Venous thrombotic events in patients treated with immune checkpoint inhibitors for non-small cell lung cancer: A retrospective multicentric cohort study

Cardiovascular toxicity of immune therapies for cancer

In addition to conventional chemoradiation and targeted cancer therapy, the use of immune based therapies, specifically immune checkpoint inhibitors (ICIs) and chimeric antigen receptor T cell therapy (CAR-T), has increased exponentially across a wide spectrum of cancers. This has been paralleled by recognition of off-target immune related adverse events that can affect almost any organ system including the cardiovascular system. The use of ICIs has been associated with myocarditis, a less common but highly fatal adverse effect, pericarditis and pericardial effusions, vasculitis, thromboembolism, and potentially accelerated atherosclerosis. CAR-T resulting in a systemic cytokine release syndrome has been associated with myriad cardiovascular consequences including arrhythmias, myocardial infarction, and heart failure. This review summarizes the current state of knowledge regarding adverse cardiovascular effects associated with ICIs and CAR-T.

Risk of Venous Thromboembolism in Patients With Stage III and IV Non-Small-Cell Lung Cancer: Nationwide Descriptive Cohort Study

BACKGROUND

Venous thromboembolism (VTE) is a common complication in patients starting cancer therapies for non-small-cell lung cancer (NSCLC). We examined the risk and timing of VTE in patients with stage IIIA, IIIB to C, and stage IV NSCLC according to received cancer treatments.

MATERIALS AND METHODS

A nationwide registry-based cohort study of patients recorded in the Danish Lung Cancer Registry (2010-2021) followed for 1 year after entry into the registry to assess the incidence of VTE. The Aalen-Johansen estimator was used to calculate the risk of VTE after treatment commencement with chemotherapy, radiotherapy, chemoradiation, immunotherapy, and targeted therapy.

RESULTS

Among the 3475 patients with stage IIIA, 4047 with stage IIIB to C, and 18,082 patients with stage IV cancer, the 1-year risk of VTE was highest in the first 6 months and varied markedly by cancer stage and cancer treatment. In stage IIIA, VTE risk was highest with chemotherapy (3.9%) and chemoradiation (4.1%). In stage IIIB to C, risks increased with chemotherapy (5.2%), immunotherapy (9.4%), and targeted therapy (6.0%). Stage IV NSCLC showed high risk with targeted therapy (12.5%) and immunotherapy (12.2%). The risk was consistently higher for pulmonary embolism than deep vein thrombosis.

CONCLUSION

VTE risks vary substantially according to cancer treatments and cancer stages. The highest risk was observed in the initial 6 months of therapy initiation. These insights emphasize the need for tailored risk assessment and vigilance in managing VTE complications in patients with NSCLC. Further research is needed to optimize individual thromboprophylaxis strategies for patients with unresectable and metastatic NSCLC.

The value of performance status in predicting venous thromboembolism in lung cancer patients treated with immune checkpoint inhibitors

INTRODUCTION

The incidence of venous thromboembolism (VTE) is notably high in lung cancer patients, particularly among those treated with immune checkpoint inhibitors (ICIs). Previous studies have focused on the relationship between Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) and VTE risk in immune checkpoint inhibitor therapy, but available evidence is inconsistent.

METHODS

The clinical data of lung cancer patients treated with ICIs were collected and analyzed from West China Hospital between January 2018 and March 2022. ECOG PS score was measured on admission. The primary outcome was the incidence of VTE, encompassing both deep vein thrombosis (DVT) and pulmonary embolism (PE). Multivariate logistic regression analysis was conducted to calculate the odds ratio (OR) and 95% confidence interval (95% CI).

RESULTS

A total of 1115 lung cancer patients receiving ICIs were eligible for this study, VTE developed in 105 (9.4%) during the 12-month follow-up, of which 95 (8.5%) had DVT,14 (1.3%) had definite PE. Poor ECOG PS (PS ≥ 2) was associated with an increased risk for VTE (OR = 5.405, 95% CI = 3.067-9.525, P < 0.001), DVT (OR = 4.669, 95% CI = 2.588-8.427, P < 0.001) and PE (OR = 8.413, 95% CI = 2.565-27.600, P < 0.001) after multivariable adjustment in the study cohort.

CONCLUSION

VTE occurred in 9.4% of lung cancer patients treated with ICIs, and poor performance status was associated with an increased risk of VTE.

Incidence of thromboembolic events in non-small cell lung cancer patients treated with immune checkpoint inhibitors: A systematic review and meta-analysis

ABSTRACT

The incidence of thromboembolic events (TEs) in non-small cell lung cancer (NSCLC) patients treated with immune checkpoint inhibitors (ICIs) has rarely been reported. The MEDLINE, EMBASE, and the Cochrane Library databases were searched. The primary outcome was the incidence of TEs, and the secondary outcome was the relationship between TEs and overall survival (OS) following ICI therapy. A subgroup analysis of TE incidents was performed according to the TE type and combination regimens. The I2 statistic was used to determine the heterogeneity, and funnel plots and Egger's test were used to assess publication bias. A total of 16,602 patients with NSCLC in 63 experimental arms were included in the analysis. The rate of TEs ranged from 0.1% to 13.8%, and the pooled overall incidence of all-grade TEs was 3% (95% confidence interval [CI], 2%-4%). The pooled rate of high-grade TEs was 1% (95% CI, 1%-2%). The venous and arterial TE rates were 3% (95% CI, 2%-4%) and 1% (95% CI, 1%-2%), respectively. Patients who received immunotherapy + chemoradiotherapy had the highest incidence of TEs (7%). The TE pooled rate was higher in patients treated with combined ICIs than in those treated with mono ICIs (4% vs. 2%). The OS was lower in patients with TEs than in those without TEs (hazard ratio, 1.4; 95% CI, 1.02%-1.92%). The incidence of TEs in NSCLC patients treated with ICIs was reasonable. Nonetheless, clinicians must be aware of potential thrombotic complications and treat them promptly.

