Anticoagulation for the Treatment of Cancer-Associated Thrombosis: A Systematic Review and Network Meta-Analysis of Randomized Trials

Comparative Effectiveness of Anticoagulants in Patients With Cancer-Associated Thrombosis

Importance

Patterns of clinical utilization and comparative effectiveness of anticoagulants for cancer-associated thrombosis (CAT) remain largely unexplored.

Objectives

To assess patterns of and factors associated with anticoagulant use and to evaluate the comparative effectiveness of contemporary anticoagulants in patients with active cancer in a clinical setting.

Design, Setting, and Participants

This retrospective cohort study obtained deidentified OptumLabs electronic health record claims data from January 1, 2012, to September 30, 2019. Adult patients (≥18 years of age) with a primary cancer diagnosis (except skin cancer) during at least 1 inpatient or 2 outpatient visits within 6 months before the venous thromboembolism (VTE) date were included. Data were analyzed from April 2020 to September 2021.

Exposures

The patients were grouped according to the anticoagulant prescribed: (1) direct oral anticoagulants (DOACs), (2) low-molecular-weight heparin (LMWH), and (3) warfarin.

Main Outcomes and Measures

Odds ratios (ORs) were used to present the association between factors of interest and utilization of anticoagulants. Main efficacy outcomes included risk of VTE recurrence and all-cause mortality. Main safety outcomes included the risk of hospitalization due to major bleeding. Relative treatment effect estimates were expressed as hazard ratios (HRs) with 95% CIs.

Results

This study included 5100 patients (mean [SD] age, 66.3 [12.3] years; 2670 [52.4%] women; 799 [15.7%] Black, 389 [7.6%] Hispanic, and 3559 [69.8%] White individuals). Overall, 2512 (49.3%), 1488 (29.2%), and 1460 (28.6%) filled prescriptions for DOACs, LMWH, and warfarin, respectively. The median (IQR) treatment duration was 3.2 (1.0-6.5) months for DOACs, 3.1 (1.0-6.8) months for warfarin, and 1.8 (0.9-3.8) months for LWMH. Patients with lung (OR, 2.07; 95% CI, 1.12-3.65), urological (OR, 1.94; 95% CI,1.08-3.49), gynecological (OR, 4.25; 95% CI, 2.31-7.82), and colorectal (OR, 2.26; 95% CI, 1.20-4.32) cancer were associated with increased prescriptions for LMWH compared with DOACs. LMWH (HR, 1.47; 95% CI, 1.14-1.90) and warfarin (HR, 1.46; 95% CI, 1.13-1.87) were associated with an increased risk of VTE recurrences compared with DOACs. LMWH was associated with an increased risk of major bleeding (HR, 2.27; 95% CI, 1.62-3.20) and higher all-cause mortality (HR, 1.61; 95% CI, 1.15-2.25) compared with DOACs.

Conclusions and Relevance

In this comparative effectiveness study of claims-based data, patients with CAT received anticoagulation for a remarkably short duration in clinical settings. DOACs was associated with a lower risk of VTE recurrence, major bleeding, and mortality. Warfarin may still be considered for patients with contraindications to DOACs and those with poor persistence on LMWH.

Acute reperfusion treatment and secondary prevention of cancer-related stroke: comprehensive overview and proposal of clinical algorithm

