Anticoagulation for people with cancer and central venous catheters

THromboprophylaxis In Sickle Cell Disease with central venous catheters (THIS): an internal pilot randomised controlled trial protocol

INTRODUCTION

Individuals with sickle cell disease (SCD) and central venous catheters (CVC) are at high risk for venous thromboembolism (VTE). Minimal data exist regarding the use of anticoagulation as thromboprophylaxis of VTE in this demographic, and as a result, clinical equipoise exists. Prophylactic dose rivaroxaban, a direct oral anticoagulant, is efficacious and safe as thromboprophylaxis in other demographics, and may be an optimal agent in SCD with CVC. Prior to conducting a full clinical trial to assess rivaroxaban as thromboprophylaxis in SCD with CVC, a pilot study is needed to gauge its feasibility.

METHODS AND ANALYSIS

THromboprophylaxis In Sickle Cell Disease pilot trial is an investigator-initiated, multicentre, double-blinded, randomised controlled trial (RCT) assessing if it is feasible and safe to conduct an adequately powered RCT comparing rivaroxaban to matching placebo as thromboprophylaxis in those with SCD and CVC. Fifty adult patients with SCD and CVC will be randomised to receive either rivaroxaban 10 mg daily or matching placebo for the duration of the CVC in situ for up to 1 year. After randomisation, follow-up visits will occur every 3 months. The primary outcomes pertain to the feasibility of a full trial and include numbers of eligible and recruited participants. Exploratory outcomes include overall incidence of VTE and bleeding complications, as well as quality of life. If the full trial is feasible, blinding will be maintained and patients in the pilot study will be included in the full trial.

ETHICS AND DISSEMINATION

The trial was initially approved by the University Health Network Research Ethics Board (REB) in Toronto, Canada. All sites will obtain approval from their respective REB prior to commencement of study activities. Study results will be disseminated through presentations at medical conferences and peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT05033314.

Cancer-Associated Thrombosis: Trends in Clinical Features, Treatment, and Outcomes From 2001 to 2020

Background

Despite advances in cancer and venous thromboembolism (VTE) management, the epidemiology of cancer-associated thrombosis management over time remains unclear.

Objectives

We analyzed data from the RIETE (Registro Informatizado de la Enfermedad Trombo Embólica) registry spanning 2001 to 2020 to investigate temporal trends in clinical characteristics and treatments for cancer-associated thrombosis.

Methods

Using multivariable survival regression, we examined temporal trends in risk-adjusted rates of symptomatic VTE recurrences, major bleeding, and death within 30 days after incident VTE.

Results

Among the 17,271 patients with cancer-associated thrombosis, there was a progressive increase in patients presenting with pulmonary embolism (from 44% in 2001-2005 to 55% in 2016-2020; P < 0.001 for trend), lung (from 12.7% to 18.1%; P < 0.001) or pancreatic cancer (from 3.8% to 5.6%; P = 0.003), and utilization of immunotherapy (from 0% to 7.4%; P < 0.001). Conversely, there was a decline in patients with prostate cancer (from 11.7% to 6.6%; P < 0.001) or carcinoma of unknown origin (from 3.5% to 0.7%; P < 0.001). At the 30-day follow-up, a reduction was observed in the proportion of patients experiencing symptomatic VTE recurrences (from 3.1% to 1.1%; P < 0.001), major bleeding (from 3.1% to 2.2%; P = 0.004), and death (from 11.9% to 8.4%; P < 0.001). Multivariable analyses revealed a decreased risk over time for VTE recurrence (adjusted subdistribution HR [asHR]: 0.94 per year; 95% CI: 0.92-0.98), major bleeding (asHR: 0.98; 95% CI: 0.96-0.99), and death (aHR: 0.97; 95% CI: 0.96-0.98).

Conclusions

In this multicenter study of cancer patients with VTE, there was a decline in thrombotic, hemorrhagic, and fatal events from 2001 to 2020. (Registro Informatizado de la Enfermedad Trombo Embólica [RIETE]; NCT02832245).

Published trends and research hotspots of central venous catheter-associated thrombosis from 1973 to 2022: A scientometric analysis

This study aims to explore the intellectual landscape and research hotspots in the central venous catheter-related thrombosis (CVC-RT) research field. Studies discussing CVC-RT published from 1973 to 2022 in the Web of Science Core Collection database were retrieved on February 24th, 2022. Citespace was used to perform a scientometric analysis to identify the intellectual landscape and research hotspots in the research fields of CVC-RT. A total of 4358 studies were retrieved, with an ascending trend in publication numbers. The United States of America was the most influential country. The Journal of Vascular Access published the most studies, and McMaster University was the most prolific institution. The results showed that the focus population of CVC-RT research has changed from pediatric patients to cancer patients, the management of CVC-RT has become more formal and standardized, and the focused CVC type has shifted to port and peripherally inserted central catheters. In addition, seventeen active burst keywords were detected, such as patient safety, clinical practice guidelines, and postthrombotic syndrome. This study comprehensively reviewed publications related to CVC-RT. The research topics on patient safety, clinical practice guidelines, and postthrombotic syndrome related to CVC-RT may be future hotspots.