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.

Lung Cancer Related Thrombosis (LCART): Focus on Immune Checkpoint Blockade

Cancer-associated thrombosis (CAT) is a common complication in lung cancer patients. Lung cancer confers an increased risk of thrombosis compared to other solid malignancies across all stages of the disease. Newer treatment agents, including checkpoint immunotherapy and targeted agents, may further increase the risk of CAT. Different risk-assessment models, such as the Khorana Risk Score, and newer approaches that incorporate genetic risk factors have been used in lung cancer patients to evaluate the risk of thrombosis. The management of CAT is based on the results of large prospective trials, which show similar benefits to low-molecular-weight heparins (LMWHs) and direct oral anticoagulants (DOACs) in ambulatory patients. The anticoagulation agent and duration of therapy should be personalized according to lung cancer stage and histology, the presence of driver mutations and use of antineoplastic therapy, including recent curative lung surgery, chemotherapy or immunotherapy. Treatment options should be evaluated in the context of the COVID-19 pandemic, which has been shown to impact the thrombotic risk in cancer patients. This review focuses on the epidemiology, pathophysiology, risk factors, novel predictive scores and management of CAT in patients with active lung cancer, with a focus on immune checkpoint inhibitors.

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.

Venous thrombotic events and impact on outcomes in patients treated with first-line single-agent pembrolizumab in PD-L1 ≥ 50% advanced non small cell lung cancer

BACKGROUND

Few data are available on the impact of venous thrombotic events (VTE) in patients with metastatic non-small cell lung cancer (mNSCLC) treated with immunotherapy.

METHODS

This is a secondary analysis of the ESKEYP study, a national, retrospective, multicenter study that consecutively included all PD-L1 ≥ 50% mNSCLC patients who initiated first-line treatment with pembrolizumab monotherapy. From May 2017 to November 2019, 845 patients were included (from availability of pembrolizumab in this indication in France to the authorization of the combination with chemotherapy). Impact of VTE and patient characteristics were analyzed.

RESULTS

Of the 748 patients (88.5%) with available data, the incidence of VTE was 14.8% (111/748). At pembrolizumab initiation, Khorana score was ≥ 2 for 55.0% (61/111) of them. Recurrence of VTE was reported for 4 of the 111 patients and 5 had bleeding complications. Patients with VTE were significantly younger, had more frequently long-term corticosteroids treatment and more often liver metastases. Progression-free survival (PFS) was significantly shorter in patients with VTE compared to patients without VTE: 6.1 (95% CI 4.1-9.0) months vs. 8.3 (6.9-10.3) months (p = 0.03). VTE did not significantly impact overall survival (OS): 15.2 (10.0-24.7) months with VTE and 22.6 (18.4-29.8) months without VTE (p = 0.07). In multivariate analysis for PFS and OS, HRs for VTE were 1.3 (0.99-1.71), p = 0.06 and 1.32 (0.99-1.76), p = 0.05.

CONCLUSION

The incidence of VTE appears to be as high with in first-line immunotherapy as with chemotherapy in patients with mNSCLC, with in patient with VTE, a no significant trend for lower PFS and OS in multivariate analysis. more marked impact on PFS than on OS.

Thrombotic risk of platinum combination chemotherapy with and without immune checkpoint inhibitors for advanced non-small cell lung cancer: a nationwide inpatient database study

OBJECTIVES

To determine the associated thromboembolism risk with adding immune checkpoint inhibitors (ICI) to platinum combination chemotherapy compared with platinum combination chemotherapy alone in patients with advanced non-small cell lung cancer.

MATERIALS AND METHODS

This study identified 75,807 patients with advanced non-small cell lung cancer from the Japanese Diagnosis Procedure Combination database who started platinum combination chemotherapy between July 2010 and March 2021. The incidence of venous thromboembolism (VTE), arterial thromboembolism (ATE), and all-cause mortality within 6 months after commencing platinum combination chemotherapy was compared between patients receiving chemotherapy with ICI (ICI group, n = 7,177) and without ICI (non-ICI group, n = 37,903). Survival time analysis was performed using the overlap weighting method with propensity scores to adjust for background factors. The subdistribution hazard ratio for developing thromboembolism was calculated using the Fine-Gray model with death as a competing risk. The hazard ratio for all-cause mortality was also calculated using the Cox proportional hazards model.

RESULTS

Overall, VTE and ATE occurred in 761 (1.0%) and 389 (0.51%) patients, respectively; mortality was 11.7%. Propensity score overlap weighting demonstrated that the subdistribution hazard ratio (95% confidence interval) for VTE and ATE in the ICI group was 1.27 (1.01-1.60) and 0.96 (0.67-1.36), respectively, compared with the non-ICI group. The mortality hazard ratio in the ICI group was 0.68 (0.62-0.74).

