Update on Guidelines for the Prevention of Cancer-Associated Thrombosis

Clinical analysis of bleeding and thrombotic events in haematological-oncology patients with severe thrombocytopenia and a high risk of thrombosis

BACKGROUND

Haematological patients with severe thrombocytopenia and high thrombotic risk face challenges related to balancing bleeding and thrombosis risks. This study investigated factors associated with bleeding and thrombosis in high-risk haematological oncology patients with severe thrombocytopenia not receiving anticoagulant therapy and characterized their clinical features when both events occurred.

METHODS

A total of 446 haematological oncology patients with Caprini scores ≥ 5 were included from July 2022 to June 2023 at Mianyang City Central Hospital. Those not receiving prophylactic anticoagulants due to an admission platelet count < 50 × 109/L were studied. Patients were categorized into bleeding/nonbleeding and thrombotic/nonthrombotic groups on the basis of hospital course. Relevant clinical data were collected, and univariate/multivariate logistic regression was used to analyse the influencing factors. The platelet count at admission was assessed via ROC curves for thrombosis prediction.

RESULTS

In the bleeding group, higher proportions of patients with leukaemia, myeloid tumours, lung infections, and a central venous catheter (CVC) with two lumens were observed, along with shorter catheter durations, lower initial and minimum platelet counts during hospitalization, and prolonged plasminogen times (all P < 0.05). The thrombotic group had a greater thrombosis history, initial platelet count, use of two venous catheter lumens, parenteral nutrition, sedation, and autologous haematopoietic stem cell transplantation (Auto-HSCT), with a lower leukaemia proportion (P < 0.05). Logistic regression identified lymphoma type and minimum platelet count as bleeding protective factors and the Charlson Comorbidity Index (CCI) score as an independent risk factor. Thrombosis history, two venous catheter lumens, and sedation were risk factors for thrombosis. The median platelet count was lower at bleeding and thrombosis than at admission (P = 0.007). The platelet count at admission had predictive value for thrombosis, especially severe thrombocytopenia, with an AUC of 0.735 (95% CI 0.613-0.858, P = 0.003) and a cut-off value of 42.5 × 109/L.

CONCLUSIONS

For haematological neoplasm patients with a high risk of venous thromboembolism (VTE), severe thrombocytopenia and high CCI scores, risk prevention and control of bleeding take precedence over thrombosis prophylaxis. Prophylactic anticoagulation is still recommended for patients with lymphoma assessed at high risk for VTE and with platelet counts of at least 42.5 × 109/L.

Validation of risk assessment scores in predicting venous thromboembolism in patients with lung cancer receiving immune checkpoint inhibitors

INTRODUCTION

Several risk scores have been proposed to predict venous thromboembolism (VTE) in hospitalized patients. However, their predictive performances in lung cancer patients receiving immune checkpoint inhibitors (ICIs) is unclear. We aimed to validate and compare their performances of the Caprini, Padua and Khorana risk scores in lung cancer patients receiving ICIs.

METHODS

This was a retrospective cohort study of patients with lung cancer treated with ICIs at West China Hospital between January 2018 and March 2022. The primary outcome was VTE during 12 months of follow-up from the first day of treatment with ICIs. The predictive performances of risk scores was determined using receiver operating characteristic (ROC) curve analysis.

RESULTS

Among the 1115 eligible patients with lung cancer who received ICIs, 105 patients (9.4%) experienced VTE during the 12-month follow-up period. There was a statistically significant difference in the cumulative incidence of VTE between the different risk levels as determined by Caprini and Padua scores (all P < 0.001). However, no significant difference was observed for the Khorana score (P = 0.488). The Caprini and Padua scores demonstrated good discriminative performances (AUC 0.743, 95% CI 0.688-0.799 for Caprini score; AUC 0.745, 95% CI 0.687-0.803 for Padua score), which were significantly better than that of the Khorana score (AUC 0.553, 95% CI, 0.493-0.613) (P < 0.05).

CONCLUSION

In our study, the Caprini and Padua risk scores had better discriminative ability than the Khorana score to identify lung cancer patients treated with ICIs who were at high risk of VTE.

