Discordant reporting of VTE in pancreatic cancer: A systematic review and meta-analysis of thromboprophylaxis versus chemotherapeutic trials

Anticoagulation for the prevention of arterial thromboembolism in cancer patients by primary tumour site: a systematic review and meta-analysis of randomized trials

AIMS

The incidence of arterial thromboembolism (ATE) among ambulatory cancer patients varies by primary tumour site. However, it is unclear whether this alters the benefit-to-harm profile of prophylactic anticoagulation for ATE prevention. Therefore, we systematically evaluated the efficacy and safety of anticoagulants for ATE prevention among ambulatory cancer patients according to the primary tumour site.

METHODS AND RESULTS

We conducted a systematic review using Medline, Embase, SCOPUS, and CENTRAL, and included randomized trials comparing prophylactic anticoagulation to no anticoagulation among ambulatory cancer patients who initiated tumour-directed systemic therapy. The incidence of symptomatic ATE (acute ischaemic stroke, acute myocardial infarction, or peripheral artery occlusion) and major bleeding, as well as risk differences (RDs) attributable to anticoagulation, were meta-analysed by primary tumour site using random-effects modelling. We included 10 randomized controlled trials with 9875 patients with follow-up ranging from 3.3 to 68 (median 6.6) months. While prophylactic anticoagulation did not reduce ATE risks overall (RD -0.49%; 95% CI -0.49% to 0.01%; I2 = 0%), it conferred a protective effect among pancreatic cancer patients (RD -3.2%; 95%CI -5.7% to -0.8%; I2 = 0%) without a detectable increase in major bleeding (RD -1.4%; 95% CI -4.6% to 1.8%; I2 = 0%). Prophylactic anticoagulation was not associated with ATE risk reduction in other tumour sites.

CONCLUSION

Based on available evidence, prophylactic anticoagulation did not reduce ATE risk among ambulatory cancer patients overall. However, we observed a lower incidence of ATE among pancreatic cancer patients randomized to receive anticoagulation. Prophylactic anticoagulant use to reduce ATEs in pancreatic cancer should be evaluated in future research.

Venous thromboembolism incidence and association with overall survival in pancreatic cancer: A Finnish nationwide cohort study

INTRODUCTION

Pancreatic cancer (PC) is associated with a high risk of venous thromboembolic events (VTEs). We investigated the incidence of VTE before and after the diagnosis of PC and its association with overall survival.

METHODS

We identified PC patients diagnosed in 2013-2016 from the Finnish Cancer Registry. Data on healthcare visits and death were collected, along with follow-up data through the end of 2020. We compared patients who underwent radical-intent surgery (RIS) to those who underwent palliative treatment (PT) alone.

RESULTS

We identified 4086 PC patients, of whom 343 (8.4%) underwent RIS and 3743 (91.6%) received PT. VTE incidence within 1 year before a PC diagnosis was higher in the PT (4.2%, n = 156) than in the RIS group (0.6%, n = 2; p < 0.001). The cumulative incidence of VTE at 12 and 24 months after a PC diagnosis was 6% (n = 21) and 9% (n = 31), respectively, within the RIS group, and 8% (n = 286) and 8% (n = 304) within the PT group. In the PT group, a VTE within 1 year before a PC diagnosis was independently associated with a worse survival {hazard ratio, HR 1.9 [95% confidence interval (CI) 1.6-2.2]}. In both groups, VTE after a PC diagnosis was associated with a worse survival [RIS group: HR 2.6 (95%CI 1.8-3.7) vs. PT group: HR 2.2 (95%CI 1.9-2.4)].

CONCLUSIONS

A VTE within 1 year before a PC diagnosis more often occurred among PT PC patients than among patients who underwent RIS. VTE might serve as a diagnostic clue to detect PC at an earlier stage.

Arterial Thrombosis in Patients with Cancer

Patients with cancer are at increased risk of arterial thromboembolic disease due to the presence of risk factors common to both the development of cancer and arterial thrombosis, the cancer itself, and the treatments provided to treat cancer. We review here the epidemiology and pathophysiology of arterial thromboembolic disease in cancer, along with its prevention and treatment strategies. We also propose a generalized approach for the management of arterial thromboembolic disease in this patient population.

