Implementation and validation of a risk stratification method at The Ottawa Hospital to guide thromboprophylaxis in ambulatory cancer patients at intermediate-high risk for venous thrombosis

Cancer-Associated Thrombosis: Epidemiology, Pathophysiological Mechanisms, Treatment, and Risk Assessment

Cancer patients represent a growing population with drastically difficult care and a lowered quality of life, especially due to the heightened risk of vast complications. Thus, it is well established so far that one of the most prominent complications in individuals with cancer is venous thromboembolism. Since there are various improved methods for screening and diagnosing cancer and its complications, the incidence of cancer-associated thrombosis has been on the rise in recent years. Therefore, the high mortality and morbidity rates among these patients are not a surprise. Consequently, there is an excruciating need for understanding the mechanisms behind this complex process, as well as the imperative for adequate analysis and application of the most suitable steps for cancer-associated thrombosis prevention. There are various and numerous mechanisms offering potential answers to cancer-associated thrombosis, some of which have already been elucidated in various preclinical and clinical scenarios, yet further and more elaborate studies are crucial to understanding and preventing this complex and harsh clinical entity. This article elaborates on the growing incidence, mortality, morbidity, and risk factors of cancer-associated thrombosis while emphasizing the pathophysiological mechanisms in the light of various types of cancer in patients and summarizes the most novel therapy and prevention guidelines recommendations.

Prediction models for venous thromboembolism in ambulatory adults with pancreatic and gastro-oesophageal cancer: protocol for systematic review and meta-analysis

INTRODUCTION

Venous thromboembolism (VTE) is a common complication of cancer. Pancreatic and gastro-oesophageal cancers are among malignancies that have the highest rates of VTE occurrence. VTE can increase cancer-related morbidity and mortality and disrupt cancer treatment. The risk of VTE can be managed with measures such as using anticoagulant drugs, although the risk of bleeding may be an impeding factor. Therefore, a VTE risk assessment should be performed before the start of anticoagulation in individual patients. Several prediction models have been published, but most of them have low sensitivity and unknown clinical applicability in pancreatic or gastro-oesphageal cancers. We intend to do this systematic review to identify all applicable published predictive models and compare their performance in those types of cancer.

METHODS AND ANALYSIS

All studies in which a prediction model for VTE have been developed, validated or compared using adult ambulatory patients with pancreatic or gastro-oesphageal cancers will be identified and the reported predictive performance indicators will be extracted. Full text peer-reviewed journal articles of observational or experimental studies published in English will be included. Five databases (Medline, EMBASE, Web of Science, CINAHL and Cochrane) will be searched. Two reviewers will independently undertake each of the phases of screening, data extraction and risk of bias assessment. The quality of the selected studies will be assessed using Prediction model Risk Of Bias Assessment Tool. The results from the review will be used for a narrative information synthesis, and if the same models have been validated in multiple studies, meta-analyses will be done to pool the predictive performance measures.

ETHICS AND DISSEMINATION

There is no need for ethics approval because the review will use previously peer-reviewed articles. The results will be published.

PROSPERO REGISTRATION NUMBER

CRD42021253887.

Cancer-associated venous thromboembolism

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

Artificial Intelligence Evidence-Based Current Status and Potential for Lower Limb Vascular Management

Consultation prioritization is fundamental in optimal healthcare management and its performance can be helped by artificial intelligence (AI)-dedicated software and by digital medicine in general. The need for remote consultation has been demonstrated not only in the pandemic-induced lock-down but also in rurality conditions for which access to health centers is constantly limited. The term “AI” indicates the use of a computer to simulate human intellectual behavior with minimal human intervention. AI is based on a “machine learning” process or on an artificial neural network. AI provides accurate diagnostic algorithms and personalized treatments in many fields, including oncology, ophthalmology, traumatology, and dermatology. AI can help vascular specialists in diagnostics of peripheral artery disease, cerebrovascular disease, and deep vein thrombosis by analyzing contrast-enhanced magnetic resonance imaging or ultrasound data and in diagnostics of pulmonary embolism on multi-slice computed angiograms. Automatic methods based on AI may be applied to detect the presence and determine the clinical class of chronic venous disease. Nevertheless, data on using AI in this field are still scarce. In this narrative review, the authors discuss available data on AI implementation in arterial and venous disease diagnostics and care.

Overview of risk assessment models for venous thromboembolism in ambulatory patients with cancer

A B S T R A C T Important progress has been made in the development of risk assessment models (RAM) for the identification of outpatients on anticancer treatment at risk of venous thromboembolism (VTE). Since the breakthrough publication of the original Khorana risk score (KRS) more than 10 years ago, a new generation of KRS-based scores have been developed, including the Vienna Cancer and Thrombosis Study, PROTECHT, CONKO, ONCOTEV, TicOnco and the CATS/MICA score. Among these the CATS/MICA score showed that a simplified score composed of only two calibrated predictors, the type of cancer and the D-dimer levels, offers a user-friendly tool for the evaluation of cancer-associated thrombosis (CAT) risk. The COMPASS-CAT score is the first that introduced a more synthetic approach of risk evaluation by combining cancer-related predictors with patient comorbidity in a score which is designed for the types of cancer frequently seen in the community (i.e. breast, lung colon or ovarian cancers) and has been externally validated in independent studies. The Throly score is registered as part of the same group as it has a similar structure to the COMPASS-CAT score and is applicable in patients with lymphoma. The incorporation of specific biomarkers of hypercoagulability to the RAM for CAT offers the possibility to perform a precision medicine approach in the prevention of CAT. The improvement of RAM for CAT with artificial intelligence methodologies and deep learning techniques is the challenge in the near future.

