The risk of thrombosis in patients with acute leukemia: occurrence of thrombosis at diagnosis and during treatment

Cerebral venous thrombosis in adult patients with acute lymphoblastic leukemia or lymphoblastic lymphoma during induction chemotherapy with l-asparaginase: The GRAALL experience

Central nervous system (CNS) thrombotic events are a well-known complication of acute lymphoblastic leukemia (ALL) induction therapy, especially with treatments including l-asparaginase (l-ASP). Data on risk factors and clinical evolution is still lacking in adult patients. We report on the clinical evolution of 22 CNS venous thrombosis cases occurring in 708 adults treated for ALL or lymphoblastic lymphoma (LL) with the Group for Research on Adult Acute Lymphoblastic Leukemia (GRAALL)-induction protocol, which included eight L-ASP (6,000 IU/m(2) ) infusions. The prevalence of CNS thrombosis was 3.1%. CNS thrombosis occurred after a median of 18 days (range: 11-31) when patients had received a median of three l-ASP injections (range: 2-7). Patients with CNS thrombosis exhibited a median antithrombin (AT) nadir of 47.5% (range: 36-67%) at Day 17 (range: D3-D28), and 95% of them exhibited AT levels lower than 60%. There were no evident increase in hereditary thrombotic risk factors prevalence, and thrombosis occurred despite heparin prophylaxis which was performed in 90% of patients. Acquired AT deficiency was frequently detected in patients with l-ASP-based therapy, and patients with CNS thrombosis received AT prophylaxis (45%) less frequently than patients without CNS thrombosis (83%), P = 0.0002). CNS thrombosis was lethal in 5% of patients, while 20% had persistent sequelae. One patient received all planned l-ASP infusions without recurrence of CNS thrombotic whereas l-ASP injections were discontinued in 20 patients during the management of thrombosis without a significant impact on overall survival (P = 0.4).

A Phase 2 study of L-asparaginase encapsulated in erythrocytes in elderly patients with Philadelphia chromosome negative acute lymphoblastic leukemia: The GRASPALL/GRAALL-SA2-2008 study

PURPOSE

The GRASPALL/GRAALL-SA2-2008 Phase II trial evaluated the safety and efficacy of L-asparaginase encapsulated within erythrocytes (GRASPA®) in patients ≥ 55 years with Philadelphia chromosome-negative acute lymphoblastic leukemia.

FINDINGS

Thirty patients received escalating doses of GRASPA® on Day 3 and 6 of induction Phases 1 and 2. The primary efficacy endpoint was asparagine depletion < 2 µmol/L for at least 7 days. This was reached in 85 and 71% of patients with 100 and 150 IU/kg respectively but not with 50 IU/kg. Grade 3/4 infection, hypertransaminasemia, hyperbilirubinemia and deep vein thrombosis occurred in 77, 20, 7, and 7% of patients, respectively. No allergic reaction or clinical pancreatitis was observed despite 17% of Grade 3/4 lipase elevation. Anti-asparaginase antibodies were detected in 50% of patients and related to a reduction in the duration of asparagine depletion during induction Phase 2 without decrease of encapsulated L-asparaginase activity. Complete remission rate was 70%. With a median follow-up of 42 months, median overall survival was 15.8 and 9.7 months, in the 100 and 150 IU/kg cohorts respectively.

CONCLUSIONS

The addition of GRASPA®, especially at the 100 IU/kg dose level, is feasible in elderly patients without excessive toxicity and associated with durable asparagine depletion. (clinicaltrials.gov identifier NCT01523782).

Patterns of Venous Thromboembolism Prophylaxis During Treatment of Acute Leukemia: Results of a North American Web-Based Survey

BACKGROUND

Venous thromboembolism (VTE) occurs in 2% to 12% of patients with acute leukemia (AL) despite disease- and therapy-associated thrombocytopenia, and it can be associated with significant morbidity and mortality. Because of the few high-quality studies, there are no evidence-based guidelines for VTE prophylaxis in this patient population. We sought to determine the spectrum of practice regarding prevention of VTE in patients with AL during induction and consolidation therapies.

METHODS

We conducted a 19-question Web-based survey directed at North American providers caring for these patients. One hundred fifty-one of 215 responses received were eligible for analysis, with a response rate of 20.9% among physicians who treated leukemias.

