous thromboembolism (CAVTE) is a preventable, life-threatening complication with a considerable morbidity and mortality. Primary venous thromboembolism (VTE) prophylaxis is currently recommended; however, the health and economic benefits have not been evaluated and compared in China. This study aimed to assess and compare the cost-effectiveness of anticoagulants in primary CAVTE prevention among cancer patients in China.

Methods

A Markov model with a 5-year horizon was established to evaluate the costs and effectiveness of direct oral anticoagulants (DOACs) compared to low-molecular-weight heparins (LMWHs) and no prevention in primary prophylaxis of CAVTE in China. Key clinical outcomes were obtained from the available clinical trials, comparing DOACs (rivaroxaban and apixaban) with LMWHs or with no thromboprophylaxis. Utility and the cost inputs were all obtained from the published literature or local data with public sources. The total costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs) were estimated as the main endpoints of the modal for each strategy. The assessment of uncertainty was performed involving deterministic sensitivity analysis and probabilistic sensitivity analysis (PSA). Impact of time horizon, generic drug price, and individual DOACs were assessed in scenario and subgroup analyses.

Results

Primary prophylaxis using DOACs were projected to yield 1.866 QALYs at a cost of $3,287.893, resulting in the ICERs of $12,895.851 (DOACs vs. no-thromboprophylaxis) and $43,613.184/QALYs (LMWHs vs. DOACs). Sensitivity analysis revealed that ICER was sensitive to the VTE and bleeding risk, drug cost of anticoagulants, self-payment ratio, and overall death rate of cancer. Probabilistic sensitivity analysis showed that DOACs and LMWHs had a 48% and 45% probability of being cost-effective at a 5-year time horizon, respectively. When the time horizon extended to 10 years, DOACs achieved a cost-effective probability of 43%. Among individual DOACs, apixaban was found to be the preferred strategy in VTE prevention due to its incremental health gain with an acceptable cost increase.

Conclusion

Primary thromboprophylaxis with DOACs was cost-effective in cancer patients at a willing-to-pay (WTP) threshold of $37,125.24/QALY in China. Cancer death rate, risk of VTE and major bleeding, and the drug cost assumed greater relevance and importance in the decision-making process for primary thromboprophylaxis in cancer.

Cancer-associated thrombosis and drug-drug interactions of antithrombotic and antineoplastic agents

Venous thromboembolism (VTE) is often associated with malignant diseases and notably contributes to morbidity and mortality in patients with cancer. Cancer-associated thrombosis (CAT) brings additional costs to health expenditures and has a negative impact on oncological outcomes. Either the recurrence rate of VTE or bleeding complications are also higher in patients with cancer. Prophylactic anticoagulation has been recommended in peri-surgical periods, inpatient settings, and high-risk ambulatory patients. Although various risk stratification scores are used, none are ideal for identifying patients who can benefit from anticoagulant prophylaxis. New risk scoring systems or biomarkers are needed to identify patients who are more likely to benefit from prophylaxis with low bleeding risk. The questions about the patients who will be given prophylaxis and those who develop thromboembolism, with which drug, and how long they will be treated are still not fully answered. Anticoagulation is the cornerstone of the treatment, but management of CAT remains complex. Low molecular weight heparins and direct oral anticoagulants are effective and safe options for the treatment of CAT. Recognizing adverse effects, drug-drug interactions, and accompanying conditions that cause dose adjustment is crucial. Prevention and treatment of VTE in patients with cancer require a multidisciplinary and patient-based approach. PLAIN LANGUAGE SUMMARY: Cancer-associated thrombosis is a significant cause of mortality and morbidity in patients with cancer. Chemotherapy, surgery, and/or use of central venous access remarkably increase the risk of thrombosis. Prophylactic anticoagulation should be considered not only in inpatient follow-up and during peri-surgical period but also ambulatory patients with a high risk of thrombosis. Many parameters, such as drug-drug interactions, primary side of cancer, and comorbidities of patients should be considered when selecting anticoagulant drugs. More accurate risk stratification scores or biomarkers are still an unmet need.

Capecitabine and Warfarin Interaction: A Case Report With Review of Literature and Management Options

Capecitabine is an orally active prodrug of 5-fluorouracil with improved safety and efficacy that is extensively used as an antineoplastic agent. It is converted to 5-Fluorouracil in the liver and tumor tissues. In vitro assays did not reveal any significant potential for interaction between capecitabine and its metabolites with warfarin. However, several reports provided clinical evidence of such interaction resulting in an elevated international normalized ratio (INR) and bleeding. Here, we report another case of capecitabine and warfarin concurrent administration that resulted in sub- or supra- therapeutic INR without any bleeding episode or venous-thromboembolic event through the follow-up period. Moreover, a review of available management options is also presented in this paper.

Thrombosis Complications in Pediatric Acute Lymphoblastic Leukemia: Risk Factors, Management, and Prevention: Is There Any Role for Pharmacologic Prophylaxis?

Pediatric acute lymphoblastic leukemia (ALL) has achieved close to 90% cure rates through extensive collaborative and integrative molecular research, clinical studies, and advances in supportive care. Despite this high achievement, venous thromboembolic complications (VTE) remain one of the most common and potentially preventable therapy-associated adverse events in ALL. The majority of thromboses events involve the upper central venous system which is related to the use and location of central venous catheters (CVC). The reported rates of symptomatic and asymptomatic CVC-related VTE range from 2.6 to 36.7% and 5.9 to 43%, respectively. Thrombosis can negatively impact not only disease-free survival [e.g., therapy delays and/or interruption, omission of chemotherapy agents (e.g., asparaginase therapy)] but also can result in long-term adverse effects that can impair the quality of life of ALL survivors (e.g., post-thrombotic syndrome, central nervous system (CNS)-thrombosis related complications: seizures, neurocognitive deficits). In this review, will discuss thrombosis pathophysiology in pediatric ALL, risk factors, treatment, and prevention strategies. In addition, the recently published clinical efficacy and safety of direct oral anticoagulants (DOACs) use in thrombosis treatment, and their potential role in primary/secondary thrombosis prevention in pediatric patients with ALL will be discussed. Future clinical trials involving the use of these novel oral anticoagulants should be studied in ALL not only for primary thrombosis prevention but also in the treatment of thrombosis and its secondary prevention. These future research findings could potentially extrapolate to VTE prevention strategies in other pediatric cancer diagnoses and children considered at high risk for VTE.

Prevention of venous thromboembolism in hematologic neoplasms: an expert consensus from SEHH-SETH

Venous thromboembolism (VTE) is a serious complication in hematologic neoplasms, so finding adequate prevention strategies is an urgent requirement. However, prospective studies with large enough cohorts are scarce, limiting the development of evidence-based thromboprophylaxis guidelines. The present position paper is addressed to all hematologists treating patients affected by hematologic neoplasms with the aim to provide clinicians with a useful tool for the prevention of VTE.

Cost-utility analysis of apixaban compared with usual care for primary thromboprophylaxis in ambulatory patients with cancer

Background:

Apixaban (2.5 mg) taken twice daily has been shown to substantially reduce the risk of venous thromboembolism (VTE) compared with placebo for the primary thromboprophylaxis of ambulatory patients with cancer who are starting chemotherapy and are at intermediate-to-high risk of VTE. We aimed to compare the health system costs and health benefits associated with primary thromboprophylaxis using apixaban with those associated with the current standard of care (where no primary thromboprophylaxis is given), from the perspective of Canada’s publicly funded health care system in this subpopulation of patients with cancer over a lifetime horizon.

Methods:

We performed a cost–utility analysis to estimate the incremental cost per quality-adjusted life-year (QALY) gained with primary thromboprophylaxis using apixaban. We obtained baseline event rates and the efficacy of apixaban from the Apixaban for the Prevention of Venous Thromboembolism in High-Risk Ambulatory Cancer Patients (AVERT) trial on apixaban prophylaxis. We estimated relative risk for bleeding, risk of complications associated with VTE treatment, mortality rates, costs and utilities from other published sources.

Results:

Over a lifetime horizon, apixaban resulted in lower costs to the health system (Can$7902.98 v. Can$14 875.82) and an improvement in QALYs (9.089 v. 9.006). The key driver of cost–effectiveness results was the relative risk of VTE as a result of apixaban. Results from the probabilistic analysis showed that at a willingness to pay of Can$50 000 per QALY, the strategy with the highest probability of being most cost-effective was apixaban, with a probability of 99.87%.

Interpretation:

We found that apixaban is a cost-saving option for the primary thromboprophylaxis of ambulatory patients with cancer who are starting chemotherapy and are at intermediate-to-high risk of VTE.

Oral anticoagulation in people with cancer who have no therapeutic or prophylactic indication for anticoagulation

BACKGROUND

Oral anticoagulants may improve the survival of people with cancer through an antithrombotic effect, yet increase the risk of bleeding.

OBJECTIVES

To evaluate the efficacy and safety of oral anticoagulants in ambulatory people with cancer undergoing chemotherapy, targeted therapy, immunotherapy, or radiotherapy (either alone or in combination), with no standard therapeutic or prophylactic indication for anticoagulation.

SEARCH METHODS

We conducted comprehensive searches on 14 June 2021, following the original electronic searches performed in February 2016 (last major search). We electronically searched the following databases: CENTRAL, MEDLINE, Embase. In addition, we handsearched conference proceedings, checked references of included studies, and searched for ongoing studies. As part of the living systematic review approach, we are running continual searches and will incorporate new evidence rapidly after it is identified.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) assessing the benefits and harms of vitamin K antagonists (VKAs) or direct oral anticoagulants (DOACs) in ambulatory people with cancer (i.e., not hospital inpatients during the time of their participation in trials) These people are typically undergoing systemic anticancer therapy, possibly including chemotherapy, targeted therapy, immunotherapy, or radiotherapy, but otherwise have no standard therapeutic or prophylactic indication for anticoagulation.

DATA COLLECTION AND ANALYSIS

Using a standardised form, two review authors independently extracted data on study design, participants, intervention outcomes of interest, and risk of bias. Outcomes of interest included all-cause mortality, pulmonary embolism, symptomatic deep vein thrombosis (DVT), major bleeding, minor bleeding and health-related quality of life. We assessed the certainty of evidence for each outcome using the GRADE approach.