Venous and Arterial Thromboembolism in Patients With Cancer: JACC: CardioOncology State-of-the-Art Review

Venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, represents a major cause of morbidity and mortality in patients with cancer. Arterial thromboembolism, including myocardial infarction and stroke, is also prevalent. Risk differs in subgroups, with higher rates observed in specific cancers including pancreas, stomach, and multiple myeloma. Thromboprophylaxis is recommended for most patients with active cancer hospitalized for medical illnesses and after major cancer surgery. Outpatient thromboprophylaxis is not routinely recommended, but emerging data suggest that a high-risk population that benefits from pharmacological thromboprophylaxis can be identified using a validated risk tool. Direct oral anticoagulants are emerging as the preferred new option for the treatment of cancer-associated VTE, although low-molecular-weight heparin remains a standard for patients at high bleeding risk. Management of VTE beyond the first 6 months and challenging clinical situations including intracranial metastases and thrombocytopenia require careful management in balancing the benefits and risks of anticoagulation and remain major knowledge gaps in evidence.

Healthcare costs of patients with cancer stratified by Khorana score risk levels

AIMS

Patients with cancer are at high risk of venous thromboembolism (VTE), which entails a high economic burden. The risk of cancer-associated VTE can be assessed using the Khorana score (KS), a validated VTE risk prediction algorithm. This study compared healthcare costs associated with different KS in a population of patients newly diagnosed with cancer.

METHODS

The Optum Clinformatics DataMart database (01/01/2012-09/30/2017) was used to select adult patients with ≥1 hospitalization or ≥2 outpatient claims with a cancer diagnosis (index date) initiated on systemic therapy or radiation therapy. Patients were classified in mutually exclusive cohorts based on KS (i.e. KS = 0, 1, 2 or ≥3). The observation period spanned from index to the earliest among the end of data availability, death, end of insurance coverage, or 12 months.

RESULTS

In total 6,194 patients (KS = 0: 2,488; KS = 1: 2,125; KS = 2: 1,074; KS ≥ 3: 507) were included. On average, patients were aged 68 years, 48-52% were female, and the Quan-Charlson comorbidity index ranged between 1.1 and 1.4. Over the observation period, all-cause total healthcare costs per patient per month (PPPM) were $8,826 (KS = 0), $11,598 (KS = 1), $14,028 (KS = 2), and $16,211 (KS ≥ 3). Using the KS = 0 cohort as a reference, adjusted PPPM costs were $2,506, $4,775, and $6,452 higher in the KS = 1, KS = 2, and KS ≥ 3 cohorts, respectively. Hospitalization and outpatient costs were the main drivers of these differences. Similar results were found for VTE-related costs, which represented 4-11% of the total all-cause cost difference between KS cohorts.

LIMITATIONS

Residual confounders; results may not be generalized to patients with other insurance plans or those who received treatments other than systemic therapy or radiation therapy.

CONCLUSIONS

This real-world analysis found that cancer patients at higher risk of VTE (based on KS) incurred significantly greater all-cause and VTE-related healthcare costs compared with cancer patients at lower risk of VTE.

Prediction and Prevention of Cancer-Associated Thromboembolism

Venous and arterial thromboembolism are prevalent, highly burdensome, and associated with risk of worse outcomes for patients with cancer. Risk for venous thromboembolism (VTE) varies widely across specific cancer subpopulations. The ability to predict risk of cancer-associated VTE is critical because an optimal thromboprophylaxis strategy is best achieved by targeting high-risk patients with cancer and avoiding prophylaxis in patients with cancer at low risk for VTE. A validated risk tool for solid tumors has been available for a decade. Newer tools have focused on specific populations, such as patients with multiple myeloma. Emerging studies continue to optimize risk prediction approaches in patients with cancer. Recent randomized trials have specifically addressed risk-adapted thromboprophylaxis using direct oral anticoagulants, and revised guidelines have included these new data to formulate recommendations for outpatient thromboprophylaxis. Implementation science approaches to enhance use of outpatient prophylaxis in the context of these guideline changes are under way. However, major knowledge gaps remain, including a lack of data for inpatient thromboprophylaxis in the cancer setting and a lack of formal tools for identifying risk of bleeding. This review describes optimal approaches to risk prediction and patient selection for primary pharmacologic thromboprophylaxis of cancer-associated VTE, addresses barriers to implementing these practices, and highlights strategies to overcome them. IMPLICATIONS FOR PRACTICE: Risk for venous thromboembolism (VTE) varies widely among patients with cancer. Individual risk can be determined using validated approaches. Inpatient and postsurgical thromboprophylaxis is more widely accepted. However, most patients with cancer develop VTE in the outpatient setting. Recent randomized trials have demonstrated benefit to risk-adapted outpatient thromboprophylaxis. High-risk patients may therefore be considered for outpatient thromboprophylaxis as recommended by recently updated guidelines. System-wide implementation approaches are necessary to improve compliance with prophylaxis.

Cancer associated thrombosis and mortality in patients with cancer stratified by khorana score risk levels

BACKGROUND

The Khorana score (KS) clinical algorithm is used to predict VTE risk in cancer patients. The study objective was to evaluate VTE and survival rates among patients newly diagnosed with cancer and stratified by KS in a real-world population.