Cancer-related stroke (CRS), referring to ischemic stroke occurring in cancer patients without other clear etiology, represents a clinical challenge, as it is associated with unfavorable clinical outcomes including high rates of recurrence and mortality. There are scarce international recommendations and limited consensus statements on CRS management. For this comprehensive overview, the available studies/reviews/meta-analyses on the use of acute reperfusion and secondary prevention treatments for cancer patients with ischemic stroke, focusing on antithrombotic agents, were collected and summarized. A practical management algorithm was designed per the available data. In short, acute reperfusion in the form of intravenous thrombolysis and mechanical thrombectomy appears to be safe in CRS and can be considered for eligible patients, though the functional outcomes are often poor, and mostly defined by the preexisting condition. Many patients carry indications for anticoagulation, in which case vitamin K antagonists are not preferred, while low-molecular weight heparins remain the treatment of choice; direct oral anticoagulants can be alternatively considered but are contraindicated for gastrointestinal malignancies. For patients without clear anticoagulation indications, no net benefit for anticoagulation compared to aspirin has been shown. Other targeted treatment options should be evaluated in an individualized approach, alongside the appropriate management of conventional cerebrovascular risk factors. Oncological treatment should be swiftly initiated/continued. In conclusion, acute CRS remains a clinical challenge, with many patients suffering recurrent stroke, despite preventive measures. More randomized-controlled clinical trials are urgently needed to pinpoint the most effective management options for this subset of stroke patients.

A consensus viewpoint on the role of direct factor Xa inhibitors in the management of cancer-associated venous thromboembolism in the UK

OBJECTIVE

Cancer patients are at high risk of venous thromboembolism (VTE), a significant cause of cancer-related death. Historically, low molecular weight heparins (LMWH) were the gold standard therapy for cancer-associated VTE, but recent evidence supports the use of direct factor Xa inhibitors in cancer-associated VTE and this is now reflected in many guidelines. However, uptake of direct factor Xa inhibitors varies and guidance on the use of direct factor Xa inhibitors in specific cancer sub-populations and clinical situations is lacking. This review presents consensus expert opinion alongside evaluation of evidence to support healthcare professionals in the use of direct factor Xa inhibitors in cancer-associated VTE.

METHODS

Recent guidelines, meta-analyses, reviews and clinical studies on anticoagulation therapy for cancer-associated VTE were used to direct clinically relevant topics and evidence to be systematically discussed using nominal group technique. The consensus manuscript and recommendations were developed based on these discussions.

RESULTS

Considerations when prescribing anticoagulant therapy for cancer-associated VTE include cancer site and stage, systemic anti-cancer therapy (including vascular access), drug-drug interactions, length of anticoagulation, quality of life and needs during palliative care. Treatment of patients with kidney or liver impairment, gastrointestinal disorders, extremes of bodyweight, elevated bleeding or recurrence risk, VTE recurrence and COVID-19 is discussed.

CONCLUSION

Anticoagulant therapy for cancer-associated VTE patients should be carefully selected with consideration given to the relative benefits of specific drugs when individualizing care. Direct factor Xa inhibitors are typically the treatment of choice for preventing VTE recurrence in non-cancer patients and should also be considered as such for cancer-associated VTE in most situations.

Direct Oral Anticoagulants Compared With Dalteparin for Treatment of Cancer-Associated Thrombosis: A Living, Interactive Systematic Review and Network Meta-analysis

OBJECTIVE

To maintain living, interactive evidence (LIvE) on the benefits and harms of different treatment options in adults with cancer-associated thrombosis (CAT).

METHODS

We have used a novel LIvE synthesis framework to maintain this living, interactive systematic review since September 19, 2018. Randomized controlled trials evaluating the efficacy and safety of direct oral anticoagulants (DOACs) compared with low-molecular-weight heparin for CAT are included in this analysis. Details of LIvE synthesis framework are available at the website https://cat.network-meta-analysis.com.

RESULTS

The results are constantly updated as new information becomes available (https://cat.network-meta-analysis.com/CAT.html). The living, interactive systematic review currently includes 4 randomized controlled trials (N=2894). Direct comparisons show that DOACs significantly decrease recurrent venous thromboembolism (VTE) events compared with dalteparin (odds ratio [OR], 0.59; 95% CI, 0.41 to 0.86; I², 25%) without significantly increasing major bleeding (OR, 1.34; 95% CI, 0.83 to 2.18; I², 28%). Mixed treatment comparisons show that apixaban (OR, 0.41; 95% credible interval [CrI], 0.16 to 0.95) and rivaroxaban (OR, 0.58; 95% CrI, 0.37 to 0.90) significantly decrease VTE recurrent events compared with dalteparin. Edoxaban significantly increases major bleeding compared with dalteparin (OR, 1.73; 95% CrI, 1.04 to 3.16), and rivaroxaban significantly increases clinically relevant nonmajor bleeding compared with dalteparin and other DOACs. There are no significant differences between DOACs in terms of VTE recurrences and major bleeding.