CONCLUSION

The addition of ICI to platinum combination therapy was associated with a higher risk of VTE compared with platinum combination therapy alone, while the risk of ATE might be comparable.

Characteristics and risk factors for advanced lung cancer with pulmonary embolism: A cross-sectional, case-control study

OBJECTIVES

Pulmonary embolism (PE) is a life-threatening complication that can occur in patients with lung cancer. In this study, we aimed to identify risk factors and examine the clinical characteristics of advanced lung cancer patients with PE.

METHODS

We conducted a retrospective review of patients admitted to our two hospitals between January 2020 and June 2022. The case group consisted of patients with lung cancer and PE, and a closely matched control group was included to identify risk factors. Statistical analysis was conducted using R language.

RESULTS

A total of 4957 patients were reviewed, and 162 patients (comprising 54 cases and 108 controls) were included in this study. The prevalence of lung cancer with PE in the study population was 1.08%. The majority of patients were male, and the most common histological subtype was adenocarcinoma (67%), followed by squamous cell carcinoma, small cell carcinoma, and poorly differentiated non-small cell lung cancer. The majority of patients had a high performance status (PS) score, with 50% experiencing respiratory failure (mainly hypoxia) and 33% with deep vein thrombosis (DVT). Forty-eight percent of patients were diagnosed with concurrent PE. Further analysis showed that PE was an independent predictor of poor survival, and a PS score of >1 was an independent risk factor for PE in patients with lung cancer.

CONCLUSION

Our study provides valuable insights into the epidemiology and prognosis of PE in lung cancer patients and suggests that a poor ECOG PS, which has not been previously reported, is an independent risk factor for PE.

The Role of Injectables in the Treatment and Prevention of Cancer-Associated Thrombosis

Cancer-associated thrombosis (CAT) is a leading cause of death among patients with cancer. CAT can manifest itself as venous thromboembolism (VTE), in the form of deep vein thrombosis or pulmonary embolism, or arterial thromboembolism. The pathophysiology of CAT is complex and depends on cancer-, patient-, treatment- and biomarkers-related factors. Treatment of VTE in patients with cancer is complex and includes three major classes of anticoagulant agents: heparin and its derivatives, e.g., low molecular weight heparins, direct oral anticoagulants (DOACs), and vitamin K inhibitors. Given the tremendous heterogeneity of clinical situations in patients with cancer and the challenges of CAT, there is no single universal treatment option for patients suffering from or at risk of CAT. Initial studies suggested that patients seemed to prefer an anticoagulant that would not interfere with their cancer treatment, suggesting the primacy of cancer over VTE, and favoring efficacy and safety over convenience of route of administration. Recent studies show that when the efficacy and safety aspects are similar, patients prefer the oral route of administration. Despite this, injectables are a valid option for many patients with cancer.

A New Risk Prediction Model for Venous Thromboembolism and Death in Ambulatory Lung Cancer Patients

(1) Background: Venous thromboembolism (VTE) is a frequent complication in ambulatory lung cancer patients during chemotherapy and is associated with increased mortality. (2) Methods: We analyzed 568 newly diagnosed metastatic lung cancer patients prospectively enrolled in the HYPERCAN study. Blood samples collected before chemotherapy were tested for thrombin generation (TG) and a panel of hemostatic biomarkers. The Khorana risk score (KRS), new-Vienna CATS, PROTECHT, and CONKO risk assessment models (RAMs) were applied. (3) Results: Within 6 months, the cumulative incidences of VTE and mortality were 12% and 29%, respectively. Patients with VTE showed significantly increased levels of D-dimer, FVIII, prothrombin fragment 1 + 2, and TG. D-dimer and ECOG performance status were identified as independent risk factors for VTE and mortality by multivariable analysis and utilized to generate a risk score that provided a cumulative incidence of VTE of 6% vs. 25%, death of 19% vs. 55%, and in the low- vs. high-risk group, respectively (p < 0.001). While all published RAMs significantly stratified patients for risk of death, only the CATS and CONKO were able to stratify patients for VTE. (4) Conclusions: A new prediction model was generated to stratify lung cancer patients for VTE and mortality risk, where other published RAMs failed.

Management of venous thromboembolism in patients with lung cancer: a state-of-the-art review

Venous thromboembolism (VTE) is common and life-threatening in patients with lung cancer. Management of VTE is critical for patients with lung cancer. Risk assessment, thromboprophylaxis and treatment of VTE constitute the core issues of VTE management in patients with lung cancer. Although its overall principles should follow recommendations in authoritative guidelines, VTE management in patients with lung cancer may be slightly special in some specific aspects. Despite the extensive validation of Khorana score for patients with all cancer types, its value in VTE risk assessment of patients with lung cancer is controversial. It is important to determine the VTE risk assessment score that can accurately and specifically assess the VTE risk of patients with lung cancer. Clinical practice patterns of thromboprophylaxis may vary by cancer types, since different sites of cancer may have different levels of VTE risk. To understand the thromboprophylaxis specific for lung cancer is of vital importance for patients with lung cancer. Although it is essential to comply with authoritative guidelines, the duration and timing of initiation of thromboprophylaxis in surgical patients with lung cancer may need further study. Taken together, the purpose of this review is to provide an overview of state-of-the-art VTE stewardship specific for patients with lung cancer.

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.

Characteristics and Outcomes of Cancer Patients With Venous Thromboembolic Events After Treatment With Immune Checkpoint Inhibitors

OBJECTIVE

This study aimed to describe the clinical characteristics and outcomes of patients with venous thromboembolism (VTE) after Immune checkpoint inhibitors (ICI), focusing on patients with gastrointestinal (GI) immune-related adverse events (irAE).