METHODS

Data from the Optum® Clinformatics® DataMart database between 01/01/2012-09/30/2017 was used to identify adults with ≥ 1 hospitalization or ≥ 2 outpatient claims with a cancer diagnosis (index date). Only patients who were initiated on chemotherapy or radiation therapy were included. Patients were classified based on KS (KS = 0, 1, 2 or ≥ 3). Time-to-first VTE and survival were evaluated from the index date to the earliest among end of data availability or insurance coverage, death, or 12 months post-index using Kaplan-Meier (KM) analyses.

RESULTS

A total of 2,488 (KS = 0); 2,125 (KS = 1), 1,074 (KS = 2), and 507 (KS ≥ 3) cancer patients were included. The 12-month KM rates of VTE were 3.1%, 5.4%, 7.9%, and 14.9% (associated median time to VTE of 2.7, 3.0, 1.4, and 1.7 months) among KS = 0, 1, 2, and ≥ 3 cohorts, respectively. Corresponding adjusted hazard ratios (95% CIs) relative to the KS = 0 cohort were 1.72 (1.25-2.38), 2.46 (1.73-3.50), and 4.99 (3.40-7.31) for the KS = 1, 2, and ≥ 3 cohorts, respectively (all P < .001). Regardless of KS, patients with VTE had significantly lower survival rates than those without.

CONCLUSIONS

This real-world claims-based cohort study of newly diagnosed cancer patients showed significantly higher rates of VTE with increased KS, confirming its predictive ability. Moreover, VTE was associated with lower survival rates within each KS cohort.

Progress in the study of cancer-associated venous thromboembolism

OBJECTIVE

Venous thromboembolism is a major cause of morbidity, mortality, and increased medical costs in tumor patients. In the current review, we summarize the progress made in the study of cancer-associated venous thromboembolism.

METHODS

By searching cancer-associated venous thromboembolism-related literature on PubMed, the epidemiology, pathological mechanisms, risk factors, risk prediction models, and prevention and treatment of cancer-associated venous thromboembolism were reviewed.

RESULTS

The pathophysiological mechanisms of cancer-associated venous thromboembolism are multifactorial. Various blood cell counts (such as platelets and white blood cells) and biomarkers (such as D-dimer and sP-selectin) were considered predictors of thrombosis in cancer patients and were incorporated into the venous thromboembolism risk stratification models. Thromboprophylaxis is currently recommended for all hospitalized cancer patients. In addition, outpatient thromboprophylaxis can be used for selected high-risk patients. Low-molecular-weight heparin was the preferred treatment for cancer-associated venous thromboembolism, but some issues arose in the long-term treatment. In this case, direct oral anticoagulants were a treatment option for tumor patients. The efficacy of direct oral anticoagulant in treating cancer patients is not inferior to low-molecular-weight heparin, but is associated with a higher risk of bleeding. Therefore, there were concerns regarding their safety.

CONCLUSION

Since thrombocytopenia, thrombosis recurrence, and bleeding are common in tumor patients, the selection of anticoagulants in this circumstance is a considerable challenge for clinicians.

Successful Model for Guideline Implementation to Prevent Cancer-Associated Thrombosis: Venous Thromboembolism Prevention in the Ambulatory Cancer Clinic

PURPOSE

Guidelines recommend venous thromboembolism (VTE) risk assessment in outpatients with cancer and pharmacologic thromboprophylaxis in selected patients at high risk for VTE. Although validated risk stratification tools are available, < 10% of oncologists use a risk assessment tool, and rates of VTE prophylaxis in high-risk patients are low in practice. We hypothesized that implementation of a systems-based program that uses the electronic health record (EHR) and offers personalized VTE prophylaxis recommendations would increase VTE risk assessment rates in patients initiating outpatient chemotherapy.

PATIENTS AND METHODS

Venous Thromboembolism Prevention in the Ambulatory Cancer Clinic (VTEPACC) was a multidisciplinary program implemented by nurses, oncologists, pharmacists, hematologists, advanced practice providers, and quality partners. We prospectively identified high-risk patients using the Khorana and Protecht scores (≥ 3 points) via an EHR-based risk assessment tool. Patients with a predicted high risk of VTE during treatment were offered a hematology consultation to consider VTE prophylaxis. Results of the consultation were communicated to the treating oncologist, and clinical outcomes were tracked.

RESULTS

A total of 918 outpatients with cancer initiating cancer-directed therapy were evaluated. VTE monthly education rates increased from < 5% before VTEPACC to 81.6% (standard deviation [SD], 11.9; range, 63.6%-97.7%) during the implementation phase and 94.7% (SD, 4.9; range, 82.1%-100%) for the full 2-year postimplementation phase. In the postimplementation phase, 213 patients (23.2%) were identified as being at high risk for developing a VTE. Referrals to hematology were offered to 151 patients (71%), with 141 patients (93%) being assessed and 93.8% receiving VTE prophylaxis.

CONCLUSION

VTEPACC is a successful model for guideline implementation to provide VTE risk assessment and prophylaxis to prevent cancer-associated thrombosis in outpatients. Methods applied can readily translate into practice and overcome the current implementation gaps between guidelines and clinical practice.