CONCLUSION

DOACs should be considered a standard of care for the treatment of CAT except in patients with a high risk of bleeding. Current evidence favors the use of apixaban for the treatment of CAT among other DOACs.

REGISTRATION

Open Science Framework (https://osf.io/dth86).

Prophylaxis Against Thromboembolic Events During Chemotherapy for Germ Cell Cancer

INTRODUCTION

Patients with advanced germ cell tumors (GCT) receiving cisplatin-based chemotherapy have high rates of thromboembolic events (TEE) which can negatively affect their overall survival. While primary TEE prophylaxis during chemotherapy may prevent these events, it is unclear which patients will benefit in this setting.

MATERIALS AND METHODS

A review of PubMed/Medline was conducted in December 2020 and all pertinent articles were evaluated for relevancy and quality of data for inclusion in the review.

RESULTS

Studies on patients receiving initial cisplatin-based chemotherapy for advanced GCT have reported up to a 19% rate of TEE. This high rate may be associated with multiple factors including retroperitoneal lymphadenopathy, advanced clinical stage, high risk Khorana scores and presence of a central line. Large phase III clinical trials have demonstrated the benefit of low-molecular-weight-heparin and direct oral anticoagulants for primary prophylaxis and against recurrent TEE. However, primary prophylaxis is currently underutilized with GCT patients starting chemotherapy.

CONCLUSION

Precise models to predict TEE risk and consideration of anticoagulation are difficult to develop owing to the relatively uncommon nature of GCT and lack of representation in primary TEE prophylaxis clinical trials. Despite these limitations, we believe that the benefits of prophylactic anticoagulation outweigh the risk of major bleeding in select GCT patients with higher risk of TEE. We have developed a simple algorithm to help guide TEE prophylaxis selection based on patient factors and route of chemotherapy administration. Given the high rate of TEE in GCT patients, we believe better utilization of primary prophylaxis in patient starting cisplatin-based chemotherapy will have clinical benefit.

Non-bacterial thrombotic endocarditis manifested by ventricular fibrillation in a patient with low grade ovarian carcinoma: case report and literature review

Background

Non-bacterial thrombotic endocarditis (NBTE) is a rare form of endocarditis notably described in patients with advanced malignancy and auto-immune diseases. It is characterized by the formation of sterile, fibrin-containing vegetations on cardiac endothelium, in the absence of positive blood cultures. It is predominantly located on the mitral- and aortic valve (AV). Vegetations in NBTE are prone to embolize. Trousseau syndrome (TS) is defined as unexplained thrombotic events that precede the diagnosis of malignancy.

Case summary

A 49-year-old pre-menopausal woman with a history of visual disturbances, recurrent deep vein thrombosis (DVT) with concurrent pulmonary emboli (PE), and uterine myomas with dysfunctional uterine bleeding was resuscitated for ventricular fibrillation. While echocardiography revealed vegetations on the AV, blood cultures remained negative. Additional work-up for the aetiology of sterile vegetations revealed a low-grade ovarian carcinoma. Cardiac analysis showed evidence of myocardial infarction in the absence of coronary atherosclerosis as a cause for ventricular fibrillation.