METHODS

In this retrospective, single-center study, we report the clinical outcomes of adult cancer patients who developed a VTE within 2 years of ICI initiation. Patients were excluded if alternate causes of VTE were present apart from malignancy and cancer therapy. The cohort was classified into those with GI-irAE, non-GI-irAE, and no irAE. A control group with ICI exposure without irAE and VTE was selected for comparative analysis.

RESULTS

Of all ICI-treated patients, 1891 (17.2%) were diagnosed with VTE. In all, 501 (4.6%) had no etiology for VTE aside from malignancy and cancer therapy. Of these, 137 patients were included and classified as: 44 GI-irAE, 42 non-GI-irAE, and 51 no irAE. Chemotherapy within 6 months of ICI therapy was associated with increased VTE risk. There was no difference in the clinical course between those exposed to chemotherapy versus ICI therapy alone, time from ICI initiation to VTE, and VTE type, recurrence, or related hospitalization. While there was no difference in VTE-related mortality, the GI-irAE group was associated with lower all-cause mortality and superior overall survival.

CONCLUSION

Combined ICI and chemotherapy use increased VTE risk. There is a similar disease course of VTE after ICI exposure, regardless of other irAEs. Co-existing GI-irAE with VTE is associated with superior overall survival. Prospective studies are needed to evaluate the relationship between ICI therapy and VTE and irAE impact on VTE outcomes.

Could PD-L1 positivity be associated with venous thrombosis in patients with non-small cell lung cancer?

The risk of venous thromboembolism (VTE) is increased in non-small cell lung cancer (NSCLC), and defining at-risk patients is important. Thus, we aimed to assess the association between programmed cell death ligand 1 (PD-L1) expression and VTE [pulmonary embolism (PE), deep venous thrombosis (DVT)] in NSCLC. In this retrospective, observational multicentre study, 369 patients with NSCLC who had PD-L1 immunohistochemistry based on biopsies taken between January 2017 and December 2019, were divided as PD-L1-positive (n = 181) and -negative (n = 188) groups, and low-positive (n = 99) and high-positive (n = 82) PD-L1 groups. Among all population, 12.5% of them developed a VTE during a median follow-up of 474 days. The rates of DVT, PE, and PE + DVT were 5.7%, 6% and 0.8%, respectively. VTE (15.5% vs. 9.5%) and DVT (3.8% vs. 7.4%) were similar between two groups, while PE was significantly higher in PD‑L1-positive group than those in PD-L1-negative group (11.1% vs 1%, p < 0.001). There were no significant differences between low- and high-positive groups in terms of VTE (14.1% vs. 17%), PE (12.1% vs. 9.8%), and DVT (2% vs. 6.1%). In the multivariate analysis, multiple metastases (Hazard ratio [HR] 4.02; 95% confidence interval [Cl] 1.18-13.63; p = 0.07) and PD-L1 positivity was associated with an increased PE risk (HR 8.39; 95% Cl 2.07-34.07; p = 0.003). In conclusion, PD-L1 positivity may be of important role in predicting the increased risk of PE in patients with NSCLC and thereby may be used to define patients likely to benefit from thromboprophylaxis.

A case of late and lethal Trousseau's syndrome induced by pembrolizumab in lung adenocarcinoma

Trousseau's syndrome is a relatively rare reported event in immunotherapy-related clinical trials, mostly occurring in the early period of immune checkpoint inhibitor (ICI) therapy. Here, we report an unusual case of late and lethal Trousseau's syndrome during pembrolizumab maintenance therapy in a lung adenocarcinoma harboring tumor protein p53 (TP53) mutation. The patient has experienced severe coagulation abnormalities manifesting as cerebral infarction, partial infarction of both kidneys and spleen after 23 cycles of pembrolizumab use and was resistant to anticoagulants. The late occurrence of coagulation abnormalities in this case reveals a possible correlation between TP53 mutations and Trousseau's syndrome when patients are treated with ICIs.

Venous thromboembolism incidence and risk factors associated with immune checkpoint inhibitors among patients with advanced non-small cell lung cancer

BACKGROUND

Venous thromboembolism (VTE) is a significant cause of morbidity and mortality in patients with lung cancer. Systemic therapies, such as chemotherapy (chemo), are associated with increased risk of VTE. Immune checkpoint inhibitors (ICIs) are a new standard of care for the treatment of lung cancer, but their association with VTE is not fully understood. We evaluated the incidence of VTE and risk factors for patients with advanced non-small cell lung cancer (aNSCLC) treated with first-line ICI-based, chemo-based, or ICI+chemo regimens.

METHODS

This retrospective cohort study used HealthCore Integrated Research Environment - Oncology data, an integrated database of administrative claims, coupled with clinical data from a cancer-care quality program. Patients with first-line treatment of stage IV non-small cell lung cancer from July 2014 to August 2020 were grouped based on three treatment types: ICI-based, chemo-based, or ICI+chemo. Patients with VTE before initiation of systemic treatment were excluded. Newly diagnosed VTE events were identified via inpatient and outpatient diagnosis codes. Cox proportional hazards models were used to investigate the factors associated with VTE risk.