RESULTS

Overall, 47% and 45% of providers reported using pharmacologic VTE prophylaxis during induction and consolidation phases, respectively. Approximately 15% of providers did not provide any VTE prophylaxis, while 36% used mechanical methods and ambulation. Among providers who did not recommend pharmacologic prophylaxis, the most commonly cited reasons were the perceived high risk of bleeding (51%), absence of data supporting use (38%), and perceived low risk of VTE (11%).

CONCLUSION

Large, prospective studies are needed to define the safest and most effective approach to VTE prevention in patients with AL.

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.

Lymphoma and venous thromboembolism: influence on mortality

BACKGROUND

The population-based incidence of acute venous thromboembolism (VTE) in adult patients diagnosed with non-Hodgkin's lymphoma has not been established, and the effect of VTE on survival is not clear.

AIM

To determine the incidence of acute VTE in California residents diagnosed with lymphoma, and to determine the effect of acute VTE on survival.

METHODS

We used the California Cancer Registry coupled with the California Patient Discharge database to identify incident cases with lymphoma, 1991-1997, and the incidence of first-time VTE in these patients. Multivariable models were constructed to evaluate risk of developing acute VTE within 2 years, and a proportional hazard model was used to predict death within 2 years, using acute VTE as a time-dependent covariate.

RESULTS

There were 16,755 patients diagnosed with non-Hodgkin's lymphoma; 29% had low-grade, 66% intermediate/aggressive grade and 5.6% had high-grade lymphoma. Acute VTE developed in 3.6% of the patients by year 1 and 4.0% by the end of year 2. Significant predictors of acute VTE included advanced stage lymphoma, number of chronic comorbidities and advancing age. Significant predictors of death within 2 years included diagnosis of acute VTE, advanced stage disease, increasing number of co-morbidities, age over 75 years and intermediate or high grade histopathology. The effect of acute VTE on death increased as the time between lymphoma diagnosis and VTE diagnosis increased (HR=1.7 95%CI:1.5-1.9 for VTEs <6 months; HR=6.5 95%CI:4.7-8.9 VTEs 12-24 months).

CONCLUSIONS

Acute VTE developed frequently in patients with lymphoma, and VTE was a strong predictor of decreased survival.

Thrombo-hemorrhagic deaths in acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) has become the most curable form of acute myeloid leukemia after the advent of all-trans retinoic acid (ATRA). However, early deaths (ED) mostly due to the disease-associated coagulopathy remain the major cause of treatment failure. In particular, hemorrhagic events account for 40-65% of ED and several prognostic factors have been identified for such hemorrhagic deaths, including poor performance status, high white blood cell (WBC) count and coagulopathy. Occurrence of thrombosis during treatment with ATRA may be associated with differentiation syndrome (DS) or represent an isolated event. Some prognostic factors have been reported to be associated with thrombosis, including increased WBC or aberrant immunophenotype of leukemic promyelocytes. Aim of this review is to report the incidence, severity, possible pathogenesis and clinical manifestations of thrombo-haemorrhagic deaths in APL.

ATRA-induced cerebral sinus thrombosis

All-trans retinoic acid (ATRA) and Idarubicin are part of the AIDA protocol employed for the treatment of Acute promyelocytic leaukaemia (APML) and has been associated with marked improvement in the prognosis. However, it is known to worsen the haematological picture during the course of induction of therapy. Herein, we present a case of an APML patient who developed a rare documented incidence of cerebral sinus thrombosis, first noticed as an ophthalmology referral. This 22 year old lady, a known APML patient was then started on chemotherapy based on AIDA protocol but 17 days into the initiation of therapy, she began to complain of blurred vision on the right eye. Anterior segments were normal but both fundi showed papilloedema with peripapillary haemorrhages. A contrast MRI that was then ordered showed multiple filling defects in numerous venous sinuses. She was started on anticoagulant treatment and the findings resolved. Though a rare case of its side-effects, ATRA usage in APML has a multitude of presentations since its primary pathology lies in the inherent pro-coagulant potential.