MAIN RESULTS

Of 12,620 identified citations, 10 RCTs fulfilled the inclusion criteria. The oral anticoagulant was a vitamin K antagonist (VKA) in six of these RCTs, and a direct oral anticoagulant (DOAC) in the remaining four RCTs (three studies used apixaban; one used rivaroxaban). The comparator was either placebo or no prophylaxis. Compared to no prophylaxis, vitamin K antagonists (VKAs) probably reduce mortality at six months slightly (risk ratio (RR) 0.93, 95% confidence interval (CI) 0.77 to 1.13; risk difference (RD) 22 fewer per 1000, 95% CI 72 fewer to 41 more; moderate-certainty evidence), and probably reduce mortality at 12 months slightly (RR 0.95, 95% CI 0.87 to 1.03; RD 29 fewer per 1000, 95% CI 75 fewer to 17 more; moderate-certainty evidence). One study assessed the effect of a VKA compared to no prophylaxis on thrombosis; the evidence was very uncertain about the effect of VKA compared to no VKA on pulmonary embolism and symptomatic DVT (RR 1.05, 95% CI 0.07 to 16.58; RD 0 fewer per 1000, 95% CI 6 fewer to 98 more; very low-certainty evidence; RR 0.08, 95% CI 0.01 to 1.42; RD 35 fewer per 1000, 95% CI 37 fewer to 16 more; very low-certainty evidence, respectively). Also, VKAs probably increase major and minor bleeding at 12 months (RR 2.93, 95% CI 1.86 to 4.62; RD 107 more per 1000, 95% CI 48 more to 201 more; moderate-certainty evidence for major bleeding, and RR 3.14, 95% CI 1.85 to 5.32; RD 167 more per 1000, 95% CI 66 more to 337 more; moderate-certainty evidence for minor bleeding). Compared to no prophylaxis, at three to six months, direct oral anticoagulants (DOACs) probably reduce mortality slightly (RR 0.94, 95% CI 0.64 to 1.38, RD 11 fewer per 1000, 95% CI 67 fewer to 70 more; moderate-certainty evidence), probably reduce the risk of pulmonary embolism slightly compared to no prophylaxis (RR 0.48, 95% CI 0.24 to 0.98; RD 24 fewer per 1000, 95% CI 35 fewer to 1 fewer; moderate-certainty evidence), probably reduce symptomatic DVT slightly (RR 0.58, 95% CI 0.30 to 1.15; RD 21 fewer per 1000, 95% CI 35 fewer to 8 more; moderate-certainty evidence), probably do not increase major bleeding (RR 1.65, 95% CI 0.72 to 3.80; RD 9 more per 1000, 95% CI 4 fewer to 40 more; moderate-certainty evidence), and may increase minor bleeding (RR 3.58, 95% CI 0.55 to 23.44; RD 55 more per 1000, 95% CI 10 fewer to 482 more; low-certainty evidence).

AUTHORS' CONCLUSIONS

In ambulatory people with cancer undergoing chemotherapy, targeted therapy, immunotherapy, or radiotherapy (either alone or in combination), the current evidence on VKA thromboprophylaxis suggests that the harm of major bleeding might outweigh the benefit of reduction in venous thromboembolism. With DOACs, the benefit of reduction in venous thromboembolic events outweighs the risk of major bleeding. Editorial note: this is a living systematic review. Living systematic reviews offer a new approach to review updating in which the review is continually updated, incorporating relevant new evidence, as it becomes available. Please refer to the 'What's new' section in the  Cochrane Database of Systematic Reviews for the current status of this review.

Antithrombotic therapy for ambulatory patients with multiple myeloma receiving immunomodulatory agents

BACKGROUND

Multiple myeloma is a malignant plasma cell disorder characterised by clonal plasma cells that cause end-organ damage such as renal failure, lytic bone lesions, hypercalcaemia and/or anaemia. People with multiple myeloma are treated with immunomodulatory agents including lenalidomide, pomalidomide, and thalidomide. Multiple myeloma is associated with an increased risk of thromboembolism, which appears to be further increased in people receiving immunomodulatory agents.

OBJECTIVES

(1) To systematically review the evidence for the relative efficacy and safety of aspirin, oral anticoagulants, or parenteral anticoagulants in ambulatory patients with multiple myeloma receiving immunomodulatory agents who otherwise have no standard therapeutic or prophylactic indication for anticoagulation. (2) To maintain this review as a living systematic review by continually running the searches and incorporating newly identified studies.

SEARCH METHODS

We conducted a comprehensive literature search that included (1) a major electronic search (14 June 2021) of the following databases: Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE via Ovid, and Embase via Ovid; (2) hand-searching of conference proceedings; (3) checking of reference lists of included studies; and (4) a search for ongoing studies in trial registries. As part of the living systematic review approach, we are running continual searches, and we will incorporate new evidence rapidly after it is identified.

SELECTION CRITERIA

Randomised controlled trials (RCTs) assessing the benefits and harms of oral anticoagulants such as vitamin K antagonist (VKA) and direct oral anticoagulants (DOAC), anti-platelet agents such as aspirin (ASA), and parenteral anticoagulants such as low molecular weight heparin (LMWH)in ambulatory patients with multiple myeloma receiving immunomodulatory agents.

DATA COLLECTION AND ANALYSIS

Using a standardised form, we extracted data in duplicate on study design, participants, interventions, outcomes of interest, and risk of bias. Outcomes of interest included all-cause mortality, symptomatic deep vein thrombosis (DVT), pulmonary embolism (PE), major bleeding, and minor bleeding. For each outcome we calculated the risk ratio (RR) with its 95% confidence interval (CI) and the risk difference (RD) with its 95% CI. We then assessed the certainty of evidence at the outcome level following the GRADE approach (GRADE Handbook).

MAIN RESULTS

We identified 1015 identified citations and included 11 articles reporting four RCTs that enrolled 1042 participants. The included studies made the following comparisons: ASA versus VKA (one study); ASA versus LMWH (two studies); VKA versus LMWH (one study); and ASA versus DOAC (two studies, one of which was an abstract). ASA versus VKA One RCT compared ASA to VKA at six months follow-up. The data did not confirm or exclude a beneficial or detrimental effect of ASA relative to VKA on all-cause mortality (RR 3.00, 95% CI 0.12 to 73.24; RD 2 more per 1000, 95% CI 1 fewer to 72 more; very low-certainty evidence); symptomatic DVT (RR 0.57, 95% CI 0.24 to 1.33; RD 27 fewer per 1000, 95% CI 48 fewer to 21 more; very low-certainty evidence); PE (RR 1.00, 95% CI 0.25 to 3.95; RD 0 fewer per 1000, 95% CI 14 fewer to 54 more; very low-certainty evidence); major bleeding (RR 7.00, 95% CI 0.36 to 134.72; RD 6 more per 1000, 95% CI 1 fewer to 134 more; very low-certainty evidence); and minor bleeding (RR 6.00, 95% CI 0.73 to 49.43; RD 23 more per 1000, 95% CI 1 fewer to 220 more; very low-certainty evidence). One RCT compared ASA to VKA at two years follow-up. The data did not confirm or exclude a beneficial or detrimental effect of ASA relative to VKA on all-cause mortality (RR 0.50, 95% CI 0.05 to 5.47; RD 5 fewer per 1000, 95% CI 9 fewer to 41 more; very low-certainty evidence); symptomatic DVT (RR 0.71, 95% CI 0.35 to 1.44; RD 22 fewer per 1000, 95% CI 50 fewer to 34 more; very low-certainty evidence); and PE (RR 1.00, 95% CI 0.25 to 3.95; RD 0 fewer per 1000, 95% CI 14 fewer to 54 more; very low-certainty evidence). ASA versus LMWH Two RCTs compared ASA to LMWH at six months follow-up. The pooled data did not confirm or exclude a beneficial or detrimental effect of ASA relative to LMWH on all-cause mortality (RR 1.00, 95% CI 0.06 to 15.81; RD 0 fewer per 1000, 95% CI 2 fewer to 38 more; very low-certainty evidence); symptomatic DVT (RR 1.23, 95% CI 0.49 to 3.08; RD 5 more per 1000, 95% CI 11 fewer to 43 more; very low-certainty evidence); PE (RR 7.71, 95% CI 0.97 to 61.44; RD 7 more per 1000, 95% CI 0 fewer to 60 more; very low-certainty evidence); major bleeding (RR 6.97, 95% CI 0.36 to 134.11; RD 6 more per 1000, 95% CI 1 fewer to 133 more; very low-certainty evidence); and minor bleeding (RR 1.42, 95% CI 0.35 to 5.78; RD 4 more per 1000, 95% CI 7 fewer to 50 more; very low-certainty evidence). One RCT compared ASA to LMWH at two years follow-up. The pooled data did not confirm or exclude a beneficial or detrimental effect of ASA relative to LMWH on all-cause mortality (RR 1.00, 95% CI 0.06 to 15.89; RD 0 fewer per 1000, 95% CI 4 fewer to 68 more; very low-certainty evidence); symptomatic DVT (RR 1.20, 95% CI 0.53 to 2.72; RD 9 more per 1000, 95% CI 21 fewer to 78 more; very low-certainty evidence); and PE (RR 9.00, 95% CI 0.49 to 166.17; RD 8 more per 1000, 95% CI 1 fewer to 165 more; very low-certainty evidence). VKA versus LMWH One RCT compared VKA to LMWH at six months follow-up. The data did not confirm or exclude a beneficial or detrimental effect of VKA relative to LMWH on all-cause mortality (RR 0.33, 95% CI 0.01 to 8.10; RD 3 fewer per 1000, 95% CI 5 fewer to 32 more; very low-certainty evidence); symptomatic DVT (RR 2.32, 95% CI 0.91 to 5.93; RD 36 more per 1000, 95% CI 2 fewer to 135 more; very low-certainty evidence); PE (RR 8.96, 95% CI 0.49 to 165.42; RD 8 more per 1000, 95% CI 1 fewer to 164 more; very low-certainty evidence); and minor bleeding (RR 0.33, 95% CI 0.03 to 3.17; RD 9 fewer per 1000, 95% CI 13 fewer to 30 more; very low-certainty evidence). The study reported that no major bleeding occurred in either arm. One RCT compared VKA to LMWH at two years follow-up. The data did not confirm or exclude a beneficial or detrimental effect of VKA relative to LMWH on all-cause mortality (RR 2.00, 95% CI 0.18 to 21.90; RD 5 more per 1000, 95% CI 4 fewer to 95 more; very low-certainty evidence); symptomatic DVT (RR 1.70, 95% CI 0.80 to 3.63; RD 32 more per 1000, 95% CI 9 fewer to 120 more; very low-certainty evidence); and PE (RR 9.00, 95% CI 0.49 to 166.17; RD 8 more per 1000, 95% CI 1 fewer to 165 more; very low-certainty evidence). ASA versus DOAC One RCT compared ASA to DOAC at six months follow-up. The data did not confirm or exclude a beneficial or detrimental effect of ASA relative to DOAC on DVT, PE, and major bleeding and minor bleeding (minor bleeding: RR 5.00, 95% CI 0.31 to 79.94; RD 4 more per 1000, 95% CI 1 fewer to 79 more; very low-certainty evidence). The study reported that no DVT, PE, or major bleeding events occurred in either arm. These results did not change in a meta-analysis including the study published as an abstract.