RESULTS

Among 2299 eligible patients (ICI-based, n=605; chemo-based, n=1092; ICI+chemo, n=602) with a median follow-up of 9.1 months, the VTE incidence rates (95% CI) per 100 person-years were 17.8 (95% CI 16.0 to 19.5) overall, 13.5 (95% CI 10.6 to 16.5) for ICI-based, 18.0 (95% CI 15.5 to 20.5) for chemo-based, and 22.4 (95% CI 20.2 to 24.5) for ICI+chemo. The 6-month cumulative incidence of VTE was 8.1% for ICI-based, 10.9% for chemo-based, and 12.8% for ICI+chemo. Pulmonary embolism was most common, accounting for 63% of the VTE events. After controlling for baseline patient characteristics, the risk of VTE was 26% lower for ICI-based regimens than for chemo-based regimens (HR 0.74, p=0.03). There was no meaningful difference in the risk between ICI+chemo and chemo-based regimens (HR 1.12, p=0.36). Previous radiation and severe obesity (body mass index ≥40) were associated with VTE.

CONCLUSIONS

VTE incidence rate per 100 person-years was common across regimens in patients with aNSCLC, but numerically lower for patients receiving ICI-based regimens compared with those receiving chemo-based and ICI+chemo regimens. VTE is a common complication of lung cancer, and there is a continued need for awareness of VTE as a comorbidity in this population.

Platelet-derived TLT-1 promotes tumor progression by suppressing CD8+ T cells

Current understanding of tumor immunosuppressive mechanisms forms the basis for modern day immunotherapies. Immunoregulatory role of platelets in cancer remains largely elusive. Platelets from non-small cell lung cancer (NSCLC) patients revealed a distinct activation phenotype. TREM-like transcript 1 (TLT-1), a platelet protein, was increased along with enhanced extracellular release from NSCLC platelets. The increased platelet TLT-1 was also evident in humanized mice with patient-derived tumors. In immunocompetent mice with syngeneic tumors, TLT-1 binding to T cells, in vivo, led to suppression of CD8 T cells, promoting tumor growth. We identified direct interaction between TLT-1 and CD3ε on T cells, implicating the NF-κB pathway in CD8 T cell suppression. Anti-TLT-1 antibody rescued patients' T cells from platelet-induced suppression ex vivo and reduced tumors in mice in vivo. Clinically, higher TLT-1 correlated with reduced survival of NSCLC patients. Our findings thus identify TLT-1 as a platelet-derived immunosuppressor that suppresses CD8 T cells and demonstrate its therapeutic and prognostic significance in cancer.

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.

Associations Between Immune-Related Venous Thromboembolism and Efficacy of Immune Checkpoint Inhibitors: A Systematic Review and Meta-Analysis

This study aims to summarize the available data and determine if the presence of venous thromboembolism (VTE) immune-related adverse event (irAE) in patients with immune checkpoint inhibitor (ICI) therapy is associated with improved treatment efficacy and clinical outcomes, which in turn was used to help optimize patient selection for anticoagulation therapy and inform rational treatment strategies for overcoming the mechanisms of ICI resistance. PubMed, Embase, Web of Science, and Cochrane Library were searched up to March 18, 2023, for studies assessing the relationship between VTE irAE development during ICI therapy and cancer outcomes. Seven primary articles with a total of 4437 patients were included in the overall survival (OS) meta-analysis. Patients with VTE had a significant increase in overall mortality compared to patients without VTE in adjusted hazard ratios (HRs 1.36, 95% confidence interval [CI] 1.06-1.75, P  =  .02). In the studies where immortal time bias (ITB) was accounted for, patients with VTE irAE also had poor OS than those without. HR and the corresponding 95% CI values in the non-ITB group were 2.53 (1.75-3.66, P < .00001) with low heterogeneity (P  =  .17, I2  =  48%) and 1.21 (1.06-1.37, P  =  .004) in the ITB group with no heterogeneity (P  =  .95, I2  =  0%), respectively. Despite the heterogeneity identified, the evidence does suggest that VTE irAE occurrence could be served as a prognostic indicator, with higher frequencies of occurrence associated with poorer OS. However, the fundamental role of this association with clinical consequences should be further investigated in large cohorts and clinical trials.

The incidence and risk of cardiovascular events associated with immune checkpoint inhibitors in Asian populations

OBJECTIVES

Immune checkpoint inhibitors are associated with adverse cardiovascular events. However, there are no data characterizing cardiovascular events among Asians on immune checkpoint inhibitors. We aim to determine the incidence and risk of cardiac events associated with immune checkpoint inhibitors in an Asian population.

METHODS

We performed a retrospective, propensity score-matched cohort study at two tertiary referral centers in Taiwan. Immune checkpoint inhibitor users were matched with non-immune checkpoint inhibitor users based on predetermined clinical variables. The primary outcome was major adverse cardiovascular events, defined as a composite of myocardial infarction, ischemic stroke, acute peripheral occlusive disease, pulmonary embolism, deep venous thrombosis, heart failure, pericardial disease, myocarditis, cardiac arrhythmias and conduction block.