Catheter-related thrombosis (CRT) in patients with solid tumors: a narrative review and clinical guidance for daily care

Central venous access devices (CVADs) including central venous catheters and peripherally inserted central catheters (PICCs) are essential in the treatment of cancer. Catheter-related thrombosis (CRT) is the most frequent non-infectious complication associated with the use of central lines. The development of CRT may cause to delays in oncologic treatment and increase morbidity leading to potentially life-threatening complications. Several local and systemic risk factors are associated with the development of CRT and should be taken into account to prevent CRT by standardizing appropriate catheter placement and maintenance. The use of primary pharmacological thromboprophylaxis in order to avoid CRT is not routinely recommended, although it can be considered in selected cases. Recommendations for the management of established CRT are based on the extrapolation of anticoagulation for lower limb venous thrombosis. The present review summarizes the current evidence and recommendations for the prevention and management of CRT and identifies areas that require further research.

Factors affecting mechanical complications of central venous access devices in children

PURPOSE

Factors leading to mechanical complications following insertion of central venous access devices (CVADs) in children are poorly understood. We aimed to quantify the rates and elucidate the mechanisms of these complications.

METHODS

Retrospective (2016-2021) review of children (< 18 years old) receiving a CVAD. Data, reported as number of cases (%) and median (IQR), were analysed by Fisher's exact test, chi-squared test and logistic regression analysis.

RESULTS

In total, 317 CVADs (245 children) were inserted. Median age was 5.0 (8.9) years, with 116 (47%) females. There were 226 (71%) implantable port devices and 91 (29%) Hickman lines. Overall, 54 (17%) lines had a mechanical complication after 0.4 (0.83) years from insertion: fracture 19 (6%), CVAD migration 14 (4.4%), occlusion 14 (4.4%), port displacement 6 (1.9%), and skin tethering to port device 1 (0.3%). Younger age and lower weight were associated with higher risk of complications (p < 0.0001). Hickman lines had a higher incidence of complications compared to implantable port devices [24/91 (26.3%) vs 30/226 (13.3%); p = 0.008].

CONCLUSION

Mechanical complications occur in 17% of CVADs at a median of < 6 months after insertion. Risk factors include younger age and lower weight. Implantable port devices have a lower complications rate.

LEVEL OF EVIDENCE

Level 4: case-series with no comparison group.

Standardized procedure prevents perioperative and early complications in totally implantable venous-access ports-a complication analysis of more than 1000 TIVAP implantations

PURPOSE

Since their invention 40 years ago, totally implantable venous-access ports (TIVAPs) have become indispensable in cancer treatment. The aim of our study was to analyze complications under standardized operative and perioperative procedures and to identify risk factors for premature port catheter explantation.

METHODS

A total of 1008 consecutive TIVAP implantations were studied for success rate, perioperative, early, and late complications. Surgical, clinical, and demographic factors were analyzed as potential risk factors for emergency port catheter explantation.

RESULTS

Successful surgical TIVAP implantation was achieved in 1005/1008 (99.7%) cases. No intraoperative or perioperative complications occurred. A total of 32 early complications and 88 late complications were observed leading to explantation in 11/32 (34.4%) and 34/88 (38.6%) cases, respectively. The most common complications were infections in 4.7% followed by thrombosis in 3.6%. Parameters that correlated with unplanned TIVAP explantation were gender (port in situ: female 95% vs. male 91%, p = 0.01), underlying disease (breast cancer 97% vs. gastrointestinal 89%, p = 0.004), indication (chemotherapy 95% vs. combination of chemotherapy and parenteral nutrition 64%, p < 0.0001), and type of complication (infection 13.4% vs. TIVAP-related complication 54% and thrombosis 95%, p < 0.0001).

CONCLUSION

Standardized operative and perioperative TIVAP implantation procedures provide excellent results and low explantation rate.

Prevention of venous thromboembolism in hematologic neoplasms: an expert consensus from SEHH-SETH

Venous thromboembolism (VTE) is a serious complication in hematologic neoplasms, so finding adequate prevention strategies is an urgent requirement. However, prospective studies with large enough cohorts are scarce, limiting the development of evidence-based thromboprophylaxis guidelines. The present position paper is addressed to all hematologists treating patients affected by hematologic neoplasms with the aim to provide clinicians with a useful tool for the prevention of VTE.