Update on Thrombosis Risk in Patients with Cancer: Focus on Novel Anticancer Immunotherapies

Thromboembolic complications, including venous thromboembolism (VTE) and arterial thromboembolism (ATE), increase mortality and morbidity, and delay treatment in patients with cancer. Therefore, an increased understanding of underlying risk profiles, the identification of risk factors and predictive biomarkers, and ultimately the development of specific cardiovascular prevention strategies in patients with cancer is needed. Medical anticancer therapies have undergone a remarkable development in recent years with the advent of targeted and immunotherapeutic treatment options, including immune checkpoint inhibitors (ICI), chimeric antigen receptor (CAR) T-cell therapies and bispecific T-cell engagers (BiTEs). These developments have important implications for the accompanied risk of thromboembolic events in patients with cancer. First, the increased use of these highly effective therapies renders a growing proportion of patients with cancer at risk of thromboembolic events for a prolonged risk period due to an increase in patient survival despite advanced cancer stages. Second, potential direct cardiovascular toxicity and prothrombotic effect of novel anticancer immunotherapies are a matter of ongoing debate, with emerging reports suggesting a relevant risk of VTE and ATE associated with ICI, and relevant dysregulations of hemostasis in the frequently observed cytokine-release syndrome associated with BiTEs and CAR T-cell therapy. The aim of the present narrative review is to summarize the implications of the emerging use of anticancer immunotherapy for thromboembolic events in patients with cancer, and to provide an overview of available data on the rates and risk factors for VTE and ATE associated with ICI, CAR T-cell therapy, and BiTEs.

Anticoagulation for the Prevention of Arterial Thrombosis in Ambulatory Cancer Patients: Systematic Review and Meta-Analysis

Background

The risk of arterial thrombotic events (ATEs) is high among patients on systemic anticancer therapies. Despite the efficacy of anticoagulants in the prevention of cancer-associated venous thromboembolism, it is unknown whether anticoagulation is effective to prevent ATEs.

Objectives

This study sought to examine the efficacy and safety of anticoagulants in ATE prevention among ambulatory cancer patients.

Methods

We performed a systematic review using Medline, Embase, Scopus, and Cochrane Central Register of Controlled Trials (CENTRAL) from inception to May 21, 2022, and included studies comparing oral or parenteral anticoagulation with no anticoagulation among ambulatory patients receiving systemic anticancer therapy with no other indication for anticoagulation. The primary outcome was ATE (myocardial infarction, ischemic stroke, intra-abdominal arterial embolism, or peripheral artery occlusion). The secondary outcomes were major and nonmajor bleeding and all-cause mortality.

Results

Fourteen randomized trials involving low-molecular-weight heparins, direct oral anticoagulants, and warfarin were included. ATEs were captured as coefficacy endpoints or adverse events. Anticoagulant use was not associated with a reduction in ATEs compared with placebo or standard treatment (RR: 0.73, 95% CI: 0.50-1.04; P = 0.08; I2 = 0%). RRs of major and minor bleeding were 1.56 (95% CI: 1.12-2.17) and 2.25 (95% CI: 1.45-3.48) with anticoagulant use. In 13 trials that reported all-cause mortality, risk of death was not reduced with anticoagulants (RR: 0.99; 95% CI: 0.95-1.02; P = 0.38; I2 = 0%).

Conclusions

Anticoagulants did not reduce ATE risk among ambulatory patients on systemic anticancer therapy and were associated with increased bleeding. Based on the current data, anticoagulants have a limited role in ATE prevention in this population as a whole.