Implications of cytogenetics for venous thromboembolism in acute myeloid leukaemia

Due to the high risk of thrombocytopenia and haemorrhage, thrombotic complications have received little attention in patients with acute myeloid leukemia (AML). Furthermore, the predictive role of cytogenetics on venous thromboembolism (VTE) has largely been ignored. This study aimed to evaluate the incidence, risk factors, and prognostic aspects of VTE in AML. A total of 811 consecutive patients with AML were enrolled and analysed retrospectively. Cox time-dependent covariate regression analysis was used to identify the significant predictors of VTE development. To minimise potential confounding factors, we used propensity-score matching to compare overall survival between patients with and without VTE. The six-month and one-year cumulative incidences of VTE were 3.1 % (95 % confidence interval [CI], 2.0-4.7) and 3.9 % (95 % CI, 2.6-5.7), respectively. Of the 26 cases of VTE, 22 (85 %) developed within 6 months of leukemia diagnosis and 13 (50 %) were catheter-related. In multivariate analysis, advanced age (≥ 65 years) (hazard ratio [HR], 2.70; p = 0.03) and increasing cytogenetic risk (common HR, 1.84; p = 0.05) were independent predictors of VTE. There was no significant association between VTE development and decreased survival (p = 0.32 for matched analysis). Advanced age and increasing cytogenetic risk, well-known predictors for clinical outcome in AML, were also independent risk factors of VTE development. Our results suggest that VTE does not hold prognostic implications for AML.

A retrospective study of venous thromboembolism in acute leukemia patients treated at the University of Texas MD Anderson Cancer Center

The purpose was to determine the incidence and prevalence of venous thromboembolism (VTE) in acute leukemia patients from our institution. We conducted a retrospective study on newly diagnosed acute leukemia patients who presented at our institution from November 1999 to May 2005. Descriptive statistics and cross-tabulation were used to describe patient characteristics. Measures of morbidity were used to address VTE risk. Chi-square testing, Fisher's exact testing, Mann-Whitney analyses, or median testing were used to determine between-group differences. Data analyses were conducted using Stata version 11 (Stata Corp., College Station, TX). Two hundred and ninety-nine patients with acute lymphoblastic leukemia (ALL) and 996 patients with acute myeloid leukemia (AML) were included. After excluding patients diagnosed with VTE prior to or at the time of leukemia diagnosis, during the mean time follow-up period of 2.5 years (range: 0.0025-10.3 years), the overall incidence rate of VTE was 3.7 per 100 person-years: 4.2 per 100 person-years for ALL and 3.4 per 100 person-years for AML. Among all patients, the majority (80.6%) developed VTE within 12 months after diagnosis and during thrombocytopenia. The most common VTE was central venous catheter (CVC)-associated upper-extremity deep venous thrombosis. Pulmonary embolism occurred in 15% of ALL patients and 8% of AML patients. VTE recurred in 20.7% of ALL patients and 18.6% of AML patients. VTE occurs frequently in patients with acute leukemia. Studies are needed to identify risk factors for the development and recurrence of VTE among patients with acute leukemia and to establish more effective methods for preventing and treating VTEs in leukemia patients who have thrombocytopenia and/or CVC.

Prompt recognition and percutaneous coronary intervention leads to favorable myocardial recovery after ST-segment elevation myocardial infarction secondary to acute promyelocytic leukemia: pediatric case report

Acute myocardial infarction (AMI) is extremely rare in children, and unlike the adult disease, the etiology of the infarction is rarely due to atherosclerotic coronary disease. This unique reported case involved a 15-year-old boy with severe chest pain who presented with an ST-segment-elevation myocardial infarction secondary to in situ thrombus formation in the left anterior descending (LAD) coronary artery. The initial electrocardiogram (ECG) had a Q-wave pattern in V6 and ST depression in the inferior leads with ST-segment elevation in reciprocal leads. The cardiac enzymes and routine labs showed evidence of myocardial damage. The boy was urgently taken to the cardiac catheterization laboratory for percutaneous coronary intervention, where complete occlusion of the LAD was found and successfully stented. Eventually, a peripheral blood smear showed pancytopenia with 38 % hypergranular blast-like cells consistent with acute myeloid leukemia (AML), and chemotherapy with all-transretinoic acid was implemented. This first pediatric case report of an AML-associated AMI emphasizes the benefit resulting from expedient reperfusion of the ischemic myocardium by quick reestablishment of coronary perfusion. It also emphasizes the limitations of existing noninvasive technologies in detecting myocardial viability.