Discussion

Unexplained thrombotic events (venous, arterial, or both) warrant further investigation, e.g., with regard to TS. NBTE is a potential source of thromboembolism in TS and a rare ante-mortem finding, which prompts additional investigation of the underlying cause. In our patient, a triad of (suspected) (i) arterial/systemic embolization (i.e. visual disturbances, splenic infarction, coronary embolism), (ii) peripheral thrombophlebitis/hypercoagulability (i.e. DVT and PE), and (iii) malignancy (i.e. gynaecological abnormalities) raised suspicion of NBTE in the setting of TS. Early diagnosis and treatment of NBTE is of importance due to the high incidence of embolization, with possible fatal outcome.

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.

Treatment of venous thromboembolism in cancer patients: a systematic review and meta-analysis on the efficacy and safety of different direct oral anticoagulants (DOACs)

Background

To evaluate the efficacy and safety of different direct oral anticoagulants (DOACs) compared with low molecular weight heparins (LMWHs) in the treatment of venous thromboembolism (VTE) in cancer patients.

Methods

Literature was searched in databases including Cochrane Library, EMBASE (Ovid), and MEDLINE (PubMed). Eligible studies were included, and data were collected independently by 2 reviewers. We conducted a systematic review of the efficacy and safety of DOACs in the treatment of VTE in cancer patients. The odds ratios (ORs) of different DOACs compared with LMWHs for VTE, deep vein thrombosis (DVT), pulmonary embolism (PE) recurrence, major bleeding, and clinically relevant non-major bleeding (CRNMB), were calculated in meta-analyses and subgroup analyses.

Results

A total of 18 articles were eligible for analyses, including 4 randomized controlled trials (RCTs) and 14 retrospective studies. Both RCTs and retrospective studies confirmed that DOACs decreased the risk of VTE recurrence [RCTs: OR, 0.60; 95% confidence interval (CI), 0.45–0.80; retrospective studies: OR, 0.73; 95% CI, 0.59–0.90] and DVT recurrence (RCTs: OR, 0.54; 95% CI, 0.36–0.80; retrospective studies: OR, 0.20; 95% CI, 0.06–0.63), but not PE recurrence or fatal PE in cancer patients. Subgroup analyses revealed an important role of rivaroxaban in decreasing recurrent VTE. Meanwhile, major bleeding events were not increased in the DOAC group, but the risks of CRNMBs were significantly elevated. Subgroup analyses confirmed the role of rivaroxaban in increasing the risk of major bleeding events and CRNMBs.

Conclusions

Compared with LMWHs, DOACs (especially rivaroxaban) significantly reduce the risk of VTE and DVT, but not PE recurrence, in patients with cancer. Although DOACs did not increase the major bleeding events in pooled analysis, rivaroxaban showed an elevated risk of this adverse effect in subgroup analysis. In addition, the risk of CRNMB events was increased after the application of DOACs including rivaroxaban.

Efficacy and safety of direct oral anticoagulants for secondary prevention of cancer associated thrombosis: a meta-analysis of randomized controlled trials

Direct oral anticoagulants (DOACs) may be good alternatives to low molecular weight heparin (LMWH) or vitamin K antagonists (VKA) for treatment of cancer associated thrombosis (CAT). We conducted a meta-analysis of ten randomized clinical trials to evaluate the efficacy and safety of DOACs in patients with CAT. All had study populations composed in entirety or in part of patients with CAT. The primary outcome (efficacy) was recurrent VTE and the secondary outcomes (safety outcomes) included major bleeding, clinically relevant non-major bleeding (CRNMB), and all bleeding (major bleeding + CRNMB). Participants treated with DOACs had lower risk of recurrent VTE, overall (RR 0.63; 95% CI 0.51-0.79; p < 0.0001), compared to LMWH (RR 0.57; 95% CI 0.40-0.83; p = 0.003), but not compared to VKA (RR 0.69; 95% CI 0.44-1.06; p = 0.09). Compared to LMWH, DOACs showed no difference in major bleeding risk (RR 1.31; 95% CI 0.78-2.18; p = 0.31), though had higher risk of CRNMB (RR 1.60; 95% CI 1.13-2.26; p = 0.008) and all bleeding (RR 1.49; 95% CI 1.10-2.01; p = 0.010). These results indicate that DOACs are more effective than LMWH for prevention of recurrent VTE with CAT though carry an increased risk for non-major bleeding compared to standard of care, LMWH.

