Incidence of thrombotic complications in adult patients with acute lymphoblastic leukaemia receiving L-asparaginase during induction therapy: a retrospective study. The GIMEMA Group

Risk factors and clinical impact of thrombosis during induction chemotherapy for pediatric acute lymphoblastic leukemia: A report from CYP-C

Thromboembolism (TE) is associated with reduced survival in pediatric acute lymphoblastic leukemia (ALL). It has been hypothesized that TE might signal leukemic aggressiveness. The objective was to determine risk factors for TE during ALL induction (TEind ) therapy and whether TEind is associated with treatment refractoriness. This retrospective cohort study using the population-based Cancer in Young People Canada (CYP-C) registry included children <15 years of age diagnosed with ALL (2000-2019) and treated at one of 12 Canadian pediatric centers outside of Ontario. Univariate and multivariable logistic regression models were used to determine risk factors for TEind and whether TEind predicted induction failure and ALL treatment intensification. The impact of TEind on overall and event-free survival was estimated using Cox proportional hazard regression models. The study included 2589 children, of which 45 (1.7%) developed a TEind . Age (<1 year and ≥10 years vs. 1-<10 years), T-cell phenotype, high-risk ALL, and central nervous system involvement were all associated with TEind in univariate analysis. Age and T-cell phenotype remained independent predictors of TEind in multivariable analysis. Induction failure occurred in 53 patients (2.1%). TEind was not associated with induction failure (OR: not estimable) or treatment intensification (adjusted OR [95% CI]: 0.66 [0.26-1.69]). TEind was independently associated with overall survival (adjusted HR [95% CI]: 2.54 [1.20-5.03]) but not event-free survival (adjusted HR [95% CI] 1.86 [0.98-3.51]). In this population-based study of children treated with contemporary chemotherapy protocols, TEind was associated with age and T-cell phenotype and mortality but did not predict induction failure.

Superior sagittal sinus thrombosis in the course of mixed phenotype acute leukaemia treated with acute lymphoblastic leukaemia-like therapy-a case report

Mixed phenotype acute leukaemia (MPAL) is associated with worse overall survival, compared with other acute leukaemias in adults. Lack of clear treatment guidelines makes the therapy challenging. ALL-like induction and consolidation treatment followed by allo-HSCT is the preferred first-line treatment. We present a case of a 36-year-old woman diagnosed with MPAL (EGIL Myelo/B) with KMT2A rearrangement, treated with the PALG-ALL-7 (including PEG-asparaginase) protocol. On day 25 after the induction therapy initiation, numbness of limbs and dizziness were observed. Therefore, the imaging studies (CT and MRI) were performed and a diagnosis of thrombosis of superior sagittal sinus of the brain was established. Routinely performed blood coagulation tests showed prolonged APTT and PT, decreased antithrombin III activity and decreased free protein S concentration. LMWH treatment and substitutional therapy with antithrombin III were started, which resulted in a significant reduction in the thrombosis associated symptoms and improvement of the neurological status after 3 days. After induction and consolidation therapy, the patient obtained complete haematological remission and negative measurable residual disease. Six months after the diagnosis, allo-HSCT was successfully performed. During the 4 months follow-up, the patient remained MRD negative and thrombotic symptoms free. To the best of our knowledge, our communication has been the first report of such complication in an MPAL patient treated with PEG-asparaginase containing protocol in adults. We recommend increased vigilance in patients manifesting any mild neurological symptoms and early decision about the MRI study performance.

Thrombosis Complications in Pediatric Acute Lymphoblastic Leukemia: Risk Factors, Management, and Prevention: Is There Any Role for Pharmacologic Prophylaxis?

Pediatric acute lymphoblastic leukemia (ALL) has achieved close to 90% cure rates through extensive collaborative and integrative molecular research, clinical studies, and advances in supportive care. Despite this high achievement, venous thromboembolic complications (VTE) remain one of the most common and potentially preventable therapy-associated adverse events in ALL. The majority of thromboses events involve the upper central venous system which is related to the use and location of central venous catheters (CVC). The reported rates of symptomatic and asymptomatic CVC-related VTE range from 2.6 to 36.7% and 5.9 to 43%, respectively. Thrombosis can negatively impact not only disease-free survival [e.g., therapy delays and/or interruption, omission of chemotherapy agents (e.g., asparaginase therapy)] but also can result in long-term adverse effects that can impair the quality of life of ALL survivors (e.g., post-thrombotic syndrome, central nervous system (CNS)-thrombosis related complications: seizures, neurocognitive deficits). In this review, will discuss thrombosis pathophysiology in pediatric ALL, risk factors, treatment, and prevention strategies. In addition, the recently published clinical efficacy and safety of direct oral anticoagulants (DOACs) use in thrombosis treatment, and their potential role in primary/secondary thrombosis prevention in pediatric patients with ALL will be discussed. Future clinical trials involving the use of these novel oral anticoagulants should be studied in ALL not only for primary thrombosis prevention but also in the treatment of thrombosis and its secondary prevention. These future research findings could potentially extrapolate to VTE prevention strategies in other pediatric cancer diagnoses and children considered at high risk for VTE.

The Growing Impact of Cardiovascular Oncology: Epidemiology and Pathophysiology

Progress in the treatment of cancer has significantly improved survival of oncologic patients in recent decades. However, anticancer therapies, particularly some new, more potent and targeted agents, are potentially cardiotoxic. As a consequence, cardiovascular complications, including heart failure, arterial hypertension, coronary artery disease, venous thromboembolism, peripheral vascular disease, arrhythmias, pericardial disease, and pulmonary hypertension, as related to cancer itself or to anticancer treatments, are increasingly observed and may adversely affect prognosis in oncologic patients. Cardiovascular oncology is an emerging field in cardiology and internal medicine, which is rapidly growing, dealing with the prevention, the early detection, and the management of cardiovascular disease, in all stages of anticancer therapy and during the survivorship period, now crucial for reducing cardiovascular morbidity and mortality in cancer patients. In this narrative review, the existing literature regarding the epidemiology of cardiovascular oncology, the mechanisms of cardiovascular complications in cancer, and the pathophysiology of cardiotoxicity related to chemotherapeutic agents, targeted therapies, immunotherapies, and radiotherapy will be analyzed and summarized.