Clinical Implementation of Predictive Models Embedded within Electronic Health Record Systems: A Systematic Review

Predictive analytics using electronic health record (EHR) data have rapidly advanced over the last decade. While model performance metrics have improved considerably, best practices for implementing predictive models into clinical settings for point-of-care risk stratification are still evolving. Here, we conducted a systematic review of articles describing predictive models integrated into EHR systems and implemented in clinical practice. We conducted an exhaustive database search and extracted data encompassing multiple facets of implementation. We assessed study quality and level of evidence. We obtained an initial 3393 articles for screening, from which a final set of 44 articles was included for data extraction and analysis. The most common clinical domains of implemented predictive models were related to thrombotic disorders/anticoagulation (25%) and sepsis (16%). The majority of studies were conducted in inpatient academic settings. Implementation challenges included alert fatigue, lack of training, and increased work burden on the care team. Of 32 studies that reported effects on clinical outcomes, 22 (69%) demonstrated improvement after model implementation. Overall, EHR-based predictive models offer promising results for improving clinical outcomes, although several gaps in the literature remain, and most study designs were observational. Future studies using randomized controlled trials may help improve the generalizability of findings.

Debate: Thromboprophylaxis should be considered in all patients with cancer - Yes

Venous thromboembolism (VTE) is a common complication among patients with cancer that is associated with significant morbidity, mortality and health care costs. There is a significant lack of awareness among health care providers and patients leading to delays in seeking medical attention or diagnosis when signs and symptoms of suspected VTE occur as well as underappreciation of potential benefits of different thromboprophylaxis options. Clinical prediction rules (e.g. Khorana risk score) can be used by clinicians to stratify patients according to their underlying risk of VTE. Low-molecular-weight-heparin and direct oral anticoagulants (rivaroxaban and apixaban) have been shown to be safe and effective thromboprophylactic options in this patient population. Health care providers should educate all patients regarding VTE and consider thromboprophylaxis in patients at higher risk of VTE complications. Decisions about thromboprophylaxis should be made with the patients and include a discussion about relative benefits and harms, costs and duration.

Prevention of Venous Thromboembolism in Pancreatic Cancer: Breaking Down a Complex Clinical Dilemma

Venous thromboembolism (VTE) frequently occurs in patients with cancer, and particularly those with pancreatic ductal adenocarcinoma (PDAC). Therapeutic anticoagulation with either low-molecular-weight heparin or a direct oral anticoagulant is clearly beneficial in patients who develop a VTE. However, whether thromboprophylaxis improves patient outcomes remains unclear. Studies assessing this risk show a 10%-25% risk of VTE, with reduction to 5%-10% with thromboprophylaxis but no impact on survival. To aid in the risk stratification of patients, several tools have been developed to identify those at highest risk for a VTE event. However, the clinical application of these risk stratification models has been limited, and most patients, even those at the highest risk, will never have a VTE event. New oral anticoagulants have greatly improved the feasibility of prophylaxis but do show increased risk of bleeding in patients with the underlying gastrointestinal dysfunction frequently found in patients with pancreatic cancer. Recently, several completed clinical trials shed new light on this complicated risk versus benefit decision. Here, we present this recent evidence and discuss important considerations for the clinician in determining whether to initiate thromboprophylaxis in patients with PDAC. IMPLICATIONS FOR PRACTICE: Given the high risk of venous thromboembolism in patients with pancreatic adenocarcinoma (PDAC), whether to initiate prophylactic anticoagulation is a complex clinical decision. This review discusses recent evidence regarding the risk stratification and treatment options for thromboprophylaxis in patients with PDAC, with the goal of providing practicing clinicians with updates on recent developments in the field. This article also highlights important considerations for individualizing the treatment approach for a given patient given the lack of general consensus of uniform recommendations for this patient population.

SEOM clinical guideline of venous thromboembolism (VTE) and cancer (2019)

In 2011, the Spanish Society of Medical Oncology (SEOM) first published a clinical guideline of venous thromboembolism (VTE) and cancer. This guideline was updated in 2014, and since then, multiple studies and clinical trials have changed the landscape of the treatment and prophylaxis of VTE in cancer patients. To incorporate the most recent evidence, including data from direct oral anticoagulants (DOACs) randomized clinical trials, SEOM presents a new update of the guideline.

What's new in the prevention and treatment of cancer-associated thrombosis?

Venous thromboembolism (VTE) is a common complication in ambulatory cancer patients receiving chemotherapy. Current clinical guidelines recommend against the use of routine primary thromboprophylaxis in unselected ambulatory cancer patients. The Khorana score is a risk assessment tool derived and prospectively validated for the identification of cancer patients at high risk of thrombotic complications. Recently, 2 randomized, controlled trials have assessed the use of low-dose direct oral Xa inhibitors, apixaban and rivaroxaban, for the prevention of cancer-associated thrombosis in ambulatory patients at intermediate to high risk of VTE (Khorana score ≥2). Taken together, these trials have shown that low-dose direct oral Xa inhibitors reduce the risk of VTE in this patient population without a significant increase in major bleeding. These results should encourage clinicians to consider the use of primary thromboprophylaxis in ambulatory cancer patients at intermediate to high risk of VTE who do not have any apparent risk factors for bleeding. The direct oral Xa inhibitors have also been assessed in the acute management of cancer-associated thrombosis. Current evidence suggests that these drugs are a convenient, effective, and safe option for the management of acute VTE in many cancer patients. Low-molecular weight heparin, however, may continue to be the treatment of choice depending on the presence of bleeding risk factors, the type of cancer, drug-drug interactions, and patient preferences.