Direct Oral Anticoagulant for the Treatment of VTE in Cancer Patients: A Systematic Review and Meta-analysis

BACKGROUND

Recent clinical guidelines suggest direct oral anticoagulants (DOACs) as treatment for cancer-associated thrombosis (CAT), but the strength of such recommendations was not clear. Newly released trials add uncertainties to the benefit and risk assessment between DOACs and conventional therapy (low-molecular-weight heparin [LMWH] or vitamin K antagonists [VKAs]).

OBJECTIVE

To evaluate the efficacy and safety of DOACs in patients with CAT, as compared with LMWH and VKAs.

METHODS

PubMed, EMBASE, Cochrane Library, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov were searched. Randomized controlled trials (RCTs) that reported outcomes of DOACs for treating CAT were included. Relative risk (RR), risk difference, and 95% CIs were pooled using the Mantel-Haenszel method.

RESULTS

A total of 8 RCTs were included. DOACs significantly reduced VTE recurrence (RR = 0.59; 95% CI = 0.48-0.73) compared with conventional therapy. Results were similar in the LMWH and VKA subgroups. DOACs had a higher, though nonsignificant, risk of major bleeding compared with LMWH (RR = 1.33; 95% CI = 0.94-1.89) but lower risk of major bleeding compared with VKAs (RR = 0.60; 95% CI = 0.39-0.93). Findings were consistent across patients with active cancer and history of cancer.

CONCLUSION AND RELEVANCE

DOACs have better efficacy to prevent recurrent VTE compared with conventional therapy. Regarding the safety profile, DOACs may carry higher risk of bleeding compared with LMWH but lower risk of bleeding compared with VKAs. Further studies are needed to inform the optimal anticoagulation approach for different types of cancers.

Effectiveness and safety of rivaroxaban compared with low-molecular-weight heparin in cancer-associated thromboembolism

Guidelines provide differing recommendations regarding direct-acting oral anticoagulants vs low-molecular-weight heparin (LMWH) for treatment of cancer-associated thrombosis (CAT). This study was undertaken to evaluate the effectiveness and safety of rivaroxaban vs LMWH for treatment of CAT. Using US Surveillance, Epidemiology and End Results-Medicare-linked data from 2013 through 2016, we evaluated adults with active breast, lung, ovarian, or pancreatic cancer, who were admitted to the hospital or treated in the emergency department for CAT and were prescribed rivaroxaban or LMWH for outpatient anticoagulation. Patients with luminal gastrointestinal or genitourinary cancers were excluded. Rivaroxaban and LMWH users were 1:1 propensity score matched. Outcomes included the composite of recurrent thrombosis or major bleeding, each outcome separately, and mortality at 6 months, using an intent-to-treat approach. On-treatment analysis after 12 months was also performed. Proportional hazards models for the subdistribution of competing risk were used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs). We included 529 rivaroxaban- and 529 LMWH-treated patients with CAT. Rivaroxaban was not associated with differences in risk of the composite outcome (HR, 0.71; 95% CI, 0.41-1.22), major bleeding (HR, 1.01; 95% CI, 0.50-2.01), or mortality (HR, 0.87; 95% CI, 0.70-1.07) vs LMWH, but it reduced recurrent thrombosis (HR, 0.37; 95% CI, 0.15-0.95). On-treatment analysis at 12 months showed similar results. Rivaroxaban may be a reasonable alternative to LMWH for patients with CAT without gastrointestinal or genitourinary cancer.