Cancer Therapy-Associated Thrombosis

[Figure: see text].

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.

Thromboembolism prophylaxis during L-asparaginase therapy in acute lymphoblastic leukemia - time to reconsider current approaches?

Acute Lymphoblastic Leukemia (ALL) is the commonest malignancy in childhood with a second incidence peak in adulthood. Improvements in pediatric therapy including the addition of L-asparaginase (L-ASP) have enabled cure rates in excess of 90% to be achieved in children. More recently L-ASP-containing pediatric protocols are being used to treat younger adults with ALL and have improved survival by approximately 2-fold. However, a toxicity associated with L-ASP-containing therapy in ALL is venous thromboembolism (VTE) which is associated with significant morbidity in this patient population and results in interruptions in L-ASP therapy that can impact on survival outcomes. The incidence of VTE among adult patients with ALL receiving L-ASP containing therapy has been reported to be as high as 43%. Despite this, there is a lack of evidence-based recommendations for VTE prophylaxis in this clinical context; low-molecular weight heparin (LMWH) and/or AT replacement have mostly been used. The low-quality data and inconveniences associated with these VTE prophylaxis regimens highlight the need to evaluate alternatives such as direct oral anticoagulants for the prevention of L-ASP-associated VTE in ALL. This narrative will review the body of evidence on primary thromboprophylaxis in adult patients with ALL receiving L-ASP containing therapy.

Potential Mechanisms of Cancer-Related Hypercoagulability

The association between cancer and thrombosis has been known for over a century and a half. However, the mechanisms that underlie this correlation are not fully characterized. Hypercoagulability in cancer patients can be classified into two main categories: Type I and Type II. Type I occurs when the balance of endogenous heparin production and degradation is disturbed, with increased degradation of endogenous heparin by tumor-secreted heparanase. Type II hypercoagulability includes all the other etiologies, with factors related to the patient, the tumor, and/or the treatment. Patients with poor performance status are at higher risk of venous thromboembolism (VTE). Tumors can result in VTE through direct pressure on blood vessels, resulting in stasis. Several medications for cancer are correlated with a high risk of thrombosis. These include hormonal therapy (e.g., tamoxifen), chemotherapy (e.g., cisplatin, thalidomide and asparaginase), molecular targeted therapy (e.g., lenvatinib, osimertinib), and anti-angiogenesis monoclonal antibodies (e.g., bevacizumab and ramucirumab).

The prevention and management of asparaginase-related venous thromboembolism in adults: Guidance from the SSC on Hemostasis and Malignancy of the ISTH

Venous thromboembolism is a common complication of asparaginase-based chemotherapy regimens for the treatment of acute lymphoblastic leukemia. Thrombosis associated with asparaginase administration poses a number of specific and often clinically challenging management decisions. This review provides guidance on the prevention and treatment of thrombosis associated with asparaginase in adults including discussions on antithrombin repletion, pharmacologic thromboprophylaxis, cerebral venous thrombosis, and therapeutic anticoagulation.

Catheter-related right atrial thrombosis

INTRODUCTION

Catheter-related right atrial thrombosis is an under-recognized complication of central venous catheter placement. We performed a retrospective review, characterizing clinical aspects of catheter-related right atrial thrombosis (CRAT).

METHODS

To identify cases, a literature search was conducted in PubMed and additional items selected by review of related items and bibliography review. Key clinical data were extracted and analyzed both in total and as stratified by hemodialysis versus non-hemodialysis groups.

RESULTS

A total of 68 catheter-related right atrial thrombosis events were reported in 63 patients (five recurrences, of which 4 involved catheter left in place following primary treatment). Median (interquartile range) time to CRAT diagnosis was longer among hemodialysis patients - 12 (4.0-24.0) weeks compared to 5.5 (1.8-16.1) weeks among non-hemodialysis patients. The most common presentations were asymptomatic in 16/68 (23.5%), fever/sepsis in 21/68 (30.9%), pulmonary embolism in 11/68 (16.2%), catheter dysfunction in 8/68 (11.8%), dyspnea in 8/68 (11.8%), and new murmur or valvular dysfunction in 8/68 (11.8%) patients. Primary treatment selection was anticoagulation in 33/68 (48.5%), surgical thrombectomy in 17/68 (25.0%), thrombolysis in 12/68 (17.6%), or no active therapy in 6/68 (8.8%) patients. Primary treatment failure for anticoagulation and thrombolysis was 27.3% and 33.3%, respectively. The most common rescue therapy was surgical thrombectomy, ultimately resulting in an overall rate of 26/62 (41.9%). Overall, per-patient mortality was 13/63 (20.6%). Intracardiac tip position - 27/34 (79.4%) - overshadowed thrombophilia - 16/63 (25.4%) - as a risk factor for CRAT.

CONCLUSION

Catheter-related right atrial thrombosis is an underdiagnosed complication of central venous catheter placement. For the hemodialysis population, a fistula-first approach is advocated. While many instances were asymptomatic, the development of unexplained fever, dyspnea, catheter dysfunction, or new murmur should trigger a search for this complication.