Venous Thromboembolism Prophylaxis and Treatment in Patients With Cancer: ASCO Clinical Practice Guideline Update

PURPOSE

To provide updated recommendations about prophylaxis and treatment of venous thromboembolism (VTE) in patients with cancer.

METHODS

PubMed and the Cochrane Library were searched for randomized controlled trials (RCTs) and meta-analyses of RCTs published from August 1, 2014, through December 4, 2018. ASCO convened an Expert Panel to review the evidence and revise previous recommendations as needed.

RESULTS

The systematic review included 35 publications on VTE prophylaxis and treatment and 18 publications on VTE risk assessment. Two RCTs of direct oral anticoagulants (DOACs) for the treatment of VTE in patients with cancer reported that edoxaban and rivaroxaban are effective but are linked with a higher risk of bleeding compared with low-molecular-weight heparin (LMWH) in patients with GI and potentially genitourinary cancers. Two additional RCTs reported on DOACs for thromboprophylaxis in ambulatory patients with cancer at increased risk of VTE.

RECOMMENDATIONS

Changes to previous recommendations: Clinicians may offer thromboprophylaxis with apixaban, rivaroxaban, or LMWH to selected high-risk outpatients with cancer; rivaroxaban and edoxaban have been added as options for VTE treatment; patients with brain metastases are now addressed in the VTE treatment section; and the recommendation regarding long-term postoperative LMWH has been expanded. Re-affirmed recommendations: Most hospitalized patients with cancer and an acute medical condition require thromboprophylaxis throughout hospitalization. Thromboprophylaxis is not routinely recommended for all outpatients with cancer. Patients undergoing major cancer surgery should receive prophylaxis starting before surgery and continuing for at least 7 to 10 days. Patients with cancer should be periodically assessed for VTE risk, and oncology professionals should provide patient education about the signs and symptoms of VTE.Additional information is available at www.asco.org/supportive-care-guidelines.

Predicting outcomes in patients with cancer and atrial fibrillation

Background:

The role of cancer-specific factors for ischemic stroke and mortality in patients with cancer and atrial fibrillation (AF) is unknown. We evaluated the utility of a previously validated risk tool for venous thromboembolism (VTE) in cancer outpatients [Khorana score (KS)] in predicting stroke and mortality in cancer patients with AF.

Methods:

We conducted a retrospective cohort study of patients with cancer and AF at the Cleveland Clinic from 2008 to 2014. Outcomes, CHADS2, CHA2DS2-VASc, and KS scores were calculated from date of cancer diagnosis. Prognostic factors were identified with Fine and Gray regression (for stroke) or Cox proportional hazards analysis (for mortality).

Results:

The study population comprised 1181 patients. Genitourinary (19%), lung (18%), and gastrointestinal (13%) were the most frequent cancers. Overall, 67% had CHADS2 ⩾ 2, 57% had an intermediate KS (1–2), and 7% high KS (⩾3). Median follow up was 26.5 months (range 0.03–76). At a median of 8.2 months (range 0–61), 45 patients (3.8%) developed a stroke and 418 (35%) died. In multivariable analysis a high KS (HR 4.5, 95% CI 3.2–6.3, p < 0.001) was associated with a quadruple risk of death and every point increase in CHADS2 score had a 20% increased risk of death (HR 1.19, 95% CI 1.1–1.2, p < 0.001). The addition of KS did not improve risk stratification for ischemic stroke to CHADS2.

Conclusion:

In patients with cancer and AF, CHADS2 and CHA2DS2-VASc but not KS were predictive of ischemic stroke. A high KS represented a unique predictor of mortality beyond traditional risk scores.

Implementation of an electronic medical record tool for early detection of deep vein thrombosis in the ambulatory oncology setting

BACKGROUND

Venous thromboembolism (VTE) is a major cause of morbidity, mortality, and hospitalization in cancer patients.

OBJECTIVES

To evaluate the feasibility of an electronic alert to identify and screen at-risk individuals and gather rates of early detection of deep vein thrombosis (DVT).

PATIENTS/METHODS

An alert was built into the electronic medical record based on a validated risk tool (Khorana Score [KS]) and outcomes evaluated in an initial silent phase. The alert functioned in real time to warn physicians of high-risk patients (KS ≥ 3) and suggested lower extremity screening ultrasonography in a subsequent active phase.

RESULTS

Of 194 consecutive patients identified as high risk in the silent phase, 14 (7.2%) developed subsequent DVT or pulmonary embolism (PE) over 90-day follow-up, with a median of 27 days. Mean 90-day emergency room (ER) visits, all-cause admissions, and length of stay (days) for patients with DVT were 1.2, 1.6, and 9.1 compared to 0.89, 0.93, and 5.1 for all patients, respectively. In the active phase, 197 consecutive alerts met inclusion criteria, and 40 patients (20.3%) received a screening ultrasound. Five (12.5%) had a DVT and were started on therapeutic anticoagulation. Of patients with alerts who had screening deferred, 13 (8.3%) were later diagnosed with DVT (median 50.5 days) and 7 (4.5%) with PE.

CONCLUSION

An automated alert may have value in early detection of DVT in high-risk cancer patients leading to earlier intervention, and could potentially prevent VTE-related morbidity.