Contributing role of extracellular vesicles on vascular endothelium haemostatic balance in cancer

Extracellular vesicles (EVs) generated during tumourigenesis are thought to play a major role in the hypercoagulant state observed in cancer patients. They exhibit negatively charged phospholipids and tissue factor (TF) that promote coagulation cascade activation. In addition, they contain surface proteins and cytoplasmic molecules, both originating from the producing cell that can impact target cells’ expression. By targeting endothelial cells of blood vessels, these EVs could disturb the physiological anticoagulant properties of these cells and be partly responsible for the vascular endothelium activation observed in cancer patients. Indeed, vascular endothelium naturally exhibits heparin-like proteoglycan, TF pathway inhibitor and protein C anticoagulant pathway that prevent thrombosis in physiological condition. An overexpression of TF and a decreased expression of coagulation cascade inhibitors have been reported after EVs’ treatment of endothelial cells. The induction of apoptosis and an increased expression of platelet adhesion molecules have also been highlighted. These events may promote thrombus formation in cancer. The aim of this paper is to provide a targeted review on the current evidence and knowledge of roles and impact of EVs on endothelial surface anticoagulant and procoagulant factors and cellular adhesion molecules expression.

Risk of thrombosis in women with malignancies undergoing ovarian stimulation for fertility preservation

BACKGROUND

Compared with the general population, cancer patients have a higher risk of venous thromboembolism as well as arterial thrombotic events such as stroke, myocardial infarction and peripheral arterial embolism. Therefore a possible concern for women with malignancies undergoing ovarian stimulation for fertility preservation is the increased risk of venous or arterial thrombosis.

METHODS

In this article, we revised current available literature on the risk of thrombosis in patients with cancer and in women undergoing ovarian stimulation, with the ultimate aim of drawing some indications for preventive measures.

RESULTS

Unfortunately, there are no specific data on the risk of thrombosis in women with cancer undergoing ovarian stimulation for fertility preservation. However, the literature suggests that the cancer type and stage, surgery, and chemotherapy all influence the risk of venous and, possibly, arterial thrombosis. Reports of cases of ovarian stimulation in women without malignancies have shown that venous thrombosis rarely occurs unless a pregnancy is achieved, while arterial thrombosis can occur in the absence of pregnancy but is usually only associated with ovarian hyperstimulation syndrome (OHSS). OHSS increases the risk of thrombotic events, but only the early form of the syndrome is relevant for women undergoing fertility preservation.

CONCLUSIONS

The available evidence on the risks of thrombosis for women undergoing ovarian stimulation for fertility preservation due to a malignancy is reassuring. However the avoidance of the early form of OHSS in women preserving oocytes/embryos due to malignancy is crucial. For these cycles, we advocate the use of a regimen of ovarian stimulation with gonadotrophin releasing hormone (GnRH) antagonists using GnRH agonists to trigger ovulation, an approach that has been shown to markedly reduce the risk of OHSS. Antithrombotic prophylaxis should be administered only to selected subgroups of women such as those with other risk factors or those who do develop early OHSS.

Thrombosis and hemostatic abnormalities in hematological malignancies

There is a paucity of data that pertain to thrombosis in patients with hematological malignancies. Recent studies showed that patients with lymphoma, multiple myeloma, and acute leukemia have an increased thrombotic risk, particularly at the time of diagnosis and during chemotherapy. We searched the PubMed database for articles on thromboembolic complications in patients with hematological malignancies published between 1996 and 2013. The incidence of thrombotic events is variable, and is influenced by the type and the stage of hematological malignancy, the antitumor therapy, and the use of central venous devices. The pathogenesis of thromboembolic disease in hematological malignancies is multifactorial. Tumor cell-derived procoagulant, fibrinolytic, or proteolytic factors, and inflammatory cytokines affect clotting activation, and chemotherapy and immunomodulatory drugs increase the thrombotic risk in patients with lymphoma, acute leukemia, and multiple myeloma. Infections might also contribute to the pathogenesis of the thromboembolic complications: endotoxins from gram-negative bacteria induce the release of tissue factor, tumor necrosis factor and interleukin-1b, and gram-positive organisms can release bacterial mucopolysaccharides that directly activate factor XII. In the setting of plasma cell dyscrasias, hyperviscosity, decreased fibrinolysis, procoagulant autoantibody production, inflammatory cytokines, acquired activated protein C resistance, and the prothrombotic effects of antimyeloma agents might be the cause of thromboembolic complications. Anticoagulant therapy is very complicated because of high risk of hemorrhage. Therefore, an accurate estimate of a patient's thrombotic risk is essential to allow physicians to target thromboprophylaxis in high-risk patients.

