Predictors of venous thromboembolism recurrence and bleeding among active cancer patients: a population-based cohort study. Blood. 2014;123:3972-3978. [PMID: 24782507 DOI: 10.1182/blood-2014-01-549733]

Risk of Recurrent Venous Thromboembolism in Patients with Cancer: An Individual Patient Data Meta-analysis and Development of a Prediction Model

BACKGROUND

 About 7% of patients with cancer-associated venous thromboembolism (CAT) develop a recurrence during anticoagulant treatment. Identification of high-risk patients may help guide treatment decisions.

AIM

 To identify clinical predictors and develop a prediction model for on-treatment recurrent CAT.

METHODS

 For this individual patient data meta-analysis, we used data from four randomized controlled trials evaluating low-molecular-weight heparin or direct oral anticoagulants (DOACs) for CAT (Hokusai VTE Cancer, SELECT-D, CLOT, and CATCH). The primary outcome was adjudicated on-treatment recurrent CAT during a 6-month follow-up. A clinical prediction model was developed using multivariable logistic regression analysis with backward selection. This model was validated using internal-external cross-validation. Performance was assessed by the c-statistic and a calibration plot.

RESULTS

 After excluding patients using vitamin K antagonists, the combined dataset comprised 2,245 patients with cancer and acute CAT who were treated with edoxaban (23%), rivaroxaban (9%), dalteparin (47%), or tinzaparin (20%). Recurrent on-treatment CAT during the 6-month follow-up occurred in 150 (6.7%) patients. Predictors included in the final model were age (restricted cubic spline), breast cancer (odds ratio [OR]: 0.42; 95% confidence interval [CI]: 0.20-0.87), metastatic disease (OR: 1.44; 95% CI: 1.01-2.05), treatment with DOAC (OR: 0.66; 95% CI: 0.44-0.98), and deep vein thrombosis only as an index event (OR: 1.72; 95% CI: 1.31-2.27). The c-statistic of the model was 0.63 (95% CI: 0.54-0.72) after internal-external cross-validation. Calibration varied across studies.

CONCLUSION

 The prediction model for recurrent CAT included five clinical predictors and has only modest discrimination. Prediction of recurrent CAT at the initiation of anticoagulation remains challenging.

Prediction model for major bleeding in anticoagulated patients with cancer-associated venous thromboembolism using machine learning and natural language processing

PURPOSE

We developed a predictive model to assess the risk of major bleeding (MB) within 6 months of primary venous thromboembolism (VTE) in cancer patients receiving anticoagulant treatment. We also sought to describe the prevalence and incidence of VTE in cancer patients, and to describe clinical characteristics at baseline and bleeding events during follow-up in patients receiving anticoagulants.

METHODS

This observational, retrospective, and multicenter study used natural language processing and machine learning (ML), to analyze unstructured clinical data from electronic health records from nine Spanish hospitals between 2014 and 2018. All adult cancer patients with VTE receiving anticoagulants were included. Both clinically- and ML-driven feature selection was performed to identify MB predictors. Logistic regression (LR), decision tree (DT), and random forest (RF) algorithms were used to train predictive models, which were validated in a hold-out dataset and compared to the previously developed CAT-BLEED score.

RESULTS

Of the 2,893,108 cancer patients screened, in-hospital VTE prevalence was 5.8% and the annual incidence ranged from 2.7 to 3.9%. We identified 21,227 patients with active cancer and VTE receiving anticoagulants (53.9% men, median age of 70 years). MB events after VTE diagnosis occurred in 10.9% of patients within the first six months. MB predictors included: hemoglobin, metastasis, age, platelets, leukocytes, and serum creatinine. The LR, DT, and RF models had AUC-ROC (95% confidence interval) values of 0.60 (0.55, 0.65), 0.60 (0.55, 0.65), and 0.61 (0.56, 0.66), respectively. These models outperformed the CAT-BLEED score with values of 0.53 (0.48, 0.59).

CONCLUSIONS

Our study shows encouraging results in identifying anticoagulated patients with cancer-associated VTE who are at high risk of MB.

Bleeding Risk in Patients with Cancer

The hemostatic system and cancer display a tight interconnection, and hemostatic imbalance frequently occurs in patients with cancer. While extensive knowledge about thrombotic risk has been generated, less is known about bleeding risk and associated risk factors. However, bleeding risk is of high significance as patients with cancer frequently receive therapeutic anticoagulation for various indications and/or are candidates for primary thromboprophylaxis. The risk of bleeding in patients with cancer is variable and difficult to assess in clinical practice. Certain clinical settings such as hospitalization, specific underlying risk factors (e.g., tumor type), and medications (e.g., anticoagulation) can contribute to the individual bleeding risk of a patient with cancer. In addition, some dynamic factors such as platelet count or kidney function have an impact. Particularly, data on baseline risk of bleeding are lacking to allow for risk assessment in cancer patients without anticoagulation. In contrast, risk assessment models for the prediction of bleeding events in cancer patients receiving anticoagulation have been developed; however, these have yet to be validated. The recognition of the importance of bleeding risk in cancer patients is growing, leading to an increasing number of studies investigating and reporting bleeding complications. As study designs and reporting of bleeding events vary, it is challenging to offer a clear synthesis of evidence. In this narrative review, we provide an overview of currently available data about incidence, risk factors, and clinical impact of bleeding events in patients with cancer, and critically review risk assessment models for bleeding in cancer patients during anticoagulant therapy.

Venous Thrombosis Recurrence After Catheter-Related Upper Extremity Deep Venous Thrombosis in Cancer Patients: A Retrospective Analysis

Long-term indwelling central venous catheters (CVC) are frequently used to secure vascular access to deliver injectable treatment. Catheter-related thrombosis (CRT) occurs in approximately 2-6% of cancer patients. We conducted a single-center retrospective study to assess the rate of venous thromboembolism (VTE) recurrence in cancer patients; 200 patients were included. Mean age was 56 ± 15.15 years, median follow-up duration was 16.5 [range: 10-36] months. The incidence of recurrence was estimated using Gray's method for competing risk with death as the competing event of VTE. Recurrent VTE occurred in 25.5% of patients with a median occurrence time of 6.5 [range: 5-11.25] months. In case of recurrence, 94.6% of patients were treated for cancer and 80.4% of them received anticoagulants; 4 major bleeds and 17 non-major bleeds occurred during follow-up. In multivariate analysis, previous VTE (Hazard Ratio (HR) 2.48 (95% CI 1.42-4.32) and presence of CVC (HR 5.56 (95% CI 1.96-15.75) were significant recurrence risk factors. After a first episode of CRT, 25.5% of patients experienced VTE recurrence as UEDVT in 30 cases (55.5%), PE in 17 cases (31.5%), and DVT in 7 cases (13%), mostly during anticoagulation therapy. Anticoagulation therapy does not avoid CRT in case of cancer and must be balanced with hemorrhagic risk.

Cerebral venous sinus thrombosis associated with cancer: analysis of the ACTION-CVT study

Nearly one fifth of patients with venous thromboembolism (VTE) have cancer. When both of these conditions occur, especially in cases of cerebral vein thrombosis (CVT), patient management is often challenging. The aim of this study was to compare the characteristics and event courses in patients affected by CVT with and without cancer. Consecutive patients with CVT from the ACTION-CVT cohort study were included if cancer status was reported. Risk factors as well as the clinical and radiological characteristics of patients were compared. Univariable and multivariable analyses were performed to assess variables associated with cancer. Kaplan-Meier method and log-rank test, logistic regression analysis, and propensity score matching were used to investigate any association between cancer-related CVT and study outcomes (primary outcome at 3-months: recurrent VTE or major hemorrhage; recurrent VTE; major hemorrhage; recanalization status; all-cause-death). Overall, 1,023 patients with CVT were included, of which 6.5% had cancer. Older age (adjusted odds ratio [aOR] 1.28 per decade increase; 95% confidence interval [CI] 1.08-1.52) and absence of headache (aOR 0.47; 95% CI 0.27-0.84) were independently associated with cancer. Patients with cancer had a higher risk of recurrent VTE or major hemorrhage (aOR 3.87; 95% CI 2.09-7.16), all-cause-death (aOR 7.56 95% CI 3.24-17.64), and major hemorrhage (aOR 3.70 95% CI 1.76-7.80). Recanalization rates, partial or complete, was not significantly different. CVT patients with cancer were more likely to be older, have no referred headache, and have worse outcomes compared to CVT patients without cancer.

Effectiveness and safety of continuous low-molecular-weight heparin versus switching to direct oral anticoagulants in cancer-associated venous thrombosis

Given the existing uncertainty regarding the effectiveness and safety of switching from low-molecular-weight heparin (LMWH) to direct oral anticoagulants (DOACs) in patients with cancer-associated venous thrombosis (CAT), we conducted a comprehensive population-based cohort study utilizing electronic health database in Hong Kong. A total of 4356 patients with CAT between 2010 and 2022 were included, with 1700 (39.0%) patients switching to DOAC treatment. Compared to continuous LMWH treatment, switching to DOACs was associated with a significantly lower risk of hospitalization due to venous thromboembolism (HR: 0.49 [95% CI = 0.35-0.68]) and all-cause mortality (HR: 0.67 [95% CI = 0.61-0.74]), with no significant difference in major bleeding (HR: 1.04 [95% CI = 0.83-1.31]) within six months. These findings provide reassurance regarding the effectiveness and safety of switching from LMWH to DOACs among patients with CAT, including vulnerable patient groups.