Thrombotic Risk from Chemotherapy and Other Cancer Therapies

Cancer patients have an increased risk of thrombosis. The development of cancer thrombosis is dependent on a number of factors including cancer type, stage, various biologic markers, and the use of central venous catheters. In addition, cancer treatment itself may increase thrombotic risk. Tamoxifen increases the risk of venous thromboembolism (VTE) by two- to sevenfold, while an impact on risk of arterial thrombosis is uncertain. Immunomodulatory imide drugs (IMiDs) such as thalidomide and lenalidomide increase the risk of VTE in patients with multiple myeloma (MM) by about 10-40% when given in combination with glucocorticoids or other chemotherapy agents; the risk of VTE in MM patients treated with IMiD-containing regimens necessitates that such patients receive thromboprophylaxis with aspirin, low-molecular-weight heparin, or warfarin. Among cytotoxic chemotherapy agents, cisplatin, and to a lesser extent fluorouracil, has been described in association with thrombosis. L-asparaginase in treatment of acute lymphoblastic leukemia is significantly associated with increased thrombosis particularly affecting the CNS, which may be due to acquired antithrombin deficiency; at some centers, plasma infusions or antithrombin replacement is used to mitigate this. Bevacizumab, an inhibitor of vascular endothelial growth factor, increases arterial and possibly venous thrombotic risk, although the literature is conflicting about the latter. Supportive care agents in cancer care, such as erythropoiesis-stimulating agents, granulocyte colony stimulating factor, and steroids, also have some impact on thrombosis. This review summarizes the mechanisms by which these and other therapies modulate thrombotic risks and how such risks may be managed.

Combination therapy of omega-3 fatty acids and acipimox for children with hypertriglyceridemia and acute lymphoblastic leukemia

BACKGROUND

Lipemic alterations are commonly seen in pediatric patients with acute lymphoblastic leukemia (ALL) treated with corticosteroids and L-asparaginase.

OBJECTIVE

In these children, hypertriglyceridemia rarely causes symptoms and mostly responds well to a low-fat diet. Only few patients demand further therapy, which is not clearly approved in the literature to date. Therefore, it may be important to compile generally accepted standard procedures for lipid-lowering therapy in the pediatric ALL population.

METHODS

We performed a study on 119 newly diagnosed pediatric patients with ALL, all treated according to the ALL-BFM 2000 protocol at our institution between the years 2000 and 2009, to evaluate the incidence of hypertriglyceridemia and the efficacy of a combination therapy with omega-3 fatty acids and acipimox in hypertriglyceridemic patients who did not respond to diet.

RESULTS

We observed hypertriglyceridemia in 34.5% of patients in this collective. In the majority, normalization of triglycerides was successfully managed by administration of a low-fat diet. However, 7.6% of patients (related to total study population) with hypertriglyceridemia did not show diminished lipid levels during diet and/or presented with symptoms such as abdominal pain, dyspnea, or anginal chest pain. In these cases, we performed a lipid-lowering combination therapy with omega-3 fatty acids and acipimox. We observed a prompt decline of serum triglycerides to normal values and an improvement of symptoms within days after onset of this therapy without occurrence of any side effects.

CONCLUSION

In summary, the combination treatment with omega-3 fatty acids and acipimox could represent an alternative to other reported lipid-lowering therapies without severe adverse reactions.

Thromboembolism in acute lymphoblastic leukemia: results of NOPHO ALL2008 protocol treatment in patients aged 1 to 45 years

Thromboembolism frequently occurs during acute lymphoblastic leukemia (ALL) therapy. We prospectively registered thromboembolic events during the treatment of 1772 consecutive Nordic/Baltic patients with ALL aged 1 to 45 years who were treated according to the Nordic Society of Pediatric Hematology and Oncology ALL2008 protocol (July 2008-April 2017). The 2.5-year cumulative incidence of thromboembolism (N = 137) was 7.9% (95% confidence interval [CI], 6.6-9.1); it was higher in patients aged at least 10 years (P < .0001). Adjusted hazard ratios (HRas) were associated with greater age (range, 10.0-17.9 years: HRa, 4.9 [95% CI, 3.1-7.8; P < .0001]; 18.0-45.9 years: HRa, 6.06 [95% CI, 3.65-10.1; P < .0001]) and mediastinal mass at ALL diagnosis (HRa, 2.1; 95% CI, 1.0-4.3; P = .04). In a multiple absolute risk regression model addressing 3 thromboembolism risk factors, age at least 10 years had the largest absolute risk ratio (RR_age, 4.7 [95% CI, 3.1-7.1]; RR_{enlarged lymph nodes}, 2.0 [95% CI, 1.2-3.1]; RR_{mediastinal mass}, 1.6 [95% CI, 1.0-2.6]). Patients aged 18.0 to 45.9 years had an increased hazard of pulmonary embolism (HRa, 11.6; 95% CI, 4.02-33.7; P < .0001), and patients aged 10.0 to 17.9 years had an increased hazard of cerebral sinus venous thrombosis (HRa, 3.3; 95% CI, 1.5-7.3; P = .003) compared with children younger than 10.0 years. Asparaginase was truncated in 38/128 patients with thromboembolism, whereas thromboembolism diagnosis was unassociated with increased hazard of relapse (P = .6). Five deaths were attributable to thromboembolism, and patients younger than 18.0 years with thromboembolism had increased hazard of dying compared with same-aged patients without thromboembolism (both P ≤ .01). In conclusion, patients aged at least 10 years could be candidates for preemptive antithrombotic prophylaxis. However, the predictive value of age 10 years or older, enlarged lymph nodes, and mediastinal mass remain to be validated in another cohort.

Venous thromboembolism in adults treated for acute lymphoblastic leukaemia: Effect of fresh frozen plasma supplementation

Treatment of acute lymphoblastic leukaemia (ALL) is frequently complicated by venous thromboembolism (VTE). The efficacy and optimal approach of VTE prevention are unclear, particularly in adult patients. We assessed the effect of thromboprophylaxis on symptomatic VTE incidence in cycle 1 of ALL treatment in adult patients. Secondly, we explored potential etiologic factors for VTE and the clinical impact of VTE on ALL outcome. We retrospectively assessed symptomatic VTE incidence and use of thromboprophylaxis in 240 adults treated for newly diagnosed ALL in the Dutch-Belgian HOVON-37 multicentre study (1999–2005). Potential etiologic factors were explored by analysis of patient and disease characteristics, impact of VTE on ALL outcome by analysis of complete remission and overall survival rates. Symptomatic VTE was observed in 24 of 240 patients (10%). Thromboprophylaxis differed by centre (prophylactic fresh frozen plasma (FFP) supplementation or no thromboprophylaxis) and was applied only during L-asparaginase in cycle 1. VTE incidence was significantly lower with FFP supplementation than without FFP (6% vs. 19%; adjusted odds ratio [OR] 0.28; 95% confidence interval [CI] 0.10–0.73). FFP did not influence antithrombin or fibrinogen plasma levels. Patients with VTE in cycle 1 had a significantly poorer complete remission rate (adjusted OR 0.18; 95% CI 0.07–0.50), particularly patients with cerebral venous thrombosis (adjusted OR 0.17; 95% CI 0.04–0.65). Our study suggests that prophylactic FFP supplementation effectively reduces symptomatic VTE incidence during ALL treatment in adults. This should be confirmed in a randomised controlled trial.