AUTHORS' CONCLUSIONS

The certainty of the available evidence for the comparative effects of ASA, VKA, LMWH, and DOAC on all-cause mortality, DVT, PE, or bleeding was either low or very low. People with multiple myeloma considering antithrombotic agents should balance the possible benefits of reduced thromboembolic complications with the possible harms and burden of anticoagulants. Editorial note: This is a living systematic review. Living systematic reviews offer a new approach to review updating in which the review is continually updated, incorporating relevant new evidence as it becomes available. Please refer to the Cochrane Database of Systematic Reviews for the current status of this review.

Current Recommendations for the Management of Cancer-Associated Venous Thromboembolism

Cancer-associated thrombosis (CAT) is a major cause of death in oncological patients. The mechanisms of thrombogenesis in cancer patients are not fully established, and it seems to be multifactorial in origin. Also, several risk factors for venous thromboembolism (VTE) are present in these patients such as tumor site, stage, histology of cancer, chemotherapy, surgery, and immobilization. Anticoagulant treatment in CAT is challenging because of high bleeding risk during treatment and recurrence of VTE. Current major guidelines recommend low molecular weight heparins (LMWHs) for early and long-term treatment of VTE in cancer patients. In the past years, direct oral anticoagulants (DOACs) are recommended as potential treatment option for VTE and have recently been proposed as a new option for treating CAT. This manuscript will give a short overview of risk factors involved in the development of CAT and a summary on the recent recommendations and guidelines for treatment of VTE in patients with malignancies, discussing also some special clinical situations (e.g. renal impairment, catheter-related thrombosis, and thrombocytopenia).

Thromboembolic risk in patients with lung cancer receiving systemic therapy

In this retrospective study, we investigated the influence of chemotherapy and immunotherapy on thromboembolic risk among United States Veterans with lung cancer during their first 6 months (180 days) following initiation of systemic therapy. Included patients received treatment with common front-line agents that were divided into four groups: chemotherapy alone, immunotherapy alone, combination of chemo- and immunotherapies, and molecularly targeted therapies (control group). The cohort experienced a 7·4% overall incidence of thrombosis, but the analysis demonstrated significantly different rates among the different groups. We explored models incorporating multiple confounding variables as well as the competing risk of death, and these results indicated that both chemo- and immunotherapies were associated with an increased incidence of thrombosis, either alone or combined, compared with the control group (7·56%, P = 2.2 × 10^-16 ; 10·2%, P = 2.2 × 10^-16 ; and 7·87%, P = 2.4 × 10^-14 respectively vs. 4·10%). The Khorana score was found to be associated with increased risk, as were vascular disease and metastases. We found an association between risk of thrombosis and the use of anticoagulation, accounting for several confounders, including history of thrombosis. Further study is warranted to better determine the drivers of thromboembolic risk and to identify ways to mitigate this risk for patients.

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.

Reflection on modern methods: generalized linear models for prognosis and intervention-theory, practice and implications for machine learning

Prediction and causal explanation are fundamentally distinct tasks of data analysis. In health applications, this difference can be understood in terms of the difference between prognosis (prediction) and prevention/treatment (causal explanation). Nevertheless, these two concepts are often conflated in practice. We use the framework of generalized linear models (GLMs) to illustrate that predictive and causal queries require distinct processes for their application and subsequent interpretation of results. In particular, we identify five primary ways in which GLMs for prediction differ from GLMs for causal inference: (i) the covariates that should be considered for inclusion in (and possibly exclusion from) the model; (ii) how a suitable set of covariates to include in the model is determined; (iii) which covariates are ultimately selected and what functional form (i.e. parameterization) they take; (iv) how the model is evaluated; and (v) how the model is interpreted. We outline some of the potential consequences of failing to acknowledge and respect these differences, and additionally consider the implications for machine learning (ML) methods. We then conclude with three recommendations that we hope will help ensure that both prediction and causal modelling are used appropriately and to greatest effect in health research.

Venous and Arterial Thromboembolism in Patients With Cancer: JACC: CardioOncology State-of-the-Art Review

Venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, represents a major cause of morbidity and mortality in patients with cancer. Arterial thromboembolism, including myocardial infarction and stroke, is also prevalent. Risk differs in subgroups, with higher rates observed in specific cancers including pancreas, stomach, and multiple myeloma. Thromboprophylaxis is recommended for most patients with active cancer hospitalized for medical illnesses and after major cancer surgery. Outpatient thromboprophylaxis is not routinely recommended, but emerging data suggest that a high-risk population that benefits from pharmacological thromboprophylaxis can be identified using a validated risk tool. Direct oral anticoagulants are emerging as the preferred new option for the treatment of cancer-associated VTE, although low-molecular-weight heparin remains a standard for patients at high bleeding risk. Management of VTE beyond the first 6 months and challenging clinical situations including intracranial metastases and thrombocytopenia require careful management in balancing the benefits and risks of anticoagulation and remain major knowledge gaps in evidence.

Extended thromboprophylaxis for medically ill patients with cancer: a systemic review and meta-analysis

Hospitalized medically ill patients with cancer are at increased risk of both venous thromboembolism and bleeding. The safety and efficacy of extended thromboprophylaxis in patients with cancer are unclear. We conducted a systematic review and meta-analysis of the literature using of MEDLINE, EMBASE, and the Cochrane CENTRAL databases to identify cancer subgroups enrolled in randomized controlled trials evaluating extended thromboprophylaxis following hospitalization. The primary outcomes were symptomatic and incidental venous thromboembolic events and hemorrhage (major hemorrhage and clinically relevant nonmajor bleeding). Four randomized controlled trials reported the outcomes of extended thromboprophylaxis in 3655 medically ill patients with active or history of cancer. The rates of venous thromboembolic events were similar between the extended-duration and standard-duration groups (odds ratio [OR], 0.85; 95% confidence interval [CI], 0.61-1.18; I2 = 0%). However, major and clinically relevant nonmajor bleeding occurred significantly more frequently in the extended-duration thromboprophylaxis group (OR, 2.10; 95% CI, 1.33-3.35; I2 = 8%). Extended thromboprophylaxis in hospitalized medically ill patients with cancer was not associated with a reduced rate of venous thromboembolic events but was associated with increased risk of hemorrhage. This study protocol was registered on PROSPERO as #CRD42020209333.

Primary thromboprophylaxis in ambulatory cancer patients with a high Khorana score: a systematic review and meta-analysis

Guidelines suggest thromboprophylaxis for ambulatory cancer patients starting chemotherapy with an intermediate to high risk of venous thromboembolism (VTE) according to Khorana score. Data on thromboprophylaxis efficacy in different Khorana score risk groups remain ambiguous. We sought to evaluate thromboprophylaxis in patients with an intermediate- to high-risk (≥2 points) Khorana score and an intermediate-risk score (2 points) or high-risk score (≥3 points) separately. MEDLINE, Embase, and CENTRAL were searched for randomized controlled trials (RCTs) comparing thromboprophylaxis with placebo or standard care in ambulatory cancer patients. Outcomes were VTE, major bleeding, and all-cause mortality. Relative risks (RRs) were calculated in a profile-likelihood random-effects model. Six RCTs were identified, involving 4626 cancer patients. Thromboprophylaxis with direct oral anticoagulants (DOACs) or low molecular weight heparin (LMWH) significantly reduced VTE risk in intermediate- to high-risk (RR, 0.51; 95% confidence interval [CI], 0.34-0.67), intermediate-risk (RR, 0.58; 95% CI, 0.36-0.83), and high-risk patients (RR, 0.45; 95% CI, 0.28-0.67); the numbers needed to treat (NNTs) were 25 (intermediate to high risk), 34 (intermediate risk), and 17 (high risk), respectively. There was no significant difference in major bleeding (RR, 1.06; 95% CI, 0.69-1.67) or all-cause mortality (RR, 0.90; 95% CI, 0.82-1.01). The numbers needed to harm (NNHs) for major bleeding in intermediate- to high-risk, intermediate-risk, and high-risk patients were 1000, -500, and 334, respectively. The overall NNH was lower in DOAC studies (100) versus LMWH studies (-500). These findings indicate thromboprophylaxis effectively reduces the risk of VTE in patients with an intermediate- to high-risk Khorana score, although the NNT is twice as high for intermediate-risk patients compared with high-risk patients.

American Society of Hematology 2021 guidelines for management of venous thromboembolism: prevention and treatment in patients with cancer

BACKGROUND

Venous thromboembolism (VTE) is a common complication among patients with cancer. Patients with cancer and VTE are at a markedly increased risk for morbidity and mortality.

OBJECTIVE

These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in their decisions about the prevention and treatment of VTE in patients with cancer.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The guideline development process was supported by updated or new systematic evidence reviews. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to assess evidence and make recommendations.

RESULTS

Recommendations address mechanical and pharmacological prophylaxis in hospitalized medical patients with cancer, those undergoing a surgical procedure, and ambulatory patients receiving cancer chemotherapy. The recommendations also address the use of anticoagulation for the initial, short-term, and long-term treatment of VTE in patients with cancer.