Cancer-associated venous thrombosis in adults (second edition): A British Society for Haematology Guideline

A shared decision on the most appropriate agent for the treatment of cancer-associated thrombosis should consider the following factors, which should be reassessed as patients continue along their cancer care pathway: risk of bleeding; tumour site; suitability of oral medications; potential for drug-drug interactions; and patient preference and values regarding choice of drug. Continuing anticoagulation beyond 6 months in patients with cancer-associated venous thromboembolism and active cancer is recommended.

Extending venous thromboembolism secondary prevention with apixaban in cancer patients. The EVE trial

BACKGROUND

Cancer-associated venous thromboembolism (VTE) management guideline recommendations include continued therapeutic anticoagulation while active cancer persists. The Federal Drug Administration label for apixaban for secondary VTE prevention includes a dose reduction to 2.5 mg twice daily after 6 months of treatment.

OBJECTIVES

The study's purpose was to determine whether this dose reduction is advisable for cancer-associated VTE.

METHODS

A randomized, double-blind trial compared apixaban 2.5 mg with 5 mg twice daily for 12 months among cancer patients with VTE who had completed 6 to 12 months of anticoagulation therapy. The primary outcome was combined major bleeding plus clinically relevant nonmajor bleeding.

RESULTS

Of 370 patients recruited, 360 were included in the intention-to-treat analyses. Major plus clinically relevant nonmajor bleeding occurred in 16 of 179 patients (8.9%) in the apixaban 2.5 mg group compared with 22 of 181 patients (12.2%) in the 5 mg group (hazard ratio [HR], 0.72; 95% CI, 0.38-1.37; P = .39). Major bleeding occurred in 2.8% of the apixaban 2.5 mg group and in 2.2% of the 5 mg group (HR, 1.26; 95% CI, 0.34-4.66; P = .73). Recurrent VTE or arterial thrombosis occurred in 9 of 179 patients (5.0%) in the apixaban 2.5 mg group and 9 of 181 patients (5.0%) in the 5 mg group (HR, 1.0; 95% CI, 0.40-2.53; P = 1.00). All-cause mortality rates were similar between groups, 13% vs 12% (HR, 1.14; 95% CI, 0.63-2.04; P = .67).

CONCLUSION

For secondary prevention of cancer-associated VTE, apixaban 2.5 mg compared with 5 mg twice daily did not lower combined bleeding events (EVE trial NCT03080883).

[Translation into French and republication of: "Anticoagulant treatment of cancer-associated thromboembolism"]

Venous thromboembolism (VTE) is a frequent and potentially fatal complication in patients with cancer. During the initial period after the thromboembolic event, a patient receiving anticoagulant treatment is exposed both to a risk of VTE recurrence and also to an elevated bleeding risk conferred by the treatment. For this reason, the choice of anticoagulant is critical. The choice should take into account patient-related factors (such as functional status, age, body mass index, platelet count and renal function), VTE-related factors (such as severity or site), cancer-related factors (such as activity and progression) and treatment related factors (such as drug-drug interactions), which all potentially influence bleeding risk, and patient preference. These should be evaluated carefully for each patient during a multidisciplinary team meeting. For most patients, apixaban or a low molecular-weight heparin is the most appropriate initial choice for anticoagulant treatment. Such treatment should be offered to all patients with active cancer for at least 6months. The patient and treatment should be re-evaluated regularly, and anticoagulant treatment changed when necessary. Continued anticoagulant treatment beyond 6months is justified if the cancer remains active or if the patient experienced recurrence of VTE in the first 6months. In other cases, the interest of continued anticoagulant treatment may be considered on an individual patient basis in collaboration with oncologists.

Risk Factors for Bleeding Events in Japanese Patients with Advanced Lung Cancer: Data from the Rising-VTE/NEJ037 Study

Despite the occurrence of various hemorrhagic events during advanced lung cancer treatment, few researchers have reported on their risk factors. Moreover, the development of cancer-related thromboembolism indicates anticoagulant use. However, adverse events such as bleeding should be monitored. In this study, we aimed to identify factors that influence the onset of hemorrhagic events in patients with lung cancer. The Rising-VTE/NEJ037 study was a multicenter, prospective, observational study. A total of 1008 patients with lung cancer who were unsuitable for radical resection or radiation were enrolled and followed up for 2 years. Multivariate analysis using a Cox proportional hazard model was performed to compare the outcomes of the time to the onset of hemorrhagic events for 2 years after registration. Hemorrhagic events occurred in 115 patients (11.4%), with 35 (30.4%) experiencing major bleeding. Significant risk factors included venous thromboembolism (VTE) (hazard ratio [HR]: 4.003, p < 0.001) and an Eastern Cooperative Oncology Group Performance Status score of 1 (HR: 2.476, p < 0.001). Factors that significantly reduced hemorrhagic event risk were female sex (HR: 0.454, p = 0.002) and M1a status (HR: 0.542, p = 0.038). VTE is a risk factor for hemorrhagic events in patients with advanced lung cancer, and risks associated with anticoagulant therapy should be considered.

Incidence of venous thromboembolism and association with PD-L1 expression in advanced non-small cell lung cancer patients treated with first-line chemo-immunotherapy

Background

Venous thromboembolism (VTE) is a serious complication in non-small cell lung cancer (NSCLC) patients. The use of thromboprophylactic therapy is subject to an accurate assessment of the VTE risk depending on patients, tumor characteristics and type of systemic antineoplastic treatments. However, little is known concerning the risk of VTE in patients suffering from an advanced NSCLC treated with first-line chemo-immunotherapy and the impact of tumor biomarkers such as PD-L1 expression.

Methods

We performed a retrospective, observational, single-centre study in a cohort of advanced NSCLC patients treated with first-line chemo-immunotherapy. The primary endpoint was the incidence of VTE. Secondary endpoints were the cumulative incidence of VTE, the impact of PD-L1 on VTE occurrence, overall survival, the rate of VTE recurrence under anticoagulant treatment and the rate of bleeding complications.

Results

109 patients were included, of whom 21 (19.3%) presented a VTE event during a median follow-up of 13 months. VTE incidence at 3, 6 and 12 months was 12.1%, 15.1% and 17.5% respectively. 61% were pulmonary embolisms, 9.5% were isolated deep vein thrombosis and 14.3% were central venous catheter-related thrombosis. Our study did not show a significant impact of PD-L1 on VTE occurrence. Overall survival at 6, 12 and 24 months was 81.9%, 74.4% and 70.3% respectively. Four patients developed a recurrent VTE under anticoagulation therapy 3 to 5 months after the first VTE event. One patient suffered from a major bleeding complication while under anticoagulation therapy, leading to death.

Conclusion

VTE is a common complication in advanced NSCLC patients treated with concomitant chemo-immunotherapy. In our study, 19.3% of patients developed a VTE during a median follow-up of 13 months. PD-L1 did not appear to be associated with VTE occurrence. We recorded high VTE recurrence rates despite anticoagulant treatment. Further investigations are needed to determine if high PD-L1 expression is associated with VTE.

Treatment Patterns of Cancer-associated Thrombosis in the Netherlands: The Four Cities Study

Background  Current guidelines recommend either low-molecular weight heparin (LMWH) or direct oral anticoagulants (DOACs) as first-line treatment in cancer-associated venous thromboembolism (VTE). Aim  This study aimed to investigate treatment regimens for cancer-associated VTE over the past 5 years, explore predictors for initial treatment (LMWH vs. DOAC), and to assess the risks of recurrent VTE and bleeding. Methods  This was a Dutch, multicenter, retrospective cohort study including consecutive patients with cancer-associated VTE between 2017 and 2021. Treatment predictors were assessed with multivariable logistic regression models. Six-month cumulative incidences for recurrent VTE and major bleeding (MB) were estimated with death as competing risk. Results  In total, 1,215 patients were included. The majority (1,134/1,192; 95%) started VTE treatment with anticoagulation: 561 LMWH (47%), 510 DOACs (43%), 27 vitamin K antagonist (2.3%), and 36 other/unknown type (3.0%). The proportion of patients primarily treated with DOACs increased from 18% (95% confidence interval [CI] 12-25) in 2017 to 70% (95% CI 62-78) in 2021. Poor performance status (adjusted odds ratio [aOR] 0.72, 95% CI 0.53-0.99) and distant metastases (aOR 0.61, 95% CI 0.45-0.82) were associated with primary treatment with LMWH. Total 6-month cumulative incidences were 6.0% (95% CI 4.8-7.5) for recurrent VTE and 7.0% (95% CI 5.7-8.6) for MB. During follow-up, 182 patients (15%) switched from LMWH to a DOAC, and 54 patients (4.4%) vice versa, for various reasons, including patient preference, recurrent thrombosis, and/or bleeding. Conclusion  DOAC use in cancer-associated VTE has increased rapidly over the past years. Changes in anticoagulation regimen were frequent over time, and were often related to recurrent thrombotic and bleeding complications, illustrating the complexity and challenges of managing cancer-associated VTE.