[Acute promyelocytic leukaemia]

BACKGROUND

Acute promyelocytic leukaemia (APL) is a subtype of acute myeloid leukaemia (AML) with unique biological and clinical features and unique therapeutic requirements. The article provides a brief description of the development, pathophysiology, diagnosis and treatment of APL.

METHOD

The article is based on the authors' own experience and reviews of key articles and national and international guidelines.

RESULTS

The disease is caused by a single genetic event, namely the translocation t(15;17), which gives rise to the oncoprotein PML-RARA. Clinical and morphological characteristics arouse suspicion of the disease, and the diagnosis is verified by detecting the translocation. At the time of diagnosis most patients have severe coagulopathy and the predominant clinical manifestation is bleeding. Early mortality is due to severe haemorrhage, usually intracranial. Early treatment start with all-trans retinoic acid (ATRA) on suspicion of APL is essential to reduce this early mortality. ATRA is also an important part of continued treatment, in combination with anthracycline-based chemotherapy and possibly arsenic. After this treatment, the prognosis for disease-free long-term survival is > 90%. There are also safe and effective treatment options for elderly patients with complex comorbidities.

INTERPRETATION

With APL it is particularly important to start disease-targeting therapy in the form of ATRA quickly because of the high risk of serious haemorrhages and high early mortality. If serious haemorrhages are avoided, the prognosis is very good.

Thrombomodulin alfa treatment in patients with acute promyelocytic leukemia and disseminated intravascular coagulation: a retrospective analysis of an open-label, multicenter, post-marketing surveillance study cohort

INTRODUCTION

Patients with acute promyelocytic leukemia (APL) can develop disseminated intravascular coagulation (DIC) that results in life-threatening hemorrhagic complications. Studies regarding the safety and efficacy of thrombomodulin alfa (TM-α; recombinant human soluble thrombomodulin) in patients with APL and DIC are limited.

MATERIALS AND METHODS

A retrospective evaluation was performed on a cohort of 172 patients with APL from an open-label, multicenter, post-marketing surveillance study of TM-α.

RESULTS

Of the 172 patients, 31 were relapse/refractory APL patients, and 141 were newly diagnosed APL patients. Within the first 30 days, 24 patients (14.0%) died, and six of those deaths (3.5%) were due to hemorrhage. In total, 12 patients (7.0%) had severe hemorrhagic complications. Both the early death rate due to hemorrhage as well as the severe hemorrhage rate did not exceed those in some recent population-based studies of patients with APL. Forty-nine patients received TM-α prior to the initiation of antileukemic treatment, and one patient experienced hemorrhagic early death (ED), suggesting that early TM-α treatment appeared to result in a reduction in the hemorrhagic ED rate. Moreover, TM-α improved coagulopathy regardless of concomitant all-trans retinoic acid treatment.

CONCLUSIONS

This study confirmed the safety and efficacy of TM-α in daily clinical practice for patients with APL and DIC. TM-α appeared to reduce hemorrhagic early deaths due to DIC in patients with APL who were receiving antileukemic treatment.

