The Khorana score for prediction of venous thromboembolism in cancer patients: a systematic review and meta-analysis

Scoring systems to predict thrombotic complications in solid tumor patients

PURPOSE OF REVIEW

To explore the use of large datasets in predicting and managing cancer-associated venous thromboembolism (CAT) by stratifying patients into risk groups. This includes evaluating current predictive models and identifying potential improvements to enhance clinical decision-making.

RECENT FINDINGS

Cancer patients are at an elevated risk of developing venous thromboembolism (VTE), which significantly impacts mortality and quality of life. Traditional approaches to risk assessment fail to account for the procoagulant changes associated with cancer, making individualized risk prediction a challenge. Current clinical guidelines as per ASCO recommend risk assessment before chemotherapy and endorse thromboprophylaxis as a standard preventive measure. Since any cancer population is highly heterogeneous in terms of VTE risk, predicting the risk of CAT is an oncological challenge. To address this, different predictive models have been developed to stratify patients by risk, enabling targeted thromboprophylaxis. However, these models vary in accuracy and utility. The present review discusses the pros and cons of these different models.

SUMMARY

The review examines existing CAT risk prediction models, highlighting their strengths, limitations, and diagnostic performance. It also identifies additional variables that could enhance these models to improve their effectiveness in guiding clinicians toward better risk stratification and treatment decisions for cancer patients.

The role of germline and somatic mutations in predicting cancer-associated thrombosis: a narrative review

PURPOSE OF REVIEW

Patients with cancer have an increased risk of venous thromboembolism (VTE). Guidelines suggest to use risk assessment tools to guide decisions about thromboprophylaxis, but current tools have modest discriminatory ability. Genetic information from the germline or tumor has the potential to improve VTE prediction. Here, we provide a clinical overview of the current role of genetics in cancer-associated VTE.

RECENT FINDINGS

Germline mutations, such as factor V Leiden and prothrombin G20210A, are associated with a 2- to 2.5-fold increased VTE risk in patients with cancer. Tumor-specific somatic mutations also contribute to VTE risk, such as ALK rearrangements increasing the risk in nonsmall cell lung cancer and IDH1 mutations decreasing the risk in gliomas. Other somatic mutations associated with VTE independent of tumor type include KRAS , STK11 , MET , KEAP1 , CTNNB1 , and CDKN2B . Incorporating data on germline or somatic mutations in risk scores improves discriminatory ability compared with the Khorana score.

SUMMARY

Specific germline and somatic mutations are associated with an increased VTE risk in patients with cancer and potentially improve performance of clinical risk scores. The increasing and widespread use of genetic testing in cancer care provides an opportunity for further development of prediction models incorporating genetic predictors.

Cancer-associated venous thromboembolism: a comprehensive review

It has been 200 years since the first case of cancer-associated thrombosis (CAT) was reported. Venous thromboembolism (VTE) remains a leading cause of morbidity and mortality in cancer patients. Malignant tumors interact with the coagulation system in complex ways. CAT continues to pose a significant challenge in clinical practice. The risk factors for CAT are complex and multifactorial, primarily including patient, cancer, and therapy-related factors. We have introduced assessment models for CAT and bleeding risk, but the performance of these models has been less than satisfactory. Currently, the main anticoagulant drugs for treating CAT include vitamin K antagonists (VKAs), low molecular weight heparin (LMWH), and direct oral anticoagulants (DOACs). We have provided a detailed overview of the advantages and disadvantages of these three types of drugs and suggestions on choosing the appropriate type of medication for different clinical scenarios. CAT incidence, pathophysiology, risk factors, risk prediction models, and recent advancements in treatment and management are summarized in this review.

Predicting a failure of postoperative thromboprophylaxis in non-small cell lung cancer: A stacking machine learning approach

BACKGROUND

Non-small-cell lung cancer (NSCLC) and its surgery significantly increase the venous thromboembolism (VTE) risk. This study explored the VTE risk factors and established a machine-learning model to predict a failure of postoperative thromboprophylaxis.

METHODS

This retrospective study included patients with NSCLC who underwent surgery between January 2018 and November 2022. The patients were randomized 7:3 to the training and test sets. Nine machine learning models were constructed. The three most predictive machine-learning classifiers were chosen as the first layer of the stacking machine-learning model, and logistic regression was the second layer of the meta-learning model.

RESULTS

This study included 362 patients, including 58 (16.0%) with VTE. Based on the multivariable logistic regression analysis, age, platelets, D-dimers, albumin, smoking history, and epidermal growth factor receptor (EGFR) exon 21 mutation were used to develop the nine machine-learning models. LGBM Classifier, RandomForest Classifier, and GNB were chosen for the first layer of the stacking machine learning model. The area under the received operating characteristics curve (ROC-AUC), accuracy, sensitivity, and specificity of the stacking machine learning model in the training/test set were 0.984/0.979, 0.949/0.954, 0.935/1.000, and 0.958/0.887, respectively. In the validation set, the final stacking machine learning model demonstrated an ROC AUC of 0.983, accuracy of 0.937, sensitivity of 0.978, and specificity of 0.947. The decision curve analyses revealed high benefits.

CONCLUSION

The stacking machine learning model based on EGFR mutation and clinical characteristics had a predictive value for postoperative VTE in patients with NSCLC.

Factors associated with thrombosis among solid organ cancer patients in Kuala Lumpur, Malaysia

BACKGROUND

Patients with solid organ cancers are at increased risk of developing cancer-associated thrombosis (CAT), a complication driven by a complex interplay of patient-specific factors, cancer characteristics, and treatment modalities. Data on CAT and its associated risk factors within diverse ethnic groups, such as the Malaysian population, remains limited. This observational, cohort study aimed to address this gap by determining the incidence of CAT and identifying associated risk factors among multi-ethnic Malaysian patients with solid organ cancers.

METHODS

This study included solid organ cancer patients aged ≥ 18 who attended HCTM and HKL from May 2022 to August 2023. The baseline demographics, and clinical characteristics, were acquired at the cancer diagnosis. Data on cancer treatment, thrombotic events and anticoagulation therapy during the study and its treatment were documented. Multivariable logistic regression analysis was performed to determine the independent factors associated with CAT in solid organ cancer.

RESULTS

A total of 250 solid organ cancer patients were included, with a mean age of 57.7 (13.7) years. This multi-ethnic cohort consisted of mostly Malay patients (55.2%), followed by Chinese (33.2%) and Indian & others (11.6%). The prevalence of CAT at baseline was 4.8%, while the incidence of CAT during follow-up was 12%. Poor performance status and obesity were associated with CAT at baseline. Univariable logistic regression showed platelets ≥ 450 × 109/L and Khorana score ≥ 3 had significantly higher risks of CAT at baseline. Stage IV disease, radiotherapy and chemotherapy, namely platinum-based chemotherapy and antimetabolites were associated with CAT during follow-up. The ROC analysis showed that the KRS significantly predicted CAT (area under the curve, 0.701 (95%CI: 0.594-0.808, p = 0.001).

CONCLUSIONS

This study highlights the prevalence of CAT at baseline and the incidence of CAT during follow-up, similar to other studies. Patients' clinical characteristics were associated with CAT at baseline while disease and treatment factors were associated with CAT at follow-up. These findings emphasise the need for targeted thromboprophylaxis in high-risk populations and highlight the importance of risk stratification tools such as the Khorana score for optimal patient management. Future studies involving larger patient cohorts and longer study duration would be beneficial. These findings provide valuable insights to inform clinical decision-making, optimise patient outcomes, and minimise potential risks.

Clinical and genetic markers of vascular toxicity in glioblastoma patients: Insights from NRG Oncology RTOG-0825

BACKGROUND

Glioblastoma (GBM) is an aggressive form of brain cancer in which treatment is associated with toxicities that can result in therapy discontinuation or death. This analysis investigated clinical and genetic markers of vascular toxicities in GBM patients during active treatment.

METHODS

In total, 591 non-Hispanic White GBM patients with clinical data were included in the analysis from NRG RTOG-0825. Genome-wide association studies (GWAS) were performed from genotyped blood samples (N = 367) by occurrence of thrombosis or hypertension (grade ≥ 2). A clinical prediction model was produced for each vascular toxicity. Significant GWAS variants were then added to the clinical model as a single nucleotide polymorphism (SNP)-dose-effect variable to produce the final genetic models.

RESULTS

Thrombosis and hypertension were experienced by 62 (11%) and 59 (10%) patients, respectively. Patients who experienced hypertension displayed improved survival over those without hypertension (median overall survival: 25.72 vs. 15.47 months, p = 0.002). The genetic model of thrombosis included corticosteroid use (odds ratio [OR]: 7.13, p = 0.02), absolute neutrophil count (OR: 1.008, p = 0.19), body surface area (OR: 18.87, p = 0.0008), and SNP-dose effect (3 variants; OR: 3.79, p < 0.0001). The genetic model of hypertension included bevacizumab use (OR: 0.97, p = 0.95) and the SNP-dose effect (6 variants; OR: 4.44, p < 0.0001).