RESULTS

Between January 2010 and November 2021, 868 immune checkpoint inhibitor users were matched 1:1 with non-immune checkpoint inhibitor users. Among immune checkpoint inhibitor users, 67 (7.7%) patients developed major adverse cardiovascular events. During a median follow-up period of 188 days, the incidence rate of major adverse cardiovascular events for immune checkpoint inhibitor and non-immune checkpoint inhibitor users was 94.8 and 46.2 per 1000 patient-years, respectively, resulting in an incidence rate ratio of 2.1 [95% confidence interval: 1.5-2.9]. In multivariate Cox proportional hazard models, immune checkpoint inhibitor users had a 60% increased risk for major adverse cardiovascular events [hazard ratio, 1.6 (95% confidence interval: 1.1-2.3)]. Immune checkpoint inhibitors use was independently associated with increased risk of ischemic stroke [hazard ratio, 3.0 (95% confidence interval: 1.0-9.0)] and pulmonary embolism [hazard ratio, 5.5 (95% confidence interval: 1.4-21.3)]. In multivariate logistic regression analysis, age > 65, metastatic disease, hypertension and baseline platelet-to-lymphocyte ratio < 180 were risk factors for major adverse cardiovascular events.

CONCLUSIONS

Among Asians, immune checkpoint inhibitors were associated with an increased risk of major adverse cardiovascular events, particularly ischemic stroke and pulmonary embolism.

The Khorana score and venous and arterial thrombosis in patients with cancer treated with immune checkpoint inhibitors: A Danish cohort study

BACKGROUND

Thrombosis is common among patients with cancer. Primary thromboprophylaxis guided by the Khorana score is endorsed by guidelines but recommendations rely mainly on data from patients treated with chemotherapy.

OBJECTIVES

To explore if the Khorana score could risk stratify patients with cancer treated with immune checkpoint inhibitors according to risk of venous and arterial thrombosis.

PATIENTS/METHODS

The study population and Khorana score were defined using administrative Danish health registries. The primary outcome was 6-month risk of venous thromboembolism after initiation of checkpoint inhibitor treatment. Secondary outcomes were arterial thrombosis and any thromboembolic event. Death was considered a competing risk event.

RESULTS

Among 3946 patients with cancer initiating checkpoint inhibitor treatment without other indications for anticoagulation, the overall 6-month incidence of venous thromboembolism was 2.6% (95% confidence interval [CI]: 2.1-3.1). Risks were 2.1% (95% CI: 1.5-3.0), 2.6% (95% CI: 2.0-3.4), and 3.7% (95% CI: 2.1-5.9) in low (score 0), intermediate (score 1-2), and high risk (score ≥3) Khorana categories, respectively. Among patients eligible for primary thromboprophylaxis according to guidelines (Khorana score ≥2), risk of venous thromboembolism was 4.1% (95% CI: 3.1-5.4). Higher Khorana risk category was also associated with higher 6-month risk of both arterial thrombosis and any thromboembolic events.

CONCLUSIONS

The Khorana score was able to risk stratify patients with cancer treated with immune checkpoint inhibitors according to 6-month risk of thromboembolic events. Risks of venous thromboembolism were lower than in randomized thromboprophylaxis trials, thus questioning the absolute benefit of routine primary thromboprophylaxis in an unselected population of patients treated with immune checkpoint inhibitors.

Venous Thromboembolism in Cancer Patients Undergoing Chemotherapy: A Systematic Review and Meta-Analysis

Objective: Venous thromboembolism (VTE) is a life-threatening complication that may exacerbate cancer prognosis. Whilst some studies indicate an increased risk of VTE in cancer patients undergoing chemotherapy, the prevalence estimates on the pooled prevalence of VTE in cancer patients undergoing chemotherapy are not known. This study aims to calculate the pooled prevalence of VTE in chemotherapy-treated cancer patients. Methods: Studies on VTE occurrence in cancer patients undergoing chemotherapy were retrieved after database search. The terms used included “cancer”, “chemotherapy”, and “venous thromboembolism”. A random-effects meta-analysis was conducted to obtain a pooled estimate of VTE prevalence in cancer patients undergoing chemotherapy. Results: A total of 102 eligible studies involving 30,671 patients (1773 with VTE, 28,898 without) were included in the meta-analysis. The pooled estimate of VTE prevalence was found to be 6%, ranging from 6% to 7% (ES 6%; 95% CI 6−7%; z = 18.53; p < 0.001). Conclusions: The estimated pooled prevalence rate of VTEs was 6% in cancer patients undergoing CRT, which was higher than the overall crude prevalence rate (5.78%). Comprehensive cancer care should consider stratified VTE risk assessment based on cancer phenotype, given that certain phenotypes of cancer such as bladder, gastric and ovarian posing particularly high risks of VTE.

Immune Checkpoint Inhibitors and Venous Thromboembolism: An Analysis of the WHO Pharmacovigilance Database

Data on venous thromboembolic events (VTEs) in patients receiving immune checkpoint inhibitors (ICIs) are scarce and conflicting. This study investigated the risk of reporting VTEs associated with ICIs in comparison with all other anticancer drugs. The World Health Organization pharmacovigilance database (VigiBase), comprising >30 million individual case safety reports, was queried. All reports on patients with cancer, involving at least one anticancer drug as a suspect or interacting drug and registered from January 1, 2008, to May 31, 2021, were included. The association between ICIs and the risk of reporting VTEs was estimated using the reporting odds ratio (ROR) as a measure of disproportionality with all other anticancer drugs as comparators. RORs were estimated as crude and adjusted RORs for age, sex, and other medications (excluding anticancer drugs) associated with risk of VTEs. Among 1,196 patients experiencing VTEs after ICI treatment, the median age was 65 years and 57.6% were men. Anti-PD-1 agents (62.5%) were the most frequently reported. ICIs were not associated with higher reporting of VTEs when compared with other anticancer drugs (crude ROR 0.63, 95% confidence interval (CI) 0.60 to 0.67 and adjusted ROR 0.70, 95% CI 0.65-0.74). No signal of disproportionate reporting was found when considering each class of ICIs. In conclusion, ICIs were not associated with higher reporting of VTEs, in comparison with all other anticancer drugs in a large-scale pharmacovigilance database. Owing to the limitations inherent to pharmacovigilance studies, prospective studies, including an adequate comparison group, are needed to assess the risk of VTEs in ICI-treated patients.