Apixaban to Prevent Venous Thromboembolism in Patients with Cancer

BACKGROUND

Patients with active cancer have an increased risk of venous thromboembolism, which results in substantial morbidity, mortality, and health care expenditures. The Khorana score (range, 0 to 6, with higher scores indicating a higher risk of venous thromboembolism) has been validated to identify patients with cancer at elevated risk for this complication and may help select those who could benefit from thromboprophylaxis.

METHODS

We conducted a randomized, placebo-controlled, double-blind clinical trial assessing the efficacy and safety of apixaban (2.5 mg twice daily) for thromboprophylaxis in ambulatory patients with cancer who were at intermediate-to-high risk for venous thromboembolism (Khorana score, ≥2) and were initiating chemotherapy. The primary efficacy outcome was objectively documented venous thromboembolism over a follow-up period of 180 days. The main safety outcome was a major bleeding episode.

RESULTS

Of the 574 patients who underwent randomization, 563 were included in the modified intention-to-treat analysis. Venous thromboembolism occurred in 12 of 288 patients (4.2%) in the apixaban group and in 28 of 275 patients (10.2%) in the placebo group (hazard ratio, 0.41; 95% confidence interval [CI], 0.26 to 0.65; P<0.001). In the modified intention-to-treat analysis, major bleeding occurred in 10 patients (3.5%) in the apixaban group and in 5 patients (1.8%) in the placebo group (hazard ratio, 2.00; 95% CI, 1.01 to 3.95; P = 0.046). During the treatment period, major bleeding occurred in 6 patients (2.1%) in the apixaban group and in 3 patients (1.1%) in the placebo group (hazard ratio, 1.89; 95% CI, 0.39 to 9.24).

CONCLUSIONS

Apixaban therapy resulted in a significantly lower rate of venous thromboembolism than did placebo among intermediate-to-high-risk ambulatory patients with cancer who were starting chemotherapy. The rate of major bleeding episodes was higher with apixaban than with placebo. (Funded by the Canadian Institutes of Health Research and Bristol-Myers Squibb-Pfizer Alliance; AVERT ClinicalTrials.gov number, NCT02048865.).

Predicting VTE in Cancer Patients: Candidate Biomarkers and Risk Assessment Models

Risk prediction of chemotherapy-associated venous thromboembolism (VTE) is a compelling challenge in contemporary oncology, as VTE may result in treatment delays, impaired quality of life, and increased mortality. Current guidelines do not recommend thromboprophylaxis for primary prevention, but assessment of the patient's individual risk of VTE prior to chemotherapy is generally advocated. In recent years, efforts have been devoted to building accurate predictive tools for VTE risk assessment in cancer patients. This review focuses on candidate biomarkers and prediction models currently under investigation, considering their advantages and disadvantages, and discussing their diagnostic performance and potential pitfalls.

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

We aimed to evaluate the performance of the Khorana score in predicting venous thromboembolic events in ambulatory cancer patients. Embase and MEDLINE were searched from January 2008 to June 2018 for studies which evaluated the Khorana score. Two authors independently screened studies for eligibility, extracted data, and assessed risk of bias. Additional data on the 6-month incidence of venous thromboembolism were sought by contacting corresponding authors. The incidence in each Khorana score risk group was estimated with random effects meta-analysis. A total of 45 articles and eight abstracts were included, comprising 55 cohorts enrolling 34,555 ambulatory cancer patients. For 27,849 patients (81%), 6-month follow-up data were obtained. Overall, 19% of patients had a Khorana score of 0 points, 64% a score of 1 or 2 points, and 17% a score of 3 or more points. The incidence of venous thromboembolism in the first six months was 5.0% (95%CI: 3.9-6.5) in patients with a low-risk Khorana score (0 points), 6.6% (95%CI: 5.6-7.7) in those with an intermediate-risk Khorana score (1 or 2 points), and 11.0% (95%CI: 8.8-13.8) in those with a high-risk Khorana score (3 points or higher). Of the patients with venous thromboembolism in the first six months, 23.4% (95%CI: 18.4-29.4) had been classified as high risk according to the Khorana score. In conclusion, the Khorana score can be used to select ambulatory cancer patients at high risk of venous thromboembolism for thromboprophylaxis; however, most events occur outside this high-risk group.

Risk prediction of cancer-associated thrombosis: Appraising the first decade and developing the future

Cancer-associated venous thromboembolism (VTE) has major consequences for patients, including morbidity and risk of mortality. However, there is substantial variation in risk depending on a multitude of clinical risk factors and many cancer patients are at low risk for VTE. This critical concept of risk variation has led to efforts to identify patients at high or low risk for developing VTE. Our research group and others have focused on understanding and predicting risk of cancer-associated VTE. This narrative review describe research efforts conducted over the past decade, beginning with the 2008 publication of the first validated risk assessment tool in this setting. We describe current applications of the "Khorana score" including identification of high- and low-risk patients, selecting and excluding patients for thromboprophylaxis and screening high-risk patients for early detection of VTE. New approaches to risk prediction including precision medicine and next-generation sequencing are discussed. Finally, we offer suggestions on improving the field of risk prediction in this setting in the near future.

Clinical Predictors of Early Mortality in Colorectal Cancer Patients Undergoing Chemotherapy: Results From a Global Prospective Cohort Study

Background

Early mortality is a major problem in colorectal cancer (CRC). We have shown that Khorana Score is predictive of early mortality in other cancers. Here, we evaluated the value of this score and other prognostic variables in predicting early mortality in CRC.

