Venous thromboembolic events in patients with brain metastases: the PICOS score

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.

Risk of intracranial hemorrhage with direct oral anticoagulation versus low molecular weight heparin in the treatment of brain tumor-associated venous thromboembolism: A meta-analysis

OBJECTIVES

Direct oral anticoagulants (DOACs) are effective in treating cancer-related thrombosis and are superior to low molecular weight heparin (LMWH) in terms of efficacy. The effects of DOACs or LMWH on intracranial hemorrhage (ICH) remain uncertain in individuals with brain tumors. We conducted a meta-analysis to compare the frequency of ICH in individuals with brain tumors treated with DOACs or LMWH.

METHODS

Two independent investigators reviewed all studies that compared the frequency of ICH in patients with brain tumors who received DOACs or LMWH. The primary outcome was the incidence of ICH. We used the Mantel-Haenszel method to estimate the combined effect and calculated 95% confidence intervals (CI).

RESULTS

This study encompassed six articles. The results indicated that cohorts treated with DOAC experienced much fewer instances of ICH compared to the LMWH cohorts (relative risk [RR] 0.39; 95% CI 0.23-0.65; P = 0.0003; I2 = 0%). The same effect was observed for the prevalence of major ICH (RR 0.34; 95% CI 0.12-0.97; P = 0.04; I2 = 0%), but there was no difference for fatal ICH. Subgroup analysis indicated that DOACs had a substantially reduced incidence of ICH in primary brain tumors (RR 0.18; 95% CI 0.06-0.50; P = 0.001; I2 = 0%), but had no impact on ICH with secondary brain tumors.

CONCLUSIONS

This meta-analysis showed that DOACs are associated with a lower risk of ICH than LMWH therapy in treating venous thromboembolism associated with brain tumors, especially in patients with primary brain tumors.

Nomogram prediction for the risk of venous thromboembolism in patients with lung cancer

OBJECTIVE

The aim of this study was to establish a nomogram graph model to accurately predict the venous thromboembolism (VTE) risk probability in the general population with lung cancer.

METHODS

Based on data from patients with lung cancer in Chongqing University Cancer Hospital of China, the independent risk factors of VTE were identified by the logistic univariable and multivariable analysis and were integrated to construct a nomogram, which was validated internally. The predictive effectiveness of the nomogram was evaluated by the receiver operating characteristic curve (ROC) and calibration curve.

RESULTS

A total of 3398 lung cancer patients were included for analysis. The nomogram incorporated eleven independent VTE risk factors including karnofsky performance scale (KPS), stage of cancer, varicosity, chronic obstructive pulmonary disease (COPD), central venous catheter (CVC), albumin, prothrombin time (PT), leukocyte counts, epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), dexamethasone, and bevacizumab. The C-index of the nomogram model was 0.843 and 0.791 in the training and validation cohort, respectively, demonstrating good discriminative power. The calibration plots of the nomogram revealed excellent agreement between the predicted and actual probabilities.

CONCLUSIONS

We established and validated a novel nomogram for predicting the risk of VTE in patients with lung cancer. The nomogram model could precisely estimate the VTE risk of individual lung cancer patients and identify high-risk patients who are in need of a specific anticoagulation treatment strategy.

The role of the neurologist in the diagnosis and treatment of brain metastases and carcinomatous meningitis

Traditionally, in the past, most of central nervous system metastases from solid tumors were associated with an advanced phase of the disease needing palliation only, while to date they increasingly develop as an early and/or solitary relapse in patients with the systemic disease under control. This review will cover all the aspects of a modern management of brain and leptomeningeal metastases from diagnosis to the different therapeutic options, either local (surgery, stereotactic radiosurgery, whole-brain radiotherapy with hippocampal avoidance) or systemic. Particular emphasis is reserved to the new-targeted drugs, that allow to target specifically driver molecular alterations. These new compounds pose new problems in terms of monitoring efficacy and adverse events, but increasingly they allow improvement of outcome in comparison to historical controls.