Central catheter-associated deep vein thrombosis in cancer: clinical course, prophylaxis, treatment

The adequate handling of central venous catheters is a key element in the management of patients with cancer. Catheter-associated deep vein thrombosis is frequently observed in patients with malignant diseases; however, despite being a common complication among these patients, objective information concerning its epidemiology, clinical course, prophylaxis and treatment strategies is very limited. The reported incidence of catheter-related thrombosis (CRT) is highly variable, depending on symptomatic events, or if patients are screened for asymptomatic thrombosis. Several factors have been identified as potential predisposing factors for CRT, both technical and pathological aspects. The anticoagulant of choice is still unclear; while low-molecular-weight heparin is most commonly used, recent studies assessing the role of direct oral anticoagulants in the treatment of CRT show promise as an alternative, but the evidence remains insufficient and the decision must be made on a case-by-case basis.

Current Recommendations for the Management of Cancer-Associated Venous Thromboembolism

Cancer-associated thrombosis (CAT) is a major cause of death in oncological patients. The mechanisms of thrombogenesis in cancer patients are not fully established, and it seems to be multifactorial in origin. Also, several risk factors for venous thromboembolism (VTE) are present in these patients such as tumor site, stage, histology of cancer, chemotherapy, surgery, and immobilization. Anticoagulant treatment in CAT is challenging because of high bleeding risk during treatment and recurrence of VTE. Current major guidelines recommend low molecular weight heparins (LMWHs) for early and long-term treatment of VTE in cancer patients. In the past years, direct oral anticoagulants (DOACs) are recommended as potential treatment option for VTE and have recently been proposed as a new option for treating CAT. This manuscript will give a short overview of risk factors involved in the development of CAT and a summary on the recent recommendations and guidelines for treatment of VTE in patients with malignancies, discussing also some special clinical situations (e.g. renal impairment, catheter-related thrombosis, and thrombocytopenia).

Primary Thromboprophylaxis in Patients with Malignancies: Daily Practice Recommendations by the Hemostasis Working Party of the German Society of Hematology and Medical Oncology (DGHO), the Society of Thrombosis and Hemostasis Research (GTH), and the Austrian Society of Hematology and Oncology (ÖGHO)

Patients with cancer, both hematologic and solid malignancies, are at increased risk for thrombosis and thromboembolism. In addition to general risk factors such as immobility and major surgery, shared by non-cancer patients, cancer patients are exposed to specific thrombotic risk factors. These include, among other factors, cancer-induced hypercoagulation, and chemotherapy-mediated endothelial dysfunction as well as tumor-cell-derived microparticles. After an episode of thrombosis in a cancer patient, secondary thromboprophylaxis to prevent recurrent thromboembolism has long been established and is typically continued as long as the cancer is active or actively treated. On the other hand, primary prophylaxis, even though firmly established in hospitalized cancer patients, has only recently been studied in ambulatory patients. This recent change is mostly due to the emergence of direct oral anticoagulants (DOACs). DOACs have a shorter half-life than vitamin K antagonists (VKA), and they overcome the need for parenteral application, the latter of which is associated with low-molecular-weight heparins (LMWH) and can be difficult for the patient to endure in the long term. Here, first, we discuss the clinical trials of primary thromboprophylaxis in the population of cancer patients in general, including the use of VKA, LMWH, and DOACs, and the potential drug interactions with pre-existing medications that need to be taken into account. Second, we focus on special situations in cancer patients where primary prophylactic anticoagulation should be considered, including myeloma, major surgery, indwelling catheters, or immobilization, concomitant diseases such as renal insufficiency, liver disease, or thrombophilia, as well as situations with a high bleeding risk, particularly thrombocytopenia, and specific drugs that may require primary thromboprophylaxis. We provide a novel algorithm intended to aid specialists but also family practitioners and nurses who care for cancer patients in the decision process of primary thromboprophylaxis in the individual patient.

Updated recommendations for the treatment of venous thromboembolism

Venous thromboembolism (VTE), which includes pulmonary embolism and deep vein thrombosis, is a condition characterized by abnormal blood clot formation in the pulmonary arteries and the deep venous vasculature. It is often serious and sometimes even fatal if not promptly and appropriately treated. Moreover, the later consequences of VTE may result in reduced quality of life. The treatment of VTE depends on various factors, including the type, cause, and patient comorbidities. Furthermore, bleeding may occur as a side effect of VTE treatment. Thus, it is necessary to carefully weigh the benefits versus the risks of VTE treatment and to actively monitor patients undergoing treatment. Asian populations are known to have lower VTE incidences than Western populations, but recent studies have shown an increase in the incidence of VTE in Asia. A variety of treatment options are currently available owing to the introduction of direct oral anticoagulants. The current VTE treatment recommendation is based on evidence from previous studies, but it should be applied with careful consideration of the racial, genetic, and social characteristics in the Korean population.

American Society of Hematology 2021 guidelines for management of venous thromboembolism: prevention and treatment in patients with cancer

BACKGROUND

Venous thromboembolism (VTE) is a common complication among patients with cancer. Patients with cancer and VTE are at a markedly increased risk for morbidity and mortality.