Safety and feasibility of lower antithrombin replacement targets in adult patients with hematological malignancies receiving asparaginase therapy<sup/>

The optimal antithrombin(AT) activity parameters for replacement as thromboprophylaxis following asparaginase remains unclear. This single-center, retrospective study evaluated two sets of AT replacement thresholds and targets in adults receiving asparaginase-containing chemotherapy. AT supplementation adhered to institutional standards, which lowered the AT activity target from 100% to 80% in 6/2014. Ninety-two patients were evaluated. Cumulative thrombosis incidence was 16% at 6 months (95%CI:6.8-24.0, maximum follow-up 315 days) with similar incidence between the 80% and 100% target groups, 14% (2 of the 14) and 13% (10 of the 78), respectively, with a small non-Line-Related DVT incidence (3%). Most thrombotic events occurred during induction chemotherapy and demonstrated no associations with replacement target, cumulative days or cumulative area under AT activity target, number of asparaginase doses, or cumulative asparaginase dose. Median estimated AT replacement expenditure was $34,963USD (IQR $16,260USD to $79,319USD) per patient. Cost-effectiveness and optimization of AT replacement for thromboprophylaxis following asparaginase requires prospective evaluation.

Activity levels of natural anticoagulant proteins in childhood acute lymphoblastic leukemia: relation to thromboembolic complications and treatment

Thromboembolism is a well recognized life-threatening complication in childhood acute lymphoblastic leukemia (ALL). Proper and early diagnosis of thromboembolism is of paramount importance to reduce mortality and morbidity. We evaluated antithrombin III (ATIII), protein C, protein S, and D-dimer in 60 children with ALL compared with 30 healthy controls, and patients were followed up for 12 months for detection of thrombotic complications. The relation between these natural anticoagulants and the development of thrombotic complications, as well as therapy was assessed to identify patients at risk of thromboembolism. ATIII, protein C, and protein S were significantly reduced (P < 0.001) with elevated D-dimer (P < 0.001) in patients with ALL compared with those in the control group. The incidence of thrombotic complications was 16.7%. Patients with thrombotic complications had significantly lower ATIII, protein C, protein S, and platelet count, whereas age, total leukocyte count, and D-dimer were increased compared with those without thrombosis (P < 0.05). Patients under chemotherapy had lower ATIII, protein C, and protein S levels with higher D-dimer compared with the newly diagnosed untreated patients (P < 0.05). ATIII and protein C were positively correlated (r = 0.573, P = 0.002), whereas both were negatively correlated with D-dimer (P < 0.001). ALL is associated with a state of hypercoagulability, which may be attributed to hemostatic derangement because of increased thrombin generation indicated by elevated D-dimer in association with decreased natural anticoagulants ATIII, protein C, and protein S. ALL children during induction/consolidation phase of chemotherapy are at high risk of developing thromboembolism complications and the prophylactic use of anticoagulant should be considered.

Approach to chemotherapy-associated thrombosis

Treatment of cancer patients with antineoplastic agents is associated with a heightened risk of thrombotic events, both arterial and venous. In this article, we review the specific agents that are implicated and the pathophysiological processes that are known to be associated with this prothrombotic state. We conclude with current recommendations for prophylactic antithrombotic therapy in these clinical situations.

L-Asparaginase lowers plasma antithrombin and mannan-binding-lectin levels: Impact on thrombotic and infectious events in children with acute lymphoblastic leukemia

BACKGROUND

L-asparaginase, a key therapeutic agent in the management of patients with acute lymphoblastic leukemia (ALL), dramatically impairs hepatic protein synthesis. We investigated the effects of prolonged exposure to L-asparaginase on antithrombin (AT), fibrinogen and mannan-binding-lectin (MBL) levels, and on the occurrence of thrombotic events (TE) and febrile neutropenia episodes (FN) in pediatric patients.

PROCEDURE

Protein levels were measured in 97 children during 30 weeks of chemotherapy with L-asparaginase and up to 1 year following remission. TE and FN episodes were recorded during this period.

RESULTS

Median AT level decreased from 0.96 IU/mL prior to treatment (range: 0.69-1.38) to 0.55 IU/mL (0.37-0.76) during therapy. Fibrinogen and MBL decreased from 3.18 g/L (1.29-7.28) and 1,177 ng/mL (57-5,343) to 1.56 g/L (0.84-2.13) and 193 ng/mL (57-544), respectively. All three proteins had recovered 1-4 weeks after L-asparaginase cessation. TE were reported in 22 (23%) patients. Of these, 11 occurred after a median of 10 administrations of L-asparaginase. Fifty-one FN were associated with infections, of which 36 occurred during treatment with L-asparaginase. Patients with low levels of MBL at diagnosis were at higher risk of FN associated with infections (RR = 1.59, 95%CI: 1.026-2.474). Both AT and MBL decreases were moderately correlated with fibrinogen (r = 0.51 and 0.58, respectively).

CONCLUSIONS

Children with ALL are exposed to significant decrease in AT, fibrinogen and MBL levels, and concomitant increased risk of thrombosis and FN with infection during L-asparaginase treatment. Measuring plasma levels of these liver-derived proteins could help predict the occurrence of adverse events.

Clinical Course of Cerebral Venous Thrombosis in Adult Acute Lymphoblastic Leukemia

BACKGROUND

Venous thromboembolism (VTE) is a frequent complication in patients with acute lymphoblastic leukemia (ALL). A significant proportion of patients develop cerebral venous thrombosis (CVT).