Vascular complications in patients with brain tumors

PURPOSE OF REVIEW

Venous thromboembolism (VTE) and other vascular events are common in patients with brain tumors, but their optimal management is not firmly established, in large part due to the competing risk of intracranial hemorrhage (ICH) in this population.

RECENT FINDINGS

There is conflicting evidence on whether therapeutic anticoagulation increases the risk of ICH in patients with brain tumors, with several metanalysis and retrospective cohort studies showing an increased risk and others showing no differences. Current guidelines recommend anticoagulating brain tumors patients with VTE with either low-molecular weight heparin (LMWH) or direct oral anticoagulants (DOACs), and several retrospective studies have shown the risk of ICH with DOACs is similar or smaller than with LMWH.

SUMMARY

An increased risk of VTE exists in a variety of brain tumor types. Most patients with brain tumors and VTE should receive therapeutic anticoagulation, and recent retrospective evidence supports the use of both LMWH and DOACs as effective and relatively safe in this setting. Patients with brain tumors are also at increased risk of other vascular tumor- or treatment-related complications whose optimal management is unclear.

Brain metastases: A Society for Neuro-Oncology (SNO) consensus review on current management and future directions

Brain metastases occur commonly in patients with advanced solid malignancies. Yet, less is known about brain metastases than cancer-related entities of similar incidence. Advances in oncologic care have heightened the importance of intracranial management. Here, in this consensus review supported by the Society for Neuro-Oncology (SNO), we review the landscape of brain metastases with particular attention to management approaches and ongoing efforts with potential to shape future paradigms of care. Each coauthor carried an area of expertise within the field of brain metastases and initially composed, edited, or reviewed their specific subsection of interest. After each subsection was accordingly written, multiple drafts of the manuscript were circulated to the entire list of authors for group discussion and feedback. The hope is that the these consensus guidelines will accelerate progress in the understanding and management of patients with brain metastases, and highlight key areas in need of further exploration that will lead to dedicated trials and other research investigations designed to advance the field.

Standardization of risk prediction model reporting in cancer-associated thrombosis: Communication from the ISTH SSC subcommittee on hemostasis and malignancy

Since the development of the Khorana score to predict risk of cancer-associated venous thromboembolism (VTE), many modified and de novo risk prediction models (RPMs) have been proposed. Comparison of the prognostic performance across models requires comprehensive reporting and standardized methods for model development, validation and evaluation. To improve the standardization of RPM reporting, the Transparent Reporting of a multivariable prediction model for Individual Prognosis or Diagnosis (TRIPOD) tool was published in 2015. To better understand the quality of reporting and development of RPMs for cancer-associated VTE, we performed a literature search of published RPMs and assessed each model using the TRIPOD checklist. Our results yielded 29 RPMs for which 30 items were evaluated. There was a non-significant (p = 0.15) improvement in reporting of the 30 items in the post-TRIPOD era (81%) versus the pre-TRIPOD era (75%). Of seven items (title, sample size, missing data handling, baseline demographics, methods and results for model performance, and supplemental resources) with the lowest reporting in the pre-TRIPOD era (<70%), there was an average improvement of 22% in the post-TRIPOD era. Only two of the 22 studies published in the post-TRIPOD era acknowledged compliance with TRIPOD. Informed by the results of this assessment, the Scientific and Standardization Committee (SSC) Subcommittee on Hemostasis & Malignancy of the International Society on Thrombosis and Hemostasis (ISTH) advocates for standardization of four key elements of RPMs for cancer-associated VTE: (1) inclusion of the TRIPOD checklist, (2) clear definition of the derivation population, with justification of sample size, (3) clear definition of predictors, and (4) external validation prior to implementation.

Venous Thrombotic Events and Anticoagulation in Brain Tumor Patients

PURPOSE OF REVIEW

Brain tumor patients have a 20-30% risk of venous thromboembolism (VTE), with management complicated by risk of intracranial hemorrhage (ICH). Here we review the epidemiology, pathogenesis, and recommended management of VTE in brain tumors.