Anticoagulant treatment of cancer-associated thromboembolism

Venous thromboembolism (VTE) is a frequent and potentially fatal complication in patients with cancer. During the initial period after the thromboembolic event, a patient receiving anticoagulant treatment is exposed both to a risk of VTE recurrence and also to an elevated bleeding risk conferred by the treatment. For this reason, the choice of anticoagulant is critical. The choice should take into account patient-related factors (such as functional status, age, body mass index, platelet count and renal function), VTE-related factors (such as severity or site), cancer-related factors (such as activity and progression) and treatment-related factors (such as drug-drug interactions), which all potentially influence bleeding risk, and patient preference. These should be evaluated carefully for each patient during a multidisciplinary team meeting. For most patients, apixaban or a low molecular-weight heparin is the most appropriate initial choice for anticoagulant treatment. Such treatment should be offered to all patients with active cancer for at least six months. The patient and treatment should be re-evaluated regularly and anticoagulant treatment changed when necessary. Continued anticoagulant treatment beyond six months is justified if the cancer remains active or if the patient experienced recurrence of VTE in the first six months. In other cases, the interest of continued anticoagulant treatment may be considered on an individual patient basis in collaboration with oncologists.

Subgroup analyses in venous thromboembolism trials reporting pharmacological interventions: A systematic review

INTRODUCTION

Randomized controlled trials (RCTs) that conduct subgroup analyses have the potential to provide information on treatment decisions in specific groups of patients from heterogeneous populations. Although we understand several factors can modify the incidence of venous thromboembolism (VTE) and the benefit/risk ratio of anticoagulation treatments, further evidence is warranted to show the heterogeneity of treatment effects in different subgroups of patients.

AIMS

The primary purpose was to evaluate the appropriateness and interpretation of subgroup analysis performed on VTE RCTs reporting pharmacological interventions.

MATERIALS AND METHODS

A systematic review of RCTs published between January 2017 and January 2022 was conducted. Claims of subgroup effects were evaluated with predefined criteria. High-quality claims of subgroup effect were further analyzed and discussed.

RESULTS

Overall, 28 RCTs with a generally low bias risk were included. The purposes of the treatments included pharmacologic thromboprophylaxis (17), therapeutic dose anticoagulation (9), and catheter-directed pharmacologic thrombolysis (2). The evaluated subgroup analyses generally presented: a high number of subgroup analyses reported, a lack of prespecification, and a lack of usage of statistical tests for interaction. The authors reported 13 claims of subgroup effect; only two were considered potentially reliable to represent heterogeneity in the direction or magnitude of treatment effect.

CONCLUSIONS

Subgroup analyses of VTE RCTs reporting pharmacologic interventions are generally methodologically poor. Most claims of subgroup effect did not meet critical criteria and lacked credibility. Clinicians in this field may proceed with scepticism when assessing claims of subgroup effects due to methodological concerns and misleading interpretations.

Impact of venous thromboembolism on the mortality in patients with cancer: a population-based cohort study

Background

Despite recent improvements in the treatment of cancer, little is known about the long-term survival in patients with cancer and venous thromboembolism. We aimed to examine the five-year mortality of venous thromboembolism in cancer patients in a large population-based cohort study.

Methods

Using Danish healthcare registries from 1995 to 2020, we obtained data on cancer patients with venous thromboembolism and comparison cohorts of cancer patients without venous thromboembolism, matched in terms of cancer type, age, sex, and year of cancer diagnosis, and adjusted for level of comorbidity and frailty using the Charlson Comorbidity Index Score and Hospital Frailty Risk Score, marital status, use of selected medications, and recent surgery (<90 days).

Findings

During the study period, 886,536 patients were diagnosed with cancer. Of 1882 cancer patients diagnosed at the time of their venous thromboembolism, 44.4% (835/1882) had distant metastases. In this cohort, the one- and five-year mortality cumulative incidences were 68% (1284/1882) and 84% (1578/1882), respectively, in contrast to 38% (2135/5549) and 67% (3653/5549) in the comparison cohort. The mortality rate ratio was 4.34 (95% confidence interval [CI], 3.95-4.78) for the first year of follow-up and 3.44 (95% CI 3.17-3.73) for the five-year follow-up period. Of the 23,366 patients diagnosed with venous thromboembolism after cancer diagnosis, 18% (4183/23,366) had distant metastases at the time of cancer diagnosis. The cumulative incidence of death at one year was 45% (10,465/23,366; mortality rate ratio 3.48, 95% CI 3.37-3.60) and at five years 69% (15,669/23,366; mortality rate ratio 2.57, 95% CI 2.50-2.63).

Interpretation

Despite improved cancer treatment, venous thromboembolism in cancer patients is strongly associated with a poor prognosis.

Funding

The study was supported by grants from the Independent Research Fund Denmark (record no. 3101-00102B) and the Karen Elise Jensen Foundation.

Risk of recurrent cancer-associated venous thromboembolism: A Danish nationwide cohort study

BACKGROUND

Predictive factors for recurrent cancer-associated venous thromboembolism have been inconsistent across previous studies. To provide data for improved risk stratification, we described the risk of recurrent venous thromboembolism overall and across age, sex, calendar period, cancer type, Ottawa risk score, cancer stage, and cancer treatment in a nationwide cohort of patients with active cancer.

METHODS

Using Danish administrative registries, we identified a cohort of all adult patients with active cancer and a first-time diagnosis of venous thromboembolism during 2003-2018. We accounted for the competing risk of death and calculated absolute risks of recurrent venous thromboembolism at six months.

RESULTS

The population included 34,072 patients with active cancer and venous thromboembolism. Recurrence risks at six months were higher for patients with genitourinary cancer (6.5%), lung cancer (6.1%), gastrointestinal cancer (5.6%), brain cancer (5.2%), and hematological cancer (5.1%) than for patients with gynecological cancer (4.7%), breast cancer (4.1%), and other cancer types (4.8%). Recurrence risks were similar for men (5.2%) and women (4.9%), with and without chemotherapy (5.1%), across Ottawa risk score group (low: 5.0%; high: 5.1%) and across calendar periods but increased with increasing cancer stage. The overall six-month all-cause mortality risk was 26%, and highest for patients with lung cancer (49%) and lowest among breast cancer patients (4.1%).

CONCLUSIONS

Six-month recurrence risk after first-time cancer-associated venous thromboembolism was high and varied by cancer type and patient characteristics. Refining risk stratification for recurrence may improve decision-making regarding treatment duration after cancer-associated thromboembolism.

The risk of recurrent venous thromboembolism after discontinuation of anticoagulant therapy in patients with cancer-associated thrombosis: a systematic review and meta-analysis

Background

The optimal duration of anticoagulation in patients with active cancer and venous thromboembolism (VTE) is unknown. Current clinical guidelines advocate anticoagulant therapy for 3-6 months and to continue anticoagulant therapy for as long as the cancer is active. However, an adequate systematic review on the rate of recurrent VTE after discontinuation of anticoagulant therapy has not been performed.

Methods

For this systemic review and meta-analysis, we searched Embase.com, Medline (Ovid), Web of Science, Cochrane Library, and Google Scholar, from database inception to February 16, 2023, for studies on anticoagulant therapy in patients with cancer and the recurrence of venous thromboembolism after discontinuation of this therapy. We included randomised controlled trials and cohort studies published in English that reported on patients who met the following: cancer and a first VTE, completed at least 3 months of anticoagulant therapy, were followed after discontinuation of anticoagulant therapy, and with symptomatic recurrent VTE as an outcome during follow-up. Study-level data were requested from study authors. The primary outcome was the rate of recurrent VTE after discontinuation of anticoagulant therapy. A Bayesian random-effects meta-analysis was used to estimate the rate of recurrent VTE per 100 person-years for the pooled studies at different time intervals after discontinuation of anticoagulation therapy. We also calculated the cumulative VTE recurrence rate at different time intervals. Forest plots were mapped and the results were summarized by the median and 95% credible interval (CIs). This study was registered with PROSPERO, CRD42021249060.

Findings

Of 3856 studies identified in our search, 33 studies were identified for inclusion. After requesting study-level data, 14 studies involving 1922 patients with cancer-associated thrombosis were included. The pooled rate of recurrent VTE per 100 person-years after discontinuation of anticoagulant therapy was 14.6 events (95% credible interval 6.5-22.8) in the first three months, decreasing to 1.1 events (95% CI 0.3-2.1) in year 2-3, and 2.2 events (95% CI 0.0-4.4) in year 3-5 after discontinuation of anticoagulant therapy. The cumulative VTE recurrence rate was 28.3% (95% CI 15.6-39.6%) at 1 year; 31.1% (95% CI 16.5-43.8%) at 2 years; 31.9% (95% CI 16.8-45.0%) at 3 years; and 35.0% (95% CI 16.8-47.4%) at 5 years after discontinuation of anticoagulant therapy.