CONCLUSIONS

In this study, germline variants were superior in predicting hypertension than clinical variables alone. Additionally, corticosteroid use was a considerable risk factor for thrombosis. Future investigations should confirm the hazard of corticosteroid use on thrombosis and the impact of bevacizumab in other malignancies after accounting for the genetic risk of hypertension.

Solid Tumors, Liquid Challenges: The Impact of Coagulation Disorders

Coagulation disorders are increasingly recognized as significant complications in patients with solid tumors, affecting morbidity and mortality outcomes. Solid tumors can provoke a hypercoagulable state through the release of pro-coagulant factors, endothelial activation, and inflammation, leading to a heightened risk of coagulation disorders. These coagulation disorders may manifest as venous thromboembolism, arterial thromboembolism, thrombotic microangiopathy, or disseminated intravascular coagulation. These disorders can complicate surgical interventions and impact treatments, including chemotherapy and immunotherapy efficacy, leading to poor outcomes. Understanding the implications of coagulation disorders in solid tumors is essential for optimizing patient management, including identifying high-risk patients, implementing prophylactic measures, elucidating biomarkers for clinical outcomes, and exploring novel therapeutic agents. This review aims to provide insights into the current knowledge surrounding coagulation disorders in solid tumors and their clinical implications.

Validation of clinical risk assessment scores for venous thromboembolism in patients with cancer: a population-based cohort study

BACKGROUND

Guidelines recommend using risk assessment tools to identify ambulatory patients with cancer at high risk of venous thromboembolism (VTE).

OBJECTIVES

We aimed to validate a new cancer-associated thrombosis (CAT) risk score in a population-based healthcare setting.

METHODS

We used healthcare registry data and electronic medical records from the Central Denmark Region to calculate the new CAT risk score and the guideline-recommended Khorana score in patients with a first-time cancer diagnosis who initiated systemic cancer therapy. Patients were followed for 6 months after initiation of therapy. The outcome was any VTE identified through hospital discharge diagnoses. Discrimination was assessed using C statistics.

RESULTS

We included 12 471 patients from 2012 to 2020. Of these, 416 (3.3%) developed VTE. The C statistic was 0.71 (95% CI, 0.68-0.74) for the new CAT score and 0.66 (95% CI, 0.63-0.70) for the Khorana score. The 6-month cumulative VTE incidence was 5.0% in 6175 patients classified as high risk by the new CAT score compared with 1.7% in 6296 patients classified as low risk. The 6-month cumulative VTE incidence was 5.2% in 4263 patients classified as high risk by the Khorana score compared with 2.4% in 8208 patients classified as low risk.

CONCLUSION

The new CAT score had a discriminatory ability similar to that reported in the derivation study. The C statistic was numerically higher than that of the Khorana score. Our findings support the implementation of the new CAT score to identify ambulatory patients with cancer who are at high risk of VTE.

The Vienna CATScore for predicting cancer-associated venous thromboembolism: an external validation across multiple time points

BACKGROUND

Patients with cancer undergoing systemic therapies have a high risk for venous thromboembolism (VTE). Risk assessment models were developed to select high-risk subgroups that might benefit from primary thromboprophylaxis, yet currently available models reportedly underperform in contemporary cancer treatment populations and risk models across multiple time points throughout therapy are not available.

PATIENTS AND METHODS

We, therefore, aimed to validate the Vienna CATScore, a nomogram-based model including tumor type and continuous D-dimer levels, in a prospective cohort study of patients initiating contemporary systemic anticancer therapies. The validity of the model was tested at study inclusion, 3 weeks, and 3 months after start of therapy.

RESULTS

Overall, 598 patients were included [49% women, median age 62 years (interquartile range 53-70 years)]. Most patients had stage IV disease (68.2%). The 6-month cumulative incidence of VTE was 9.2% [95% confidence interval (CI) 6.8% to 11.5%]. The Vienna CATScore demonstrated good discriminatory ability (c-statistics: 0.69, 95% CI 0.61-0.76) at study baseline and across all evaluated time points (c-statistics: 0.68, 95% CI 0.63-0.73). Applying a 6-month predicted VTE risk threshold of 8%, the CATScore effectively distinguished between low- and high-risk groups at study inclusion (7.1% versus 15.1% observed VTE risk, P = 0.004) and across all three time points (6.3% versus 13.6% observed VTE risk, P < 0.001). Assuming a 50% risk reduction with thromboprophylaxis, this threshold resulted in a number needed to treat (NNT) of 13 and 15, respectively, in the high-risk group, while the NNT was 28 and 32, respectively, in the low-risk group.

CONCLUSIONS

This external validation of the Vienna CATScore confirms its effectiveness in predicting VTE risk in the initial months of state-of-the-art systemic anticancer therapies and across multiple time points.

Venous Thromboembolism Incidence and Risk Factors in Patients Undergoing Hematopoietic Stem Cell Transplantation

Malignancy is a well-known risk factor for venous thromboembolism (VTE), and the Khorana risk score is effective for screening patients with solid tumors. However, there is a lack of validated screening tools and established risk factors for patients undergoing hematopoietic stem cell transplantation (HCT). Current literature reports a 2.5% to 8.5% incidence of VTE in HCT recipients. Anticoagulation is difficult to manage post-transplantation, given prolonged thrombocytopenia and the likelihood of bleeding. By identifying risk factors, a predictive model may be developed to prospectively test prophylaxis strategies in patients at the highest risk of a thromboembolic event (TE). This retrospective single-center study evaluated the cumulative incidence of TE at 6 months following allogeneic or autologous HCT in adult subjects undergoing transplantation between March 2014 and December 2019. The study also aimed to identify risk factors for developing a TE, evaluate the time from HCT to TE, and compare 1-year survival following HCT between patients with a TE and those without a TE. In evaluating the incidence of TE, ICD-9 and ICD-10 codes were used to determine cancer diagnosis, TE events occurring up 180 days after HCT, and comorbidities of interest. Each subject was reviewed for data accuracy by a manual retrospective chart review. Statistical tests including the cumulative incidence method with competing risks, Gray's test, and univariate and multivariate Cox proportional hazards models were used to analyze the time to first TE, evaluate risk factors, and assess 1-year survival post-HCT in relation to TEs occurring within 180 days of HCT. Variables examined included age, sex, body mass index, transplant type, hospital length of stay (LOS), history of TE prior to transplantation, active infections, graft-versus-host disease (GVHD), veno-occlusive disorder, cytomegalovirus serostatus, and other factors. The study included 636 evaluable patients; the majority were male (57.9%) and white (68.7%) and had undergone autologous HCT (68.4%). Twenty-nine patients (4.6%) experienced a TE within 180 days post-transplantation. TEs were more common in the allogeneic HCT recipients (n = 13/201; 6.5%) compared to the autologous HCT recipients (n = 16/435; 3.7%; P = .122). The cumulative incidence of TE was higher in patients who developed an active infection compared to those who did not (7.6% versus 3.1%; P = .011). Hospital LOS (hazard ratio [HR], 1.03; 95% confidence interval [CI], 1.0 to 1.06; P = .036) and active infection (HR, 2.34; 95% CI, 1.1 to 4.95; P = .027) were significantly associated with TE in univariate analysis but were not retained in the final multivariate model. There was no difference in 1-year survival between all patients who experienced a TE and those who did not; however, in the autologous HCT group, 1-year survival rate was significantly lower in patients with a TE compared to those without TE (80.4% versus 95.3%; P = .01) (Figure 3C). None of the examined variables, including a history of TE and GVHD, were associated with TE risk. Although the overall incidence of TE in our study was low, many patients received pharmacologic or mechanical prophylaxis, suggesting that such strategies may be effective in mitigating TE risk. Such factors as infection and hospital LOS may further increase TE risk. Providers should continuously monitor for risk factors and signs and symptoms of TE post-transplantation. It is also imperative to consider chemical prophylaxis if counts are recovered during hospitalization.

Prevention and Treatment of Venous Thromboembolism Associated with Amivantamab-Based Therapies in Patients with Lung Cancer-Provisional Clinical Opinion Based on Existing Clinical Practice Guidelines

Improved efficacy has been shown for amivantamab and amivantamab-based combination therapies in patients with epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC) compared to established treatment options in clinical trials. However, a high risk of venous thromboembolism (VTE) was observed in patients treated with amivantamab-based therapies, with considerable differences in VTE risk according to the line of systemic treatment, concomitant treatment with lazertinib, and intravenous vs. subcutaneous amivantamab administration. Based on early reports of high VTE rates, prophylactic anticoagulation has been implemented in ongoing clinical trials for the first 4 months of amivantamab-lazertinib therapy. However, open questions remain concerning the type, dosing, and duration of primary pharmacological thromboprophylaxis in patients treated with amivantamab-based therapies. Therefore, the aim of this clinical opinion piece is to provide provisional guidance on how to mitigate VTE risk in patients treated with amivantamab-based therapies following existing clinical practice guidelines on primary thromboprophylaxis and treatment of VTE in ambulatory patients with cancer.