METHODS

To investigate risk factors for and the clinical course of CVT in ALL patients, we describe all cases of CVT which occurred in a well-defined cohort of 240 adults, treated for newly diagnosed ALL in the HOVON (Dutch-Belgian Hemato-Oncology Cooperative Group)-37 study. We conducted a nested case-control study to explore the relevance of early symptoms and risk factors for CVT in ALL patients.

RESULTS

Nine of 240 patients developed CVT (4%). CVT occurred during or shortly after L-asparaginase therapy (in 8 cases) and shortly after intrathecal methotrexate injections (in all cases) during cycle I of remission induction treatment. CVT was associated with prior headache and seizures. In 5 of 9 patients with CVT, headache before the diagnosis of CVT occurred within 3 days after lumbar puncture and initially had a postural character.

CONCLUSIONS

CVT is relatively common in adult ALL patients. Our data suggest that CVT in adult ALL patients results from the additive effects of multiple risk factors, with a particular role for asparaginase and the effects of lumbar punctures for intrathecal therapy.

Haemostatic alterations induced by treatment with asparaginases and clinical consequences

The benefit of asparaginase for treating acute lymphoid leukaemia (ALL) has been well established. Native asparaginase derives from Escherichia coli (colaspase) or Erwinia chrysanthemi (crisantaspase); in a third preparation, colaspase is pegylated. Depletion of asparagine leads to decreased synthesis of procoagulant, anticoagulant, and fibrinolytic proteins, with resultant hypercoagulability and greater risk of venous thromboembolism (VTE). Colaspase and crisantaspase are not dose-equivalent, with crisantaspase displaying haemostatic toxicity only at dosages much higher and administered more frequently than those of colaspase. Cerebral venous thrombosis and pulmonary embolism are two life-endangering manifestations that occur during treatment with asparaginase particularly in children and in adults with ALL, respectively. Approximately one-third of VTEs are located in the upper extremities and are central venous line-related. Other risk factors are longer duration of asparaginase treatment and concomitant use of prednisone, anthracyclines, and oral contraceptives. The risk associated with inherited thrombophilia is uncertain but is clearly enhanced by other risk factors or by the use of prednisone. VTE prevention with fresh frozen plasma is not recommended; the efficacy of antithrombin (AT) concentrates has occasionally been reported, but these reports should be confirmed by proper studies, and AT should not be routinely employed. Therapeutic or prophylactic heparin doses are only partially effective, and direct thrombin or factor Xa inhibitors could play significant roles in the near future.

Impact of genetic polymorphisms on chemotherapy toxicity in childhood acute lymphoblastic leukemia

The efficacy of chemotherapy in pediatric acute lymphoblastic leukemia (ALL) patients has significantly increased in the last 20 years; as a result, the focus of research is slowly shifting from trying to increase survival rates to reduce chemotherapy-related toxicity. At the present time, the cornerstone of therapy for ALL is still formed by a reduced number of drugs with a highly toxic profile. In recent years, a number of genetic polymorphisms have been identified that can play a significant role in modifying the pharmacokinetics and pharmacodynamics of these drugs. The best example is that of the TPMT gene, whose genotyping is being incorporated to clinical practice in order to individualize doses of mercaptopurine. However, there are additional genes that are relevant for the metabolism, activity, and/or transport of other chemotherapy drugs that are widely use in ALL, such as methotrexate, cyclophosphamide, vincristine, L-asparaginase, etoposide, cytarabine, or cytotoxic antibiotics. These genes can also be affected by genetic alterations that could therefore have clinical consequences. In this review we will discuss recent data on this field, with special focus on those polymorphisms that could be used in clinical practice to tailor chemotherapy for ALL in order to reduce the occurrence of serious adverse effects.

The coagulopathy and thrombotic risk associated with L-asparaginase treatment in adults with acute lymphoblastic leukaemia

The dramatic improvements seen in the outcome of paediatric patients with acute lymphoblastic leukaemia (ALL) have led to increasing incorporation of L-asparaginase (L-Asp) in adult treatment protocols. However, its use is associated with a disruption in the physiological balance between haemostatic and anticoagulant pathways, with the predominant clinical manifestation being thrombosis. Although L-Asp therapy is known to be associated with an acquired deficiency of antithrombin (AT), the concurrent depletion of fibrinogen and other haemostatic proteins means that the precise mechanism of thrombosis remains to be defined. In vitro coagulation assays are often prolonged but thrombosis rather than haemorrhage is the primary concern. Management of thrombotic events in these patients is based around agents that rely on AT for their anticoagulant effect, even though it is usually depleted. There is currently only limited evidence supporting the use of AT concentrates in either primary prevention or management following an established event. Evidence-based guidelines for prevention and management strategies are lacking.

Central nervous system chemotoxicity during treatment of pediatric acute lymphoblastic leukemia/lymphoma

In the last decades, increasing success rates are being obtained in the chemotherapy of pediatric leukemia and lymphoma. However, the cornerstone of this treatment is still formed by a reduced number of drugs with a highly toxic profile. In particular, central nervous system complications remain a challenging clinical problem, requiring rapid detection and prompt treatment to limit permanent damage. Furthermore, clinicians are often challenged to discriminate between CNS involvement by the disease, toxicity of drugs or infections. This clinically oriented review will help recognize and handle the main neurologic adverse effects induced by chemotherapy in pediatric patients with lymphoblastic leukemia/lymphoma. Different clinical entities and putative drugs involved are discussed in each chapter, with clinical cases illustrating the most relevant and challenging events. In addition, specific clinical-radiological patterns of some of these neurologic events are detailed. Finally, the role of pharmacogenetics, with special focus on those polymorphisms that could help explain the occurrence of neurotoxicity, is also discussed.