CONCLUSIONS

Strong recommendations include not using thromboprophylaxis in ambulatory patients receiving cancer chemotherapy at low risk of VTE and to use low-molecular-weight heparin (LMWH) for initial treatment of VTE in patients with cancer. Conditional recommendations include using thromboprophylaxis in hospitalized medical patients with cancer, LMWH or fondaparinux for surgical patients with cancer, LMWH or direct oral anticoagulants (DOAC) in ambulatory patients with cancer receiving systemic therapy at high risk of VTE and LMWH or DOAC for initial treatment of VTE, DOAC for the short-term treatment of VTE, and LMWH or DOAC for the long-term treatment of VTE in patients with cancer.

Aberrant Factors of Fibrinolysis and Coagulation in Pancreatic Cancer

Aberrant factors associated with fibrinolysis and thrombosis are found in many cancer patients, which can promote metastasis and are associated with poor prognosis. The relationship between tumor-associated fibrinolysis and thrombosis is poorly understood in pancreatic cancer. This review provides a brief highlight of existing studies that the fibrinolysis and coagulation systems were activated in pancreatic cancer patients, along with aberrant high concentrations of tissue plasminogen activator (t-PA), urine plasminogen activator (u-PA), D-dimer, fibrinogen, or platelets. These factors cooperate with each other, propelling tumor cell shedding, localization, adhesion to distant metastasis. The relationship between thrombosis or fibrinolysis and cancer immune escape is also investigated. In addition, the potential prevention and therapy strategies of pancreatic cancer targeting factors in fibrinolysis and coagulation systems are also been discussed, in which we highlight two effective agents aspirin and low-molecular weight heparin (LMWH). Summarily, this review provides new directions for the research and treatment of pancreatic cancer.

Primary prophylaxis for venous thromboembolism in ambulatory cancer patients receiving chemotherapy

BACKGROUND

Venous thromboembolism (VTE) often complicates the clinical course of cancer. The risk is further increased by chemotherapy, but the trade-off between safety and efficacy of primary thromboprophylaxis in cancer patients treated with chemotherapy is uncertain. This is the third update of a review first published in February 2012.

OBJECTIVES

To assess the efficacy and safety of primary thromboprophylaxis for VTE in ambulatory cancer patients receiving chemotherapy compared with placebo or no thromboprophylaxis, or an active control intervention.

SEARCH METHODS

For this update, the Cochrane Vascular Information Specialist searched the Cochrane Vascular, CENTRAL, MEDLINE, Embase and CINAHL databases and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 3 August 2020. We also searched the reference lists of identified studies and contacted content experts and trialists for relevant references.

SELECTION CRITERIA

Randomised controlled trials comparing any oral or parenteral anticoagulant or mechanical intervention to no thromboprophylaxis or placebo, or comparing two different anticoagulants.

DATA COLLECTION AND ANALYSIS

We extracted data on risk of bias, participant characteristics, interventions, and outcomes including symptomatic VTE and major bleeding as the primary effectiveness and safety outcomes, respectively. We applied GRADE to assess the certainty of evidence.

MAIN RESULTS

We identified six additional randomised controlled trials (3326 participants) for this update, bringing the included study total to 32 (15,678 participants), all evaluating pharmacological interventions and performed mainly in people with locally advanced or metastatic cancer. The certainty of the evidence ranged from high to very low across the different outcomes and comparisons. The main limiting factors were imprecision and risk of bias. Thromboprophylaxis with direct oral anticoagulants (direct factor Xa inhibitors apixaban and rivaroxaban) may decrease the incidence of symptomatic VTE (risk ratio (RR) 0.43, 95% confidence interval (CI) 0.18 to 1.06; 3 studies, 1526 participants; low-certainty evidence); and probably increases the risk of major bleeding compared with placebo (RR 1.74, 95% CI 0.82 to 3.68; 3 studies, 1494 participants; moderate-certainty evidence). When compared with no thromboprophylaxis, low-molecular-weight heparin (LMWH) reduced the incidence of symptomatic VTE (RR 0.62, 95% CI 0.46 to 0.83; 11 studies, 3931 participants; high-certainty evidence); and probably increased the risk of major bleeding events (RR 1.63, 95% CI 1.12 to 2.35; 15 studies, 7282 participants; moderate-certainty evidence). In participants with multiple myeloma, LMWH resulted in lower symptomatic VTE compared with the vitamin K antagonist warfarin (RR 0.33, 95% CI 0.14 to 0.83; 1 study, 439 participants; high-certainty evidence), while LMWH probably lowers symptomatic VTE more than aspirin (RR 0.51, 95% CI 0.22 to 1.17; 2 studies, 781 participants; moderate-certainty evidence). Major bleeding was observed in none of the participants with multiple myeloma treated with LMWH or warfarin and in less than 1% of those treated with aspirin. Only one study evaluated unfractionated heparin against no thromboprophylaxis, but did not report on VTE or major bleeding. When compared with placebo or no thromboprophylaxis, warfarin may importantly reduce symptomatic VTE (RR 0.15, 95% CI 0.02 to 1.20; 1 study, 311 participants; low-certainty evidence) and may result in a large increase in major bleeding (RR 3.82, 95% CI 0.97 to 15.04; 4 studies, 994 participants; low-certainty evidence). One study evaluated antithrombin versus no antithrombin in children. This study did not report on symptomatic VTE but did report any VTE (symptomatic and incidental VTE). The effect of antithrombin on any VTE and major bleeding is uncertain (any VTE: RR 0.84, 95% CI 0.41 to 1.73; major bleeding: RR 0.78, 95% CI 0.03 to 18.57; 1 study, 85 participants; very low-certainty evidence).

AUTHORS' CONCLUSIONS

In ambulatory cancer patients, primary thromboprophylaxis with direct factor Xa inhibitors may reduce the incidence of symptomatic VTE (low-certainty evidence) and probably increases the risk of major bleeding (moderate-certainty evidence) when compared with placebo. LMWH decreases the incidence of symptomatic VTE (high-certainty evidence), but increases the risk of major bleeding (moderate-certainty evidence) when compared with placebo or no thromboprophylaxis. Evidence for the use of thromboprophylaxis with anticoagulants other than direct factor Xa inhibitors and LMWH is limited. More studies are warranted to evaluate the efficacy and safety of primary prophylaxis in specific types of chemotherapeutic agents and types of cancer, such as gastrointestinal or genitourinary cancer.

Venous Thromboembolism Prophylaxis with Low-Molecular-Weight Heparin in Primary Central Nervous System Lymphoma

BACKGROUND

Venous thromboembolism (VTE) is a frequent, potentially lethal complication in individuals with cancer. Patients with brain tumors are at particularly high risk for VTE. Primary central nervous system lymphoma (PCNSL) is a rare subtype of diffuse large B cell lymphoma, involving the craniospinal axis. The incidence of VTE in patients with PCNSL was reported as very high, occurring mostly in the early period of therapy.

OBJECTIVES

We aimed to evaluate the efficacy and safety of prophylactic low-molecular-weight heparin (LMWH) throughout the treatment of PCNSL.

PATIENTS

All patients >18 years of age diagnosed and treated for PCNSL at our institution in 2005-2017 were included.

RESULTS

There were 44 patients; mean age at diagnosis was 61.5 years. Three patients (6.8%) had a personal history of thrombosis, 11 (25%) had a history of diabetes or smoking, and 32 (72%) had an Eastern Cooperative Oncology Group performance status of 0-1 at diagnosis. During treatment with LMWH, no VTE events were recorded; 2 (4.5%) patients experienced a minor bleeding event and 1 (2.3%) a major bleeding event.

CONCLUSIONS

Among our 44 patients with PCNSL treated with prophylactic LMWH, no VTE events were recorded, and only 1 (asymptomatic) intracranial bleed was recorded. Within the limitations of a retrospective nonrandomized study, our findings suggest that VTE prophylaxis may be beneficial for individuals with PCNSL.

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

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

Management of Cancer-Associated Thrombosis: An Evolving Area

The management of cancer-associated thrombosis (CAT) is an evolving area. With the use of direct oral anticoagulants as a new option in the management of CAT, clinicians now face several choices for the individual cancer patient with venous thromboembolism. A personalized approach, matching the right drug to the right patient, based on drug properties, efficacy and safety, side effect profile of each drug, and patient values and preference, will probably supplant the one size fits all approach of use of only low-molecular-weight heparin in the near future. We herein present eight translational, clinical research, and review articles on recent advances in the management of CAT published in the Special Issue “Treatment for Cancer-Associated Thrombosis” of Cancers. For now, a multidisciplinary patient-centered approach involving a close cooperation between oncologists and other specialists is warranted to guide clinical decision making and optimize the treatment of VTE in cancer patient.

Prophylaxis of thromboembolism during therapy with asparaginase in adults with acute lymphoblastic leukaemia

BACKGROUND

The risk of venous thromboembolism is increased in adults and enhanced by asparaginase-based chemotherapy, and venous thromboembolism introduces a secondary risk of treatment delay and premature discontinuation of key anti-leukaemic agents, potentially compromising survival. Yet, the trade-off between benefits and harms of primary thromboprophylaxis in adults with acute lymphoblastic leukaemia (ALL) treated according to asparaginase-based regimens is uncertain.  OBJECTIVES: The primary objectives were to assess the benefits and harms of primary thromboprophylaxis for first-time symptomatic venous thromboembolism in adults with ALL receiving asparaginase-based therapy compared with placebo or no thromboprophylaxis. The secondary objectives were to compare the benefits and harms of different groups of primary systemic thromboprophylaxis by stratifying the main results per type of drug (heparins, vitamin K antagonists, synthetic pentasaccharides, parenteral direct thrombin inhibitors, direct oral anticoagulants, and blood-derived products for antithrombin substitution).