Evaluation of the incidence, predictors, risk assessment scores and outcomes of thromboembolism in a cohort of Egyptian NHL patients - Real World Experience

Non-Hodgkin's Lymphoma (NHL) is the most common subtype of lymphoma. The incidence of venous thromboembolism (VTE) in aggressive NHL was estimated recently to be 11%. Several risk assessment scores and factors are available to help identify cancer patients at risk for developing VTE. Patients with a pathologically confirmed diagnosis of NHL were identified at the Oncology Center of Mansoura University. The study included 777 patients: 719 with DLBCL-NOS, 26 with Anaplastic-B-cell, and 32 with T-cell-rich-NHL. Data were retrospectively collected from electronic medical records, including clinical, radiological, and laboratory information related to VTE and NHL. The median age at NHL diagnosis was 53 years, (range: 18-98). There was a male predominance, 51.4% of the cases. At initial lymphoma diagnosis, VTE was identified in 46 (5.9%) patients, and 61 (7.9%) patients experienced VTE while undergoing chemotherapy. According to logistic regression analysis, a PS (performance status) ≥ 2, bulky lesions, and mediastinal masses were significant predictors of VTE at presentation, with P-values of 0.022, 0.002, and < 0.001, respectively. Meanwhile, NHL patients who developed VTE during chemotherapy had significantly poorer PS, higher absolute neutrophilic counts (ANC), neutrophil/lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR) and lactate dehydrogenase (LDH) levels than lymphoma patients without VTE, with P-values of 0.003,  0.034, 0.049, 0.01 and 0.007, respectively, as determined by multivariate analysis. The ROC curve identified the cut-off values of 4.875 × 109/L for ANC, 2.985 for NLR, 144.85 for PLR, and 417.5 U/L for LDH as potential markers for predicting VTE in NHL patients. Patients with a PS ≥ 2 and values exceeding these cut-offs for ANC, NLR, and PLR experienced significantly higher incidences of VTE than other groups, with P-values of 0.003, < 0.001, < 0.001, and < 0.001, respectively. At the end of the follow-up, the overall survival was significantly shortened by VTE occurring during chemotherapy, hypoalbuminemia,  intermediate-high and high international prognostic index (IPI) scores (intermediate-high and high), responses other than CR and relapse, all with P-values < 0.05. ECOG PS and Inflammatory markers such as NLR, PLR, and neutrophilic count could serve as predictors of the development of thrombotic events in patients with NHL-DLBCL. Additionally, the occurrence of VTE during chemotherapy is an independent poor prognostic marker for overall survival (OS).

Clinical guidelines for prevention and treatment of CAT in Japan and other countries

Cancer-associated thrombosis (CAT) is an important prognostic factor for an increasing number of cancer patients. Understanding of CAT among cancer care providers has grown in recent years, and guidelines for the prevention and treatment of CAT have been published in Japan and around the world. In this article, we introduce these major guidelines and discuss differences we identified between the Japanese guidelines and those of other countries, with a focus on problems and issues. Insurance coverage of low-molecular-weight heparin and indications for primary prevention with direct oral anticoagulants in particular require urgent consideration.

Risk of Venous Thromboembolism by Cancer Type: A Network Meta-Analysis

Patients with cancer have an increased risk of venous thromboembolism (VTE). Comparing tumor-specific VTE risk is complicated by factors such as surgery, disease stage, and chemotherapy. Network meta-analysis (NMA) using cancer types as network nodes enabled us to estimate VTE rates by leveraging comparisons across cancer types while adjusting for baseline VTE risk in individual studies. This study was conducted to estimate the risk of VTE by cancer type and factors influencing VTE risk. The Embase, MEDLINE, and Cochrane Library repositories were systematically searched to identify clinical trials and observational studies published from 2005 to 2022 that assessed the risk of primary cancer-related VTE among two or more distinct cancer types. Studies with similar cancer populations and study methods reporting VTE occurring within 1 year of diagnosis were included in the NMA. Relative VTE rates across cancer types were estimated with random-effects Bayesian NMAs. Absolute VTE rates were calculated from these estimates using the average VTE incidence in lung cancer (the most frequently reported type) as the "anchor." From 2,603 records reviewed, 30 studies were included in this NMA. The general network described 3,948,752 patients and 18 cancer types: 3.1% experienced VTE within 1 year of diagnosis, with cancer-specific rates ranging from 0.7 to 7.4%. Consistent with existing VTE risk prediction tools, pancreatic cancer was associated with higher-than-average VTE risk. Other cancer types with high VTE risk were brain and ovarian cancers. The relative rankings of VTE risk for certain cancers changed based on disease stage and/or receipt of chemotherapy or surgery.