OBJECTIVE

These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in their decisions about the prevention and treatment of VTE in patients with cancer.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The guideline development process was supported by updated or new systematic evidence reviews. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to assess evidence and make recommendations.

RESULTS

Recommendations address mechanical and pharmacological prophylaxis in hospitalized medical patients with cancer, those undergoing a surgical procedure, and ambulatory patients receiving cancer chemotherapy. The recommendations also address the use of anticoagulation for the initial, short-term, and long-term treatment of VTE in patients with cancer.

CONCLUSIONS

Strong recommendations include not using thromboprophylaxis in ambulatory patients receiving cancer chemotherapy at low risk of VTE and to use low-molecular-weight heparin (LMWH) for initial treatment of VTE in patients with cancer. Conditional recommendations include using thromboprophylaxis in hospitalized medical patients with cancer, LMWH or fondaparinux for surgical patients with cancer, LMWH or direct oral anticoagulants (DOAC) in ambulatory patients with cancer receiving systemic therapy at high risk of VTE and LMWH or DOAC for initial treatment of VTE, DOAC for the short-term treatment of VTE, and LMWH or DOAC for the long-term treatment of VTE in patients with cancer.

Long-Term Follow-Up and Clinical Relevance of Incidental Findings of Fibrin Sheath and Thrombosis on Computed Tomography Scans of Cancer Patients with Port Catheters

Purpose

This retrospective study examined the incidence, progression, and clinical relevance of catheter-related thrombosis (CRT) and/or fibrin sheaths presenting as incidental findings on routine staging computed tomography (CT) scans performed in cancer patients.

Patients and Methods

Patients who underwent central venous port catheter (CVC) placement in a tertiary care hospital between September 2010 and August 2013 were followed up for up to five years. Two radiologists assessed the presence of fibrin sheath and thrombosis in consensus in staging CT scan. Patient demographics, type of cancer, preoperative comorbidities, date of CVC placement and CTs, preexisting anticoagulation, as well as the type and treatment of catheter-related complications were determined from the electronic medical record.

Results

A total of 194 patients with 530 CT scans and a mean follow-up time of 394 days were included. Fibrin sheaths and thromboses were seen on 46 scans (8.7%) in 30 patients and 80 scans (15.1%) in 35 patients. The incidence of fibrin sheaths and thromboses was found to be 15.5% and 18%, respectively. The comparison to initial CT reports results indicated that fibrin sheaths or thromboses were missed in 106 examinations (20%). Catheter-associated complications were reported in 14 patients (21.5%) without specific therapy.

Conclusion

Fibrin sheaths and CRTs are often overlooked on routine CT scans when patients are asymptomatic. The subsequent high complication rate demonstrates the clinical relevance of the initial incidental finding on CT scan. Further studies should elucidate the effect of thrombolytic agents and interventional radiologic treatment in asymptomatic patients.

Incidence, prognostic factors, and outcomes of venous thromboembolism in critically ill patients: data from two prospective cohort studies

Background

The objective of this study was to describe the prevalence, incidence, prognostic factors, and outcomes of venous thromboembolism in critically ill patients receiving contemporary thrombosis prophylaxis.

Methods

We conducted a pooled analysis of two prospective cohort studies. The outcomes of interest were in-hospital pulmonary embolism or lower extremity deep vein thrombosis (PE-LDVT), in-hospital nonleg deep vein thrombosis (NLDVT), and 90-day mortality. Multivariable logistic regression analysis was used to evaluate the association between predefined baseline prognostic factors and PE-LDVT or NLDVT. Cox regression analysis was used to evaluate the association between PE-LDVT or NLDVT and 90-day mortality.

Results

A total of 2208 patients were included. The prevalence of any venous thromboembolism during 3 months before ICU admission was 3.6% (95% CI 2.8–4.4%). Out of 2166 patients, 47 (2.2%; 95% CI 1.6–2.9%) developed PE-LDVT and 38 patients (1.8%; 95% CI 1.2–2.4%) developed NLDVT. Renal replacement therapy (OR 3.5 95% CI 1.4–8.6), respiratory failure (OR 2.0; 95% CI 1.1–3.8), and previous VTE (OR 3.6; 95% CI 1.7–7.7) were associated with PE-LDVT. Central venous catheters (OR 5.4; 95% CI 1.7–17.8) and infection (OR 2.2; 95% CI 1.1–4.3) were associated with NLDVT. Occurrence of PE-LDVT but not NLDVT was associated with increased 90-day mortality (HR 2.7; 95% CI 1.6–4.6, respectively, 0.92; 95% CI 0.41–2.1).

Conclusion

Thrombotic events are common in critically ill patients, both before and after ICU admittance. Development of PE-LDVT but not NLDVT was associated with increased mortality. Prognostic factors for developing PE-LDVT or NLDVT despite prophylaxis can be identified at ICU admission and may be used to select patients at higher risk in future randomized clinical trials.

Trial registration

NCT03773939.