Central nervous system complications of cancer therapy

As more effective therapies prolong the survival of patients with cancer, therapy-related toxicities, particularly those affecting the central nervous system (CNS) become increasingly important. CNS complications can cause significant morbidity and can limit the dose or duration of otherwise effective treatments. Because effects on the CNS are disabling and often permanent and treatments remain limited, it is important that clinicians recognize the effects of cancer therapy on the CNS. Cytotoxic chemotherapy and radiation are well-known causes of neurotoxicity, but there is increasing recognition that novel therapies are also sources of adverse effects on the CNS. This review highlights the CNS complications that result from radiation, chemotherapy, and novel therapeutics.

Prevention and management of asparaginase/pegasparaginase-associated toxicities in adults and older adolescents: recommendations of an expert panel

The rapidly increasing use of pegasparaginase (pegASNase) in adults, after a half century of use of asparaginase (ASNase) in children, has prompted a need for guidelines in the management and prevention of toxicities of asparagine depletion in adults. Accordingly, an initial set of recommendations are provided herein. Major advantages of pegASNase are its 2-3-week duration of action, in contrast to less than 3 days with native ASNase, and the flexibility of intravenous or intramuscular administration of pegASNase and associated patient and physician convenience. The most frequent toxicities of both types of ASNase are hepatic and pancreatic, with pancreatitis being the most serious. Other toxicities are hypersensitivity reactions, thrombosis, nausea/vomiting, and fatigue. Whether or not the replacement of one dose of pegASNase for 6-9 doses of native ASNase can be achieved in adults with similar efficacy and acceptable toxicities to those achieved in children remains to be established.

The frequency and management of asparaginase-related thrombosis in paediatric and adult patients with acute lymphoblastic leukaemia treated on Dana-Farber Cancer Institute consortium protocols

The optimal management of asparaginase-associated thrombotic complications is not well-defined. We report the features, management and outcome of paediatric (ages 0-18years) and adult (18-50years) patients with acute lymphoblastic leukaemia (ALL) with asparaginase-related venous thromboembolic events (VTE) treated at Dana-Farber Cancer Institute on clinical trials for newly diagnosed ALL between 1991-2008. Of 548 patients, 43 (8%) had VTE, including 27/501 (5%) paediatric and 16/47 (34%) adult patients. Sinus venous thrombosis occurred in 1·6% of patients. Age was the only significant predictor of VTE, with those aged >30years at very high risk (VTE rate 42%). 74% of patients received low molecular weight heparin after VTE. Complications of anticoagulation included epistaxis (9%), bruising (2%) and, in two adult patients, major bleeding. Thirty patients (70%) ultimately received at least 85% of the intended doses of asparaginase. 33% of patients experienced recurrent VTE (paediatric 17% vs. adults 47%, P=0·07). The 48-month event-free survival for patients with VTE was 85±6% compared with 88±2% for those without VTE (P=0·36). This study confirms that, after VTE, asparaginase can be restarted with closely monitored anticoagulation after imaging demonstrates clot stabilization or improvement. With this management strategy, a history of VTE does not appear to adversely impact prognosis.

[Pharmacologically-induced neurocatastrophes]

Drug-induced adverse reactions represent a significant health problem in developed countries. These events cause 5% of hospital admissions and are one of the main causes of mortality. Neurological manifestations are among the most frequent. This article reviews catastrophic cerebrovascular situations and confusional syndromes, as well as epilepsy, structural encephalopathy, neuromuscular disorders, catastrophic movement disorders and infections, all of which can be drug-induced.

Thromboprophylaxis during chemotherapy in patients with advanced cancer

Venous thromboembolism is a common and potentially fatal complication in patients with advanced cancer. In these patients chemotherapy has been identified as an independent risk factor for venous thromboembolism. The annual incidence of venous thromboembolism in cancer patients who receive chemotherapy is estimated to be about 10%. This risk increases up to 15-20% depending on type and combination of anticancer agents. The occurrence of venous thromboembolic events in cancer patients is associated with a poor prognosis. The benefit of antithrombotic prophylaxis for venous thromboembolism in cancer patients who receive chemotherapy has been recently evaluated in a randomized, placebo-controlled, double-blind trial (the PROTECHT study). The aim of this study was to evaluate the efficacy and safety of the low molecular weight heparin nadroparin in the prevention of venous and arterial thromboembolic events during chemotherapy. The results of the PROTECHT study demonstrated that nadroparin reduces by 50% the rate of thromboembolic events in ambulatory patients with metastatic or locally advanced cancer while they receiving chemotherapy. The antithrombotic effect was more evident in patients with lung and gastrointestinal cancer. In future studies the clinical benefit of antithrombotic prophylaxis should be evaluated in cancer patients at particularly high risk for thromboembolism.

Preliminary in vivo evaluation of the protein transduction domain-modified ATTEMPTS approach in enhancing asparaginase therapy

Asparaginase (ASNase) is an enzyme drug presently approved for the induction of remission in the treatment of patients with acute lymphoblastic leukemia (ALL). The cytotoxic effect of ASNase is derived from its ability to deplete asparagine, an essential amino acid required by certain types of leukemia cells for protein synthesis and survival. Despite its efficacy in enhancing disease remission rate and prolonging complete remission duration in ALL patients, ASNase therapy is nevertheless confounded by a number of serious toxic effects, particularly to organs associated with high protein production (e.g., liver, pancreas), due to the systemic depletion of asparagine. Presented herein is a modified version of our previously established ATTEMPTS protein delivery system that carries the potential to permit a tumor specific, intracellular delivery of ASNase, thereby allowing for a significant reduction of ASNase-induced systemic toxicity. In a previous paper, we already demonstrated the in vitro feasibility of this heparin/protamine-regulated, TAT-mediated system in delivering ASNase directly into ASNase-sensitive murine lymphoma cells. In this article, we further validated the in vivo applicability of this system in animals harboring ASNase-encapsulated L5178Y lymphoma cells. Preliminary results showed that animals inoculated with L5178Y cells containing TAT-ASNase exhibited an extended survival rate of approximately 13% over those harboring L5178Y cells without the encapsulation of ASNase. Furthermore, the TAT-ASNase-treated mice also displayed a significantly improved hematological and liver histological status than the control groups. These findings bring promise to the use of the modified ATTEMPTS delivery system in achieving enhanced ASNase therapy.