Immune Checkpoint Inhibitors-Associated Thrombosis: Incidence, Risk Factors and Management

Immune checkpoint inhibitors (ICIs) target programmed cell death (PD) 1 receptor and its ligand PD-L1, and have become an integral part of treatment regimens in many cancers including lung cancer, renal cell carcinoma, melanoma, and more. Cancer is associated with a significantly increased risk of venous thromboembolism compared to non-cancer patients, and the risks increase further with anticancer therapies including ICIs. Cancer-associated thrombosis can lead to hospitalizations, delayed cancer treatment, and mortality. While thrombosis was not reported as a major complication in initial clinical trials leading to the approval of ICIs, emerging evidence from post-marketing studies revealed concerning risks of thrombosis in patients receiving ICIs. However, results remained heterogenous given differences in study designs and populations. Recent studies also showed that C-reactive protein dynamics might be an easily accessible biomarker for thrombosis and disease response in this population. In addition, early findings indicated that a commonly used anticoagulant for cancer-associated thrombosis, factor Xa inhibitors, might have potential synergistic antitumor effects when combined with ICIs. Herein we will review the current literature on the incidence, risk factors, and management of thrombosis in patients with cancer receiving ICIs. We aim to provide valuable information for clinicians in managing these patients.

Clinical impact of venous thromboembolism in non-small cell lung cancer patients receiving immunotherapy

BACKGROUND

Prospective investigation on cancer-associated venous thromboembolism (VTE) in non-small cell lung cancer (NSCLC) during treatment with immune checkpoint inhibitors (ICIs) is lacking.

PATIENTS AND METHODS

A prospective real-world study using combined computed tomography venography and pulmonary angiography (CTVPA) to screen patients with NSCLC for VTE (cohort A). A retrospective multicenter cohort without additional screening with CTVPA was included as control (cohort B). A model with VTE as a time-dependent event using competing risk analysis model with death as a competing event was used to evaluate outcomes and differences in cumulative VTE incidences.

RESULTS

Cohort A (n = 146) and cohort B (n = 426) had median follow-up for VTE of 16.5 months (IQR 6.7-35.6). Cumulative VTE events at 1, 3, 6, and 12 months were 7.5 %, 9.6 %, 13.0 %, 14.4 % for cohort A and 1.9 %, 3.8 %, 4.9 %, 5.6 % for cohort B with SHR 2.42 (CI 95 % 1.37-4.27) p = 0.0024. Recurrent VTE comprised 52 % and 37 %, respectively. In multivariate overall survival analysis, VTE was significantly associated with impaired OS (HR 2.12 CI 95 % [1.49-3.03], p < 0.0001). Risk factors for VTE comprised prior VTE and ICI administered in first line.

CONCLUSION

Cumulative VTE incidence in NSCLC patients following palliative ICI may be significantly higher than reported in randomised clinical trials and retrospective real-world reports. VTE development during ICI impair OS significantly. Thus, more focus on VTE during ICI is warranted to optimise both prevention and management of VTE. Whether there is a causal relationship between VTE and ICI remains to be explored.

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.

Assessing the risk of thromboembolism in cancer patients receiving immunotherapy

Malignancy has long been implicated with hypercoagulability, leading to an increased rate of both venous and arterial thromboembolic events (VTE and ATE). Immunotherapy has established itself as a cornerstone of modern cancer therapy by promoting antitumor immune responses, though there have been some suggestions that immune-related adverse events could include increased rates of VTE and ATE. In this review, we examine the available evidence regarding the use of immune checkpoint inhibitors (ICIs) and thrombosis. First, we describe the potential mechanisms by which ICIs might lead to thrombophilia given the overlap between the immune system, coagulation cascade, and platelet adhesion and activation. In addition, while there are some preclinical data evaluating immunotherapy-associated ATEs in animal models, there is a paucity of evidence exploring potential mechanism of VTEs in ICIs. Second, we review the incidence of ATE and VTE in patients receiving ICIs in the published literature. Finally, we discuss current limitations in understanding, areas of conflicting evidence, and approaches to further investigation.

Thrombotic Complications Associated with Immune Checkpoint Inhibitors

Simple Summary

Patients with cancer commonly develop blood clots, which can cause issues including hospitalizations and complications and can affect cancer treatments. Cancer therapies can be one of the reasons for blood clots. A type of cancer therapy called “immune checkpoint inhibitors” has been used more and more often in recent years for different types of cancer. Recent reports revealed an increasing concern of blood clots related to immune checkpoint inhibitors. In this review, we will summarize data from the available studies and discuss the rates, risk factors, prevention, and treatment strategies for blood clots related to immune checkpoint inhibitors.