Primary prophylaxis for venous thromboembolism in ambulatory cancer patients receiving chemotherapy

BACKGROUND

Venous thromboembolism (VTE) often complicates the clinical course of cancer. The risk is further increased by chemotherapy, but the trade-off between safety and efficacy of primary thromboprophylaxis in cancer patients treated with chemotherapy is uncertain. This is the third update of a review first published in February 2012.

OBJECTIVES

To assess the efficacy and safety of primary thromboprophylaxis for VTE in ambulatory cancer patients receiving chemotherapy compared with placebo or no thromboprophylaxis, or an active control intervention.

SEARCH METHODS

For this update, the Cochrane Vascular Information Specialist searched the Cochrane Vascular, CENTRAL, MEDLINE, Embase and CINAHL databases and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 3 August 2020. We also searched the reference lists of identified studies and contacted content experts and trialists for relevant references.

SELECTION CRITERIA

Randomised controlled trials comparing any oral or parenteral anticoagulant or mechanical intervention to no thromboprophylaxis or placebo, or comparing two different anticoagulants.

DATA COLLECTION AND ANALYSIS

We extracted data on risk of bias, participant characteristics, interventions, and outcomes including symptomatic VTE and major bleeding as the primary effectiveness and safety outcomes, respectively. We applied GRADE to assess the certainty of evidence.

MAIN RESULTS

We identified six additional randomised controlled trials (3326 participants) for this update, bringing the included study total to 32 (15,678 participants), all evaluating pharmacological interventions and performed mainly in people with locally advanced or metastatic cancer. The certainty of the evidence ranged from high to very low across the different outcomes and comparisons. The main limiting factors were imprecision and risk of bias. Thromboprophylaxis with direct oral anticoagulants (direct factor Xa inhibitors apixaban and rivaroxaban) may decrease the incidence of symptomatic VTE (risk ratio (RR) 0.43, 95% confidence interval (CI) 0.18 to 1.06; 3 studies, 1526 participants; low-certainty evidence); and probably increases the risk of major bleeding compared with placebo (RR 1.74, 95% CI 0.82 to 3.68; 3 studies, 1494 participants; moderate-certainty evidence). When compared with no thromboprophylaxis, low-molecular-weight heparin (LMWH) reduced the incidence of symptomatic VTE (RR 0.62, 95% CI 0.46 to 0.83; 11 studies, 3931 participants; high-certainty evidence); and probably increased the risk of major bleeding events (RR 1.63, 95% CI 1.12 to 2.35; 15 studies, 7282 participants; moderate-certainty evidence). In participants with multiple myeloma, LMWH resulted in lower symptomatic VTE compared with the vitamin K antagonist warfarin (RR 0.33, 95% CI 0.14 to 0.83; 1 study, 439 participants; high-certainty evidence), while LMWH probably lowers symptomatic VTE more than aspirin (RR 0.51, 95% CI 0.22 to 1.17; 2 studies, 781 participants; moderate-certainty evidence). Major bleeding was observed in none of the participants with multiple myeloma treated with LMWH or warfarin and in less than 1% of those treated with aspirin. Only one study evaluated unfractionated heparin against no thromboprophylaxis, but did not report on VTE or major bleeding. When compared with placebo or no thromboprophylaxis, warfarin may importantly reduce symptomatic VTE (RR 0.15, 95% CI 0.02 to 1.20; 1 study, 311 participants; low-certainty evidence) and may result in a large increase in major bleeding (RR 3.82, 95% CI 0.97 to 15.04; 4 studies, 994 participants; low-certainty evidence). One study evaluated antithrombin versus no antithrombin in children. This study did not report on symptomatic VTE but did report any VTE (symptomatic and incidental VTE). The effect of antithrombin on any VTE and major bleeding is uncertain (any VTE: RR 0.84, 95% CI 0.41 to 1.73; major bleeding: RR 0.78, 95% CI 0.03 to 18.57; 1 study, 85 participants; very low-certainty evidence).

AUTHORS' CONCLUSIONS

In ambulatory cancer patients, primary thromboprophylaxis with direct factor Xa inhibitors may reduce the incidence of symptomatic VTE (low-certainty evidence) and probably increases the risk of major bleeding (moderate-certainty evidence) when compared with placebo. LMWH decreases the incidence of symptomatic VTE (high-certainty evidence), but increases the risk of major bleeding (moderate-certainty evidence) when compared with placebo or no thromboprophylaxis. Evidence for the use of thromboprophylaxis with anticoagulants other than direct factor Xa inhibitors and LMWH is limited. More studies are warranted to evaluate the efficacy and safety of primary prophylaxis in specific types of chemotherapeutic agents and types of cancer, such as gastrointestinal or genitourinary cancer.