Insights into Cancer-Associated Thrombosis Leading Towards Ischemic Stroke

Stroke leads to significant disability in most patients, whereas cancer elevates the occurrence of stroke. The incidence of cancer-associated stroke (CAS) is projected to rise as a result of improvements in cancer therapies. Various forms of cancer have been demonstrated to be linked to ischemic stroke. Cancer might influence stroke pathophysiology either directly or through coagulation that creates a hypercoagulative state, in addition to infections. Treatment methods for cancer, including chemotherapy, radiotherapy, and surgery, have all been demonstrated to increase the risk of stroke as well. This review discusses the subtypes, epidemiology, pathophysiology, mechanisms of stroke within cancer patients, biomarkers, and signaling pathways of stroke in cancer while providing vital information on the involved transcription factors, treatment, and management of patients with cancer-associated ischemic stroke. Atherosclerosis, extracellular vesicles (EVs), and signaling biomolecules can also affect CAS. Overall, stroke is a significant and not uncommon complication of cancer, and there is an immediate demand for neurologists and oncologists to create strategies for screening and preventing strokes in cancer patients.

Risk assessment and prevention of cancer-associated venous thromboembolism in ambulatory patients with solid malignancies

Venous thromboembolism remains a major cause of morbidity and mortality among ambulatory cancer patients, necessitating effective risk assessment and prevention strategies. Despite the availability of risk assessment models and guidelines recommending primary thromboprophylaxis with low-molecular-weight heparins or direct oral anticoagulants, the application of these strategies is inconsistent. This review provides an overview of the current state-of-the-art venous thromboembolism risk assessment and thromboprophylaxis in ambulatory patients with cancer, focusing on existing risk assessment models and the latest guideline recommendations. Finally, it summarizes gaps in knowledge, discusses future directions, and highlights recent advances and state-of-the-art research presented at the 2024 International Society on Thrombosis and Haemostasis Congress in Bangkok, Thailand.

Thrombotic Risk Assessment, P-Selectin, and Thromboprophylaxis Use Among, Cancer Patients at the University of Calabar Teaching Hospital, Calabar

Background

Venous thromboembolism is the second leading cause of mortality among cancer patients. The Khorana Risk Assessment Score (KRAS) is widely acknowledged as the most validated tool in this context.

Aim

To assess the thrombotic risk in cancer patients using the modified Khorana Risk Assessment Score, examine the association between modified KRAS and soluble P-selectin levels, and document the utilization of thromboprophylaxis among cancer patients at the University of Calabar Teaching Hospital.

Methods

This was a cross-sectional hospital-based recruiting 100 cancer patients. Seven millilitres of blood were collected for complete blood count and P-selectin assay. Continuous variables were expressed as mean and standard deviation, while categorical variables were summarized using frequencies. Chi-square was employed to compare VTE risk status across genders, different cancer types, and guideline compliance. The significance level was set at 0.05.

Results

Participants age ranged from 19 to 87 years, with a male-to-female ratio of 1:1.6. The most common female cancer was Breast at 40.32% and prostate cancer at 65.79% was the most common in males. Seventy nine percent and 21% of participants had intermediate and high-risk modified KRAS scores respectively. The median level of soluble P-selectin among cancer patients was 23.00 within the interquartile range. Significant associations were observed between cancer types and sex, VTE risk assessment and cancer types, and cancer types and risk score.

Conclusion

The risk of VTE among cancer patients ranges from intermediate to high, going by the modified Khorana risk score irrespective of the P selectin level, with underutilization of thromboprophylaxis. There is little adherence to the Khorana score in our setting, hence the need for greater application and knowledge of this predictive score in clinical practice to improve outcomes and quality of life.

Effect of direct oral anticoagulants compared to enoxaparin on objective response to immune checkpoint inhibitors in patients with lung cancer

INTRODUCTION

A hypoxic tumor microenvironment inhibits the normal functioning of immune cells. Studies have hypothesized that anticoagulants that can penetrate and bind to factor Xa in the tumor microenvironment, can enhance T-cell function and augment immunotherapy activity. This study compared objective response rate and progression-free survival of lung cancer patients on concomitant immunotherapy treated with direct-acting oral anticoagulants versus enoxaparin.

METHODS

This single-center retrospective study included 73 adults with stage-IV lung cancer who received at least two cycles of immunotherapy and one month of anticoagulant therapy with direct-acting oral anticoagulants (Arm A) versus enoxaparin (Arm B) between June 1, 2016, to September 30, 2022. Primary endpoint was objective response rate, and secondary endpoints were rates of complete response, progression-free survival, incidence of thrombotic events, and major bleeding.

RESULTS

Objective response rate at 6 months was 24.5% versus 25% while progression-free survival at 6 months was 54.7% versus 45% in Arm A versus Arm B, respectively. Complete response rates at 6 months were 7.5% in Arm A versus 0% in Arm B. One patient in Arm A and two in Arm B had a recurrent deep vein thrombosis. Nine patients in Arm A and two in Arm B were diagnosed with new deep vein thrombosis. One patient in Arm B was diagnosed with new pulmonary embolism. Two major bleeding events occurred in Arm B.

CONCLUSIONS

Our study suggests a trend toward improved progression-free survival at 6 months with no new safety concerns in lung cancer patients on concurrent immunotherapy and direct-acting oral anticoagulants.

Characterization of thrombosis risk in ambulatory patients with cancer: results of the observational, prospective, multicenter CARTAGO study

BACKGROUND

Venous thromboembolism (VTE) is one of the leading causes of death in patients with cancer. Currently, there is a need to develop an easily applicable risk model that can identify patients who will benefit from receiving primary thromboprophylaxis to reduce the incidence of VTE.

PATIENTS AND METHODS

This was a non-interventional, multicenter, observational, prospective study carried out in 62 Oncology and Hematology services in Spain and Portugal between January 2018 and December 2019. The main objective of the CARTAGO study was to develop a predictive model within a competitive risk framework to assess the risk of VTE in patients with cancer undergoing chemotherapy, biological, or hormonal treatment.

RESULTS

A total of 1596 patients were analyzed. VTE events occurred in 124 (8%) during the 6-month follow-up period (42% of deep vein thrombosis [DVT], 48% of pulmonary embolism [PE], and 10% of both DVT and PE). Four variables were selected for the multivariate predictive model to determine the risk of VTE (tumor type, D-dimer, compression of a vessel by the tumor, and leukocyte count). The 4 variables were associated with an increased risk of VTE (C-statistic, 0.646 [95%CI, 0.620-0.673]). The most significant variables in the internal validation with bootstrapping were the "very high risk" tumors (hazard ratio [HR] 2.032; 95%CI, 1.287-3.211).

CONCLUSION

The CARTAGO model predicts the VTE risk in patients with cancer receiving anticancer therapy in an outpatient setting. This model can easily aid in identifying ambulatory patients who would probably benefit from primary thromboprophylaxis.

Preventative and curative treatment of venous thromboembolic disease in cancer patients

Cancer-associated venous thromboembolism (CAT) is common in patients with cancer and associated with significant morbidity and mortality. The incidence of CAT continues to rise, complicating patient care and burdening healthcare systems. Patients with cancer experiencing VTE face poorer prognoses, making prevention and effective management imperative. This narrative review synthesizes evidence on thromboprophylaxis in ambulatory patients with cancer receiving systemic therapy and acute treatment strategies for CAT. Risk assessment models (e.g., Khorana score) aid in identifying high-risk patients who may benefit from thromboprophylaxis. Pharmacological thromboprophylaxis with low molecular weight heparins (LMWHs) and direct oral anticoagulants (DOACs) has been shown to reduce the risk of CAT without significantly increasing the risk of bleeding complications. However, implementation of risk-based strategies remains limited in clinical practice. For acute CAT management, LMWHs have been the standard of care, but DOACs are increasingly favored due to their convenience and efficacy. However, challenges persist, including bleeding risks and drug interactions. Emerging therapies targeting Factor XI inhibitors present promising alternatives, potentially addressing current limitations in anticoagulation management for CAT.

Circulating Blood Biomarkers and Risk of Venous Thromboembolism in Cancer Patients: A Systematic Review and Meta-Analysis

BACKGROUND

 Cancer patients have an increased risk of venous thromboembolism (VTE). Currently, the availability of highly discriminatory prediction models for VTE in cancer patients is limited. The implementation of biomarkers in prediction models might lead to refined VTE risk prediction. In this systematic review and meta-analysis, we aimed to evaluate candidate biomarkers and their association with cancer-associated VTE.

METHODS

 We searched Medline, EMBASE, and Cochrane Central for studies that evaluated biomarkers in adult cancer patients from inception to September 2022. We included studies reporting on VTE after a cancer diagnosis with biomarker measurements performed at a defined time point. Median/mean differences (for continuous measures) and odds ratios (for dichotomous measures) with 95% confidence intervals were estimated and pooled using random-effects models.