Interpretation

This meta-analysis demonstrates a high rate of recurrent VTE over time after discontinuation of anticoagulant therapy in patients with cancer-associated thrombosis. Our results support the current clinical guidelines to continue anticoagulant therapy in patients with active cancer.

Funding

Erasmus MC.

Development of a predictive model of venous thromboembolism recurrence in anticoagulated cancer patients using machine learning

INTRODUCTION

Patients with cancer and venous thromboembolism (VTE) show a high risk of VTE recurrence during anticoagulant treatment. This study aimed to develop a predictive model to assess the risk of VTE recurrence within 6 months at the moment of primary VTE diagnosis in these patients.

MATERIALS AND METHODS

Using the EHRead® technology, based on Natural Language Processing (NLP) and machine learning (ML), the unstructured data in electronic health records from 9 Spanish hospitals between 2014 and 2018 were extracted. Both clinically- and ML-driven feature selection were performed to identify predictors for VTE recurrence. Logistic regression (LR), decision tree (DT), and random forest (RF) algorithms were used to train different prediction models, which were subsequently validated in a hold-out data set.

RESULTS

A total of 16,407 anticoagulated cancer patients with diagnosis of VTE were identified (54.4 % male and median age 70). Deep vein thrombosis, pulmonary embolism and metastases were observed in 67.2 %, 26.6 %, and 47.7 % of the patients, respectively. During the study follow-up, 11.4 % of the patients developed a recurrent VTE, being more frequent in patients with lung cancer. Feature selection and model training based on ML identified primary pulmonary embolism, deep vein thrombosis, metastasis, adenocarcinoma, hemoglobin and serum creatinine levels, platelet and leukocyte count, family history of VTE, and patients' age as predictors of VTE recurrence within 6 months of VTE diagnosis. The LR model had an AUC-ROC (95 % CI) of 0.66 (0.61, 0.70), the DT of 0.69 (0.65, 0.72) and the RF of 0.68 (0.63, 0.72).

CONCLUSIONS

This is the first ML-based predictive model designed to predict 6-months VTE recurrence in patients with cancer. These results hold great potential to assist clinicians to identify the high-risk patients and improve their clinical management.

Hand grip strength in venous thromboembolism: risk of recurrence and mortality

Background

There is limited information on the relationship between muscle strength and recurrence and mortality after incident venous thromboembolism (VTE).

Objectives

To investigate whether weak hand grip strength (HGS) was associated with risk of recurrence and mortality in patients with VTE recruited from the general population.

Methods

Participants from the Tromsø Study with a first-time VTE (n = 545) were included, and all VTE recurrences and deaths among the participants were recorded in the period 1994 to 2020. Weak HGS was defined as lowest 25th percentile of the general population, and incidence rates for VTE recurrence and mortality according to weak vs normal (>25th percentile) HGS, with 95% CIs, were estimated.

Results

There were 90 recurrences and 350 deaths during a median of 3.7 years of follow-up. The fully adjusted hazard ratio (HR) for overall VTE recurrence for those with weak HGS vs those with normal HGS was 2.02 (95% CI, 1.23-3.30). The corresponding HRs for recurrence were 2.22 (95% CI, 1.18-4.17) in patients with a first deep vein thrombosis and 1.60 (95% CI, 0.72-3.57) in patients with a first pulmonary embolism. The cumulative 1-year survival was 74.9% and 77.8% in those with weak and normal HGS, respectively. For overall mortality after incident VTE, the fully adjusted HR for those with weak HGS was 1.34 (95% CI, 1.04-1.72).

Conclusion

Weak HGS was associated with an increased risk of recurrent VTE, and the association appeared to be particularly pronounced after incident deep vein thrombosis. There was a slightly lower survival probability among those with weak HGS than among those with normal HGS.

Effectiveness and safety of anticoagulants among venous thromboembolism cancer patients with and without brain cancer

INTRODUCTION

Patients with brain cancer are at a high risk of developing venous thromboembolism (VTE) and are underrepresented in clinical trials. This study compared the risk of recurrent VTE (rVTE), major bleeding (MB), and clinically relevant non-major bleeding (CRNMB) among VTE cancer patients initiating apixaban, low molecular weight heparin (LMWH), or warfarin stratified by patients with brain vs other cancer types.

MATERIALS AND METHODS

Active cancer patients initiating apixaban, LMWH, or warfarin within 30 days after VTE diagnosis were identified from 4 US commercial and the Medicare databases. Inverse probability of treatment weights (IPTW) was used to balance patient characteristics. Cox proportional hazards models were used to evaluate the interaction between brain cancer status and treatment on outcomes (rVTE, MB, and CRNMB), with a p-value <0.1 indicating a significant interaction.

RESULTS

Of 30,586 patients with active cancer (5 % had brain cancer), apixaban (vs. LMWH and warfarin) was associated with lower risk of rVTE, MB, and CRNMB. Generally, no significant interactions (P > 0.1) were found between brain cancer status and anticoagulant treatment across outcomes. The exception was MB for apixaban [vs LMWH (p-value for interaction = 0.091)] with a higher reduction among those with brain cancer (HR = 0.32) than those with (HR = 0.72) other cancer.

CONCLUSIONS

Among VTE patients with all types of cancer, apixaban (vs LMWH and warfarin) was associated with a lower risk of rVTE, MB, and CRNMB. In general, anticoagulant treatment effects were not significantly different between VTE patients with brain cancer and those with other cancer.

Trends and factors associated with outpatient anticoagulant treatment initiation among VTE patients with active cancer

BACKGROUND

Patients with venous thromboembolism (VTE) and cancer are at higher risk of recurrent VTE and mortality. Clinical guidelines recommend anticoagulant treatment for these patients. This study assessed trends in outpatient anticoagulant treatment and factors associated with this treatment initiation in outpatient setting among this high-risk patient population.

OBJECTIVE

To study trends and factors associated with anticoagulant treatment initiation among patients with VTE and cancer.

METHODS

VTE cancer patients age ≥65 were identified from the SEER-Medicare database from 01JAN2014-31DEC2019. Patients were enrolled for ≥6 months prior to their first VTE (i.e. index event) and without evidence of other reasons for anticoagulation (i.e., atrial fibrillation). Patients were also required to be enrolled for ≥30 days after index. Cancer status was identified from SEER or Medicare database in the 6 months pre- through 30 days post-VTE. Patients were classified into treated or untreated cohorts depending on whether they initiated outpatient anticoagulant treatment within 30 days post-index. The trends of treated vs. untreated were evaluated by quarter. Logistic regression was used to identify demographic-, VTE-, cancer- and comorbid-related factors associated with anticoagulant treatment initiation.

RESULTS

A total of 28,468 VTE-cancer patients met all study criteria. Of these, ~46 % initiated outpatient anticoagulant treatment within 30 days, and ~54 % did not. The above rates were stable from 2014 to 2019. Factors such as VTE diagnosis in inpatient setting, pulmonary embolism (PE) diagnosis, and pancreatic cancer were associated with increased odds whereas bleeding history and some comorbid factors were associated with decreased odds of initiating anticoagulant treatment.

CONCLUSION

Over half of VTE patients with cancer did not initiate outpatient anticoagulant treatment within the first 30-days after VTE diagnosis. This trend was stable from 2014 to 2019. A range of cancer-, VTE-, and comorbid-related factors were associated with the likelihood of the treatment initiation.

Influence of primary cancer site on clinical outcomes of anticoagulation for associated venous thromboembolism

INTRODUCTION

The outcome of anticoagulation for cancer-associated venous thromboembolism (Ca-VTE) differs according to cancer location, but data are limited and inconsistent.

MATERIALS AND METHODS

Patients with acute venous thromboembolism (VTE) enrolled between 03/01/2013 and 04/30/2021 were followed prospectively to assess VTE recurrence, major bleeding (MB), clinically relevant non-major bleeding (CRNMB), and death.

RESULTS

There were 1702 (45.3 %) patients with Ca-VTE including: gastrointestinal (n = 340), pancreatic (n = 223), hematologic (n = 188), genitourinary (n = 163), lung (n = 139), ovarian (n = 109), breast (n = 97), renal (n = 75), prostate (n = 73), hepatobiliary (n = 70), brain (n = 57), and other cancers (n = 168); 2057 VTE patients had no cancer (NoCa-VTE). Hepatobiliary cancer had the highest VTE recurrence (all rates 100 person-years) of all cancers and higher compared to NoCa-VTE (13.69, p = 0.01), while the MB rate, although numerically higher (15.91), was not different (p = 0.09). Another 3 cancers had higher VTE recurrence but similar MB rates compared to NoCa-VTE: genitourinary [(9.59, p = 0.01) and (7.03, p = 1.0)], pancreatic [(9.74, p < 0.001) and (5.47, p = 1.00)], and hematologic [(5.29, p = 0.05) and (3.59, p = 1.0)]. Renal cancer had the highest rate of MB among all cancers and was higher than that of NoCa-VTE (16.49; p < 0.001), with no difference in VTE recurrence (1.62; p = 1.0). VTE recurrence and MB rates were not significantly different between NoCa-VTE and gastrointestinal, lung, breast, prostate, and brain cancers. CRNMB rates were similar and mortality higher in Ca-VTE patients, except for prostate and breast cancer, compared to NoCa-VTE.