Methods

CANTARISK was a prospective, noninterventional, global cohort study in patients with CRC initiating a new chemotherapy regimen. Data were collected at zero, two, four, and six months. Early mortality was defined as death within six months of enrollment. All data were compiled centrally and analyzed after the study closed. Statistically significant univariate associations were tested in multivariable models; adjusted odds ratios (ORs) are presented. Statistical tests were two-sided.

Results

From 2011 to 2012, 1789 CRC patients were enrolled. The median age was 62 years; 71% were Caucasian. One-third (35%) had a rectal primary, and 65% had metastatic disease. There were 184 (10.3%) patients who died during their first six months in the study. For low, intermediate, and high Khorana Score, there were 8.1%, 11.2% and 32.5% deaths, respectively. In multivariable analyses, Khorana Score was an independent predictor of early death (OR for high/intermediate vs low score = 1.70, P = .0027), in addition to age (OR for each incremental year = 1.03, P = .0014), presence of metastatic disease (OR = 3.28, P < .0001), and Easter Cooperative Oncology Group Performance Status Score of 2 or higher (OR = 3.85, P < .0001).

Conclusions

This study demonstrates that Khorana Score is predictive of early mortality in CRC patients. Intermediate- or high-risk patients, as defined by this score, may benefit from additional interventions aimed at reducing early mortality.

IQCA-TAVV: To explore the effect of P-selectin, GPIIb/IIIa, IL-2, IL-6 and IL-8 on deep venous thrombosis

Deep vein thrombosis (DVT) associates with considerable morbidity, functional disability and mortality. Due to the lack of suitable inhibitor the correlation of various factors in DVT onset remains unknown. In this context we analyzed the structure of anti-platelet aggregation agent, P-selectin down-regulator, GPIIb/IIIa down-regulator and anti-inflammatory agent, thereby designed N-(3S-1,2,3,4-tetrahydroisoquinoline-3-carbonyl)- Thr-Ala-Arg-Gly-Asp(Val)-Val (IQCA-TAVV) as an inhibitor of DVT to receive evaluations. The docking predicted that IQCA-TAVV can target P-selectin and GPIIb/IIIa. The UV showed that IQCA-TAVV can act on P-selectin and GPIIb/IIIa. ELISA indicated that IQCA-TAVV concentration dependently inhibited activated platelets to express P-selectin and GPIIb/IIIa, and the minimal effective concentration was 1 nM. IC50 of IQCA-TAVV against platelet aggregation induced by arachidonic acid, adenosine diphosphate and platelet activating factor fell within a range of 0.13 nM to 0.30 nM. In vivo IQCA-TAVV dose-dependently inhibited venous thrombosis and the minimal effective dose was 1 nmol/kg. On ear edema model the anti-inflammation activity of 10 nmol/kg IQCA-TAVV equaled that of 1.1mmol/kg aspirin. The concentration of IL-2, IL-6 and IL-8 in the serum of the ear edema mice were also significantly decreased by 10 nmol/kg IQCA-TAVV. Even at 1 μmol/kg of dose IQCA-TAVV still did not injure the kidney, the liver, and the nerves of healthy mice. Thereby IQCA-TAVV depicts a relationship of three levels (inhibiting platelet activation, targeting externalized membrane receptor, decreasing serum inflammatory factor) for the down-regulation of P-selectin, GPIIb/IIIa, IL-2, IL-6 and IL-8 in DVT.

Rivaroxaban for Preventing Venous Thromboembolism in High-Risk Ambulatory Patients with Cancer: Rationale and Design of the CASSINI Trial. Rationale and Design of the CASSINI Trial

Venous thromboembolism (VTE) is a frequent complication of cancer associated with morbidity, mortality, increased hospitalizations and higher health care costs. Cancer patients at increased risk for VTE can be identified using a validated risk assessment score, and the incidence of VTE can be reduced in high-risk settings using anticoagulation. Rivaroxaban is a potent, oral, direct, factor Xa inhibitor approved for the prevention and treatment of thromboembolic events, including VTE. CASSINI is a double-blind, randomized, parallel-group, multicentre study comparing rivaroxaban with placebo in adult ambulatory patients with various cancers who are initiating systemic cancer therapy and are at high risk of VTE (Khorana score ≥ 2). Patients with primary brain tumours or those at risk for bleeding are excluded. Approximately 700 patients will be randomized 1:1 to rivaroxaban 10 mg daily or placebo for up to 6 months if there is no evidence of VTE from compression ultrasonography (CU) during screening or from routine care imaging within 30 days prior to randomization. Mandatory CU will also be performed at weeks 8 and 16 (±7 days), and at study end (±3 days). The primary efficacy hypothesis is that anticoagulation with rivaroxaban reduces the composite of objectively confirmed symptomatic or asymptomatic, lower-extremity, proximal deep-vein thrombosis (DVT); symptomatic, upper-extremity DVT; symptomatic or incidental pulmonary embolism; and VTE-related death compared with placebo. The primary safety objective is to assess major bleeding events (Clinical trial information: NCT02555878).