RESULTS

 We included 113 studies in the systematic review. Of these, 50 studies were included in the meta-analysis. We identified two biomarkers at cancer diagnosis (factor VIII and time to peak thrombin), three biomarkers pre-chemotherapy (D-dimer, fibrinogen, and mean platelet volume), and one biomarker preoperatively (platelet count) that had significant median or mean differences. Additionally, we found that hemoglobin <100 g/L and white blood count >11 × 109/L were significantly associated with future VTE risk only when measured at cancer diagnosis. Pre-chemotherapy neutrophil-to-lymphocyte ratio ≥3 and preoperative platelet count ≥400 × 109/L were also found to be associated with future VTE risk.

CONCLUSION

 In conclusion, this study identified nine candidate blood biomarkers that may help in optimizing VTE prediction in cancer patients that should be further explored in future studies.

Venous thromboembolism during neoadjuvant chemotherapy for ovarian cancer

OBJECTIVE

To determine the incidence of venous thromboembolism in patients with advanced epithelial ovarian cancer undergoing neoadjuvant chemotherapy in UK gynecological cancer centers. Secondary outcomes included incidence and timing of venous thromboembolism since cancer presentation, impact on cancer treatment, and mortality.

METHODS

All UK gynecological cancer centers were invited to participate in this multi-center retrospective audit through the British Gynecological Cancer Society. Data were captured on all patients undergoing neoadjuvant chemotherapy for International Federation of Gynecology and Obstetrics (FIGO) stage III/IV epithelial ovarian cancer within a 12-month period during 2021-2022. Patients on anticoagulation prior to cancer presentation were excluded. Patients who were diagnosed with venous thromboembolism between cancer presentation and commencing neoadjuvant chemotherapy were also excluded from our analysis of venous thromboembolism rates from neoadjuvant chemotherapy.

RESULTS

Fourteen UK gynecological cancer centers returned data on 660 eligible patients. The median age was 67 years (range 34-96). In total, 131/660 (19.8%) patients were diagnosed with venous thromboembolism from cancer presentation until discharge following cytoreductive surgery. Between commencing neoadjuvant chemotherapy and post-operative discharge, 65/594 (10.9%) patients developed venous thromboembolism (median 11.3%, IQR 5.9-11.3); 55/594 (9.3%) during neoadjuvant chemotherapy, 10/594 (1.7%) during post-operative admission. There was no significant difference across centers (p=0.47). Of these 65 patients, 44 (68%) were diagnosed with pulmonary embolism and 30 (46%) with deep-vein thrombosis (nine had both), including in major abdominal/pelvic vessels, with 36 (55%) presenting symptomatically and 29 (45%) diagnosed incidentally on imaging. Venous thromboembolism resulted in mortality (n=3/65, 5%), and delays/changes/cancelation of treatment (n=18/65, 28%).

CONCLUSION

Across a large, representative sample of UK gynecological cancer centers, one in five patients undergoing neoadjuvant chemotherapy were diagnosed with a potentially preventable venous thromboembolism, including one in nine diagnosed after commencing chemotherapy. This led to adverse clinical consequences for one third, including delay to oncological treatment and mortality. This high venous thromboembolism rate justifies the consideration of thromboprophylaxis in this patient group.

External validation of the Khorana score for the prediction of venous thromboembolism in cancer patients: A systematic review and meta-analysis

BACKGROUND

Venous thromboembolism is the leading cause of death in cancer patients, second only to tumor progression. The Khorana score is recommended by clinical guidelines for identifying ambulatory cancer patients at high risk of venous thromboembolism during chemotherapy. However, its predictive performance is debated among cancer patients.

OBJECTIVES

To map the applicability of the Khorana score in cancer patients and to assess its predictive performance across various cancer types, providing guidance for clinicians and nurses to use it more appropriately.

DESIGN

Systematic review and meta-analysis.

METHODS

A comprehensive literature search of the electronic database was first conducted on August 30, 2023, and updated on May 20, 2024. Studies examining the Khorana score's predictive performance (including but not limited to the areas under the curve, C-index, and calibration plot) in cancer patients were included. The Prediction Model Risk of Bias Assessment Tool (PROBAST) was applied to evaluate the methodological quality of the included studies. Data synthesis was achieved via random-effects meta-analysis using the R studio software. The subgroup analysis was performed according to the study design, clinical setting, cancer type, anti-cancer treatment stage, and country.

RESULTS

The review incorporated 67 studies, including 58 observational studies and nine randomized controlled trials. All included studies assessed the Khorana score's discrimination, with the C-index ranging from 0.40 to 0.84. The pooled C-index for randomized controlled trials was 0.61 (95 % CI 0.51-0.70), while observational studies showed a pooled C-index of 0.59 (95 % CI 0.57-0.60). Subgroup analyses revealed the pooled C-index for lung cancer, lymphoma, gastrointestinal cancer, and mixed cancer patients as 0.60 (95 % CI 0.53-0.67), 0.56 (95 % CI 0.51-0.61), 0.59 (95 % CI 0.39-0.76), and 0.60 (95 % CI 0.58-0.61), respectively. Inpatient and outpatient settings had the pooled C-index of 0.60 (95 % CI 0.58-0.63) and 0.58 (95 % CI 0.55-0.61), respectively. Calibration was assessed in only four studies. All included studies were identified to have a high risk of bias according to PROBAST.

CONCLUSION

The Khorana score has been widely validated in various types of cancer patients; however, it exhibited poor capability (pooled C-index<0.7) in accurately discriminating VTE risk among most types of cancer patients either in inpatient or outpatient settings. The Khorana score should be used with caution, and high-quality studies are needed to further validate its predictive performance.

REGISTRATION

The protocol for this study is registered with PROSPERO (registration number: CRD42023470320).

Elevated Platelet Aggregation in Patients with Ovarian Cancer: More than Just Increased Platelet Count

Background: Patients with ovarian cancer have high platelet counts, which correlate with disease burden, incidence, and lethality of blood clots (thrombosis). We hypothesized that elevated aggregation is associated with both increased platelet number and altered behavior of platelets in patients with ovarian cancer. Methods: Healthy controls and patients with suspected or diagnosed ovarian cancer were evaluated for complete blood counts. To evaluate the effects of platelet count versus platelet behavior, equal platelet-rich plasma (PRP) volumes versus equal platelet numbers were used in platelet aggregation assays. Arachidonic acid, adenosine diphosphate, and collagen platelet agonists were used to induce aggregation. Volunteers were grouped into healthy controls (23), benign/borderline cases (7), and cancer cases (25 ovarian, 1 colorectal, and 2 endometrial). Results: The rate and amount of platelet aggregation were higher in patients compared to healthy controls regardless of whether the same platelet number or PRP volume was used. Compared to healthy controls, patients with untreated ovarian cancer exhibited high levels of platelet activation markers, P-selectin (27.06 vs. 31.06 ng/mL, p = 0.03), and beta-thromboglobulin (3.073 vs. 4.091 µg/mL, p = 0.02) in their plasma. The significance of the elevation and its correlations with platelet number or PRP volume varied depending on the agonist. Platelet (305.88 vs. 134.12, p < 0.0001) and white blood cell (8.459 vs. 5.395, p < 0.01) counts (×109/L) were elevated pre-chemotherapy and decreased post-chemotherapy, respectively. Conclusions: Elevated platelet aggregation is caused by both altered platelet number and behavior in patients with ovarian cancer. These results support the study of antiplatelet agents for thrombosis prevention in these patients.

How I treat acute venous thromboembolism in patients with brain tumors

ABSTRACT

Venous thromboembolism (VTE) is a common complication in patients with brain tumors. The management of acute VTE is particularly challenging due to an elevated risk of intracranial hemorrhage (ICH). Risk of developing ICH on anticoagulation is influenced by a number of factors including tumor type, recent surgery, concomitant medications, platelet counts, and radiographic features. In patients with a heightened risk for ICH, the benefits of anticoagulation need to be balanced against a likelihood of developing major hemorrhagic complications. Management decisions include whether to administer anticoagulation, at what dose, placement of an inferior vena cava filter, monitoring for development of hemorrhage or progressive thrombus, and escalation of anticoagulant dose. This article discusses the complexities of treating acute VTE in patients with brain tumors and outlines treatment algorithms based on the presence or absence of ICH at the time of VTE diagnosis. Through case-based scenarios, we illustrate our approach to anticoagulation, emphasizing individualized risk assessments and evidence-based practices to optimize treatment outcomes while minimizing the risks of hemorrhagic events in patients with brain tumors.

Primary Prevention of Cancer-Associated Thrombosis: Current Perspectives

Over the past two decades, the incidence of cancer-associated thrombosis (CAT) has increased. It is nowadays a common and often serious complication among patients with cancer. Although medical thromboprophylaxis is recommended for most surgical and nonsurgical cancer patients, it has been infrequently used in ambulatory patients with cancer because of the burden of treatment and concerns about bleeding. However, various risk assessment scores are now available and randomized placebo-controlled trials have established the efficacy of low-molecular-weight heparin or the direct oral Xa inhibitors rivaroxaban and apixaban in ambulatory patients with cancer at high risk of venous thromboembolism (VTE). This review provides an overview of (1) primary thromboprophylaxis in the setting of hospitalized surgical and medical patients, (2) extended thromboprophylaxis after hospital discharge, (3) performance of risk assessment tools for CAT, and (4) primary thromboprophylaxis in ambulatory patients with cancer. The aim is to provide support to physicians in identifying ambulatory patients with cancer at high VTE risk who benefit most from medical thromboprophylaxis according to current recommendations from international guidelines.