CONCLUSIONS

Significant differences in clinical outcomes indicate that anticoagulation strategies may need to be tailored to the primary cancer location.

Anticoagulant Therapy for Cancer-Associated Thrombosis : A Cost-Effectiveness Analysis

BACKGROUND

Direct oral anticoagulants (DOACs) offer an alternative to low-molecular-weight heparin (LMWH) and warfarin for treating cancer-associated thrombosis (CAT).

OBJECTIVE

To determine the cost and effectiveness of DOACs versus LMWH.

DESIGN

Cohort-state transition decision analytic model.

DATA SOURCES

Network meta-analysis comparing DOACs versus LMWH.

TARGET POPULATION

Adult patients with cancer at the time they develop thrombosis.

TIME HORIZON

Lifetime.

PERSPECTIVE

Health care sector.

INTERVENTION

Strategies of 1) enoxaparin, 2) apixaban, 3) edoxaban, and 4) rivaroxaban for treatment of CAT.

OUTCOME MEASURES

Incremental cost-effectiveness ratio (ICER) in 2022 U.S. dollars per quality-adjusted life-year (QALY) gained.

RESULTS OF BASE-CASE ANALYSIS

In the base-case scenario, using drug prices from the U.S. Department of Veterans Affairs Federal Supply Schedule, apixaban dominated enoxaparin and edoxaban by being less costly and more effective. Rivaroxaban was slightly more effective than apixaban, with an ICER of $493 246. In a scenario analysis using "real-world" drug prices from GoodRx, rivaroxaban was cost-effective with an ICER of $50 053 per QALY.

RESULTS OF SENSITIVITY ANALYSIS

Results were highly sensitive to monthly drug costs. Probabilistic sensitivity analyses showed that at a willingness-to-pay threshold of $50 000 per QALY, apixaban was preferred in 80% of simulations. However, sensitivity analyses also demonstrated that apixaban only remained cost-effective if monthly medication costs were below $530. Above this, rivaroxaban became cost-effective.

LIMITATIONS

An assumption was made that patients would continue anticoagulation indefinitely unless they suffered a major bleed. Nonmedical costs such as patient and caregiver loss of productivity were not accounted for, and long-term thrombotic complications were not explicitly modeled.

CONCLUSION

The 3 DOACs are more effective and more cost-effective than LMWH. The most cost-effective DOAC depends on the relative cost of each of these agents. These are important considerations for treating physicians and health policymakers.

PRIMARY FUNDING SOURCE

None.

Machine learning algorithm as a prognostic tool for venous thromboembolism in allogeneic transplant patients

As a serious complication after allogenic hematopoietic stem cell transplantation (allo-HSCT), venous thromboembolism (VTE) is significantly related to increased nonrelapse mortality. Therefore distinguishing patients at high risk of death who should receive specific therapeutic management is key to improving survival. This study aimed to establish a machine learning-based prognostic model for the identification of post-transplantation VTE patients who have a high risk of death. We retrospectively evaluated 256 consecutive VTE patients who underwent allo-HSCT at our center between 2008 and 2019. These patients were further randomly divided into (1) a derivation (80%) cohort of 205 patients and (2) a test (20%) cohort of 51 patients. The least absolute shrinkage and selection operator (LASSO) approach was used to choose the potential predictors from the primary dataset. Eight machine learning classifiers were used to produce 8 candidate models. A 10-fold cross-validation procedure was used to internally evaluate the models and to select the best-performing model for external assessment using the test cohort. In total, 256 of 7238 patients were diagnosed with VTE after transplantation. Among them, 118 patients (46.1%) had catheter-related venous thrombosis, 107 (41.8%) had isolated deep-vein thrombosis (DVT), 20 (7.8%) had isolated pulmonary embolism (PE), and 11 (4.3%) had concomitant DVT and PE. The 2-year overall survival (OS) rate of patients with VTE was 68.8%. Using LASSO regression, 8 potential features were selected from the 54 candidate variables. The best-performing algorithm based on the 10-fold cross-validation runs was a logistic regression classifier. Therefore a prognostic model named BRIDGE was then established to predict the 2-year OS rate. The areas under the curves of the BRIDGE model were 0.883, 0.871, and 0.858 for the training, validation, and test cohorts, respectively. The Hosmer-Lemeshow goodness-of-fit test showed a high agreement between the predicted and observed outcomes. Decision curve analysis indicated that VTE patients could benefit from the clinical application of the prognostic model. A BRIDGE risk score calculator for predicting the study result is available online (47.94.162.105:8080/bridge/). We established the BRIDGE model to precisely predict the risk for all-cause death in VTE patients after allo-HSCT. Identifying VTE patients who have a high risk of death can help physicians treat these patients in advance, which will improve patient survival.

Survival Implications of Thrombus Recurrence or Bleeding in Cancer Patients Receiving Anticoagulation for Venous Thromboembolism Treatment

BACKGROUND

 Study aims were to analyze prospectively collected data from patients with cancer-associated venous thromboembolism (VTE) to determine the impact of VTE recurrence and anticoagulant-related bleeding on all-cause mortality.

PATIENTS/METHODS

 Consecutive cancer patients with acute VTE treated with anticoagulants (March 1, 2013-November 30, 2021) were included in this analysis. Anticoagulant therapy-associated VTE recurrences, major bleeding, and clinically relevant nonmajor bleeding (CRNMB) were assessed for their impact on all-cause mortality outcomes.

RESULTS

 This study included 1,812 cancer patients with VTE. Of these, there were 97 (5.4%) with recurrent VTE, 98 (5.4%) with major, and 104 (5.7%) with CRNMB while receiving anticoagulants. Recurrent VTE (hazard ratio [HR]: 1.52; 95% confidence interval [CI]: 1.16-2.00; p = 0.0028), major bleeding (HR: 1.82; 95% CI: 1.41-2.31; p = 0.006), and CRNMB (HR; 1.38; 95% CI: 1.05-1.81; p = 0.018) each adversely influenced mortality outcomes. Deep vein thrombosis as the incident thrombotic event type was associated with VTE recurrence (HR: 1.78; 95% CI: 1.08-2.89; p = 0.02). Neither cancer type nor stage, chemotherapy, or Ottawa risk category influenced VTE recurrence. Higher body weights (HR: 1.01; 95% CI: 1.00-1.01; p = 0.005) were associated with increased major bleeding, while high Ottawa scores (HR: 0.66; 95% CI: 0.46-0.96; p = 0.03) and apixaban treatment (HR: 0.62; 95% CI: 0.45-0.84; p = 0.002) were associated with fewer major bleeding outcomes.

CONCLUSION

 Among cancer patients receiving anticoagulant therapy for VTE, adverse outcomes such as VTE recurrence, major bleeding, or CRNMB increase mortality risk by 40 to 80%. Identifying variables predicting these outcomes may help risk-stratify patients with poor prognosis.

Comparative Safety and Effectiveness of Direct Oral Anticoagulants and Warfarin during Chemotherapy in Cancer Patients with Venous Thromboembolism Aged 75 Years or Older: A Nationwide Inpatient Database Study

INTRODUCTION

Venous thromboembolism (VTE) is a life-threatening complication occurring in cancer patients. Direct oral anticoagulants (DOACs) or warfarin are widely prescribed for treating cancer-associated VTE. However, data are sparse as to the effectiveness and bleeding complications associated with these medications in elderly patients. The purpose of this study was to compare effectiveness and safety profiles between DOACs and warfarin in elderly cancer patients undergoing chemotherapy.

METHODS

Using the Diagnosis Procedure Combination inpatient database, we retrospectively identified cancer patients aged ≥75 years who developed VTE during chemotherapy (n = 4,278, January 2016 to March 2020). Eligible patients were divided into those receiving warfarin (n = 557) and DOACs (n = 3,721). We conducted a 1:4 propensity score matching analysis to adjust for measured confounders. The primary outcome was VTE recurrence requiring hospitalization. Secondary outcomes were major bleeding requiring hospitalization and inhospital death from all causes within 6 months.

RESULTS

The propensity-matched cohort included 557 patients in the warfarin group and 2,278 patients in the DOACs group. The proportion of VTE recurrence requiring hospitalization was lower in the DOACs group (5.3% vs. 7.5%; odds ratio [OR], 0.69; 95% confidence interval [CI], 0.48-0.98). The proportion of recurrent deep vein thrombosis was 6.3% and 4.4%, while that of recurrent pulmonary emboli was 1.3% and 1.3% in the warfarin and DOACs groups, respectively. No statistically significant differences were found in the proportion of major bleeding events requiring hospitalization (1.6% vs. 1.1%; OR, 1.47; 95% CI, 0.62-3.50) or all-cause inhospital mortality (11.1% vs. 9.9%; OR, 1.14; 95% CI, 0.84-1.56) between the DOACs and warfarin groups.