Direct oral anticoagulant versus low-molecular-weight heparin for treatment of venous thromboembolism in cancer patients: An updated meta-analysis of randomized controlled trials

BACKGROUND

Cancer associated venous thromboembolism (VTE) results in significant morbidity and mortality. Low molecular weight heparin (LMWH) has been standard of care for treatment of cancer-associated VTE, however direct oral anticoagulants (DOACs) are emerging as alternative treatment options.

OBJECTIVE

To compare the benefits and harms of DOACs versus LMWH for treatment of VTE in cancer.

DATA SOURCES

MEDLINE, Embase, and the Cochrane Collaboration Central Register of Controlled Trials from inception to April 2020.

STUDY SELECTION

Randomized controlled trials (RCT) comparing DOACs with LMWH for treatment of VTE in cancer patients.

DATA SYNTHESIS

Four good-quality RCTs, met inclusion criteria. Compared with LMWH, DOACs were associated with lower rates of VTE recurrence (RR 0.62; 95% CI: 0.44-0.87; P = 0.006), and DVT recurrence (RR 0.61; 95% CI: 0.4-0.94; P = 0.02) but not PE recurrence (RR 0.73; 95% CI: 0.51-1.04; P = 0.08), in cancer patients. However, the risk of clinically relevant non-major bleeding (CRNMB) (RR 1.58; 95% CI: 1.11-2.24; P = 0.01), and major bleeding in gastrointestinal cancer (RR 2.55; 95% CI 1.24-5.27, P = 0.01), were higher with DOACs. The risk of overall major bleeding (RR 1.33; 95% CI: 0.84-2.1; P = 0.22), all-cause mortality (RR 0.99; 95% CI: 0.84-1.17; P = 0.92), VTE-related mortality (RR: 1; 95% CI: 0.29-3.44; P = 1) and bleeding-related mortality (RR: 0.71; 95% CI: 0.17-2.91; P = 0.63), were similar in both treatment groups.

CONCLUSION

Among cancer patients with VTE, treatment with DOACs is associated with a significant reduction of VTE and DVT recurrence, compared to LMWH. These benefits were offset by an increased risk of CRNMB, and major bleeding in gastrointestinal cancer.

Brazilian cardio-oncology: the 10-year experience of the Instituto do Cancer do Estado de Sao Paulo

Background

In recent years, the field of cardio-oncology has grown worldwide, bringing benefits to cancer patients in terms of survival and quality of life. This study reports the experience of a pioneer cardio-oncology programme at University Cancer Hospital in Brazil over a period of 10 years, describing the clinical profile of patients and the clinical outcomes.

Methods

A retrospective study was conducted on a cohort of patients treated at the cardio-oncology programme from April 2009 to February 2019. We analysed the characteristics of patients and outcomes, including mortality, according to the type of clinical indication for outpatient care (general cardiology, perioperative evaluation and follow-up and treatment cardiotoxicity).

Results

From a total of 26,435 medical consultations, we obtained the data of 4535 individuals among the medical care outpatients. When we analysed the clinical characteristics of patients considering the clinical indication - general cardiology, perioperative evaluation and cardiotoxicity outpatient clinics, differences were observed with respect to age (59 [48–66], 66 [58–74] and 69 [62–76], p < 0.001), diabetes (67 [15%], 635 [22.6%] and 379 [29.8%]; p < 0.001), hypertension (196 [43.8%], 1649 [58.7%] and 890 [70.1%], p < 0.001) and dyslipidaemia (87 [19.7%), 735 [26.2%] and 459 [36.2%], p < 0.001). A similar overall mortality rate was observed in the groups (47.5% vs. 45.7% vs. 44.9% [p = 0.650]).

Conclusion

The number of oncologic patients in the Cardio-Oncology Programme has grown in the last decade. A well-structured cardio-oncology programme is the key to achieving the true essence of this area, namely, ongoing care for cancer patients throughout the disease treatment process, optimizing their cardiovascular status to ensure they can receive the best therapy against cancer.