External Validation of Risk Scores for Predicting Venous Thromboembolism in Ambulatory Patients with Lung Cancer

BACKGROUND

The purpose of this study was to evaluate the discriminatory capability of the Khorana, PROTECHT, CONKO, and COMPASS-CAT scores in ambulatory patients with lung cancer.

METHODS

This retrospective cohort study included 591 patients with newly diagnosed lung cancer. A symptomatic or incidental VTE occurred in 108 patients.

RESULTS

The Khorana score at a 2-point threshold had a discriminatory capability with an odds ratio (OR) of 1.80 and an AUC of 0.57 for 6 months, and an OR of 1.51 and an AUC of 0.55 for 12 months. The CONKO score at a 2-point threshold had a stronger discriminatory capability for both 6 months and 12 months with ORs of 3.00 and 2.13, and AUCs of 0.63 and 0.59, respectively. Additionally, higher white blood cell counts, higher neutrophil counts, hypoalbuminaemia, and not undergoing lung surgery were related to VTE occurrence (p < 0.05).

CONCLUSIONS

The Khorana score with the 2-point threshold was validated in ambulatory patients with lung cancer, with the results indicating a decline in its discriminatory capability over time (at 12 months vs. 6 months from diagnosis). The CONKO score at the original 2-point threshold showed a stronger discriminatory capability but further validation with a larger sample size is recommended. The identified predictors should be further investigated in future research.

Positive predictive value and sensitivity of cancer-associated venous thromboembolism diagnoses in the Danish National Patient Register

INTRODUCTION

Hospital discharge diagnoses from administrative registries are frequently used in studies of cancer-associated venous thromboembolism, but the validity of International Classification of Diseases (ICD) codes for identifying such events is unknown.

MATERIALS AND METHODS

Using patient samples from the Danish National Patient Register, we calculated positive predictive values (PPV), i.e., the proportion of registered ICD codes, which could be confirmed after manual search of the electronic health record. Sensitivity was estimated in a sample of patients with imaging-verified venous thromboembolism but without prior knowledge about their ICD coding status. Sensitivity was calculated as the proportion of these patients, who were discharged with an ICD code for venous thromboembolism.

RESULTS

The overall PPV of an ICD-10 diagnosis of cancer-associated venous thromboembolism was 75.9 % (95 % confidence interval 71.3-80.0). In subgroups, the PPV was particularly low for recurrent venous thromboembolism (44.2 %), diagnoses in a secondary position (55.7 %), outpatient diagnoses (65.3 %), and diagnoses given at surgical (66.7 %), emergency wards (48.4 %), or via hospices/palliative teams (0 %). The overall sensitivity was 68 %, meaning 32 % of patients with cancer diagnosed in hospital with venous thromboembolism were discharged without any registered ICD code for venous thromboembolism.

CONCLUSIONS

The positive predictive value of an ICD diagnosis of cancer-associated venous thromboembolism in the Danish Patient Register was overall adequate for research purposes, but with notable variation across subgroups. Sensitivity was limited, as 1/3 of patients with venous thromboembolism were discharged without any relevant ICD code. Cautious interpretation of incidence of cancer-associated venous thromboembolism based on administrative register-based data is warranted.

Treating cancer-associated venous thromboembolism: A practical approach

Venous thromboembolism (VTE) is a common and potentially life-threatening complication in patients with cancer. Both cancer and its treatments increase the risk of developing VTE. Specific cancer types and individual patient comorbidities increase the risk of developing cancer-associated VTE, and the risk of bleeding is increased with anticoagulation therapies. The aims of this article are to summarize the latest evidence for treating cancer-associated VTE, discuss the practical considerations involved, and share best practices for VTE treatment in patients with cancer. The article pays particular attention to challenging contexts including patients with brain, lung, gastrointestinal, and genitourinary tumors and those with hematological malignancies. Furthermore, the article summarizes specific clinical scenarios that require additional treatment considerations, including extremes of body weight, nausea and gastrointestinal disturbances, compromised renal function, and anemia, and touches upon the relevance of drug-drug interactions. Historically, vitamin K antagonists and low-molecular-weight heparins (LMWHs) have been used as therapy for cancer-associated VTE. The development of direct oral anticoagulants has provided additional treatment options, which, in certain instances, offer advantages over LMWHs. There are numerous factors that need to be considered when treating cancer-associated VTE, and although various treatment guidelines are helpful, they do not reflect each unique scenario that may arise in clinical practice. This article provides a summary of the latest evidence and a practical approach for treating cancer-associated VTE.

DNA liquid biopsy-based prediction of cancer-associated venous thromboembolism

Cancer-associated venous thromboembolism (VTE) is a major source of oncologic cost, morbidity and mortality. Identifying high-risk patients for prophylactic anticoagulation is challenging and adds to clinician burden. Circulating tumor DNA (ctDNA) sequencing assays ('liquid biopsies') are widely implemented, but their utility for VTE prognostication is unknown. Here we analyzed three plasma sequencing cohorts: a pan-cancer discovery cohort of 4,141 patients with non-small cell lung cancer (NSCLC) or breast, pancreatic and other cancers; a prospective validation cohort consisting of 1,426 patients with the same cancer types; and an international generalizability cohort of 463 patients with advanced NSCLC. ctDNA detection was associated with VTE independent of clinical and radiographic features. A machine learning model trained on liquid biopsy data outperformed previous risk scores (discovery, validation and generalizability c-indices 0.74, 0.73 and 0.67, respectively, versus 0.57, 0.61 and 0.54 for the Khorana score). In real-world data, anticoagulation was associated with lower VTE rates if ctDNA was detected (n = 2,522, adjusted hazard ratio (HR) = 0.50, 95% confidence interval (CI): 0.30-0.81); ctDNA- patients (n = 1,619) did not benefit from anticoagulation (adjusted HR = 0.89, 95% CI: 0.40-2.0). These results provide preliminary evidence that liquid biopsies may improve VTE risk stratification in addition to clinical parameters. Interventional, randomized prospective studies are needed to confirm the clinical utility of liquid biopsies for guiding anticoagulation in patients with cancer.

Venous thromboembolism risk assessment scale for prediction of venous thromboembolism in inpatients with cancer: A meta-analysis

AIMS

This meta-analysis was conducted to evaluate the validity of the Caprini venous thromboembolism (VTE) risk assessment scale in predicting the risk of VTE in inpatients with cancer.

METHODS

Studies relating to the Caprini VTE risk assessment scale were systematically retrieved from the MEDLINE, EMBASE, Web of Science, Cochrane Library, BIOSIS Previews, EBSCOhost, and China National Knowledge Infrastructure (CNKI) databases up to May 1, 2022. Two reviewers independently conducted data extraction and quality evaluation. MetaDisc 1.4 and Stata 15.0 software were used for data analysis.

RESULTS

We included 10 studies with 23,644 subjects in our analyses. The results showed that the pooled sensitivity (SEN) and specificity (SPE) were 0.59 (95 % CI: 0.55 to 0.63) and 0.57 (95 % CI:0.57 to 0.58), respectively; the pooled diagnostic odds ratio (DOR) was 6.05 (95 % CI: 2.70 to 13.58); and the area under the curve (AUC) of the summary receiver operating characteristic (SROC) curve was 0.76. Subgroup analysis was performed according to ethnicity (Chinese or non-Chinese), study design (prospective/retrospective), Caprini RAM version (2005/2009), and cut-off (≤7 or > 7).

CONCLUSION

The Caprini VTE risk assessment scale has a moderate ability to predict VTE in surgical inpatients with cancer, as well as in Western populations; Caprini 2009 has a stronger predictive ability than 2005, and its predictive power is better if the cut-off value is >7. Future studies in clinical practice and specific specialties are needed to explore the optimal cut-off value of different cancers. This will improve our accuracy in understanding the risk of VTE in inpatients and help promote timely and targeted prevention. In turn, this will reduce the incidence of VTE and improve the quality of life of inpatients with cancer.