CONCLUSION

Our findings suggest that DOACs may be more effective than warfarin in terms of VTE recurrence requiring hospitalization and that these medications may be equivalent in terms of safety.

Incidence and Predictors of Recurrence and Mortality Following First Venous Thromboembolism Among the Saudi Population: Single-Center Cohort Study

Background

Little is written about recurrence and mortality rates after a first episode of venous thromboembolism (VTE) among Saudi population.

Aim

Determine incidence rates and assess predictors of recurrence and mortality following the first VTE event.

Patients and Methods

A total of 1124 patients aged ≥18 years with symptomatic VTE confirmed by imaging tests were evaluated. The incidence of VTE recurrence and mortality were assessed. The association between patient characteristics, and VTE recurrence and mortality was explored by estimating the hazard ratio (HR) and 95% confidence interval (CI). The difference between cancer-related, provoked and unprovoked VTE in terms of recurrence and mortality was explored using Kaplan–Meier curves.

Results

The annual incidence rate of the first VTE was 1.7 per 1000 patients. Of 1124 patients with first VTE, 214 (19%) developed recurrent VTE, and 192 (17%) died with overall incidence rates of 15.8 per 100 person-years (95% CI, 13.8–18.0) and 10.0 per 100 person-years (95% CI, 8.7–11.5). Intensive care unit (ICU) admission (HR, 2.15; 95% CI, 1.67–3.10), presence of active cancer (HR, 2.97; 95% CI, 1.87–3.95), immobilization (HR, 2.52; 95% CI, 1.79–3.67), infection (HR, 2.32; 95% CI, 1.94–3.45), and pulmonary embolism ± deep venous thrombosis (HR, 2.22; 95% CI, 1.56–3.16) were found to be independent predictors of recurrent VTE. Recurrence carries a high hazard of mortality (HR, 5.21; 95% CI, 3.61–7.51). The estimated median time to VTE recurrence was lower in cancer-related VTE (18.7 months) compared with provoked (29.0 months) and unprovoked VTE (28.4 months). The estimated survival median time was lower in cancer-related VTE (21.8 months) compared with provoked (30.5 months) and unprovoked VTE (29.8 months).

Conclusion

Immobilization and presence of active cancer, infection, and PE ± DVT were significant predictors of recurrent VTE. Patients who developed recurrent VTE had a 5.2-fold higher hazard of mortality compared with patients with no VTE recurrence.

Risk assessment and molecular mechanism study of drug-drug interactions between rivaroxaban and tyrosine kinase inhibitors mediated by CYP2J2/3A4 and BCRP/P-gp

Cancer patients generally has a high risk of thrombotic diseases. However, anticoagulant therapy always aggravates bleeding risks. Rivaroxaban is one of the most widely used direct oral anticoagulants, which is used as anticoagulant treatment or prophylaxis in clinical practice. The present study aimed to systemically estimate the combination safety of rivaroxaban with tyrosine kinase inhibitors (TKIs) based on human cytochrome P450 (CYPs) and efflux transporters and to explore the drug–drug interaction (DDI) mechanisms in vivo and in vitro. In vivo pharmacokinetic experiments and in vitro enzyme incubation assays and bidirectional transport studies were conducted. Imatinib significantly increased the rivaroxaban C_max value by 90.43% (p < 0.05) and the area under the curve value by 119.96% (p < 0.01) by inhibiting CYP2J2- and CYP3A4-mediated metabolism and breast cancer resistance protein (BCRP)- and P-glycoprotein (P-gp)-mediated efflux transportation in the absorption phase. In contrast, the combination of sunitinib with rivaroxaban reduced the exposure in vivo by 62.32% (p < 0.05) and the C_max value by 72.56% (p < 0.05). In addition, gefitinib potently inhibited CYP2J2- and CYP3A4-mediated rivaroxaban metabolism with K_i values of 2.99 μΜ and 4.91 μΜ, respectively; however, it almost did not affect the pharmacokinetics of rivaroxaban in vivo. Taken together, clinically significant DDIs were observed in the combinations of rivaroxaban with imatinib and sunitinib. Imatinib increased the bleeding risks of rivaroxaban, while sunitinib had a risk of reducing therapy efficiency. Therefore, more attention should be paid to aviod harmful DDIs in the combinations of rivaroxaban with TKIs.

Enoxaparin versus dalteparin or tinzaparin in patients with cancer and venous thromboembolism: The RIETECAT study

Background

Venous thromboembolism (VTE) is a frequent complication in patients with cancer and a leading cause of morbidity and death.

Objectives

The objective of the RIETECAT study was to compare the long‐term effectiveness and safety of enoxaparin versus dalteparin or tinzaparin for the secondary prevention of VTE in adults with active cancer.

Methods

We used the data from the multicenter, multinational RIETE registry to compare the rates of VTE recurrences, major bleeding, or death over 6 months in patients with active cancer and acute VTE using full doses of enoxaparin versus dalteparin or tinzaparin, and a multivariable Cox proportional hazard model was used to analyze the primary end point.

Results

From January 2009 to June 2018, 4451 patients with active cancer received full doses of the study drugs: enoxaparin, 3526 patients; and dalteparin or tinzaparin, 925 (754 + 171) patients. There was limited difference in VTE recurrences (2.0% vs 2.5%) and mortality rate (19% vs 17%) between the enoxaparin and dalteparin or tinzaparin subgroups. However, there was a slight numerical increase in major bleeding (3.1% vs 1.9%). Propensity score matching confirmed that there were no differences in the risk for VTE recurrences (adjusted hazard ratio [aHR], 0.81; 95% confidence interval [CI], 0.48‐1.38), major bleeding (aHR, 1.40; 95% CI, 0.80‐2.46), or death (aHR, 1.07; 95% CI, 0.88‐1.30) between subgroups.

Conclusions

In RIETECAT, in patients with cancer and VTE receiving full‐dose enoxaparin or dalteparin or tinzaparin, no statistically significant differences were observed regarding effectiveness and safety outcomes over a 6‐month period.

Biomarkers of Venous Thromboembolism Recurrence after Discontinuation of Low Molecular Weight Heparin Treatment for Cancer-Associated Thrombosis (HISPALIS-Study)

The most appropriate duration of anticoagulant treatment for cancer-associated venous thromboembolism (CAT) remains unclear. We have conducted a prospective multicenter study in CAT patients with more than 6 months of anticoagulant treatment to predict the risk of venous thromboembolism (VTE) recurrence after anticoagulation discontinuation. Blood samples were obtained when patients stopped the anticoagulation, at 21 days and at 90 days. In each sample we assessed different coagulation-related biomarkers: D-dimer (DD), high-sensitivity C-reactive protein (hs-CRP), P-selectin (PS), phospholipids, soluble tissue factor, factor VIII and the thrombin generation test. It was evaluated 325 CAT patients and 166 patients were included in the study, mean age 64 ± 17 years. VTE recurrence until 6 months after stopping anticoagulation treatment was 9.87% [95% confidence interval (CI): 6−15]. The biomarkers sub-distribution hazard ratios were 6.32 for ratio DD basal/DD 21 days > 2 (95% CI: 1.82−21.90), 6.36 for hs-CRP > 4.5 (95% CI: 1.73−23.40) and 5.58 for PS > 40 (95% CI: 1.46−21.30) after 21 days of stopping anticoagulation. This is the first study that has identified the DD ratio, hs-CRP and PS as potential biomarkers of VTE recurrence in cancer patients after the discontinuation of anticoagulation treatment. A risk-adapted strategy may allow the identification of the optimal time to withdraw the anticoagulation in each CAT patient.

Unanswered questions in cancer-associated thrombosis

Cancer-associated venous thromboembolism (VTE) is a leading cause of morbidity and mortality in patients with cancer. Treatment of cancer-associated VTE comes with a heightened risk of anticoagulant-related bleeding that differs by choice of anticoagulant as well as by patient- and disease-specific risk factors. Available data from randomized controlled trials and observational studies in cancer-associated VTE suggest that direct oral anticoagulants are effective, continuing anticoagulation beyond six months is indicated in those with active cancer and that patients who develop 'breakthrough' thrombotic events can be effectively treated. We review the evidence that addresses these key clinical questions and offer pragmatic approaches in individualizing care. While significant investigative efforts over the past decade have made impactful advances, future research is needed to better define the factors that contribute to anticoagulant-related bleeding and VTE recurrence, in order to aid clinical decision-making that improves the care of patients with cancer-associated VTE.

Treatment and secondary prophylaxis of venous thromboembolism in cancer patients

Cancer-associated thrombosis (CAT) adversely affects the quality of life and survival of people with cancer. A holistic approach is optimal for the treatment and secondary prophylaxis of venous thromboembolism (VTE) including shared decision-making around anticoagulation, considering individual risk factors for VTE recurrence, morbidities from VTE, and resources available in cancer centres around the world. Taking a global perspective on availability and cost, this paper guides the reader through the wider aspects of treatment and secondary thromboprophylaxis which, in turn, influence the recent international guidelines.