Assessing the risk and prognosis of thrombotic complications in cancer patients

CONTEXT

Cancer is characterized by the development of a prothrombotic state. Approximately 15% to 20% and 1.5% to 3.1% of cancer patients develop venous and arterial thrombosis, respectively, whereas 18% to 20% of idiopathic venous events are caused by an occult neoplasia. The highest risk is observed in hematologic, gastrointestinal, and lung malignancies, as well as in patients with active disease, especially in the first 3 months after cancer diagnosis. Hospitalization, surgical interventions, and implanted venous devices increase the thrombotic risk. Patients with metastatic disease, febrile neutropenia, infections, and severe comorbidities experience more frequently a thrombotic event. A contemporary prechemotherapy predictive model incorporates both clinical and biologic parameters, such as the primary cancer site, platelet count, white blood cell count, hemoglobin, use of erythropoietic agents, and body mass index. Several studies aim to clarify the prognostic value of tissue factor, P-selectin, thrombin generation, microparticles, and D-dimers.

OBJECTIVES

To summarize current views on epidemiology, risk factors, and predictive variables, discussing the future perspectives and existing limitations in clinical practice.

DATA SOURCES

Review of published literature, including review papers, epidemiologic studies, and clinical trials, in online medical databases.

CONCLUSIONS

The thrombogenic properties of tumor cells affect the prognosis and quality of life for the cancer population. Despite the improved awareness and prompt use of thromboprophylaxis, recent studies reported increased rates of thrombotic events, whereas the annual risks for thrombosis recurrence and bleeding are 21% and 12%, respectively. The clinical use of risk factors and prognostic parameters could allow for patient risk stratification and individualization of anticoagulant treatment.

Phosphatidylserine index as a marker of the procoagulant phenotype of acute myelogenous leukemia cells

Patients with acute myelogenous leukemia (AML) are at risk for thrombotic complications. Risk to develop thrombosis is closely tied to leukemia subtype, and studies have shown an association between leukocytosis and thrombosis in AML M3. We evaluated the relative roles of cell count and the surface expression of tissue factor (TF) and phosphatidylserine (PS) in the procoagulant phenotype of AML cell lines. The TF-positive AML M3 cell lines, NB4 and HL60, and AML M2 cell line, AML14, exhibited both extrinsic tenase and prothrombinase activity in a purified system and promoted experimental thrombus formation. In contrast, the TF-negative AML cell line, HEL, exhibited only prothrombinase activity and did not affect the rate of occlusive thrombus formation. In plasma, NB4, HL60 and AML14 shortened clotting times in a cell-count, PS- and TF-dependent manner. Exposure of cultured NB4, HL60, and AML14 cells to the chemotherapeutic agent daunorubicin increased their extrinsic tenase activity and PS expression. Clot initiation time inversely correlated with logarithm of PS index, defined as the product of multiplying leukocyte count with cell surface PS exposure. We propose that leukemia cell PS index may serve as a biomarker for procoagulant activity.

Infections increase the risk of central venous catheter-related thrombosis in adult acute myeloid leukemia

INTRODUCTION

Central venous catheters (CVC) related thrombosis (CRT) represents a well known complication in patients with acute myeloid leukemia (AML) receiving intensive chemotherapy but the efficacy of antithrombotic prophylaxis still remains controversial.

PATIENTS AND METHODS

We analyzed 71 consecutive AML patients whose CVC was inserted before each chemotherapy cycle for an overall number of 106 CVC placements. In 47/106 insertions, a prophylaxis with 100 IU/kg/day low molecular weight heparin (LMWH) was administered for 7 days after CVC insertion and additional 7 after CVC removal. This unconventional dose of LMWH, although higher than usual, appeared adequate for a short-course approach. LMWH was delivered regardless of the platelet (PLT) count once provided that it should have been maintained above 20 x 10(9)/L by transfusions.

RESULTS

Of 106 insertions, we observed 19 (18%) episodes of CRT, 58 (54%) of sepsis and 50 (47%) infections of CVC-exit site with no difference between LMWH and no-LMWH group. Occurrence of CRT was significantly associated with CVC-exit site infections (14/19, p=0.01) and sepsis (16/19, p=0.005) with no difference between LMWH and no-LMWH group. In multivariate analysis, both CVC-exit site infections and sepsis were confirmed to be independent risk factors for CRT development.

CONCLUSION

Our retrospective study, although based on a small sample size, suggests that the occurrence of CVC-exit site infections and neutropenic sepsis following chemotherapy significantly increases the risk of CRT in AML, independently from the use of LMWH prophylaxis.