The risk of venous thromboembolism in primary central nervous system lymphoma: a systematic review and meta-analysis

Primary central nervous system lymphoma (PCNSL) is a rare extranodal lymphoma localized to the central nervous system. Small single-center studies have suggested that patients with PCNSL may be at high risk of venous thromboembolism (VTE). This systematic review aimed to estimate the risk of VTE in patients with PCNSL. A systematic review was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. MEDLINE, Embase, and CINAHL were searched from 1990 to 2022. Prospective and retrospective observational studies as well as clinical trials were included. The primary efficacy outcome was VTE, and the primary safety outcome was major bleeding as defined by the individual studies. After screening 883 studies, 46 studies (3688 patients) with PCNSL were included. Mean age was 62.4 years. Five studies explored the use of thromboprophylaxis (acetyl salicylic acid or anticoagulation [n = 1]) and low-molecular-weight heparin (n = 4). Overall, 420 patients developed VTE (11.4%), including 17 fatal events (4% of all VTE). Two studies that reported on VTE prophylaxis representing 77 patients identified 8 breakthrough VTE events (10.4%). Most studies (n = 34; 74.5%) did not report major bleeding complications. Among studies reporting on bleeding, 174 major bleeding (7.4%) events were reported out of 2361 patients, 3 of which were attributed to thromboprophylaxis. Patients with PCNSL seem to be at high risk of both VTE and bleeding complications. Future clinical trials in this population should routinely collect data on incidence of VTE and bleeding to help clinicians assess the risk-to-benefit ratio of thromboprophylaxis in this high-risk patient population.

Development and Validation of an ICU-Venous Thromboembolism Prediction Model Using Machine Learning Approaches: A Multicenter Study

Purpose

The purpose of this study was to establish and validate machine learning-based models for predicting the risk of venous thromboembolism (VTE) in intensive care unit (ICU) patients.

Patients and Methods

The clinical data of 1494 ICU patients who underwent Doppler ultrasonography or venography between December 2020 and March 2023 were extracted from three tertiary hospitals. The Boruta algorithm was used to screen the essential variables associated with VTE. Five machine learning algorithms were employed: Random Forest (RF), eXtreme Gradient Boosting (XGBoost), Support Vector Machine (SVM), Gradient Boosting Decision Tree (GBDT), and Logistic Regression (LR). Hyperparameter optimization was conducted on the predictive model of the training dataset. The performance in the validation dataset was measured using indicators, including the area under curve (AUC) of the receiver operating characteristic (ROC) curve, specificity, and F1 score. Finally, the optimal model was interpreted using the SHapley Additive exPlanation (SHAP) package.

Results

The incidence of VTE among the ICU patients in this study was 26.04%. We screened 19 crucial features for the risk prediction model development. Among the five models, the RF model performed best, with an AUC of 0.788 (95% CI: 0.738-0.838), an accuracy of 0.759 (95% CI: 0.709-0.809), a sensitivity of 0.633, and a Brier score of 0.166.

Conclusion

A machine learning-based model for prediction of VTE in ICU patients were successfully developed, which could assist clinical medical staff in identifying high-risk populations for VTE in the early stages so that prevention measures can be implemented to reduce the burden on the ICU patients.

Venous thromboembolism in adrenocortical carcinoma: a retrospective analysis

BACKGROUND

Venous thromboembolism (VTE) is a leading cause of death in patients with cancer. Limited data exist about VTE in patients with adrenocortical carcinoma (ACC). The primary objective of this study was to identify the prevalence of VTE in a cohort of patients with ACC. Secondary objectives were to determine the impact of VTE events on overall survival (OS) and to describe the characteristics of VTE in patients with ACC.

PATIENTS AND METHODS

We retrospectively reviewed data from 289 patients with ACC cared for at a major referral center from February 2010 to June 2022.

RESULTS

VTE prevalence was 18.7% (54 events). Thirty patients (55.6%) had pulmonary embolism (PE); 12 patients (22.2%) had deep vein thrombosis (DVT); and 12 patients (22.2%) had both PE and DVT. VTE occurred after ACC diagnosis in 50 patients (92.6%) including 44 patients (88%) with stage 3 or 4 ACC. VTEs were CTCAE grade ≤2 in 32 cases (59.3%), grade 3 in 17 (31.5%), and grade 4 in 2 (3.7%). Thirteen patients (24%) died within 6 months after VTE diagnosis, although there was no statistically significant association between VTE and overall survival.

CONCLUSION

Despite the potential to underestimate the prevalence of VTEs, we found a high frequency of VTE events in patients with ACC. A majority of VTEs occurred in the context of advanced ACC and we observed high short-term mortality. Further studies are needed to validate our findings and investigate mechanisms associated with VTE in ACC.

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

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

Risk assessment models for PICC-related venous thrombosis in adult patients with cancer: A network meta-analysis

OBJECTIVES

This review aims to compare the performance of available risk assessment models (RAMs) for predicting peripherally inserted central catheter-related venous thrombosis (PICC-RVT) in adult patients with cancer.

METHODS

A systematic search was conducted across ten databases from inception to October 20, 2023. Studies were eligible if they compared the accuracy of a RAM to that of another RAM for predicting the risk of PICC-RVT in adult patients with cancer. Two reviewers independently performed the study selection, data extraction and risk of bias assessments. A Bayesian network meta-analysis (NMA) was used to evaluate the performance of the RAMs.

RESULTS

A total of 1931 studies were screened, and 7 studies with 10 RAMs were included in the review. The most widely used RAMs were the Caprini (4 studies), Padua prediction score (3 studies), Autar (3 studies), Michigan risk score (2 studies) and Seeley score (2 studies). The sensitivity, specificity and accuracy varied markedly between the models. Notably, the Caprini score achieved higher sensitivity than 4 RAMs (Wells, Revised Geneva, modified MRS, MRS). The Michigan risk score had greater specificity than did the other 6 RAMs (Caprini, Autar, Padua, Seeley, the novel RAM, Wells). The predictive accuracy of the MRS is significantly greater than that of the Caprini and Autar RAM.

CONCLUSION

The MRS could be the most accurate RAM for identifying patients at high risk of PICC-RVT. However, as limited studies are available, more rigorous studies should be conducted to examine the accuracy of the Michigan risk score for PICC-RVT in different contexts.

A meta-analysis to assess the risk of bleeding and thrombosis following chimeric antigen receptor T-cell therapy: Communication from the ISTH SSC Subcommittee on Hemostasis and Malignancy

BACKGROUND

Chimeric antigen receptor T-cell (CAR T-cell) therapy is increasingly utilized for treatment of hematologic malignancies. Hematologic toxicities including thrombosis and bleeding complications have been reported. Accurate estimates for thrombotic and bleeding outcomes are lacking.

OBJECTIVES

We performed a systematic review and meta-analysis in patients who received CAR T-cell therapy for an underlying hematologic malignancy with the objective to: a) assess the thrombosis and bleeding risk associated with CAR T-cell therapy, b) assess the impact of CRS and ICANS on the risks of thrombosis and bleeding, and c) assess the safety of anticoagulant or antiplatelet use in the period following treatment with CAR T-cell therapy.

METHODS

We searched MEDLINE, EMBASE, and Cochrane CENTRAL up to February 2022 for studies reporting thrombotic or bleeding outcomes in patients receiving CAR T-cell therapy. Pooled event rates were calculated using a random-effects model. We performed subgroup analyses stratified by follow-up duration, CAR T-cell target antigen, and underlying hematologic malignancy.

RESULTS

We included 47 studies with a total of 7040 patients. High heterogeneity between studies precluded reporting of overall pooled rates of thrombotic and bleeding events. In studies with follow-up duration of ≤6 months, the pooled incidence of venous thrombotic events was 2.4% (95% CI, 1.4%-3.4%; I2 = 0%) per patient-month, whereas the rate was 0.1% (95% CI, 0%-0.1%; I2 = 0%) per patient-month for studies with longer follow-up periods (>6 months). The pooled incidences of any bleeding events per patient-month in studies with follow-up duration of ≤6 months and >6 months were 1.9% (95% CI, 0.6%-3.1%; I2 = 78%) and 0.3% (95% CI: 0%-0.8%, I2 = 40%), respectively. Secondary analyses by CAR T-cell target antigen, underlying malignancy, and primary outcome of the studies did not reveal significant differences in the rates of thromboembolism, any bleeding events, or major bleeding events.

CONCLUSION

The risk of both thrombosis and bleeding following CAR T-cell therapy appears to be highest in the initial months following infusion.

Venous and Arterial Thromboembolism in Lung Cancer Patients: A Retrospective Analysis

Background: Patients with lung cancer face an increased incidence of venous (VTE) and arterial (ATE) thromboembolism. Risk factors for thrombosis remain unclear, particularly the impact of the use of immune checkpoint inhibitors (ICIs). We sought to compare the incidence of VTE and ATE in lung cancer patients receiving platinum-based therapy versus those receiving ICIs alone or in combination with chemotherapy and to validate the Khorana risk score for predicting VTE in the era of ICIs. Methods: A retrospective single-institution data analysis of 173 patients diagnosed with locally advanced or metastatic lung cancer at the Jena University hospital between 2015 and 2021. Results: The study revealed a high incidence of VTE (17.9%) and ATE (5.8%). The VTE risk was higher in patients diagnosed with adenocarcinoma (OR 0.29, 95% CI 0.09-0.93) than in patients with other histological types. A prior venous event was associated with an increased risk of recurrent VTE (OR 4.46, 95% CI 1.20-16.63). The incidence of thrombosis under first-line platinum-based chemotherapy did not differ from the incidence under ICIs (p = 0.19). There were no differences in the subgroup of patients who received ICIs alone or combined immunochemotherapy (p = 0.43). The Khorana score failed to predict the risk of VTE correctly. Conclusions: We did not find evidence supporting the theory that ICI therapy (alone or combined) increases the risk of thrombotic events. Adenocarcinoma and a prior history of VTE were strongly associated with an increased risk of VTE. Other scores for thrombotic risk assessment in lung cancer patients should be tested in prospective studies.