Development and Validation of a New Clinical Prediction Model of Catheter-Related Thrombosis Based on Vascular Ultrasound Diagnosis in Cancer Patients

Background: Central venous catheters are convenient for drug delivery and improved comfort for cancer patients, but they also cause serious complications. The most common complication is catheter-related thrombosis (CRT). Objectives: This study aimed to evaluate the incidence and risk factors for CRT in cancer patients and develop an effective prediction model for CRT in cancer patients. Methods: The development of our prediction model was based on a retrospective cohort (n = 3,131) from the National Cancer Center. Our prediction model was confirmed in a prospective cohort from the National Cancer Center (n = 685) and a retrospective cohort from the Hunan Cancer Hospital (n = 61). The predictive accuracy and discriminative ability were determined by receiver operating characteristic (ROC) curves and calibration plots. Results: Multivariate analysis demonstrated that sex, cancer type, catheter type, position of the catheter tip, chemotherapy status, and antiplatelet/anticoagulation status at baseline were independent risk factors for CRT. The area under the ROC curve of our prediction model was 0.741 (CI: 0.715-0.766) in the primary cohort and 0.754 (CI: 0.704-0.803) and 0.658 (CI: 0.470-0.845) in validation cohorts 1 and 2, respectively. The model also showed good calibration and clinical impact in the primary and validation cohorts. Conclusions: Our model is a novel prediction tool for CRT risk that accurately assigns cancer patients into high- and low-risk groups. Our model will be valuable for clinicians when making decisions regarding thromboprophylaxis.

Prophylaxis of thromboembolism during therapy with asparaginase in adults with acute lymphoblastic leukaemia

BACKGROUND

The risk of venous thromboembolism is increased in adults and enhanced by asparaginase-based chemotherapy, and venous thromboembolism introduces a secondary risk of treatment delay and premature discontinuation of key anti-leukaemic agents, potentially compromising survival. Yet, the trade-off between benefits and harms of primary thromboprophylaxis in adults with acute lymphoblastic leukaemia (ALL) treated according to asparaginase-based regimens is uncertain.  OBJECTIVES: The primary objectives were to assess the benefits and harms of primary thromboprophylaxis for first-time symptomatic venous thromboembolism in adults with ALL receiving asparaginase-based therapy compared with placebo or no thromboprophylaxis. The secondary objectives were to compare the benefits and harms of different groups of primary systemic thromboprophylaxis by stratifying the main results per type of drug (heparins, vitamin K antagonists, synthetic pentasaccharides, parenteral direct thrombin inhibitors, direct oral anticoagulants, and blood-derived products for antithrombin substitution).