Characterization of coagulopathy and outcomes in cancer patients with severe COVID -19 illness: Longitudinal changes in hospitalized cancer patients

There is a lack of data focused on the specific coagulopathic derangements in COVID‐19 versus non‐COVID‐19 acutely ill cancer patients. Our objective was to characterize features of coagulopathy in cancer patients with active COVID‐19 illness who required hospitalization at MD Anderson in the Texas Medical Center and to correlate those features with thrombotic complications, critical illness, and mortality within the first 30 days after hospital admission for COVID‐19 illness. COVID‐19 and non‐COVID‐19 hospitalized cancer patients, with at least five consecutive measures of PT, PTT, d‐dimer, and CBC during the same period, were matched 1:1 to perform a retrospective analysis. We reviewed complete blood cell counts with differential, PT, PTT, fibrinogen, D‐Dimer, serum ferritin, IL‐6, CRP, and peripheral blood smears. Clinical outcomes were thrombosis, mechanical ventilation, critical illness, and death. Compared with matched hospitalized cancer patients without COVID‐19, we found elevated neutrophil and lower lymphocyte counts in those with critical illness ( p =  0.00) or death ( p =  0.00); only neutrophils correlated with thrombosis. COVID‐19 cancer patients with a platelet count decline during the hospital stay had more frequent critical illness ( p =  0.00) and fatal outcomes ( p =  0.00). Of the inflammatory markers, interleukin‐6 showed consistently higher levels in the COVID‐19 patients with poor outcomes. The findings of unique platelet changes and coagulopathy during severe COVID‐19 illness in the cancer population are of interest to explore disease mechanisms and future risk stratification strategies to help with the management of cancer patients with COVID‐19.

Patterns of Thromboembolism in Patients with Advanced Pancreatic Cancer Undergoing First-Line Chemotherapy with FOLFIRINOX or Gemcitabine/nab-Paclitaxel

INTRODUCTION

Recent advances in prophylactic anticoagulation and antineoplastic treatment for advanced pancreatic cancer (aPC) warrant an updated reassessment of thromboembolic risk in this population. This multicenter retrospective cohort study aims to comprehensively characterize incidence, risk factors, and outcomes of venous (VTE) and arterial thromboembolism (ATE) in homogenously treated patients with aPC.

METHODS

Four hundred and fifty-five patients with aPC undergoing palliative first-line chemotherapy (Gemcitabine/nab-Paclitaxel (GN) or FOLIRINOX) were included. Primary outcomes were objectively confirmed VTE and/or ATE.

RESULTS

Over a median follow-up of 26 months, 86 VTE (cumulative incidence: 20.0%; 95% confidence interval [CI]: 16.3-24.0) and 11 ATE events (cumulative incidence: 2.8%; 95% CI: 1.5-4.9) were observed. VTE diagnosis was associated with increased mortality (transition hazard ratio [THR]: 1.59 [95% CI: 1.21-2.09]) and increased risk of cancer progression (THR: 1.47 [95% CI: 1.08-2.01]), while the impact of ATE on mortality was numerically but not statistically significant (THR: 1.85 [95% CI: 0.87-3.94]). The strongest predictor of increased VTE risk was history of cancer-associated VTE (subdistribution hazard ratio [SHR]: 3.29 [95% CI: 2.09-5.18]), while the Khorana score (SHR: 0.78 [0.57-1.06]) failed to predict VTE risk. A history of cerebrovascular disease was associated with markedly increased ATE risk (SHR: 22.05 [95% CI: 6.83-71.22], p < 0.001), especially ischemic stroke. Risk of VTE/ATE did not significantly differ according to type of first-line chemotherapy.

CONCLUSION

Patients with aPC undergoing palliative first-line chemotherapy with FOLFIRINOX or GN face a high risk for VTE/ATE and its diagnosis is linked to worse clinical outcomes. VTE-risk prediction models have limited ability to sub-stratify thrombotic events in this high-risk scenario.

Treatment Algorithm in Cancer-Associated Thrombosis: Updated Canadian Expert Consensus

Patients with cancer-associated thrombosis (CAT) are at high risk of recurrent venous thromboembolism (VTE) and major bleeding complications. Risks vary significantly between individuals based on cancer status, treatment, and other characteristics. To facilitate the evidence-based management of anticoagulant therapy in this patient population, a committee of 11 Canadian clinical experts updated a consensus-based algorithm for the acute and extended treatment of symptomatic and incidental CAT that was developed in 2018. Following a systematic review of the literature, updates to the algorithm were discussed during an online teleconference, and the algorithm was subsequently refined based on feedback from committee members. Clinicians using this treatment algorithm should consider bleeding risk, type of cancer, and drug-drug interactions, as well as patient and clinician preferences, in tailoring anticoagulation for patients with CAT. Anticoagulant therapy should be adapted as the patient's cancer status and management change over time.

Direct oral anticoagulants versus low molecular weight heparins for the treatment of cancer-associated thrombosis: a cost-effectiveness analysis

BACKGROUND

Recently, direct oral anticoagulants (DOACs) have been included in guidelines for the treatment of cancer-associated thrombosis (CAT) to be extended to suitable cancer patients. The purpose of this study was to compare the cost-effectiveness of using DOACs and low molecular weight heparins (LMWHs) for treating CAT from the perspective of the Chinese healthcare system.

METHODS

A Markov model was constructed to estimate the cost-effectiveness of the two strategies with a 6-month and 5-year time horizon. Input parameters were either sourced from the clinical trial, published literature. The primary outcome of the model was reported as incremental cost-effectiveness ratios (ICERs). Sensitivity analyses were performed to test model uncertainty.

RESULTS

The 6-month cost of DOACs was $ 654.65 with 0.40 quality adjusted life-years (QALYs) while the 6-month cost of LMWHs was $USD 1719.31 with 0.37 QALYs. Similarly, treatment with DOACs had a lower cost ($USD 657.85 vs. $USD 1716.56) and more health benefits (0.40 QALYs vs. 0.37 QALYs) than treatment with LMWHs in a subgroup of patients with gastrointestinal malignancy. We found treatment with DOACs would result in a large reduction in cost ($USD 1447.22 vs. $USD 3374.70) but a small reduction in QALYs (3.07 QALYs vs. 3.09 QALYs) compared with LMWHs over a 5-year time frame, resulting in an ICER of $USD 112895.50/QALYs. Sensitivity analysis confirmed the robustness of the results.

CONCLUSION

As compared to LMWHs, DOACs can be a cost-saving anticoagulant choice for the treatment of CAT in the general oncology population and gastrointestinal malignancy population.

Management of Cancer-Associated Thrombosis: Unmet Needs and Future Perspectives

Patients with cancer are at a high risk of symptomatic venous thromboembolism (VTE), which is a common cause of morbidity and mortality in this patient population. Increased risk of recurrent VTE and bleeding complications are two major challenges associated with therapeutic anticoagulation in these patients. Long-term therapy with low-molecular-weight heparins (LMWHs) has been the standard of care for the treatment of cancer-associated VTE given its favorable risk–benefit ratio in comparison with vitamin K antagonists. Direct oral anticoagulants (DOACs), which offer the convenience of oral administration and have a rapid onset of action, have recently emerged as a new treatment option for patients with cancer-associated thrombosis (CT). Randomized clinical trial data with head-to-head comparisons between DOACs and LMWHs showed that overall, DOACs have a similar efficacy profile but a higher risk of bleeding was observed in some of these studies. This review aims to identify unmet needs in the treatment of CT. We discuss important considerations for clinicians tailoring anticoagulation (1) drug–drug interactions, (2) risk of bleeding (e.g., gastrointestinal bleeding), (3) thrombocytopenia, hematological malignancies, (4) metastatic or primary brain tumors, and (5) renal impairment. Additional research is warranted in several clinical scenarios to help clinicians on the best therapeutic approach.

Effectiveness and safety of apixaban, LMWH, and warfarin among high-risk subgroups of VTE patients with active cancer

OBJECTIVE

This pooled claims database study evaluated the risk of recurrent Venous Thromboembolism (VTE) and major bleeding (MB) among patients with VTE and active cancer prescribed apixaban, low-molecular weight heparin (LMWH), or warfarin stratified by high-risk subgroups.

METHODS

Patients diagnosed with VTE in the setting of active cancer who initiated apixaban, LMWH, or warfarin were identified using four US commercial claims databases from 01SEP2014 to the end of the study period (MarketScan: 01MAR2014-30JUNE2017; Optum and Humana: 01MAR2014-31DEC2017; PharMetrics: 01MAR2014-31MAR2018). Stabilized inverse probability treatment weighting (IPTW) was used to balance treatment cohorts. Cox proportional hazard models were used to evaluate the risk of recurrent VTE and MB for each subgroup stratification: VTE risk level based on cancer types, metastatic diagnosis, cancer treatment, chemotherapy, gastrointestinal cancer, and index VTE event type (PE vs. DVT). Statistical significance (p < .10) of the interaction between treatment effects and subgroups was evaluated.