Pancreatic Cancer and Venous Thromboembolism

Pancreatic ductal adenocarcinoma (PDAC) accounts for more than 90% of all pancreatic cancers and is the most fatal of all cancers. The treatment response from combination chemotherapies is far from satisfactory and surgery remains the mainstay of curative strategies. These challenges warrant identifying effective treatments for combating this deadly cancer. PDAC tumor progression is associated with the robust activation of the coagulation system. Notably, cancer-associated thrombosis (CAT) is a significant risk factor in PDAC. CAT is a concept whereby cancer cells promote thromboembolism, primarily venous thromboembolism (VTE). Of all cancer types, PDAC is associated with the highest risk of developing VTE. Hypoxia in a PDAC tumor microenvironment also elevates thrombotic risk. Direct oral anticoagulants (DOACs) or low-molecular-weight heparin (LMWH) are used only as thromboprophylaxis in PDAC. However, a precision medicine approach is recommended to determine the precise dose and duration of thromboprophylaxis in clinical setting.

Machine learning in cancer-associated thrombosis: hype or hope in untangling the clot

The goal of machine learning (ML) is to create informative signals and useful tasks by leveraging large datasets to derive computational algorithms. ML has the potential to revolutionize the healthcare industry by boosting productivity, enhancing safe and effective patient care, and lightening the load on clinicians. In addition to gaining mechanistic insights into cancer-associated thrombosis (CAT), ML can be used to improve patient outcomes, streamline healthcare delivery, and spur innovation. Our review paper delves into the present and potential applications of this cutting-edge technology, encompassing three areas: i) computer vision-assisted diagnosis of thromboembolism from radiology data; ii) case detection from electronic health records using natural language processing; iii) algorithms for CAT prediction and risk stratification. The availability of large, well-annotated, high-quality datasets, overfitting, limited generalizability, the risk of propagating inherent bias, and a lack of transparency among patients and clinicians are among the challenges that must be overcome in order to effectively develop ML in the health sector. To guarantee that this powerful instrument can be utilized to maximize innovation in CAT, clinicians can collaborate with stakeholders such as computer scientists, regulatory bodies, and patient groups.

Cancer-associated thrombosis in hematologic malignancies

Patients with hematologic malignancies are often complicated not only by severe bleeding due to thrombocytopenia and disseminated intravascular coagulation but also by thromboembolic events, just like in patients with solid cancers, and these events can negatively impact patient outcomes. Nevertheless, the prevention and treatment of cancer-associated thrombosis (CAT) in hematologic malignancies has not been adequately investigated due to the limited size, heterogeneity, and unique pathophysiology of the patient population. This article summarizes the current understanding, risk factors, prediction models, and optimal prevention and treatment strategies of CAT in hematologic malignancies on a disease-by-disease basis, including acute leukemia, lymphoma, myeloma, and myeloproliferative neoplasms. Specific considerations of novel molecular targeted therapeutics introduced in recent years, such as immunomodulatory drugs and tyrosine kinase inhibitors, are also discussed based on the latest clinical trials.

In Search of the Perfect Thrombosis and Bleeding-Associated Cancer Scale

Thrombosis and bleeding are commonly observed in cancer patients, and their management is crucial for positive patient outcomes. A comprehensive, prophylactic, and therapeutic management of venous thrombosis should focus on identifying the patients who would benefit most from treatment to reduce mortality and minimize the risk of thrombosis recurrence without significantly increasing the risk of bleeding. Existing cancer scales provide valuable information for assessing the overall burden of cancer and guiding treatment decisions, but their ability to predict thrombotic and bleeding events remains limited. With increasing knowledge of the pathophysiology of cancer and the availability of advanced anticancer therapies, new risk factors for cancer-associated thrombosis and bleeding are being identified. In this report, we analyze the current literature and identify new risk factors for venous thrombosis and bleeding which are not included in routinely used risk scores. While some existing cancer scales partially capture the risk of thrombosis and bleeding, there is a need for more specific and accurate scales tailored to these complications. The development of such scales could improve risk stratification, aid in treatment selection, and enhance patient care. Therefore, further research and development of novel cancer scales focused on thrombosis and bleeding are warranted to optimize patient management and outcomes.

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.

Cellular Components Contributing to the Development of Venous Thrombosis in Patients with Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive type of cancer and has a poor prognosis. Patients with PDAC are at high risk of developing thromboembolic events, which is a leading cause of morbidity and mortality following cancer progression. Plasma-derived coagulation is the most studied process in cancer-associated thrombosis. Other blood components, such as platelets, red blood cells, and white blood cells, have been gaining less attention. This narrative review addresses the literature on the role of cellular components in the development of venous thromboembolism (VTE) in patients with PDAC. Blood cells seem to play an important role in the development of VTE. Altered blood cell counts, i.e., leukocytosis, thrombocytosis, and anemia, have been found to associate with VTE risk. Tumor-related activation of leukocytes leads to the release of tissue factor-expressing microvesicles and the formation of neutrophil extracellular traps, initiating coagulation and forming a scaffold for thrombi. Tissue factor-expressing microvesicles are also thought to be released by PDAC cells. PDAC cells have been shown to stimulate platelet activation and aggregation, proposedly via the secretion of podoplanin and mucins. Hypofibrinolysis, partially explained by increased plasminogen activator inhibitor-1 activity, is observed in PDAC. In short, PDAC-associated hypercoagulability is a complex and multifactorial process. A better understanding of cellular contributions to hypercoagulability might lead to the improvement of diagnostic tests to identify PDAC patients at highest risk of VTE.

Incidence of venous thromboembolism and predictive ability of age-adjusted international prognostic index for prediction of venous thromboembolism in Asian patients with diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is one of the malignancies at high risk for the development of venous thromboembolism (VTE). We aimed to evaluate the incidence of VTE and the predictive ability of the age-adjusted international prognostic index (aaIPI) for the prediction of VTE among DLBCL patients. This was a retrospective cohort study including adult patients with newly diagnosed DLBCL. Differences in VTE occurrence within one year after diagnosis of DLBCL were estimated across aaIPI groups using the Kaplan-Meier model, Cox's model, and Gray's model with deaths regarded as competing events. Five hundred and ninety-one newly diagnosed DLBCL patients with a median age of 58 (range 16-93) years were included in this study. At a median follow-up time of 365 (range 2-365) days, VTE events were objectively diagnosed in 32 patients, giving a one-year cumulative incidence of VTE of 5.4% (95% confidence interval [CI], 3.7-7.6). Patients with aaIPI ≥ 2 had a significantly higher risk of VTE than patients with aaIPI < 2 (hazard ratio, 3.5; 95% CI, 1.6-7.8; p = 0.001 based on Cox's model and sub-distribution hazard ratio, 3.0; 95% CI, 1.3-6.7; p = 0.007 using Gray's model). The C-statistic of aaIPI was 0.65 (95% CI, 0.58-0.72). We demonstrated that the incidence of VTE in Asian DLBCL patients was not uncommon. The aaIPI was effective in determining the risk of VTE in DLBCL patients, even when including death as a competing event. aaIPI may be helpful in identifying patients at higher risk of VTE in DLBCL patients.

The association of tumor-expressed REG4, SPINK4 and alpha-1 antitrypsin with cancer-associated thrombosis in colorectal cancer

Novel biomarkers are needed to improve current imperfect risk prediction models for cancer-associated thrombosis (CAT). We recently identified an RNA-sequencing profile that associates with CAT in colorectal cancer (CRC) patients, with REG4, SPINK4, and SERPINA1 as the top-3 upregulated genes at mRNA level. In the current study, we investigated whether protein expression of REG4, SPINK4 and alpha-1 antitrypsin (A1AT, encoded by SERPINA1) in the tumor associated with CAT in an independent cohort of CRC patients. From 418 patients with resected CRC, 18 patients who developed CAT were age, sex, and tumor stage-matched to 18 CRC patients without CAT. Protein expression was detected by immunohistochemical staining and scored blindly by assessing the H-score (percentage positive cells*scoring intensity). The association with CAT was assessed by means of logistic regression, using patients with an H-score below 33 as reference group. The odds ratios (ORs) for developing CAT for patients with A1AThigh, REG4high, SPINK4high tumors were 3.5 (95%CI 0.8-14.5), 2.0 (95%CI 0.5-7.6) and 2.0 (95%CI 0.5-7.4) when compared to A1ATlow, REG4low, SPINK4low, respectively. The OR was increased to 24.0 (95%CI 1.1-505.1) when two proteins were combined (A1AThigh/REG4high). This nested case-control study shows that combined protein expression of A1AT and REG4 associate with CAT in patients with colorectal cancer. Therefore, REG4/A1AT are potential biomarkers to improve the identification of patients with CRC who may benefit from thromboprophylaxis.