SEARCH METHODS

We conducted a comprehensive literature search on 02 June 2020, with no language restrictions, including (1) electronic searches of Pubmed/MEDLINE; Embase/Ovid; Scopus/Elsevier; Web of Science Core Collection/Clarivate Analytics; and Cochrane Central Register of Controlled Trials (CENTRAL) and (2) handsearches of (i) reference lists of identified studies and related reviews; (ii) clinical trials registries (ClinicalTrials.gov registry; the International Standard Randomized Controlled Trial Number (ISRCTN) registry; the World Health Organisation's International Clinical Trials Registry Platform (ICTRP); and pharmaceutical manufacturers of asparaginase including Servier, Takeda, Jazz Pharmaceuticals, Ohara Pharmaceuticals, and Kyowa Pharmaceuticals), and (iii) conference proceedings (from the annual meetings of the American Society of Hematology (ASH); the European Haematology Association (EHA); the American Society of Clinical Oncology (ASCO); and the International Society on Thrombosis and Haemostasis (ISTH)). We conducted all searches from 1970 (the time of introduction of asparaginase in ALL treatment). We contacted the authors of relevant studies to identify any unpublished material, missing data, or information regarding ongoing studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs); including quasi-randomised, controlled clinical, cross-over, and cluster-randomised trial designs) comparing any parenteral/oral preemptive anticoagulant or mechanical intervention with placebo or no thromboprophylaxis, or comparing two different pre-emptive anticoagulant interventions in adults aged at least 18 years with ALL treated according to asparaginase-based chemotherapy regimens. For the description of harms, non-randomised observational studies with a control group were eligible for inclusion.  DATA COLLECTION AND ANALYSIS: Using a standardised data collection form, two review authors independently screened and selected studies, extracted data, assessed risk of bias for each outcome using standardised tools (RoB 2.0 tool for RCTs and ROBINS-I tool for non-randomised studies) and the certainty of evidence for each outcome using the GRADE approach. Primary outcomes included first-time symptomatic venous thromboembolism, all-cause mortality, and major bleeding. Secondary outcomes included asymptomatic venous thromboembolism, venous thromboembolism-related mortality, adverse events (i.e. clinically relevant non-major bleeding and heparin-induced thrombocytopenia for trials using heparins), and quality of life. Analyses were performed according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions. For non-randomised studies, we evaluated all studies (including studies judged to be at critical risk of bias in at least one of the ROBINS-I domains) in a sensitivity analysis exploring confounding.  MAIN RESULTS: We identified 23 non-randomised studies that met the inclusion criteria of this review, of which 10 studies provided no outcome data for adults with ALL. We included the remaining 13 studies in the 'Risk of bias' assessment, in which we identified invalid control group definition in two studies and judged outcomes of nine studies to be at critical risk of bias in at least one of the ROBINS-I domains and outcomes of two studies at serious risk of bias. We did not assess the benefits of thromboprophylaxis, as no RCTs were included. In the main descriptive analysis of harms, we included two retrospective non-randomised studies with outcomes judged to be at serious risk of bias. One study evaluated antithrombin concentrates compared to no antithrombin concentrates. We are uncertain whether antithrombin concentrates have an effect on all-cause mortality (risk ratio (RR) 0.55, 95% confidence interval (CI) 0.26 to 1.19 (intention-to-treat analysis); one study, 40 participants; very low certainty of evidence). We are uncertain whether antithrombin concentrates have an effect on venous thromboembolism-related mortality (RR 0.10, 95% CI 0.01 to 1.94 (intention-to-treat analysis); one study, 40 participants; very low certainty of evidence). We do not know whether antithrombin concentrates have an effect on major bleeding, clinically relevant non-major bleeding, and quality of life in adults with ALL treated with asparaginase-based chemotherapy, as data were insufficient. The remaining study (224 participants) evaluated prophylaxis with low-molecular-weight heparin versus no prophylaxis. However, this study reported insufficient data regarding harms including all-cause mortality, major bleeding, venous thromboembolism-related mortality, clinically relevant non-major bleeding, heparin-induced thrombocytopenia, and quality of life. In the sensitivity analysis of harms, exploring the effect of confounding, we also included nine non-randomised studies with outcomes judged to be at critical risk of bias primarily due to uncontrolled confounding. Three studies (179 participants) evaluated the effect of antithrombin concentrates and six studies (1224 participants) evaluated the effect of prophylaxis with different types of heparins. When analysing all-cause mortality; venous thromboembolism-related mortality; and major bleeding (studies of heparin only) including all studies with extractable outcomes for each comparison (antithrombin and low-molecular-weight heparin), we observed small study sizes; few events; wide CIs crossing the line of no effect; and substantial heterogeneity by visual inspection of the forest plots. Although the observed heterogeneity could arise through the inclusion of a small number of studies with differences in participants; interventions; and outcome assessments, the likelihood that bias due to uncontrolled confounding was the cause of heterogeneity is inevitable. Subgroup analyses were not possible due to insufficient data.  AUTHORS' CONCLUSIONS: We do not know from the currently available evidence, if thromboprophylaxis used for adults with ALL treated according to asparaginase-based regimens is associated with clinically appreciable benefits and acceptable harms. The existing research on this question is solely of non-randomised design, seriously to critically confounded, and underpowered with substantial imprecision. Any estimates of effect based on the existing insufficient evidence is very uncertain and is likely to change with future research.

Central Venous Catheter Thrombosis in Cancer: A Multi-Centre Retrospective Study Investigating Risk Factors and Contemporary Trends in Management

Objectives:

Central venous access is needed to facilitate chemotherapy for many cancer patients. Central venous catheter-related thrombosis (CVCT) is a major complication that can cause significant morbidity and mortality. We sought to explore the rate of CVCT in a general cancer population in Australia and to identify factors associated with increased risk of thrombosis.

Design:

This is a multi-centre retrospective cohort study.

Setting and participants:

We analysed key patient, treatment, and cancer-related factors for 317 patients with cancer and central venous catheters inserted for systemic therapy.

Main outcome measures:

Symptomatic CVCT confirmed with imaging and management of patients with CVCT.

Results:

A total of 402 cases of central line insertion were analysed. Central venous catheter-related thrombosis occurred in 24 patients (6.0%). Having a peripherally inserted central catheter (PICC; HR = 3.78, 95% CI = 1.28-11.19, P = .02) compared with an implantable port and a body mass index of ⩾25.0 kg/m² (HR = 3.60, 95% CI = 1.31-9.85, P = .01) were independently associated with increased risk of thrombosis. Central venous catheter-related thrombosis was managed mostly with removal of the catheter (19 of 24 cases) and anticoagulation, including direct-acting oral anticoagulants in 5 patients.

Conclusions:

This work explored rates of CVCT in a general cancer population, observing increased rates in those with PICCs or increased body mass index.

Venous thromboembolism in primary central nervous system lymphoma during frontline chemoimmunotherapy

BACKGROUND

In primary central nervous system lymphoma (PCNSL), venous thromboembolism (VTE) can cause significant morbidity and hinder chemotherapy delivery.

OBJECTIVES

To assess VTE incidence, timing and adequacy of inpatient and outpatient VTE prophylaxis in patients with PCNSL receiving chemoimmunotherapy with curative intent.