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

OPINION STATEMENT

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

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

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

Efficacy and Safety of Direct Oral Anticoagulants for Secondary Prevention of Cancer-Associated Thrombosis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials and Prospective Cohort Studies

Background: Venous thromboembolism (VTE) is a common complication in patients with cancer. Direct oral anticoagulants (DOACs) have been proved to be effective on anticoagulation therapy in many diseases. However, the efficacy and the safety of DOACs in the secondary prevention of cancer-associated thrombosis (CAT) remain unclear. To assess the value of DOACs in patients with CAT, we performed a systematic review and meta-analysis of randomized controlled trials and prospective cohort studies. Methods: Medline, Embase, and the Cochrane Library were searched from their earliest date through to June 2018. Two investigators independently assessed eligibility. Data were extracted by one investigator and verified by the second investigator. The efficacy outcome of this study was recurrent VTE, whereas the safety outcome was major and clinically relevant nonmajor bleeding. Relative risks (RRs) and their corresponding 95% confidence interval (CI) were determined. To pool the results, the Mantel-Haenszel fixed-effects or random-effects models were used. Results: A total of nine articles (six randomized controlled trials and three prospective studies) involving 2,697 patients with CAT who were prescribed DOACs (apixaban, edoxaban, rivaroxaban, or dabigatran) and 2,852 patients who were prescribed traditional anticoagulants [vitamin K antagonists (VKAs), low molecular weight heparin (LMWH), dalteparin, or enoxaparin] were compared. VTE recurrence in the DOAC group was significantly lower than that observed in the traditional anticoagulant group (RR: 0.60; 95%CI: 0.49-0.75; I 2: 0%; p < 0.00001). No significant difference in bleeding risk between both groups was found (RR: 0.95; 95%CI: 0.67-1.36; I 2: 75%; p = 0.79). Conclusions: Our findings showed that anticoagulant therapy with DOACs may be more effective than traditional anticoagulants to prevent recurrent VTE in patients with CAT, while the safety of DOACs may be equal to that of traditional anticoagulants. These findings support the use of DOACs as the first-line therapy for secondary prevention of CAT in most cancer patients.

Extended treatment of cancer-associated thrombosis

Venous thromboembolism (VTE) is a growing concern in patients with cancer. Current guidelines recommend that cancer patients with VTE should receive anticoagulation for at least 3-6 months. However, the question as to whether anticoagulants should be continued after 3 to 6 months of treatment remains open. In presence of an active malignancy, physicians should weigh the benefits and burdens of ongoing anticoagulation taking into account the clinical status, patient expectations, and the risk of bleeding. As the length of time from the index event increases, the available evidence is not conclusive. The most critical unresolved issues include the decision to continue or discontinue anticoagulation and the selection of the most appropriate anticoagulant agent. On this background, our article provides an overview of the available studies focusing on extended (i.e., >6 months) anticoagulation treatment in cancer-associated thrombosis, with the ultimate goal of refining real-world clinical decision-making in this patient population.

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

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

Management of anticoagulation in patients with metastatic castration-resistant prostate cancer receiving abiraterone + prednisone

PURPOSE

Abiraterone has been proven to be an effective agent used in the management of metastatic castration-resistant prostate cancer, significantly improving overall and progression-free survival. Due to the pharmacodynamic and pharmacokinetic properties of abiraterone, concurrent use with anticoagulation may pose a challenge for clinicians. Thrombosis within the cancer setting continues to increase patient mortality; therefore, appropriate anticoagulation through the use of a management algorithm can reduce adverse events and increase quality of life.

METHODS

A review of the literature was preformed by a medical oncologist, haematologist and pharmacists to identify relevant randomized controlled trials, meta-analyses and retrospective studies. Major society guidelines were reviewed to further aid in developing the anticoagulation protocol for non-valvular atrial fibrillation and venous thromboembolism within this patient population. After reviewing the literature, a clinical framework was designed to aid clinicians in the management of those patients receiving abiraterone concurrently with an anticoagulant.