Plasma tissue factor activity in lung cancer patients predicts venous thromboembolism and poor overall survival

Background

Biomarkers to identify lung cancer (LC) patients with high risk of venous thromboembolism (VTE) are needed.

Objectives

To evaluate the usefulness of plasma tissue factor activity (TFA) and D-dimer levels for the prediction of VTE and overall survival in patients with LC.

Methods

In a prospective multicenter observational cohort of consecutive LC patients, TFA and D-dimer levels were measured at diagnosis before any cancer treatment (V1) and between 8 and 12 weeks after diagnosis (V2).

Results

Among 302 patients, 38 (12.6%) experienced VTE within the first year after diagnosis. V1-TFA and V1-D-dimer levels were significantly (P = .02) higher in patients who presented VTE within 3 months than in patients without VTE: V1-TFA was 2.02 (25th-75th percentiles, 0.20-4.01) vs 0.49 (0.20-3.09) ng/mL and V1-D-dimer was 1.42 (0.64-4.40) vs 0.69 (0.39-1.53) μg/mL, respectively. Cutoffs of 1.92 ng/mL for TFA and 1.26 μg/mL for D-dimer could discriminate both groups of patients. In multivariate analysis, V1-TFA > 1.92 ng/mL was the only significant predictor of VTE risk at 1 year (hazard ratio, 2.10; 95% CI, 1.06-4.16; P = .03). V2-TFA, quantified in 251 patients, decreased significantly compared with V1-TFA (0.20 vs 0.56 ng/mL, P < .05), but a V2-TFA level > 0.77 ng/mL could predict VTE in the following 3 months. Median overall survival was worse for patients with V1-TFA > 1.92 ng/mL (14.6 vs 23.8 months) and V1-D-dimer > 1.26 μg/mL (13.8 vs 24 months, P < .001).

Conclusion

High plasma TFA levels are associated with the occurrence of VTE within the next 3 months after each visit (V1 or V2) and poor survival.

Models for predicting venous thromboembolism in ambulatory patients with lung cancer: A systematic review and meta-analysis

AIMS

The incidence of venous thromboembolism (VTE) in patients with lung cancer is relatively high, and risk stratification models are vital for the targeted application of thromboprophylaxis. We aimed to review VTE risk prediction models that have been developed in patients with lung cancer and evaluated their performance.

METHODS AND RESULTS

Twenty-four eligible studies involving 123,493 patients were included. The pooled incidence of VTE within 12 months was 11 % (95 % CI 8 %-14 %). With the identified four VTE risk assessment tools, meta-analyses did not show a significant discriminatory capability of stratifying VTE risk for Khorana, PROTECHT and CONKO scores. The pooled sensitivity and specificity of the Khorana score were 24 % (95 % CI 11 %-44 %) and 84 % (95 % CI 73 %-91 %) at the 3-point cut-off, and 43 % (95 % CI 35 %-52 %) and 61 % (95 % CI 52 %-69 %) at the 2-point cut-off. However, a COMPASS-CAT score of ≥ 7 points indicated a significantly high VTE risk, with a RR of 4.68 (95 % CI 1.05-20.80).

CONCLUSIONS

The Khorana score lacked discriminatory capability in identifying patients with lung cancer at high VTE risk, regardless of the cut-off value. The COMPASS-CAT score had better performance, but further validation is needed. The results indicate the need for robust VTE risk assessment tools specifically designed and validated for lung cancer patients. Future research should include relevant biomarkers as important predictors and consider the combined use of risk tools. PROSPERO registration number: CRD42021245907.

Novel Insights in Venous Thromboembolism Risk Assessment Methods in Ambulatory Cancer Patients: From the Guidelines to Clinical Practice

Many cancer patients will experience venous thromboembolism (VTE) at some stage, with the highest rate in the initial period following diagnosis. Novel cancer therapies may further enhance the risk. VTE in a cancer setting is associated with poor prognostic, a decreased quality of life, and high healthcare costs. If thromboprophylaxis in hospitalized cancer patients and perioperative settings is widely accepted in clinical practice and supported by the guidelines, it is not the same situation in ambulatory cancer patient settings. The guidelines do not recommend primary thromboprophylaxis, except in high-risk cases. However, nowadays, risk stratification is still challenging, although many tools have been developed. The Khrorana score remains the most used method, but it has many limits. This narrative review aims to present the current relevant knowledge of VTE risk assessment in ambulatory cancer patients, starting from the guideline recommendations and continuing with the specific risk assessment methods and machine learning models approaches. Biomarkers, genetic, and clinical features were tested alone or in groups. Old and new models used in VTE risk assessment are exposed, underlining their clinical utility. Imaging and biomolecular approaches to VTE screening of outpatients with cancer are also presented, which could help clinical decisions.

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.

The Application of Existing Risk Assessment Models (RAMS) to Predict the Occurrence of Venous Thromboembolic Events among Patients with Classic Hodgkin Lymphoma

Background: A majority of patients included in risk assessment models (RAMs) developed to predict venous thromboembolic events (VTE) in lymphoma were non-Hodgkin lymphoma. Our study aims to evaluate the incidence and predictors of VTE, utilizing different RAMs, in patients with classic Hodgkin lymphoma (cHL) treated with adriamycin, bleomycin, vinblastine, and dacarbazine (ABVD). Methods: Adult patients with cHL, treated and followed at our center, were included. Correlations between different variables, Khorana score, and thrombosis in lymphoma (ThroLy) RAMs with VTE were examined using Fisher's exact test and logistic regression analysis. Results: A total of 321 patients were included, with a median age of 29 (range: 18-83) years. Of them, 169 (52.6%) had advanced-stage disease. Combined modality treatment was given to 169 (52.6%) patients. A total of 52 (16.2%) patients had relapsed or refractory disease. VTE were reported in 15 (4.7%) patients and were mostly during the administration of first-line (n = 8, 53.3%), or salvage chemotherapy (n = 6, 40.0%). There was no correlation between a Khorana score > 2 (p = 0.689) or ThroLy score > 3 (p = 0.335) and VTE. Older age (p = 0.014) and relapsed or refractory disease (p = 0.003) significantly correlated with VTE. Conclusions: VTE are uncommon in cHL. The commonly used RAMs failed to predict VTE. However, older age and relapsed or refractory disease significantly increased this risk.

Cancer-associated thrombosis: What about microRNAs targeting the tissue factor coagulation pathway?

Cancer patients are often diagnosed with venous thromboembolism (VTE), a cardiovascular disease that substantially decreases their quality of life and survival rate. Haemostasis in these patients is deregulated, which is reflected in the common presentation of a blood hypercoagulation state. Despite the inconsistent results, existing evidence suggests that the expression of microRNAs (miRNAs) is deregulated in the context of venous thrombogenesis in the general population. However, few miRNAs are known to be linked to cancer-associated VTE due to the lack of studies with oncological patients. Parallelly, coagulation factor III, also known as tissue factor (TF), tissue factor pathway inhibitor 1 (TFPI1) and tissue factor pathway inhibitor 2 (TFPI2) have been proposed to have a central role in cancer-associated VTE and tumour progression. Yet, contrary to what was expected, the role of miRNAs targeting the TF coagulation pathway (or extrinsic coagulation pathway) is poorly explored in cancer-induced thrombogenesis. In this review, in addition to miRNAs implicated in VTE, TF and TFPI1/2-targeting miRNAs were revised. Future studies should clarify the implications of these non-coding RNAs in tumour coagulome.

Long Non-Coding RNAs: Bridging Cancer-Associated Thrombosis and Clinical Outcome of Ovarian Cancer Patients

Ovarian cancer (OC) and venous thromboembolism (VTE) have a close relationship, in which tumour cells surpass the haemostatic system to drive cancer progression. Long non-coding RNAs (lncRNAs) have been implicated in VTE pathogenesis, yet their roles in cancer-associated thrombosis (CAT) and their prognostic value are unexplored. Understanding how these lncRNAs influence venous thrombogenesis and ovarian tumorigenesis may lead to the identification of valuable biomarkers for VTE and OC management. Thus, this study evaluated the impact of five lncRNAs, namely MALAT1, TUG1, NEAT1, XIST and MEG8, on a cohort of 40 OC patients. Patients who developed VTE after OC diagnosis had worse overall survival compared to their counterparts (log-rank test, p = 0.028). Elevated pre-chemotherapy MEG8 levels in peripheral blood cells (PBCs) predicted VTE after OC diagnosis (Mann-Whitney U test, p = 0.037; Χ2 test, p = 0.033). In opposition, its low levels were linked to a higher risk of OC progression (adjusted hazard ratio (aHR) = 3.00; p = 0.039). Furthermore, low pre-chemotherapy NEAT1 levels in PBCs were associated with a higher risk of death (aHR = 6.25; p = 0.008). As for the remaining lncRNAs, no significant association with VTE incidence, OC progression or related mortality was observed. Future investigation with external validation in larger cohorts is needed to dissect the implications of the evaluated lncRNAs in OC patients.