SEARCH METHODS

We conducted a comprehensive literature search on 02 June 2020, with no language restrictions, including (1) electronic searches of Pubmed/MEDLINE; Embase/Ovid; Scopus/Elsevier; Web of Science Core Collection/Clarivate Analytics; and Cochrane Central Register of Controlled Trials (CENTRAL) and (2) handsearches of (i) reference lists of identified studies and related reviews; (ii) clinical trials registries (ClinicalTrials.gov registry; the International Standard Randomized Controlled Trial Number (ISRCTN) registry; the World Health Organisation's International Clinical Trials Registry Platform (ICTRP); and pharmaceutical manufacturers of asparaginase including Servier, Takeda, Jazz Pharmaceuticals, Ohara Pharmaceuticals, and Kyowa Pharmaceuticals), and (iii) conference proceedings (from the annual meetings of the American Society of Hematology (ASH); the European Haematology Association (EHA); the American Society of Clinical Oncology (ASCO); and the International Society on Thrombosis and Haemostasis (ISTH)). We conducted all searches from 1970 (the time of introduction of asparaginase in ALL treatment). We contacted the authors of relevant studies to identify any unpublished material, missing data, or information regarding ongoing studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs); including quasi-randomised, controlled clinical, cross-over, and cluster-randomised trial designs) comparing any parenteral/oral preemptive anticoagulant or mechanical intervention with placebo or no thromboprophylaxis, or comparing two different pre-emptive anticoagulant interventions in adults aged at least 18 years with ALL treated according to asparaginase-based chemotherapy regimens. For the description of harms, non-randomised observational studies with a control group were eligible for inclusion.  DATA COLLECTION AND ANALYSIS: Using a standardised data collection form, two review authors independently screened and selected studies, extracted data, assessed risk of bias for each outcome using standardised tools (RoB 2.0 tool for RCTs and ROBINS-I tool for non-randomised studies) and the certainty of evidence for each outcome using the GRADE approach. Primary outcomes included first-time symptomatic venous thromboembolism, all-cause mortality, and major bleeding. Secondary outcomes included asymptomatic venous thromboembolism, venous thromboembolism-related mortality, adverse events (i.e. clinically relevant non-major bleeding and heparin-induced thrombocytopenia for trials using heparins), and quality of life. Analyses were performed according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions. For non-randomised studies, we evaluated all studies (including studies judged to be at critical risk of bias in at least one of the ROBINS-I domains) in a sensitivity analysis exploring confounding.  MAIN RESULTS: We identified 23 non-randomised studies that met the inclusion criteria of this review, of which 10 studies provided no outcome data for adults with ALL. We included the remaining 13 studies in the 'Risk of bias' assessment, in which we identified invalid control group definition in two studies and judged outcomes of nine studies to be at critical risk of bias in at least one of the ROBINS-I domains and outcomes of two studies at serious risk of bias. We did not assess the benefits of thromboprophylaxis, as no RCTs were included. In the main descriptive analysis of harms, we included two retrospective non-randomised studies with outcomes judged to be at serious risk of bias. One study evaluated antithrombin concentrates compared to no antithrombin concentrates. We are uncertain whether antithrombin concentrates have an effect on all-cause mortality (risk ratio (RR) 0.55, 95% confidence interval (CI) 0.26 to 1.19 (intention-to-treat analysis); one study, 40 participants; very low certainty of evidence). We are uncertain whether antithrombin concentrates have an effect on venous thromboembolism-related mortality (RR 0.10, 95% CI 0.01 to 1.94 (intention-to-treat analysis); one study, 40 participants; very low certainty of evidence). We do not know whether antithrombin concentrates have an effect on major bleeding, clinically relevant non-major bleeding, and quality of life in adults with ALL treated with asparaginase-based chemotherapy, as data were insufficient. The remaining study (224 participants) evaluated prophylaxis with low-molecular-weight heparin versus no prophylaxis. However, this study reported insufficient data regarding harms including all-cause mortality, major bleeding, venous thromboembolism-related mortality, clinically relevant non-major bleeding, heparin-induced thrombocytopenia, and quality of life. In the sensitivity analysis of harms, exploring the effect of confounding, we also included nine non-randomised studies with outcomes judged to be at critical risk of bias primarily due to uncontrolled confounding. Three studies (179 participants) evaluated the effect of antithrombin concentrates and six studies (1224 participants) evaluated the effect of prophylaxis with different types of heparins. When analysing all-cause mortality; venous thromboembolism-related mortality; and major bleeding (studies of heparin only) including all studies with extractable outcomes for each comparison (antithrombin and low-molecular-weight heparin), we observed small study sizes; few events; wide CIs crossing the line of no effect; and substantial heterogeneity by visual inspection of the forest plots. Although the observed heterogeneity could arise through the inclusion of a small number of studies with differences in participants; interventions; and outcome assessments, the likelihood that bias due to uncontrolled confounding was the cause of heterogeneity is inevitable. Subgroup analyses were not possible due to insufficient data.  AUTHORS' CONCLUSIONS: We do not know from the currently available evidence, if thromboprophylaxis used for adults with ALL treated according to asparaginase-based regimens is associated with clinically appreciable benefits and acceptable harms. The existing research on this question is solely of non-randomised design, seriously to critically confounded, and underpowered with substantial imprecision. Any estimates of effect based on the existing insufficient evidence is very uncertain and is likely to change with future research.

Paraneoplastic Thromboembolism and Thrombophilia: Significance in Visceral Medicine

Background

Venous (VTE) and arterial thromboembolism (ATE) are frequent complications of cancer. Risk assessment models (RAM) for stratification of the thrombotic risk in patients with gastrointestinal (GI) cancer have several limitations.

Summary

While pancreatic and stomach cancer are considered very high risk in all RAM, the risk of colorectal cancer differs between RAM, and esophageal cancer and cholangiocarcinoma were underrepresented or not included in any RAM. In addition, up to 49% of patients with pancreatic cancer develop splanchnic vein thrombosis (SVT). Prophylaxis with low-molecular-weight heparins (LMWH) in ambulatory cancer patients is associated with a positive risk-benefit ratio only in high-risk patients and LMWH have been the standard of care for the treatment of cancer-associated VTE and SVT over the last years. Direct oral anticoagulants (DOAC) have been shown to be equally effective compared to LMWH, but bleedings from the GI tract are more frequent. Therefore, recent guidelines suggest the use of DOAC for VTE treatment and for prophylaxis in ambulatory patients at high risk for VTE, but patients at high risk for bleeding, especially with active luminal cancer, should receive LMWH.

Key Messages

This review discusses RAM and the current options for prophylaxis and treatment of cancer-associated ATE, VTE, and SVT focusing on GI cancers.

Prevention and treatment of cancer-associated thrombosis

Cancer is a hypercoagulable state with an associated increased risk of venous thromboembolism (vte) that is further amplified in individuals who undergo chemotherapy. Compared with patients having cancer alone or vte alone, patients who develop cancer-associated vte have a significantly poorer prognosis. The risks of recurrent vte despite appropriate anticoagulation therapy and of bleeding are also higher in patients with cancer than in those without. For those reasons, the prevention and appropriate management of cancer-associated thrombosis is of paramount importance. Although low-molecular-weight heparin has been the standard of care for the prevention and treatment of cancer-associated thrombosis, direct oral anticoagulants are increasingly being adopted as an effective and safe alternative.

Successful Model for Guideline Implementation to Prevent Cancer-Associated Thrombosis: Venous Thromboembolism Prevention in the Ambulatory Cancer Clinic

PURPOSE

Guidelines recommend venous thromboembolism (VTE) risk assessment in outpatients with cancer and pharmacologic thromboprophylaxis in selected patients at high risk for VTE. Although validated risk stratification tools are available, < 10% of oncologists use a risk assessment tool, and rates of VTE prophylaxis in high-risk patients are low in practice. We hypothesized that implementation of a systems-based program that uses the electronic health record (EHR) and offers personalized VTE prophylaxis recommendations would increase VTE risk assessment rates in patients initiating outpatient chemotherapy.

PATIENTS AND METHODS

Venous Thromboembolism Prevention in the Ambulatory Cancer Clinic (VTEPACC) was a multidisciplinary program implemented by nurses, oncologists, pharmacists, hematologists, advanced practice providers, and quality partners. We prospectively identified high-risk patients using the Khorana and Protecht scores (≥ 3 points) via an EHR-based risk assessment tool. Patients with a predicted high risk of VTE during treatment were offered a hematology consultation to consider VTE prophylaxis. Results of the consultation were communicated to the treating oncologist, and clinical outcomes were tracked.

RESULTS

A total of 918 outpatients with cancer initiating cancer-directed therapy were evaluated. VTE monthly education rates increased from < 5% before VTEPACC to 81.6% (standard deviation [SD], 11.9; range, 63.6%-97.7%) during the implementation phase and 94.7% (SD, 4.9; range, 82.1%-100%) for the full 2-year postimplementation phase. In the postimplementation phase, 213 patients (23.2%) were identified as being at high risk for developing a VTE. Referrals to hematology were offered to 151 patients (71%), with 141 patients (93%) being assessed and 93.8% receiving VTE prophylaxis.

CONCLUSION

VTEPACC is a successful model for guideline implementation to provide VTE risk assessment and prophylaxis to prevent cancer-associated thrombosis in outpatients. Methods applied can readily translate into practice and overcome the current implementation gaps between guidelines and clinical practice.

Risk Prediction and New Prophylaxis Strategies for Thromboembolism in Cancer

In the general population, the incidence of thromboembolic events is 117 cases/100,000 inhabitants/year, while in cancer patient incidence, it is four-fold higher, especially in patients who receive chemotherapy and who are affected by pancreatic, lung or gastric cancer. At the basis of venous thromboembolism (VTE) there is the so-called Virchow triad, but tumor cells can activate coagulation pathway by various direct and indirect mechanisms, and chemotherapy can contribute to VTE onset. For these reasons, several studies were conducted in order to assess efficacy and safety of the use of anticoagulant therapy in cancer patients, both in prophylaxis setting and in therapy setting. With this review, we aim to record principal findings and current guidelines about thromboprophylaxis in cancer patients, with particular attention to subjects with additional risk factors such as patients receiving chemotherapy or undergoing surgery, hospitalized patients for acute medical intercurrent event and patients with central venous catheters. Nonetheless we added a brief insight about acute and maintenance therapy of manifested venous thromboembolism in cancer patients.