RESULTS

Eligible subjects included 3393 apixaban, 6108 LMWH, and 4585 warfarin patients. After IPTW, all patient characteristics were balanced. Analyses stratified by the VTE risk level, metastatic diagnosis, cancer treatment, chemotherapy, gastrointestinal cancer and index VTE event type showed generally consistent results according to the respective subgroup (most of the p values for interaction >0.10). Two significant interactions were observed between apixaban vs. LMWH and VTE risk level (interaction p = .051) and metastatic diagnosis (interaction p < .001) for recurrent VTE; one significant interactions were observed between apixaban vs. LMWH and cancer treatment for MB (interaction p = .074). Additionally, for warfarin vs. LMWH, two significant interactions were observed between treatment and VTE risk level (interaction p = .005) and metastatic diagnosis (interaction p = .002) for recurrent VTE.

CONCLUSIONS

Across these high-risk subgroups of VTE cancer patients, treatment outcomes associated with apixaban were generally positive compared to LMWH and warfarin.

Treatment of venous thromboembolism in patients with cancer: from clinical trials to real life

Approximately one-fifth of all cases of venous thromboembolism (VTE) are related to cancer. VTE complications may have a substantial impact on prognosis, quality of life and care in patients with cancer. Patients with cancer-related VTE are at increased risk of developing recurrent VTE compared to patients without cancer, but also have a higher risk of major bleeding. In the last years, direct oral anticoagulants (DOACs) have been evaluated in a head-to-head comparison with low molecular weight heparin (LMWH) in two randomized trials for the long-term treatment of VTE in patients with advanced cancer. The results of these trials show that DOACs have a similar efficacy profile, but probably higher risk of bleeding, compared to LMWH dalteparin. Because DOACs offer a simple oral treatment regimen without the need for anticoagulation monitoring, they could be attractive alternatives to LMWHs in these setting. The American Society of Clinical Oncology guidelines, published in August 2019, recommend LMWH, edoxaban and rivaroxaban as first-choice therapies for long-term anticoagulation in cancer patients with VTE. However, several practical issues should be considered concerning the long-term use of DOAC treatment in patients with cancer. Major concerns have been highlighted about the gastrointestinal bleeding risk in patients with gastrointestinal cancers and the potential drug-drug interactions in combination for some specific anticancer therapies. Several studies comparing DOACs with LMWH are currently ongoing to refine our knowledge concerning treatment with DOACs in patients with cancer-associated VTE.

Which patients are at high risk of recurrent venous thromboembolism (deep vein thrombosis and pulmonary embolism)?

Recurrent venous thromboembolism (VTE, or deep vein thrombosis and pulmonary embolism) is associated with mortality and long-term morbidity. The circumstances in which an index VTE event occurred are crucial when personalized VTE recurrence risk is assessed. Patients who experience a VTE event in the setting of a transient major risk factor (such as surgery associated with general anesthesia for >30 minutes) are predicted to have a low VTE recurrence risk following discontinuation of anticoagulation, and limited-duration anticoagulation is generally recommended. In contrast, those patients whose VTE event occurred in the absence of risk factors or who have persistent risk factors have a higher VTE recurrence risk. Here, we review the literature surrounding VTE recurrence risk in a range of clinical conditions. We describe gender-specific risks, including VTE recurrence risk following hormone- and pregnancy-associated VTE events. Finally, we discuss how the competing impacts of VTE recurrence and bleeding have shaped international guideline recommendations.

Clinical history of cancer-associated splanchnic vein thrombosis

BACKGROUND

Cancer represents a risk factor for splanchnic vein thrombosis (SVT) and usual site venous thromboembolism (VTE).

OBJECTIVES

To compare characteristics and outcomes of patients with cancer-associated SVT and usual site VTE.

PATIENTS/METHODS

Patients with solid cancer and SVT were enrolled in an international, prospective registry between May 2008 and January 2012. The comparison cohort included (1:1 ratio) patients with solid cancer and usual site VTE treated at two thrombosis centers who had a minimum of 12 months follow-up at December 2019 or experienced one of the outcomes within 12 months follow-up. Recurrent VTE, major bleeding, and all-cause mortality were evaluated at 12-month follow-up.

RESULTS

A total of 264 patients (132 in each cohort) were enrolled. Patients with SVT were less likely to have metastatic disease (36.1% vs 72.5%) or receive cancer therapy at thrombosis diagnosis (29.6% vs 64.9%). The most frequent cancer types were hepatobiliary and pancreatic in the SVT cohort and gastrointestinal in the usual site VTE cohort. Fewer patients with SVT received anticoagulation (68.9% vs 99.2%), and treatment duration was shorter (6.0 vs 11.0 months). The cumulative incidence of major bleeding (2.3% vs 4.7%) was nonsignificantly lower in the SVT cohort, whereas recurrent thrombosis (4.7% vs 5.5%) and all-cause mortality (41.7% vs 39.4%) were comparable between the two cohorts.

CONCLUSIONS

The risk of recurrent thrombosis and bleeding appears to be similar in cancer patients with SVT and cancer patients with usual site VTE, despite some differences in baseline characteristics and anticoagulant treatment. Further prospective studies are warranted to confirm these findings.

Treatment of venous thromboembolism in cancer patients: The dark side of the moon

Venous thromboembolism (VTE) is a common complication in patients with cancer. The risk of emergent VTE is four- to seven-fold higher in cancer patients compared to non-cancer patients. Although the therapeutic armamentarium for cancer-associated VTE has been recently implemented, anticoagulant treatment remains challenging because of the increased risk of recurrent VTE and bleeding. Several international societies and expert panels released clinical practice guidelines on VTE treatment which are mostly focused on the general cancer population. Nevertheless, recommendations for the management of VTE in patients with peculiar clinical presentations are inconsistent and remain elusive due to the lack of pertinent evidence. The challenging clinical scenarios include, among others, patients with thrombocytopenia, renal impairment, gastrointestinal cancer, primary or metastatic brain cancer, distal thrombosis of the lower extremities, catheter-related VTE, splanchnic thrombosis, incidental VTE, extreme body weight, recurrent VTE during treatment, as well as the optimal duration of anticoagulant treatment in patients with active disease who have received 3 to 6 months of anticoagulation. Herein, we present a critical overview on VTE management in these challenging clinical settings, discuss potential approaches, and include some calls to action for future clinical research.

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.

Individualised Risk Assessments for Recurrent Venous Thromboembolism: New Frontiers in the Era of Direct Oral Anticoagulants

Venous thromboembolism (VTE) is a leading cause of morbidity and mortality and is associated with high recurrence rates. The introduction of direct oral anticoagulants (DOACs) in the 2010s has changed the landscape of VTE management. DOACs have become the preferred anticoagulant therapy for their ease of use, predictable pharmacokinetics, and improved safety profile. Increasingly, guidelines have recommended long term anticoagulation for some indications such as following first unprovoked major VTE, although an objective individualised risk assessment for VTE recurrence remains elusive. The balance of preventing VTE recurrence needs to be weighed against the not insignificant bleeding risk, which is cumulative with prolonged use. Hence, there is a need for an individualised, targeted approach for assessing the risk of VTE recurrence, especially in those patients in whom the balance between benefit and risk of long-term anticoagulation is not clear. Clinical factors alone do not provide the level of discrimination required on an individual level. Laboratory data from global coagulation assays and biomarkers may provide enhanced risk assessment ability and are an active area of research. A review of the prediction models and biomarkers for assessing VTE recurrence risk is provided, with an emphasis on contemporary developments in the era of DOACs and global coagulation assays.

Clinical controversies in the treatment of cancer-associated venous thromboembolism

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

Cost of Venous Thromboembolic Disease in Patients with Lung Cancer: Costecat Study

Background: Patients with lung cancer (LC) are at significantly higher risk of developing venous thromboembolism (VTE), which may lead to increased use of health resources and the cost of the disease management. The main aim of the study was to determine the cost of the management of VTE events in patients with LC treated with Low Molecular Weight Heparins (LMWH) in Spain. Methods: Costecat was an observational, ambispective pharmacoeconomic study. Patients with LC, with a first episode of VTE (symptomatic or incidental) in treatment with LMWH, were recruited from six third-level hospitals and followed up for six months. Sociodemographic, clinical and resource use variables of VTE-related implications and its treatment were collected. Direct healthcare costs and direct non-healthcare costs were recorded. Data collection was documented in an electronic case report. Costs (€2018) were estimated from the healthcare perspective. Statistical analysis was performed using the statistical program R 3.4.3 version (30 November 2017). Results: Forty-seven patients were included. Mean age was 65.4 years, 66.0% were male. The percentage of patients with LC who had metastatic disease was 78.7%. Twenty-three patients (48.9%) needed hospital admissions due to thromboembolic episode. Total average cost of patients with cancer associated VTE (CAT) was €10,969.6 per patient/semester. The hospitalizations represent 65.8% of total costs (7207.3 € SD 13,996.9 €), followed by LMWH therapy which represents 18.6% (2033.8 € SD:630.5 €). Conclusions: Venous thromboembolism episodes induce an economic impact on patients and healthcare systems. Direct healthcare costs are the major burden of the total cost, in which hospitalizations are the main drivers of cost.