Thromboembolism in Adults with Acute Lymphoblastic Leukemia During Induction with L-Asparaginase-containing Multi-agent Regimens: Incidence, Risk Factors, and Possible Role of Antithrombin

Thromboembolism (TE) is a known complication of L-asparaginase (ASP) therapy of acute lymphoblastic leukemia (ALL), possibly attributable to reduced synthesis of natural anticoagulants, in particular antithrombin (AT). This retrospective single institution study was performed to determine the TE incidence among adults undergoing induction with contemporary, ASP-containing regimens. Ten of 54 (18.5%) consecutive adults developed symptomatic, objectively confirmed TE, at a median of 5.5 days after the first ASP dose. These were notable for CNS and upper extremity localization, varied significantly according to ALL immunophenotype (precursor B: 11% vs. T cell: 33%), without apparent effect of schedule or total dose of ASP. Median baseline AT level was 94% and fell to a nadir of 47% (P < 0.0001) during ASP therapy. Prophylactic AT had been given to 17 during ASP therapy. None of these developed TE vs. 10/37 (27%) without replacement (P = 0.021). These observations merit further study to gain insight into disease and/or therapy-specific pathogenesis of TE in this population and call for the prospective evaluation of appropriate prophylactic interventions.

Cerebral thrombotic complications in adolescent leukemia/lymphoma patients treated with L-asparaginase-containing chemotherapy

We described the cerebral thrombotic complications developed in 2 adolescent patients treated with L-asparaginase-containing regimens. For determining risk factors, we retrospectively analysed hemostatic markers in 19 pediatric patients with leukemia or lymphoma who were treated with either 1 of the 2 L-asparaginase-containing regimens; 11 were treated with VLP1 and the remaining 8 were treated with the VLAD protocol. The data indicated that low coagulation factors in association with increased plasma D-dimer levels during or post-L-asparaginase administration combined with fresh frozen plasma infusion might have activated coagulation processes in these patients. Careful management is required to prevent such episodes in patients with markedly decreased coagulation factors and increased D-dimer levels following L-asparaginase administration.

Clinical course and outcome in children with acute lymphoblastic leukemia and asparaginase-associated pancreatitis

BACKGROUND

Asparaginase, an agent used in the treatment of acute lymphoblastic leukemia (ALL), is associated with the development of pancreatitis. The clinical course and long-term outcome of patients experiencing this complication has not been extensively detailed.

PROCEDURE

We reviewed the clinical course for all children with ALL diagnosed with pancreatitis at the Dana-Farber Cancer Institute/Children's Hospital Boston between 1987 and 2003. The outcome of these patients was compared with that of patients with ALL who did not experience pancreatitis.

RESULTS

Twenty-eight of 403 children (7%) were diagnosed with pancreatitis. Patients 10-18 years old at diagnosis had 2.4 times the risk of developing pancreatitis compared with younger patients. Pancreatitis typically occurred early in the course of therapy (median 4 weeks after first dose of asparaginase). Ninety-three percent of affected patients were hospitalized and 57% received parenteral nutrition. No patient developed chronic sequelae or died as a result of pancreatitis. Sixteen (57%) patients were re-treated with asparaginase, 10 of whom had another episode of pancreatitis. No significant differences in event-free survival were observed when comparing patients with and without a history of pancreatitis.

CONCLUSION

Asparaginase-associated pancreatitis was more common in older children, and caused significant acute morbidity. It tended to occur after the first few doses of asparaginase, suggesting a predisposition to this complication rather than a cumulative drug effect. Re-treatment with asparaginase after an episode of pancreatitis was associated with a high risk of recurrent pancreatitis.

Differential diagnosis of nontraumatic intracerebral hemorrhage

A wide variety of nontraumatic pathologies can result in intracerebral hemorrhage (ICH). Primary causes such as arterial hypertension or cerebral amyloid angiopathy can be differentiated from secondary pathologies, such as neoplasms, arterio-venous malformations, coagulopathies, hemorrhagic ischemic strokes, and cerebral venous and sinus thrombosis.Here, the authors first provide some general information on epidemiology, clinical presentation, and imaging appearance of ICHs followed by a detailed discussion of the different underlying pathologic entities and their imaging presentation.

PTD-modified ATTEMPTS system for enhanced asparaginase therapy: a proof-of-concept investigation

Macromolecular drugs such as proteins and gene products are presumably the most desirable therapeutic agents due to their unmatched substrate specificity and reaction efficiency. Yet, clinical use of these drugs has met with limited success, primarily due to the impermeable nature of the cell membrane that restricts cellular drug uptake to only small (<600 Da) and hydrophobic molecules. The recent discovery of the protein transduction domain (PTD) membrane-penetrating peptides, such as HIV-TAT, has finally offered the possibility of resolving this cell-membrane barrier for macromolecular drug delivery. Via covalent linkages, these PTD peptides have been shown to ferry the attached macromolecular species across membranes of all cell types, both in vitro and in vivo. Nevertheless, the lack of selectivity for PTD-mediated internalization restricts the application of this cell uptake method in clinical practice, due to concerns of inducing systemic toxicity caused by the carried drugs. Presented herein is a modified version of our previously established "ATTEMPTS" approach in delivery of macromolecular drugs, which integrates the cell-penetrating PTDs into a heparin/protamine-regulated delivery system. In vitro findings using asparaginase (ASNase) as a model macromolecular anti-tumor agent were able to validate the feasibility of this delivery system. The chemically constructed TAT-ASNase conjugates not only were able to translocate into the MOLT-4 cells and elicit the cytotoxic effects, but also this PTD-mediated intracellular drug uptake could be regulated (with on/off control) by the addition of heparin and protamine. This modified ATTEMPTS system therefore presents a new avenue of treatment of various types of cancers and other diseases with macromolecular drugs. In vitro characterization and a preliminary proof-of-concept animal investigation that demonstrates the feasibility of this PTD-mediated ASNase therapeutic system is subsequently described.