RESULTS

In this review, we describe the potential interactions between abiraterone and various anticoagulants and provide management strategies based on the most recent literature for atrial fibrillation, venous thromboembolism and mechanical heart valves to avoid potential drug-drug interactions.

CONCLUSION

Abiraterone therapy has become a mainstay of the management of advanced prostate cancer and is often used over prolonged years. In this review, we have summarized a framework of how to use abiraterone in men with prostate cancer on anticoagulants. Evidence available to date suggests that patients with an indication for anticoagulation such as atrial fibrillation, venous thromboembolism and mechanical heart valves can be treated safely with abiraterone in the appropriate setting, with appropriate monitoring.

Anticoagulant therapy for acute venous thrombo-embolism in cancer patients: A systematic review and network meta-analysis

Background

Low-molecular-weight heparin (LMWH) is usually recommended for the treatment of cancer-associated thrombosis (CAT) but this treatment requires burdensome daily injections. We did a systematic review to compare the efficacy and safety of direct oral anticoagulants (DOAC), vitamin K antagonists (VKA) and LMWH in patients with CAT.

Methods

We searched Pubmed, Embase and CENTRAL for randomised controlled trials comparing DOAC, VKA and LMWH in patients with CAT. Pairwise and network meta-analyses were computed for venous thromboembolism (VTE) recurrence and bleeding complications.

Results

We identified 14 studies, including 4,661 patients. In pairwise comparison, DOAC were superior to LMWH to prevent VTE recurrence (HR 0.63; 95% CI 0.42–0.96) and LMWH was superior to VKA (HR 0.53; 95% CI 0.40–0.70). The rate of major bleeding was higher with DOAC compared to LMWH (HR 1.78; 95% CI 1.11–2.87). In the network meta-analysis, DOAC had a lower, but non-significant, rate of VTE recurrence compared to LMWH (HR 0.74; 95% CI 0.54–1.01). Both DOAC (HR 0.42; 95% CI 0.29–0.61) and LMWH (HR 0.57; 95% CI 0.44–0.75) were associated with lower rates of recurrence compared to VKA. No significant difference in major bleeding rate was observed in the network meta-analysis. Inconsistency was observed between pairwise and network meta-analysis comparisons for major bleeding.

Conclusions

DOAC are effective to prevent VTE recurrence in patients with CAT but are associated with an increased risk of bleeding compared to LMWH. The choice of anticoagulant should be personalised, taking into account the patient’s bleeding risk, including cancer site, and patient’s values and preferences.

Direct Oral Anticoagulant Drugs: On the Treatment of Cancer-Related Venous Thromboembolism and their Potential Anti-Neoplastic Effect

Cancer patients develop a hypercoagulable state with a four- to seven-fold higher thromboembolic risk compared to non-cancer patients. Thromboembolic events can precede the diagnosis of cancer, but they more often occur at diagnosis or during treatment. After malignancy itself, they represent the second cause of death. Low molecular weight heparins are the backbone of the treatment of cancer-associated thromboembolism. This treatment paradigm is possibly changing, as direct oral anticoagulants (DOACs) may prove to be an alternative therapeutic option. The currently available DOACs were approved during the first and second decades of the 21st century for various clinical indications. Three molecules (apixaban, edoxaban and rivaroxaban) are targeting the activated factor X and one (dabigatran) is directed against the activated factor II, thrombin. The major trials analyzed the effect of these agents in the general population, with only a small proportion of cancer patients. Two published and several ongoing studies are specifically investigating the use of DOACs in cancer-associated thromboembolism. This article will review the current available literature on the use of DOACs in cancer patients. Furthermore, we will discuss published data suggesting potential anti-cancer actions exerted by non-anticoagulant effects of DOACs. As soon as more prospective data becomes available, DOACs are likely to be considered as a potential new therapeutic option in the armamentarium for patients suffering of cancer-associated thromboembolism.