Immune checkpoint inhibitors-associated thrombosis in patients with lung cancer and melanoma: a study of the Spanish society of medical oncology (SEOM) thrombosis and cancer group

Purpose

Immune Checkpoint Inhibitors (ICI) can be associated with thrombotic events, both venous and arterial (VTE/AT). However, there is a paucity of information regarding patients in routine clinical practice.

Methods/patients

Retrospective, multicenter study promoted by the Thrombosis and Cancer Section of the Spanish Society of Medical Oncology (SEOM). Patients with melanoma and lung cancer who initiated ICI between 01/01/2015 and 31/12/2019 were recruited. Minimum follow-up was 6 months (unless it was not possible because of death). The primary objective was to calculate the incidence of ICI-associated VTE/AT and the secondary objectives included to analyze its impact on survival and to identify predictor variables for VTE/AT.

Results

665 patients with lung cancer were enrolled. The incidence of VTE/AT during follow-up was 8.4%. Median overall survival (OS) was lower in the VTE/AT group (12 months 95% CI 4.84–19.16 vs. 19 months 95% CI 16.11–21.9; p = 0.0049). Neutrophil/lymphocyte ratio (NLR) and anemia upon initiation of IT, as well as a history of thrombosis between cancer diagnosis and the start of ICI, were predictive variables for developing of VTE/AT (p < 0.05). 291 patients with melanoma were enrolled. There was a 5.8% incidence rate of VTE/AT during follow-up. Median OS was lower in the VTE/AT group (10 months 95% CI 0.0–20.27 vs. 29 months 95% CI 19.58–36.42; p = 0.034). NLR and lactate dehydrogenase (LDH) at the beginning of ICI were predictor variables for VTE/AT (p < 0.05).

Conclusions

ICI increases the risk of VTE/AT in patients with lung cancer and melanoma, which impact OS.

Hemostasis and tumor immunity

Significant data have accumulated demonstrating a reciprocal relationship between cancer and the hemostatic system whereby cancer promotes life‐threatening hemostatic system dysregulation (e.g., thromboembolism, consumptive coagulopathy), and hemostatic system components directly contribute to cancer pathogenesis. The mechanistic underpinnings of this relationship continue to be defined, but it is becoming increasingly clear that many of these mechanisms involve crosstalk between the hemostatic and immune systems. This is perhaps not surprising given that there is ample evidence for bidirectional crosstalk between the hemostatic and immune systems at multiple levels that likely evolved to coordinate the response to injury, host defense, and tissue repair. Much of the data linking hemostasis and immunity in cancer biology focus on innate immune system components. However, the advent of adaptive immunity‐based cancer therapies such as immune checkpoint inhibitors has revealed that the relationship of hemostasis and immunity in cancer extends to the adaptive immune system. Adaptive immunity‐based cancer therapies appear to be associated with an increased risk of thromboembolic complications, and hemostatic system components appear to regulate adaptive immune functions through diverse mechanisms to affect tumor progression. In this review, the evidence for crosstalk between hemostatic and adaptive immune system components is discussed, and the implications of this relationship in the context of cancer therapy are reviewed. A better understanding of these relationships will likely lead to strategies to make existing adaptive immune based therapies safer by decreasing thromboembolic risk and may also lead to novel targets to improve adaptive immune‐based cancer treatments.

Old is new again: emergence of thromboembolic complications in cancer patients on immunotherapy

Cancer immunotherapy has emerged as one of the most important new treatments for cancer in many years, moving rapidly to front-line therapy for several cancers. Cancer immunotherapy is based on treatment with immune checkpoint inhibitors (ICI), which are monoclonal antibodies directed toward immunoregulatory proteins including PD-1, PD-L1 and CTLA-4. ICI inhibit interactions between these proteins and their ligands, disabling physiologic immune regulatory networks and enhancing anti-tumor immunity. However, since the immune response cannot be directed specifically to the tumor, ICI are associated with immune-related adverse events (irAEs) resulting from immune-mediated attack of normal tissues. We and others have reported a high incidence of thrombosis in patients treated with ICI, which may approach 20%. Given the rapidly increasing use of ICIs, it is clear that ICI-Associated Thrombosis (IAT) is a major emerging clinical problem. However, there is a remarkable knowledge gap concerning mechanisms of IAT. IAT may be a composite irAE resulting from activation of blood and vascular cells, leading to thromboinflammation. Cancer itself is an inflammatory disorder, and inducing further inflammation through ICI administration may stimulate procoagulant activity by multiple cell types. Moreover, some blood and vascular cells express ICI target proteins. Here, we review the results of several studies describing the clinical manifestations of IAT, as well as our recent studies demonstrating that elevated levels of myeloid derived suppressor cells and inflammatory cytokines may serve as biomarkers of IAT. It is hoped that the concepts reviewed here may stimulate further research into this important clinical problem.