Management of stroke in cancer

Cerebrovascular disorders, including brain infarction, brain hemorrhage, and cerebral venous thrombosis, can occur as an early sign of cancer, but typically occur late in the clinical course. These disorders are due to a variety of pathogenic mechanisms, including coagulation disorders associated with the cancer, invasion or compression of vessels from tumor in or adjacent to the brain, and the adverse effects of cancer therapy. The appropriate therapy for these cerebrovascular disorders is empiric in most instances, because as yet there are no prospective treatment trials for them. A review of the existing literature reveals that improvement in patient quality of life and prevention of further cerebrovascular events can be obtained in some clinical situations.

Thromboprophylaxis during chemotherapy after advanced cancer

Venous thromboembolism is a common and life-threatening complication in patients with advanced cancer. Chemotherapy has been identified as a risk factor for venous thromboembolism in cancer patients. The annual incidence of venous thromboembolism in cancer patients receiving chemotherapy is estimated to be about 10%. This risk increases up to 15-20% depending on type and combination of anticancer drugs. Hormonal and supportive therapies are also associated with increased risk for thrombembolic complications. Emerging data support the hypothesis that the occurrence of venous thrombembolic events in cancer patients is associated with a poor prognosis. The benefit of antithrombotic prophylaxis for venous thrombembolism in cancer patients receiving chemotherapy remains to be established. A randomized, placebo controlled, double blind trial (the PROTECHT study) designed to evaluate the efficacy and safety of the low-molecular-weight heparin nadroparin in the prophylaxis of venous and arterial thrombembolic events during chemotherapy has been recently completed and the results are currently analysed.

Treatment of endothelium with the chemotherapy agent vincristine affects activated protein C generation to a greater degree in newborn plasma than in adult plasma

INTRODUCTION

Activated protein C (APC) is well-established as a physiologically important anticoagulant. During development, plasma concentrations of protein C and alpha(2)macroglobulin, factors involved in APC generation, differ from adult levels. Chemotherapy drugs can perturb endothelial expression of PC-activating receptors. This study examines the effect of chemotherapy treatment of endothelium on APC generation in newborn and adult plasma.

MATERIALS AND METHODS

APC generations were initiated on endothelial cells treated with vincristine or media by recalcifying defibrinated plasma with buffer containing thromboplastin. APC generation was terminated by mixing timed subsamples into FFRCMK-EDTA or heparin, followed by EDTA. APC-PCI and APC-alpha(1)AT were assayed by ELISA. APC-alpha(2)M was measured chromogenically. Since heparin converts free APC to APC-PCI, the difference between APC-PCI detected in heparin subsamples and APC-PCI detected in FFRCMK-EDTA subsamples gave the free APC. Cellular expression of EPCR and TM were measured by flow cytometry and Western blot.

RESULTS

Vincristine-treated endothelium decreased free APC generation in newborn plasma to a greater degree than in adult plasma. APC-PCI levels in both adult and newborn plasma were unaffected by chemotherapy. Vincristine treatment reduced levels of APC-alpha(1) AT and APC-alpha(2) M to a greater degree in newborn plasma versus adult plasma. Expression of EPCR was reduced in cells treated with vincristine. Conversely, TM was reduced on the cell surface, but increased in whole cell lysates.

CONCLUSIONS

The differential response of newborn and adult plasma PC components to chemotherapy-mediated changes in cell surface components may be a factor in the increased risk of thrombosis in children receiving chemotherapy.

Severe acute hypertriglyceridemia during acute lymphoblastic leukemia induction successfully treated with plasmapheresis

Children suffering from Acute Lymphoblastic Leukaemia (ALL) treated with asparaginase and corticosteroids are at risk of developing severe lipid abnormalities. The authors report the case of a 10-year-old male with extremely high plasma triglyceride concentrations (4,000 mg/dl) during the induction phase of ALL associated with mild pancreatitis. Hypertriglyceridemia was successfully managed with plasmapheresis with a decrease in triglyceride levels to 590 mg/dl. Apheresis appears to be safe and effective in reducing hypertriglyceridemia and preventing related complications.

Low-molecular-weight heparin in cancer-associated thrombosis: treatment, secondary prevention, and survival

OBJECTIVES

Venous thromboembolism (VTE) occurs more frequently in cancer patients than in non-cancer patients and outcomes are poor in patients with both cancer and thrombosis. Patients with cancer who develop thrombosis are more likely to experience a recurrence of VTE and have increased bleeding complications while receiving oral anticoagulant treatment. The purpose of this paper is to discuss the causes and outcomes of thrombosis in cancer patients, the limitations of warfarin therapy, the guidelines and data for the use of low-molecular-weight heparins (LMWHs) in the treatment and secondary prevention of thrombosis in cancer patients, and emerging data regarding survival with the use of LMWH in cancer patients.

METHODS

Literature for this paper has been collected using multiple sources, including primary, secondary, and tertiary references. Online searches have been conducted utilizing the PubMed and OVID databases, and abstracts from the Proceedings of the American Society of Clinical Oncology and the American Society of Hematology Annual Meeting and Exhibition. The following key terms were used in the search: cancer, deep vein thrombosis, pulmonary embolism, anticoagulation, LMWHs, guidelines, survival, cost.

RESULTS

The long-term use of LMWHs in the settings of cancer and thrombosis are supported by recent clinical trial evidence that demonstrate their equivalent safety and improved efficacy when compared to oral anticoagulants resulting in their inclusion in current guidelines. Finally, newer studies offer further evidence of improved outcomes with dalteparin and nadroparin, including possible survival benefits.

CONCLUSIONS

Treatment with LMWHs has been shown to be more effective than warfarin in the extended treatment of VTE in patients with cancer and is safe in this setting. Use of a LMWH for at least the first 3-6 months of long-term treatment is now considered the standard of care for patients with cancer and is recommended in numerous guidelines. Additionally, further evaluation of the survival benefits of LMWH in cancer patients is warranted.