Primary Thromboprophylaxis in Ambulatory Pancreatic Cancer Patients Receiving Chemotherapy: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Patients with pancreatic cancer (PC) carry the highest risk of venous thromboembolism (VTE) amongst all cancer patients. Appropriate use of primary thromboprophylaxis might significantly and safely reduce its burden. We performed a systematic review of published studies and meeting abstracts using MEDLINE and EMBASE through July 2020 to evaluate the efficacy and safety of primary thromboprophylaxis in ambulatory PC patients receiving chemotherapy. The Mantel–Haenszel random effect model was used to estimate the pooled event-based risk ratio (RR) and the pooled absolute risk difference (RD) with a 95% confidence interval (CI). Five randomized controlled studies with 1003 PC patients were included in this meta-analysis. Compared to placebo, thromboprophylaxis significantly decreased the risk of VTE (pooled RR 0.31, 95% CI 0.19–0.51, p < 0.00001, I² = 8%; absolute RD −0.08, 95% CI −0.12–−0.05, p < 0.00001, I² = 0%), with an estimated number needed to treat of 11.9 patients to prevent one VTE event. Similar reductions of VTE were observed in studies with parenteral (RR 0.30, 95% CI 0.17–0.53) versus oral anticoagulants (RR 0.37, 95% CI 0.14–0.99) and in studies using prophylactic doses of anticoagulants (RR 0.34, 95% CI 0.17–0.70) versus supra-prophylactic doses of anticoagulants (RR 0.27, 95% CI 0.08–0.90). The pooled RR for major bleeding was 1.08 (95% CI 0.47–2.52, p = 0.85, I² = 0%) and the absolute RD was 0.00 (95% CI −0.02–0.03, p = 0.85, I² = 0%). Evidence supports a net clinical benefit of thromboprophylaxis in ambulatory PC patients receiving chemotherapy. Adequately powered randomized phase III studies assessing the most effective anticoagulant and the optimal dose, schedule and duration of thromboprophylaxis to be used are warranted.

Dynamic assessment of venous thromboembolism risk in patients with cancer by longitudinal D-Dimer analysis: A prospective study

BACKGROUND

Venous thromboembolism (VTE) is a frequent complication of cancer. Elevated D-dimer is associated with an increased risk of cancer-associated VTE. Whether changes in D-dimer over time harbor additional prognostic information that may be exploited clinically for dynamic prediction of VTE is unclear.

OBJECTIVES

To explore the potential role of longitudinal D-dimer trajectories for personalized prediction of cancer-associated VTE.

PATIENTS/METHODS

A total of 167 patients with active malignancy were prospectively enrolled (gastrointestinal: n = 59 [35%], lung: n = 56 [34%], brain: n = 50 [30%], others: n = 2 [1%]; metastatic disease: n = 74 [44%]). D-dimer (median = 0.8 µg/mL [25th-75th percentile: 0.4-2.0]) was measured at baseline and during 602 monthly follow-up visits. Joint models of longitudinal and time-to-event data were implemented to quantify the association between D-dimer trajectories and prospective risk of VTE.

RESULTS

VTE occurred in 20 patients (250-day VTE risk = 12.1%, 95% confidence interval [CI], 7.8-18.5). D-dimer increased by 34%/month (0.47 µg/mL/month, 95% CI, 0.22-0.72, P < .0001) in patients who developed VTE, but remained constant in patients who did not develop VTE (change/month = -0.06 µg/mL, 95% CI, -0.15 to 0.02, P = .121). In joint modeling, a doubling of the D-dimer trajectory was associated with a 2.8-fold increase in the risk of VTE (hazard ratio = 2.78, 95% CI, 1.69-4.58, P < .0001). This finding was independent of established VTE risk factors. Highly personalized, dynamic predictions of VTE conditional on individual patients' D-dimer trajectories could be obtained.

CONCLUSIONS

D-dimer increases before the onset of cancer-associated VTE, but remains constant over time in patients without VTE. This study represents proof-of-concept that longitudinal trajectories of D-Dimer may advance the personalized assessment of VTE risk in the oncologic setting.

Efficacy and safety of thromboprophylaxis in cancer patients: a systematic review and meta-analysis

BACKGROUND

Thrombosis is a common complication in patients with cancer. Whether thromboprophylaxis could benefit patients with cancer is unclear. The aim of this systematic review was to determine the efficacy and safety of thromboprophylaxis in patients with cancer undergoing surgery or chemotherapy.

METHODS

We searched the Cochrane Library, EMBASE, MEDLINE, EBSCOhost, and Web of Science for studies published before May 2018 to investigate whether thromboprophylaxis measures were more effective than a placebo in patients with cancer.

RESULTS

In total, 33 trials with 11,942 patients with cancer were identified. In patients with cancer undergoing surgery, the administration of thromboprophylaxis was associated with decreasing trends in venous thromboembolism (VTE) [relative risk (RR) 0.51, 95% confidence interval (CI) 0.32-0.81] and DVT (RR 0.53, 95% CI 0.33-0.87). In patients with cancer undergoing chemotherapy, the administration of thromboprophylaxis reduced the incidences of VTE, DVT, and pulmonary embolism compared with no thromboprophylaxis (RR 0.54, 95% CI 0.40-0.73; RR 0.47, 95% CI 0.31-0.73; RR 0.51, 95% CI 0.32-0.81, respectively). The pooled results regarding major bleeding showed no significant difference between prophylaxis and no prophylaxis in either the surgical or the chemotherapy groups (RR 2.35, 95% CI 0.74-7.52, p = 0.1482, I2 = 0%; RR 1.30, 95% CI 0.93-1.83, p = 0.1274, I2 = 0%, respectively).

CONCLUSION

Thromboprophylaxis did not increase major bleeding events or the incidence of thrombocytopenia. All-cause mortality was not significantly different between those who received thromboprophylaxis and those who did not. This meta-analysis provides evidence that thromboprophylaxis can reduce the number of VTE and DVT events, with no apparent increase in the incidence of major bleeding in patients with cancer.

Preventing Venous Thromboembolism in Ambulatory Patients with Cancer: A Narrative Review

Venous thromboembolism (VTE) is frequent among patients with cancer. Ambulatory cancer patients starting chemotherapy have a 5% to 10% risk of cancer associated thrombosis (CAT) within the first year after cancer diagnosis. This risk may vary according to patient characteristics, cancer location, cancer stage, or the type of chemotherapeutic regimen. Landmark studies evaluating thrombophrophylaxis with low molecular weight heparin (LMWH) for ambulatory cancer patients have shown a relative reduction in the rate of symptomatic VTE of about one half. However, the absolute risk reduction is modest among unselected patients given a rather low risk of events resulting in a number needed to treat (NNT) of 40 to 50. Moreover, this modest benefit is mitigated by a trend towards an increased risk of bleeding, and the economic and patient burden due to daily injections of LMWH. For these reasons, routine thromboprophylaxis is not recommended by expert societies. Advances in VTE risk stratification among cancer patients, and growing evidence regarding efficacy and safety of direct oral anticoagulants (DOACs) for the treatment and prevention of CAT have led to reconsider the paradigms of this risk-benefit assessment. This narrative review aims to summarize the recent evidence provided by randomized trials comparing DOACs to placebo in ambulatory cancer patients and its impact on expert recommendations and clinical practice.

Conduct and reporting of citation searching in Cochrane systematic reviews: A cross-sectional study

BACKGROUND

The search for studies for a systematic review should be conducted systematically and reported transparently to facilitate reproduction. This study aimed to report on the conduct and reporting of backward citation searching (ie, checking reference lists) and forward citation searching in a cross section of Cochrane reviews. Citation searching uses the citation network surrounding a source study to identify additional studies.

METHODS

Cochrane reviews were identified by searching the Cochrane Database of Systematic Reviews using the wildcard symbol and date limiting to the 3-month period November 2016 to January 2017. Cochrane reviews thus identified were screened for mention of citation searching. Descriptive detail on the conduct and reporting of citation searching was captured in data extraction forms and described and evaluated.

RESULTS

Two hundred fifteen Cochrane reviews were identified. One hundred seventy-two reviews reported backward citation searching, and 18 reviews reported forward citation searching. Web of Science was the most frequently reported citation index. The studies used for backward citation searching consisted mainly of studies meeting the inclusion criteria. One-third of reviews that reported forward citation searching used selected studies of importance. Reporting of citation searching was compliant with the Methodological Expectations of Cochrane Intervention Reviews (MECIR) standards, but full transparency requires additional detail that only a minority of reviews reported.

CONCLUSION

The conduct of backward citation searching was more uniform than forward citation searching. This might be due to lack of MECIR guidance for forward citation searching. Reporting was generally compliant with MECIR, but this is not always sufficient to ensure full transparency.

Primary Thromboprophylaxis in Ambulatory Cancer Patients: Where Do We Stand?

Venous thromboembolism (VTE), comprising deep-vein thrombosis and pulmonary embolism, is a frequent complication in ambulatory cancer patients. Despite the high risk, routine thromboprophylaxis is not recommended because of the high number needed to treat and the risk of bleeding. Two recent trials demonstrated that the number needed to treat can be reduced by selecting cancer patients at high risk for VTE with prediction scores, leading the latest guidelines to suggest such an approach in clinical practice. Yet, the interpretation of these trial results and the translation of the guideline recommendations to clinical practice may be less straightforward. In this clinically-oriented review, some of the controversies are addressed by focusing on the burden of VTE in cancer patients, discussing the performance of available risk assessment scores, and summarizing the findings of recent trials. This overview can help oncologists, hematologists, and vascular medicine specialists decide about thromboprophylaxis in ambulatory cancer patients.

SEOM clinical guideline of venous thromboembolism (VTE) and cancer (2019)

In 2011, the Spanish Society of Medical Oncology (SEOM) first published a clinical guideline of venous thromboembolism (VTE) and cancer. This guideline was updated in 2014, and since then, multiple studies and clinical trials have changed the landscape of the treatment and prophylaxis of VTE in cancer patients. To incorporate the most recent evidence, including data from direct oral anticoagulants (DOACs) randomized clinical trials, SEOM presents a new update of the guideline.