Exploring the Mechanisms Underlying the Cardiotoxic Effects of Immune Checkpoint Inhibitor Therapies

Adaptive immune response modulation has taken a central position in cancer therapy in recent decades. Treatment with immune checkpoint inhibitors (ICIs) is now indicated in many cancer types with exceptional results. The two major inhibitory pathways involved are cytotoxic T-lymphocyte-associated protein 4 (CTLA4) and programmed cell death protein 1 (PD-1). Unfortunately, immune activation is not tumor-specific, and as a result, most patients will experience some form of adverse reaction. Most immune-related adverse events (IRAEs) involve the skin and gastrointestinal (GI) tract; however, any organ can be involved. Cardiotoxicity ranges from arrhythmias to life-threatening myocarditis with very high mortality rates. To date, most treatments of ICI cardiotoxicity include immune suppression, which is also not cardiac-specific and may result in hampering of tumor clearance. Understanding the mechanisms behind immune activation in the heart is crucial for the development of specific treatments. Histological data and other models have shown mainly CD4 and CD8 infiltration during ICI-induced cardiotoxicity. Inhibition of CTLA4 seems to result in the proliferation of more diverse T0cell populations, some of which with autoantigen recognition. Inhibition of PD-1 interaction with PD ligand 1/2 (PD-L1/PD-L2) results in release from inhibition of exhausted self-recognizing T cells. However, CTLA4, PD-1, and their ligands are expressed on a wide range of cells, indicating a much more intricate mechanism. This is further complicated by the identification of multiple co-stimulatory and co-inhibitory signals, as well as the association of myocarditis with antibody-driven myasthenia gravis and myositis IRAEs. In this review, we focus on the recent advances in unraveling the complexity of the mechanisms driving ICI cardiotoxicity and discuss novel therapeutic strategies for directly targeting specific underlying mechanisms to reduce IRAEs and improve outcomes.

Profile of metastatic lung cancer patients susceptible to development of thromboembolism during immunotherapy

BACKGROUND

Thromboembolism (TE) is a serious complication in lung cancer patients; however, risk factors for developing TE during treatment with immuno-oncology (IO) drugs are unclear.

MATERIALS AND METHODS

A retrospective study of lung cancer patients hospitalized in Tokyo Medical and Dental University was performed to clarify the association between TE and systemic therapy, especially IOs. Patients were divided into an IO cohort, a chemotherapy cohort (CT cohort), and a control cohort (patients without recurrence after surgery). Association studies of variables relevant to TE were performed.

RESULTS

A total of 592 patients were enrolled (IO cohort, 120; CT cohort, 294; control cohort, 178). Eight patients (6.7%) in the IO cohort, seven (2.4%) in the CT cohort, and three (1.7%) in the control cohort developed TE. Least Absolute Shrinkage and Selection Operator (LASSO) regression analysis identified IO, a history of TE, poor performance status (PS), and prior anticoagulation therapy as being associated with TE. Subsequent multivariate logistic regression analysis identified a history of TE (odds ratio (OR), 6.03; 95% confidence interval (CI), 2.09-17.40; P = 0.01) and poor PS (OR, 3.84; 95% CI, 1.34-11.00; P < 0.001) as potential risk factors for developing TE. The incidence of TE in the IO cohort patients with both of these characteristics was significantly higher (OR, 52.82; 95% CI, 6.72-506.37; P < 0.001) than that in the control cohort.

CONCLUSION

Lung cancer patients with a history of TE and poor PS are at increased risk of TE during treatment with IOs.

MICRO ABSTRACT

The profiles of lung cancer patients susceptible to development of thromboembolism (TE) during immunotherapy are unclear, even though TE is associated with a worse prognosis. Here, association studies of variables relevant to TE revealed that patients with a history of TE and poor performance status are at higher risk of developing TE during immunotherapy.

Cancer-associated venous thromboembolism

Cancer-associated thrombosis (including venous thromboembolism (VTE) and arterial events) is highly consequential for patients with cancer and is associated with worsened survival. Despite substantial improvements in cancer treatment, the risk of VTE has increased in recent years; VTE rates additionally depend on the type of cancer (with pancreas, stomach and primary brain tumours having the highest risk) as well as on individual patient's and cancer treatment factors. Multiple cancer-specific mechanisms of VTE have been identified and can be classified as mechanisms in which the tumour expresses proteins that alter host systems, such as levels of platelets and leukocytes, and in which the tumour expresses procoagulant proteins released into the circulation that directly activate the coagulation cascade or platelets, such as tissue factor and podoplanin, respectively. As signs and symptoms of VTE may be non-specific, diagnosis requires clinical assessment, evaluation of pre-test probability, and objective diagnostic testing with ultrasonography or CT. Risk assessment tools have been validated to identify patients at risk of VTE. Primary prevention of VTE (thromboprophylaxis) has long been recommended in the inpatient and post-surgical settings, and is now an option in the outpatient setting for individuals with high-risk cancer. Anticoagulant therapy is the cornerstone of therapy, with low molecular weight heparin or newer options such as direct oral anticoagulants. Personalized treatment incorporating risk of bleeding and patient preferences is essential, especially as a diagnosis of VTE is often considered by patients even more distressing than their cancer diagnosis, and can severely affect the quality of life. Future research should focus on current knowledge gaps including optimizing risk assessment tools, biomarker discovery, next-generation anticoagulant development and implementation science.

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 thromboembolism (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 is 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.