PATIENTS/METHODS

We reviewed patients diagnosed with PCNSL between 1997 and 2018 who received methotrexate, procarbazine, and vincristine ± Rituximab. Patient demographics, VTE prophylaxis and incidence, adverse events of anticoagulation, and survival outcomes were collected.

RESULTS

Fifty-one PCNSL patients were included (median 67 years [range, 32-87], 30 males [59%]). Thirteen patients (25%, 95% confidence interval [CI], 14-40) developed VTE at a median of 1.6 months from diagnosis (range, 0-4). Patients with Khorana Risk Score ≥2 were more likely to have VTE than those with a KRS < 2 (60% vs 15%; P = .01). Eighty-five percent had deviations from inpatient VTE prophylaxis guidelines, and outpatient prophylaxis was not routinely administered. Three patients required inferior vena cava filters. Hemorrhagic complications of anticoagulation included an intracranial hemorrhage from therapeutic anticoagulation and three cases of major bleeding from prophylactic anticoagulation. No patients died from VTE or its treatment.

CONCLUSIONS

Patients with newly diagnosed PCNSL are at high risk of VTE. Further research is required into optimal VTE prophylaxis in PCNSL.

Low Dose Low-Molecular-Weight Heparin for Thrombosis Prophylaxis: Systematic Review with Meta-Analysis and Trial Sequential Analysis

International guidelines recommend low-molecular-weight heparin (LMWH) as first-line pharmacological option for the prevention of venous thromboembolism (VTE) in many patient categories. Guidance on the optimal prophylactic dose is lacking. We conducted a systematic review with meta-analysis and trial sequential analysis (TSA) of randomized controlled trials to assess benefits and harms of low-dose LMWH versus placebo or no treatment for thrombosis prophylaxis in patients at risk of VTE. PubMed, Cochrane Library, Web of Science, and Embase were searched up to June 2019. Results were presented as relative risk (RR) with conventional and TSA-adjusted confidence intervals (CI). Forty-four trials with a total of 22,579 participants were included. Six (14%) had overall low risk of bias. Low-dose LMWH was not statistically significantly associated with all-cause mortality (RR 0.99; 95%CI 0.85-1.14; TSA-adjusted CI 0.89-1.16) but did reduce symptomatic VTE (RR 0.62; 95%CI 0.48-0.81; TSA-adjusted CI 0.44-0.89) and any VTE (RR 0.61; 95%CI 0.50-0.75; TSA-adjusted CI 0.49-0.82). Analyses on major bleeding (RR 1.07; 95%CI 0.72-1.59), as well as serious adverse events (SAE) and clinically relevant non-major bleeding were inconclusive. There was very low to moderate-quality evidence that low-dose LMWH for thrombosis prophylaxis did not decrease all-cause mortality but reduced the incidence of symptomatic and asymptomatic VTE, while the analysis of the effects on bleeding and adverse events remained inconclusive.

Prospective observational study on the complications and tolerability of a peripherally inserted central catheter (PICC) in neuro-oncological patients

PURPOSE

The use of central venous catheters with peripheral insertion (PICC) has increased rapidly in recent years, particularly in cancer patients. The benefits provided may occasionally be affected by relevant complications, such as infections and thrombotic events, especially in neuro-oncological patients. To date, the risk of PICC-related complications in this subset of patients is unknown, as is tolerability. As a primary objective, this study aimed to collect complications related to PICCs in primary neuro-oncological patients. As a secondary objective, the study aimed to evaluate PICC tolerability.

METHODS

Neuro-oncological patients with PICCs that were placed as part of normal clinical practice at IRCCS Neurologico C. Besta were consecutively enrolled in the study. PICC-related complications were recorded immediately (during the procedure), early (within 1 week after PICC insertion), and late (1-3-5 months after PICC placement). At the same time points, all patients were also evaluated for tolerability through interviews with semi-structured, open-ended questions.

RESULTS

Sixty patients were enrolled (41 males and 19 females, with a median age of 56.2 years). Excluding loss to follow-up, 33/49 patients developed at least one complication related to the PICC. Immediate complications mainly included hematoma (8), accidental arterial puncture (4), and primary malpositioning (3). Regarding early and late complications, 3 device-related infections, 8 thrombotic events, and 20 mechanical complications were registered. Semi-structured interviews revealed an overall positive experience with the device. The most negative impact was on hygiene habits, with 34 patients becoming caregiver-dependent. Over time, almost all patients became used to the device and perceived greater security during chemotherapy. A strongly negative issue was the difficulty of relying on competently trained healthcare personnel in outpatient setting.

CONCLUSION

The results showed a nonnegligible increased thromboembolic risk in neuro-oncological patients with PICCs, almost double that in historical oncological populations. It is essential to extend the study to a greater number of patients to achieve reliable results and to identify patients at high risk. The device seems to be positively accepted by the majority of patients, without affecting activities of daily living.