Prevention of venous thromboembolism in patients with cancer with direct oral anticoagulants: A systematic review and meta-analysis

BACKGROUND

Patients with cancer are of a high level risk of venous thromboembolism (VTE). Low molecular weight heparin (LMWH) is recommended as the normal treatment for cancer-associated venous thrombosis. Recently, some studies suggest that patients with cancer-associated venous thrombosis can get a good efficacy and safety profile from treating with direct oral anticoagulants (DOACs) compared with other anticoagulants. However, when it comes to the efficacy of DAOCs in preventing VTE in patient with cancer, the data are limited. Thus, we performed such a meta-analysis to determine the efficacy and safety of DOACs in preventing VTE in patient with cancer compared with LMWHs.

METHODS

Medline/PubMed and CENTRAL (The Cochrane Central Register of Controlled Trials) were systematically searched for relevant studies. For each trial, data on VTE, major bleeding, or bleeding were extracted by 2 reviewers independently. Pooled risk ratios (RRs) were calculated by using Review Manager 5.3 software and the significance was determined by the Z test.

RESULTS

A total of 6 studies with 7185 patients were included in our meta-analysis. DOACs (RR = 0.55, 95% confidence interval [95%CI]: 0.34-0.90, I = 31%) had a similar prevention effect of VTE to LMWH (RR = 0.59, 95% CI: 0.37-0.95, I = 59%). DOACs (RR = 1.52, 95% CI: 0.99-2.33, I = 0%) yielded a similar bleeding occurrence rate compared with LMWH (RR = 1.35, 95% CI: 1.07-1.70, I = 35%). DOACs (RR = 1.95, 95% CI: 0.88-4.30, I = 0%) showed a sight higher major bleeding occurrence rate than LMWH (RR = 1.38, 95% CI: 0.88-2.14, I = 0%).

CONCLUSION

DOACs show comparable efficacy to LMWH in cancer patients without VTE with a slightly higher major bleeding occurrence rate. DOACs are inclined to be an alternative thromboprophylaxis strategy in cancer patients as they have superiorities compared to traditional anticoagulation agents. Further studies are still demanded as exiting relevant researches are limited.

Long-term performance of risk scores for venous thromboembolism in ambulatory cancer patients

The long-term performance of prediction scores for venous thromboembolism (VTE) in cancer patients has been poorly investigated. We evaluated the discriminatory performance of the Khorana, PROTECHT, CONKO, and ONKOTEV scores for the first 3-6 months and for 12 months, and re-assessed scores after 3-6 months to determine the influence of variations in patients' risk classification on performance. Retrospective cohort of ambulatory patients with active cancer who were scheduled to receive first or new line of chemotherapy. The primary outcome was symptomatic or incidental VTE. A total of 776 patients were included of whom 540 (70%) had distant metastases. The time-dependent c-statistics of Khorana, PROTECHT, CONKO, and ONKOTEV scores at 6 months were 0.61 (95% CI 0.56 to 0.66), 0.61 (95% CI 0.55 to 0.66), 0.60 (95% CI 0.54 to 0.66), and 0.59 (0.52 to 0.66), respectively, with a tendency to decrease during follow-up. None of the scores discriminated between high and low risk patients at the conventional 3-point positivity threshold. The use of a 2-point positivity threshold improved performance of all scores and captured a higher proportion of VTE. The accuracy of risk scores re-assessed at 3-6 months was modest. The Khorana, PROTECHT, CONKO, and ONKOTEV scores are not sufficiently accurate when used at a conventional threshold of 3 points. Performance improves at positivity threshold of 2 points, as evaluated in recent randomized studies on VTE prophylaxis. Score accuracy tends to decrease over time suggesting the need of periodic re-evaluation to estimate possible variation of risk.

What's new in the prevention and treatment of cancer-associated thrombosis?

Venous thromboembolism (VTE) is a common complication in ambulatory cancer patients receiving chemotherapy. Current clinical guidelines recommend against the use of routine primary thromboprophylaxis in unselected ambulatory cancer patients. The Khorana score is a risk assessment tool derived and prospectively validated for the identification of cancer patients at high risk of thrombotic complications. Recently, 2 randomized, controlled trials have assessed the use of low-dose direct oral Xa inhibitors, apixaban and rivaroxaban, for the prevention of cancer-associated thrombosis in ambulatory patients at intermediate to high risk of VTE (Khorana score ≥2). Taken together, these trials have shown that low-dose direct oral Xa inhibitors reduce the risk of VTE in this patient population without a significant increase in major bleeding. These results should encourage clinicians to consider the use of primary thromboprophylaxis in ambulatory cancer patients at intermediate to high risk of VTE who do not have any apparent risk factors for bleeding. The direct oral Xa inhibitors have also been assessed in the acute management of cancer-associated thrombosis. Current evidence suggests that these drugs are a convenient, effective, and safe option for the management of acute VTE in many cancer patients. Low-molecular weight heparin, however, may continue to be the treatment of choice depending on the presence of bleeding risk factors, the type of cancer, drug-drug interactions, and patient preferences.

Low Dose Low-Molecular-Weight Heparin for Thrombosis Prophylaxis: Systematic Review with Meta-Analysis and Trial Sequential Analysis

International guidelines recommend low-molecular-weight heparin (LMWH) as first-line pharmacological option for the prevention of venous thromboembolism (VTE) in many patient categories. Guidance on the optimal prophylactic dose is lacking. We conducted a systematic review with meta-analysis and trial sequential analysis (TSA) of randomized controlled trials to assess benefits and harms of low-dose LMWH versus placebo or no treatment for thrombosis prophylaxis in patients at risk of VTE. PubMed, Cochrane Library, Web of Science, and Embase were searched up to June 2019. Results were presented as relative risk (RR) with conventional and TSA-adjusted confidence intervals (CI). Forty-four trials with a total of 22,579 participants were included. Six (14%) had overall low risk of bias. Low-dose LMWH was not statistically significantly associated with all-cause mortality (RR 0.99; 95%CI 0.85-1.14; TSA-adjusted CI 0.89-1.16) but did reduce symptomatic VTE (RR 0.62; 95%CI 0.48-0.81; TSA-adjusted CI 0.44-0.89) and any VTE (RR 0.61; 95%CI 0.50-0.75; TSA-adjusted CI 0.49-0.82). Analyses on major bleeding (RR 1.07; 95%CI 0.72-1.59), as well as serious adverse events (SAE) and clinically relevant non-major bleeding were inconclusive. There was very low to moderate-quality evidence that low-dose LMWH for thrombosis prophylaxis did not decrease all-cause mortality but reduced the incidence of symptomatic and asymptomatic VTE, while the analysis of the effects on bleeding and adverse events remained inconclusive.

Prevention and Treatment of Cancer-Associated Venous Thromboembolism: a Review

PURPOSE OF REVIEW

Patients with cancer have an increased risk of venous thromboembolism (VTE). Cancer-associated VTE is associated with an increased risk of morbidity and mortality. Treatment of VTE in cancer is associated with higher rates of recurrent thrombosis as well as major bleeding compared with the general population. The goal of this review is to provide a summary of current evidence for the prevention and treatment of cancer-associated VTE.

RECENT FINDINGS

Validated risk prediction models are available to aide clinicians in identifying patients with cancer with the highest risk of VTE. Those patients with intermediate to high risk of VTE may benefit from primary prophylaxis with apixaban or rivaroxaban. Low-molecular-weight heparin is superior to vitamin K antagonists for the treatment of cancer-associated VTE. There is mounting evidence to support use of the direct oral anticoagulants for VTE in patients with cancer. Decisions on type and duration of anticoagulation in patients with cancer, either for primary or secondary prevention, should be made on a case-by-case basis with taking into account the individual patient bleeding and thrombotic risk.

Using non-vitamin K oral anticoagulants in specific patient populations: a study of Korean cases

Non-vitamin K oral anticoagulants (NOACs) are increasingly used as alternatives to conventional therapies and have considerable accumulated real-world clinical data in patients with non-valvular atrial fibrillation (NVAF) or venous thromboembolism (VTE). However, it is not easy to make a complete changeover to NOACs in real-world clinical practice because NOACs still have challenges in specific patient populations (eg, Asian patients, NVAF patients presenting with acute coronary syndrome [ACS], dialysis patients with NVAF, patients with cancer-associated VTE, etc.). Clinical data on the optimal dose of NOACs in Asian patients with NVAF are not sufficient. The intensity of NOAC and antiplatelet treatment and the duration of antiplatelet treatment should be adjusted according to the bleeding and thrombotic risk profiles of the individual NVAF patient presenting with ACS. Increased bleeding risk and unclear efficacy of NOACs in dialysis patients with NVAF should be considered when making decisions on whether to give NOACs for these patients. If dialysis patients with NVAF require anticoagulant for stroke prevention, then apixaban could be considered while awaiting more clinical efficacy and safety data. Additional studies are needed to determine the utility of continuing treatment with reduced-dose NOACs for long-term therapy after VTE. We have enough experiences in using NOACs in cancer patients showing the benefit of antithrombotic treatment counterbalanced the bleeding risk; however, some challenges of cancer-associated VTE management exist due to differences in cancer types or chemotherapy regimens and comorbidities. Different dosing regimens among NOACs may impact on medication adherence; thus, individual patient preference should be considered in choosing a particular NOAC. A significant proportion of patients remain on warfarin because of the high price of NOACs and variability in reimbursement coverage. To compensate clinical-evidence and achieve optimal use of NOACs, we should pay attention to the outcomes of ongoing studies and evaluate more real-world data.

The role of ADAMTS-13 and von Willebrand factor in cancer patients: Results from the Vienna Cancer and Thrombosis Study

BACKGROUND

Cancer-associated venous thromboembolism (VTE) is an important complication in the course of a malignant disease. Low ADAMTS-13 (a disintegrin-like and metalloproteinase with thrombospondin type 1 motif 13) and increased von Willebrand Factor (VWF) levels in cancer patients have been described numerously.

OBJECTIVES

Investigation of the influence of ADAMTS-13 and VWF on the probability of VTE and survival in malignancy.

PATIENTS/METHODS

In the framework of the ongoing prospective Cancer and Thrombosis Study (CATS) ADAMTS-13 activity and VWF antigen levels were investigated in cancer patients.