Abstract

Thromboembolism is a common complication in patients with cancer and is associated with significant morbidity and mortality. Anticancer treatment is a known risk factor of cancer-associated thrombosis. Immune checkpoint inhibitors have become a mainstay of treatment in various cancers. Both venous and arterial thrombosis have been increasingly reported as adverse events associated with immune checkpoint inhibitors in recent studies, with a cumulative incidence of venous thrombosis to be 5–8% at 6 months and over 10% at 12 months. Additionally, rates of approximately 1–5% for arterial thrombosis were reported at 12 months. Data also showed an association of thromboembolism with adverse survival. Many pertinent clinical questions in this population deserve further investigation, including the risks of thrombosis associated with immune checkpoint inhibitors as compared to those with traditional systemic therapy, associated risk factors, and the optimal prevention and treatment strategies. In this review, we synthesize data from available literature, provide relevant information for clinicians and potential future directions for research.

Vascular events with immune checkpoint inhibitors in melanoma or non-small cell lung cancer: A systematic review and meta-analysis

The incidence of venous and arterial thromboembolic events in advanced cancer patients treated with immune checkpoint inhibitors (ICIs) has been sporadically reported. We performed a systematic review and meta-analysis to assess the rate of vascular events in patients with melanoma and non-small cell lung cancer (NSCLC) treated with ICIs. A systematic search of MEDLINE and EMBASE was performed to identify randomized clinical trials and prospective studies. The main outcomes were venous thromboembolism (VTE), stroke or systemic embolism (SE) and myocardial infarction (MI). Secondary outcomes were fatal VTE, fatal stroke or SE and fatal MI. Pooled proportions with 95% confidence intervals (CI) were calculated using random-effects models. A total of 59 trials, 25 in 5,578 patients with melanoma and 34 in 6,543 patients with NSCLC were included. In patients with melanoma, rates of VTE, stroke or SE and MI were 1.5% (95% CI 0.8-2.8), 1.7% (95% CI 0.8-3.7) and 0.4% (95% CI 0.2-0.9), respectively. In patients with NSCLC, corresponding rates were 1.9% (95% CI 1.2-3.2), 1.2% (95% CI 0.6-2.5), and 1.1% (95% CI 0.5-2.1), respectively. Rates of fatal VTE and MI were similar in melanoma and NSCLC patients. Rates of fatal stroke or SE were 1.9% (95% CI 0.4-9.5) and 0.7% (95% CI 0.2-2.3) in melanoma and NSCLC patients, respectively. Rates of VTE (3.1% vs. 1.1%) and myocardial infarction (3.4% Vs. 0.5%) were numerically higher in NSCLC patients treated with combined-ICIs vs mono-ICIs. Our study shows a not negligible rate of vascular events in patients with melanoma or NSCLC treated with ICIs.

Burden of venous thromboembolism in patients with pancreatic cancer

Pancreatic cancer (PC) is a devastating malignancy with fewer than 10% of patients being alive at 5 years after diagnosis. Venous thromboembolism (VTE) occurs in approximatively 20% of patients with PC, resulting in increased morbidity, mortality and significant health care costs. The management of VTE is particularly challenging in these frail patients. Adequate selection of the most appropriate anticoagulant for each individual patient according to the current international guidelines is warranted for overcoming treatment challenges. The International Initiative on Thrombosis and Cancer multi-language web-based mobile application (downloadable for free at www.itaccme.com) has been developed to help clinicians in decision making in the most complex situations. In this narrative review, we will discuss the contemporary epidemiology and burden of VTE in PC patients, the performances and limitations of current risk assessment models to predict the risk of VTE, as well as evidence from recent clinical trials for the primary prophylaxis and treatment of cancer-associated VTE that support up-dated clinical practice guidelines.