RECENT FINDINGS

New risk factors and molecular mechanisms of VTE in brain tumor patients have emerged, including the protective effect of IDH mutation in gliomas and the potential role of podoplanin-mediated platelet aggregation in thrombogenesis in these tumors. Recent studies show that the risk of ICH is not significantly higher in brain tumor patients receiving anticoagulation. Based on systemic cancer trials, direct oral anticoagulants (DOACs) may be a suitable alternative to traditional heparin treatment, but the applicability of these findings to brain tumors is unclear. Anticoagulation is indicated in the treatment of VTE for brain tumor patients, and appears to be reasonably safe; based on retrospective evidence, DOACs may be a reasonable agent.

Risk of major bleeding associated with concomitant use of anticancer drugs and direct oral anticoagulant in patients with cancer and atrial fibrillation

This study evaluated the risk of major bleeding associated with concomitant use of direct oral anticoagulant (DOAC) and anticancer drugs (ACDs), which share metabolic pathways, in patients with atrial fibrillation (AF) and cancer. We performed a retrospective cohort study using Taiwan's National Health Insurance database and included patients with AF and cancer who received DOAC prescriptions from 1 to 2012 to 31 December 2017. The incidence of major bleeding in person-quarters with concomitant use of DOAC and any of 15 ACDs with inhibitory or competitive effects of CYP3A4 or P-gp activity (docetaxel, vinorelbine, methotrexate, irinotecan, etoposide, doxorubicin, cyclophosphamide, imatinib, nilotinib, abiraterone, bicalutamide, tamoxifen, anastrozole, cyclosporine, tacrolimus) was compared with that in person-quarters with DOAC alone. Adjusted incidence-rate differences between DOAC use with and without concurrent ACDs were estimated using Poisson regression models weighted by the inverse probability of treatment. In 13,158 patients with AF and cancer (76.9 ± 8.9 years; male 60%), 1545 major bleeding events occurred during 90,540 DOAC-exposed person-quarters. Concurrent use of DOAC and any of 15 ACDs occurred in only 18% of patients. Compared with use of DOAC alone, concomitant use of DOAC and these ACDs was not associated with an increased risk of major bleeding. Co-medication with DOAC and ACDs with inhibitory or competitive effects on CYP3A4 or P-gp activity was not associated with a higher risk of major bleeding than DOAC alone. Our findings may provide clinicians with confidence regarding the safety of concurrent use of DOAC and ACDs in patients with AF and cancer.

Local blood coagulation drives cancer cell arrest and brain metastasis in a mouse model

Clinically relevant brain metastases (BMs) frequently form in cancer patients, with limited options for effective treatment. Circulating cancer cells must first permanently arrest in brain microvessels to colonize the brain, but the critical factors in this process are not well understood. Here, in vivo multiphoton laser-scanning microscopy of the entire brain metastatic cascade allowed unprecedented insights into how blood clot formation and von Willebrand factor (VWF) deposition determine the arrest of circulating cancer cells and subsequent brain colonization in mice. Clot formation in brain microvessels occurred frequently (>95%) and specifically at intravascularly arrested cancer cells, allowing their long-term arrest. An extensive clot embedded ∼20% of brain-arrested cancer cells, and those were more likely to successfully extravasate and form a macrometastasis. Mechanistically, the generation of tissue factor-mediated thrombin by cancer cells accounted for local activation of plasmatic coagulation in the brain. Thrombin inhibition by treatment with low molecular weight heparin or dabigatran and an anti-VWF antibody prevented clot formation, cancer cell arrest, extravasation, and the formation of brain macrometastases. In contrast, tumor cells were not able to directly activate platelets, and antiplatelet treatments did reduce platelet dispositions at intravascular cancer cells but did not reduce overall formation of BMs. In conclusion, our data show that plasmatic coagulation is activated early by intravascular tumor cells in the brain with subsequent clot formation, which led us to discover a novel and specific mechanism that is crucial for brain colonization. Direct or indirect thrombin and VWF inhibitors emerge as promising drug candidates for trials on prevention of BMs.