Predicting risk of venous thromboembolism in hospitalized cancer patients: Utility of a risk assessment tool

Inpatient venous thromboembolism (VTE) is a priority preventable illness; risk in cancer varies and prophylaxis is inconsistently used. A previously validated tool (Khorana Score, [KS]) identifies VTE risk in cancer outpatients with 5 easily available variables but has not been studied in the inpatient setting. We evaluated the validity of KS in predicting VTE risk in hospitalized cancer patients. We conducted a retrospective cohort study of consecutive oncology inpatients at the Cleveland Clinic from 11/2012 to 12/2014 (n = 3531). Patients were excluded for VTE on admission (n = 304), incomplete KS data (n = 439) or other reasons (n = 8). Data collected included demographics, cancer type, length of stay (LOS), anticoagulant use, and laboratory values. Multivariate risk factors were identified with stepwise logistic regression, confirmed with bootstrap analysis. Of 2780 patients included, 106 (3.8%) developed VTE during hospitalization. Median age was 62 (range, 19-98) years and 56% were male. Median LOS was 5 (range, 0-152) days. High risk KS (≥ 3) was significantly associated with VTE in uni- and multivariate analyses (OR 2.5, 95% [confidence interval] CI 1.3-4.9). Other significant variables included male gender (OR 1.67, 1.1-2.53), older age (OR 0.86, 0.75-0.99) and use of anticoagulants (OR 0.57, 0.39-0.85). Recursive partitioning analysis suggested optimal cut point for KS is 2 (OR 1.82, 1.23-2.69). This is the first report validating KS as a risk tool to predict VTE in hospitalized cancer patients. Using this tool could lead to more consistent and successful application of inpatient thromboprophylaxis.

Cancer and Venous Thromboembolic Disease: A Review

Venous thromboembolism (VTE), including deep-vein thrombosis and pulmonary embolism, represents a major cause of morbidity and mortality in cancer patients. Patients with cancer are six times more likely to develop VTE than their noncancer counterparts, and VTE is the second leading cause of death in cancer patients. Despite the publication of major consensus guidelines setting out recommendations for thromboprophylaxis in cancer patients, there remains a gulf between these guidelines and clinical practice. In general, thromboprophylaxis is recommended for most patients hospitalized with active cancer. Furthermore, outpatient thromboprophylaxis may be used in carefully selected high-risk ambulatory patients. Certain areas of controversy still remain. Although low-molecular-weight heparin has been shown to be superior to vitamin K antagonists in cancer patients, the role of direct oral anticoagulants is still uncertain. Moreover, recurrent thromboembolism, bleeding, and thrombocytopenia are frequently seen in cancer patients. Optimal anticoagulation in such instances presents a major challenge to clinicians. Modern computed tomography techniques have resulted in an increase in the detection of "incidental" VTE. Despite a growing body of evidence promulgating standard anticoagulant treatment in such cases, these cases present further challenges for members of the multidisciplinary team. The Oncologist 2017;22:199-207Implications for Practice: This article discusses venous thromboembolism (VTE) in patients with malignancy. Practical guidance is offered on how to prevent, diagnose, and treat VTE in cancer patients. The management of "challenging" cases of VTE is also discussed.

Primary prophylaxis of VTE in cancer outpatients

Cancer patients have a significantly higher risk of developing venous thromboembolism (VTE) compared to non-cancer patients and several studies suggest that VTE risk among ambulatory cancer patients varies widely. Recently, predictive models capable of risk-stratifying a broad range of ambulatory cancer outpatients have been developed and validated; using the Khorana model a score of 2 is associated with an intermediate-high risk for VTE. However, the use of VTE prophylaxis in ambulatory patients who have cancer remains controversial. Even if important randomized clinical trials showed decreased rates of VTE events among patients who were receiving chemotherapy, the effect of prophylaxis on morbidity, mortality, and costs has not been rigorously studied. Outpatients with active cancer should be assessed for thrombosis risk and although most do not routinely require thromboprophylaxis, it should be considered for high risk patients.

Risk Assessment for Venous Thromboembolism in Chemotherapy-Treated Ambulatory Cancer Patients

OBJECTIVE

To design a precision medicine approach aimed at exploiting significant patterns in data, in order to produce venous thromboembolism (VTE) risk predictors for cancer outpatients that might be of advantage over the currently recommended model (Khorana score).

DESIGN

Multiple kernel learning (MKL) based on support vector machines and random optimization (RO) models were used to produce VTE risk predictors (referred to as machine learning [ML]-RO) yielding the best classification performance over a training (3-fold cross-validation) and testing set.

RESULTS

Attributes of the patient data set ( n = 1179) were clustered into 9 groups according to clinical significance. Our analysis produced 6 ML-RO models in the training set, which yielded better likelihood ratios (LRs) than baseline models. Of interest, the most significant LRs were observed in 2 ML-RO approaches not including the Khorana score (ML-RO-2: positive likelihood ratio [+LR] = 1.68, negative likelihood ratio [-LR] = 0.24; ML-RO-3: +LR = 1.64, -LR = 0.37). The enhanced performance of ML-RO approaches over the Khorana score was further confirmed by the analysis of the areas under the Precision-Recall curve (AUCPR), and the approaches were superior in the ML-RO approaches (best performances: ML-RO-2: AUCPR = 0.212; ML-RO-3-K: AUCPR = 0.146) compared with the Khorana score (AUCPR = 0.096). Of interest, the best-fitting model was ML-RO-2, in which blood lipids and body mass index/performance status retained the strongest weights, with a weaker association with tumor site/stage and drugs.

CONCLUSIONS

Although the monocentric validation of the presented predictors might represent a limitation, these results demonstrate that a model based on MKL and RO may represent a novel methodological approach to derive VTE risk classifiers. Moreover, this study highlights the advantages of optimizing the relative importance of groups of clinical attributes in the selection of VTE risk predictors.