Efficacy and Safety of a DOAC Compared to Unfractionated Heparin and A Low Molecular Weight Heparin in the Prevention of Thromboembolism in Hematopoietic Stem Cell Transplant Recipients

Background

Hematopoietic stem cell transplantation (HSCT) patients are at risk of thromboembolic events, making thromboprophylaxis crucial.

Objectives

This study aimed to compare apixaban, a direct factor Xa inhibitor (DOAC), with dalteparin and unfractionated heparin for thromboprophylaxis in HSCT recipients. The safety outcome included the assessment of hemorrhagic events.

Methods

In this open-label randomized clinical trial, 182 HSCT recipients were divided into three groups: Apixaban (n = 61, 2.5 mg two times a day), dalteparin (n = 59, 5000 IU daily), and unfractionated heparin (n = 62, 5000 IU twice daily). These anticoagulant regimens were administered after central vein catheterization and during hospitalization. The primary clinical outcome was the risk of thrombosis, and the secondary outcome was the rate of bleeding. Relevant laboratory results were analyzed using appropriate statistical tests.

Results

Among the 61 patients in the apixaban group, six experienced thrombosis (9.83%), with four (6.65%) of them on anticoagulants. In the dalteparin group, three patients (5%) developed thrombosis, two of whom (3.38%) were on anticoagulants. In the heparin group, all four thrombosis cases (6.4%) occurred in patients on anticoagulants (P = 0.543 overall and P = 0.776 in anticoagulant users). Only two cases of bleeding were reported (1.09% overall), one in the dalteparin group (1.69%) and the other in the apixaban group (1.63%).

Conclusions

Apixaban, dalteparin, and heparin demonstrated similar effectiveness in preventing thromboembolism in HSCT recipients. Furthermore, the comparison of bleeding rates across the study groups did not reveal significant differences. Larger studies with higher event rates may yield more precise conclusions.

Ambulatory cancer patients: who should definitely receive antithrombotic prophylaxis and who should never receive

Up to 15-20% of cancer patients experience one or more episodes of venous thromboembolism during cancer disease. Approximately 80% of all cancer-associated venous thromboembolic events occur in non-hospitalized patients. Routine thromboprophylaxis for outpatients with cancer who start new anticancer treatment is currently not recommended by the international guidelines due to the high heterogeneity of these patients in terms of VTE or bleeding risks, the difficulties in selecting patients at high risk, and the uncertainty of duration of prophylaxis. Although the international guidelines endorsed the Khorana score for estimating the thrombotic risk in ambulatory cancer patients, the discriminatory performance of this score is not completely convincing and varies according to the cancer type. Consequently, a minority of ambulatory patients with cancer receive an accurate screening for primary prophylaxis of VTE. The aim of this review is to provide support to physicians in identifying those ambulatory patients with cancer for whom thromboprophylaxis should be prescribed and those that should not be candidate to thromboprophylaxis. In absence of high bleeding risk, primary thromboprophylaxis should be recommended in patients with pancreatic cancer and, probably, in patients with lung cancer harboring ALK/ROS1 translocations. Patients with upper gastrointestinal cancers are at high risk of VTE, but a careful assessment of bleeding risk should be made before deciding on antithrombotic prophylaxis. Primary prevention of VTE is not recommended in cancer patients at increased risk of bleeding as patients with brain cancer, with moderate-to-severe thrombocytopenia or severe renal impairment.

Neutrophil interactions with T cells, platelets, endothelial cells, and of course tumor cells

Neutrophils sense microbes and host inflammatory mediators, and traffic to sites of infection where they direct a broad armamentarium of antimicrobial products against pathogens. Neutrophils are also activated by damage-associated molecular patterns (DAMPs), which are products of cellular injury that stimulate the innate immune system through pathways that are similar to those activated by microbes. Neutrophils and platelets become activated by injury, and cluster and cross-signal to each other with the cumulative effect of driving antimicrobial defense and hemostasis. In addition, neutrophil extracellular traps are extracellular chromatin and granular constituents that are generated in response to microbial and damage motifs and are pro-thrombotic and injurious. Although neutrophils can worsen tissue injury, neutrophils may also have a role in facilitating wound repair following injury. A central theme of this review relates to how critical functions of neutrophils that evolved to respond to infection and damage modulate the tumor microenvironment (TME) in ways that can promote or limit tumor progression. Neutrophils are reprogrammed by the TME, and, in turn, can cross-signal to tumor cells and reshape the immune landscape of tumors. Importantly, promising new therapeutic strategies have been developed to target neutrophil recruitment and function to make cancer immunotherapy more effective.