RESULTS

In total, 795 patients with various tumor types (364 female/431 male, median age 62 years) were included; of those, 56 developed VTE and 359 patients died during a median follow-up time of 730 days. The hazard ratio (HR) of VTE per doubling of VWF level was 1.56 (95% confidence interval [CI] 1.13-2.16) in multivariable competing risk analysis. ADAMTS-13 levels showed no correlation with the incidence of VTE in univariate competing risk analysis. The HR of mortality per doubling of VWF level was 1.46 (95% CI 1.28-1.66) and per SD increment of ADAMTS-13was 0.90 (95% CI 0.81-1.00) in multivariable Cox regression analysis. Patients with VWF >75th percentile and concomitant low (<25th percentile) or medium (25-75th percentile) ADAMTS-13 values had the highest probability of mortality (HR 4.31 and 4.75, respectively).

CONCLUSIONS

High VWF levels were significantly associated with the risk of developing VTE in cancer patients, whereas ADAMTS-13 was not. Low ADAMTS-13 and increased VWF levels were independently associated with worse overall survival.

Direct Oral Anticoagulants and Cancer-Associated Thrombosis Management. Where Do We Stand in 2019?

Direct oral anticoagulants (DOACs) are now widely used for the management of venous thromboembolism (VTE) that now includes cancer-associated thrombosis. This review summarizes recent data on VTE prophylaxis and treatment, new challenges, guidelines, and updates as well as the current place for DOACs on the emerging cancer-associated VTE management landscape.

Recent advances in the treatment and prevention of venous thromboembolism in cancer patients: role of the direct oral anticoagulants and their unique challenges

Venous thromboembolism (VTE) is a common complication in patients with cancer and is associated with poor prognosis. Low-molecular-weight heparins (LMWHs) are the standard of care for the treatment of cancer-associated thrombosis. Primary VTE prophylaxis with LMWH is recommended after cancer surgery and in hospitalized patients with reduced mobility. However, owing to wide variations in VTE and bleeding risk, based on disease stage, anti-cancer treatments, and individual patient characteristics, routine primary prophylaxis is not recommended in ambulatory cancer patients undergoing chemotherapy. Efforts are under way to validate risk assessment models that will help identify those patients in whom the benefits of primary prophylaxis will outweigh the risks. In recent months, long-awaited dedicated clinical trials assessing the direct oral anticoagulants (DOACs) in patients with cancer have reported promising results. In comparison with the LMWHs, the DOACs were reported to be non-inferior to prevent VTE recurrence. However, there was an increased risk of bleeding, particularly in gastrointestinal cancers. Safe and optimal treatment with the DOACs in the patient with cancer will require vigilant patient selection based on patient characteristics, co-morbidities, and the potential for drug-drug interactions.

Updated meta-analysis on prevention of venous thromboembolism in ambulatory cancer patients

Randomized clinical trials have evaluated the role of anticoagulants in the prevention of venous thromboembolism (VTE) in ambulatory cancer patients treated with chemotherapy. This meta-analysis is aimed at providing an updated evaluation of the efficacy and safety of anticoagulant prophylaxis in this clinical setting. Medline and Scopus were searched to retrieve randomized controlled trials on the prevention of VTE in ambulatory cancer patients. Two groups of trials were identified with VTE or death as the primary outcome, respectively. VTE was the primary outcome of this analysis. Anticoagulant prophylaxis reduced the incidence of VTE in studies in which the primary outcome was VTE [14 studies, 8,226 patients; odds ratio (OR)=0.45; 95% confidence interval (95% CI): 0.36-0.56] or death (8 studies, 3,727 patients; OR=0.61; 95% CI: 0.47-0.81). When these studies were pooled together, VTE was reduced by 49% (95% CI: 0.43-0.61) with no significant increase in major bleeding (OR=1.30, 95% CI: 0.98-1.73). The risk of major bleeding was increased in studies with VTE as the primary outcome (OR=1.43, 95% CI: 1.01-2.04). Similar reductions of VTE were observed in studies with parenteral (OR=0.43, 95% CI: 0.33-0.56) or oral anticoagulants (OR=0.49, 95% CI: 0.33-0.74). The reduction in VTE was confirmed in patients with lung (OR=0.42, 95% CI: 0.26-0.67) or pancreatic cancer (OR=0.26, 95% CI: 0.14-0.48), in estimated high-risk patients, in high-quality studies and with respect to symptomatic VTE. In conclusion, prophylaxis with oral or parenteral anticoagulants reduces the risk of VTE in ambulatory cancer patients, with an acceptable increase in major bleeding.

Recent Advances in the Management of Cancer-Associated Thrombosis: New Hopes but New Challenges

Venous thromboembolism (VTE) is a common cause of morbidity and mortality in cancer patients and leads to a significant increase in health care costs. Cancer patients often suffer from multiple co-morbidities and have both a greater risk of VTE recurrence and bleeding compared to non-cancer patients. Anticoagulation is therefore challenging. For many years, long-term therapy with Low-Molecular-Weight Heparin (LMWH) was the standard of care for the management of cancer-associated VTE. Direct oral anticoagulants (DOAC), which offer the convenience of an oral administration and have a rapid onset of action, have recently been proposed as a new option in this setting. Head-to-head comparisons between DOAC and LMWHs for the treatment of established VTE are now available, and data on the efficacy and safety of these drugs for primary prophylaxis of VTE in ambulatory cancer patients receiving systemic anticancer therapy are emerging. This narrative review aims to summarize the main recent advances in the prevention and treatment of cancer-associated VTE, including recent data on the use of individualized factors to stratify the risk of VTE in each individual patient, quality-of-life in patients treated with LMWH, and the place that DOACs will likely take in the cancer-associated VTE management landscape.

Dynamic Thromboembolic Risk Modelling to Target Appropriate Preventative Strategies for Patients with Non-Small Cell Lung Cancer

Prevention of cancer-associated thromboembolism (TE) remains a significant clinical challenge and priority world-wide safety initiative. In this prospective non-small cell lung cancer (NSCLC) cohort, longitudinal TE risk profiling (clinical and biomarker) was undertaken to develop risk stratification models for targeted TE prevention. These were compared with published models from Khorana, CATS, PROTECHT, CONKO, and CATS/MICA. The NSCLC cohort of 129 patients, median follow-up 22.0 months (range 5.6—31.3), demonstrated a hypercoagulable profile in >75% patients and TE incidence of 19%. High TE risk patients were those receiving chemotherapy with baseline fibrinogen ≥ 4 g/L and d-dimer ≥ 0.5 mg/L; or baseline d-dimer ≥ 1.5 mg/L; or month 1 d-dimer ≥ 1.5 mg/L. The model predicted TE with 100% sensitivity and 34% specificity (c-index 0.67), with TE incidence 27% vs. 0% for high vs. low-risk. A comparison using the Khorana, PROTECHT, and CONKO methods were not discriminatory; TE incidence 17–25% vs. 14–19% for high vs. low-risk (c-index 0.51–0.59). Continuous d-dimer (CATS/MICA model) was also not predictive of TE. Independent of tumour stage, high TE risk was associated with cancer progression (HR 1.9, p = 0.01) and mortality (HR 2.2, p = 0.02). The model was tested for scalability in a prospective gastrointestinal cancer cohort with equipotency demonstrated; 80% sensitivity and 39% specificity. This proposed TE risk prediction model is simple, practical, potent and can be used in the clinic for real-time, decision-making for targeted thromboprophylaxis. Validation in a multicentre randomised interventional study is underway (ACTRN12618000811202).

Early venous thromboembolism at the beginning of palliative chemotherapy is a poor prognostic factor in patients with metastatic pancreatic cancer: a retrospective study

Background

This study investigated the prognostic effects of venous thromboembolism (VTE)-related factors in patients with metastatic pancreatic cancer receiving palliative chemotherapy. Predictive factors for VTE were also investigated.

Methods

A total of 216 patients diagnosed with metastatic pancreatic cancer who received gemcitabine-based palliative chemotherapy at our institution were retrospectively evaluated.

Results

VTE occurred in 51 (23.6%) patients during treatment and did not affect survival. However, patients who were diagnosed with VTE at the beginning of chemotherapy showed poor prognosis compared with patients diagnosed with VTE during chemotherapy: all patients (hazard ratio [HR] 1.897, p = 0.008); patients diagnosed with VTE (HR = 3.768, p = 0.001). Low serum sodium (Na) (< 135 mmol/L) and high Khorana score (≥3) were strong predictive factors of early VTE (odds ratio [OR] 5.109; 95% confidence interval [95% CI] = 1.010–25.845; p = 0.049 for Khorana score, OR 10.304; 95% CI = 1.036–102.466; p = 0.047) for hyponatremia).

Conclusions

Our study demonstrated that occurrence and detection of VTE in the early period of chemotherapy was the most significant VTE-related prognostic factor in patients with metastatic pancreatic cancer receiving chemotherapy. Prediction using the Khorana score and serum Na levels would be helpful in early diagnosis of VTE.

Beneficial effect of additional treatment with widely available anticancer agents in advanced small lung cell carcinoma: A case report

Small-cell lung carcinoma is a type of lung cancer characterized by very poor prognosis, as the majority of the patients have already developed metastases at initial diagnosis. Small-cell lung cancer accounts for ~15% of all lung cancer cases. The present study reports the case of a female patient with advanced-stage small-cell lung cancer. The patient received the standard treatments (6 cycles of platinum and etoposide chemotherapy followed by Gamma Knife treatment of suspicious mediastinal lymphnodes); in addition, naturally derived agents (curcumin, parthenolide, betuline, sulforaphane, withanolides, lactoferrin, pomegranate fruit extract, flaxseed and dioscorea) were alternately administered at increased doses, while previously prescribed medications for other comorbidities (metformin and atorvastatin) were continued. Complete regression of the tumour was observed, and the patient remains in full remission and cancer-free for >7 years. Moreover, no treatment-related side effects and no drug interactions were observed.

Venous thromboembolism prophylaxis for ambulatory cancer patients, can we do better?

Patients with cancer are at a much higher risk of thromboembolic events. Such events are occasionally associated with significant complications that can negatively affect patients' quality of life. Thromboprophylaxis is widely practiced, but much of the emphasis is given for those admitted with acute medical illnesses or following major surgical procedures. However, a significant percentage of thrombotic events encountered in routine clinical practice are among ambulatory patients where current guidelines do not recommend routine thromboprophylaxis.