Acute promyelocytic leukemia-associated thrombosis

Patients with acute promyelocytic leukemia (APL) are prone to both bleeding and thrombosis. The bleeding complications are well known. In contrast, APL-associated thrombosis is relatively underappreciated. We aimed to explore the issue of APL-associated thrombosis events. In the past 20 years, 127 cases with APL were found in our hospital database. We collected their coagulation laboratory profiles, including leukemia burdens, white blood cell and platelet counts, prothrombin time, activated partial thromboplastin time, fibrinogen levels, and disseminated intravascular coagulation scores. Data were compared between patients with or without thrombosis. Clinical outcomes and potential risk factors were obtained for analysis. Ten cases with APL-associated thrombosis were found. The incidence of thrombosis was 7.9% in our cohort. Five patients had cerebral infarction, 5 had catheter-related thrombosis and 1 had acute myocardial infarction. No laboratory data were associated with clinical thrombosis. Three patients died during the induction phase but thrombosis was not the direct cause of death for any of them. We conclude that patients with APL are susceptible to thrombosis in addition to bleeding. Laboratory coagulation parameters did not predict thrombosis in our series. Ischemic stroke and catheter-related thrombosis were the most common events in our Taiwanese cohort. Such a thrombosis pattern is unique and worth further investigation.

Thrombosis in acute promyelocytic leukemia

INTRODUCTION

Compared to bleeding, major thromboses are a less commonly encountered problem in acute promyelocytic leukemia (APL), and our knowledge about the epidemiology of major thromboses in APL stems mainly from individual case reports. The purpose of this study was to provide a better understanding of the epidemiology of APL-related thrombosis as a first step towards developing preventive strategies.

MATERIALS AND METHODS

We report a rare case of catastrophic acute myocardial infarction in a patient with APL while she developed the all-trans retinoic acid (ATRA) syndrome. We describe the pathogenesis of APL-related thrombosis and review all previously reported cases of major thromboses in APL.

RESULTS

We found 94 cases of major thromboses in patients with APL. Both genders were almost equally affected. More than 80% of events occurred before or during induction therapy with deep vein thrombosis/pulmonary embolism (DVT/PE), cardiac events, and cerebrovascular accidents (CVA) constituting more than 75% of all cases. Arterial events were slightly more common than venous events. Only 2 arterial events occurred after completion of induction therapy. Thrombosis was associated with life-threatening hemorrhage in about 15%, significant coagulative defects in about 50%, and ATRA syndrome in about 13% of cases. Cardiac thrombotic events, DVT/PE, and CVA were associated with ATRA syndrome in 24%, 4.5%, and 5% of cases, respectively (p=0.09). None of the observed trends and associations reached statistical significance.

CONCLUSIONS

This review advances our understanding of the epidemiology of major thromboses in APL. With accumulation of more cases in the literature, some of our results may become statistically significant.

Do circulating tumor cells play a role in coagulation and thrombosis?

Cancer induces a hypercoagulable state, and patients with cancer who suffer a thrombotic event have a worse prognosis than those who do not. Recurrent pathologic thrombi in patients with cancer are clinically managed with anticoagulant medications; however, anticoagulant prophylaxis is not routinely prescribed owing to a complex variety of patient and diagnosis related factors. Early identification of patients at risk for cancer-associated thrombosis would allow for personalization of anticoagulant prophylaxis and likely reduce morbidity and mortality for many cancers. The environment in which a thrombosis develops in a patient with cancer is complex and unique from patients without cancer, which creates therapeutic challenges but may also provide targets for the development of clinical assays in this context. Circulating tumor cells (CTCs) may play a role in the association between cancer and thrombosis. Cancer metastasis, the leading cause of cancer-related deaths, is facilitated by the hematogenous spread of CTCs, and CTCs accompany metastatic disease across all major types of carcinomas. The role of CTCs in the pathogenesis of thrombosis has not been studied due to the previous difficulty in identifying these rare cells, but the interaction between these circulating cells and the coagulation system is an area of study that demands attention. The development of CTC detection platforms presents a new tool by which to characterize the role for CTCs in cancer-related hypercoagulability. In addition, this area of study presents a new avenue for assessing the risk of cancer-associated thrombosis and represents a potential tool for predicting which patients may benefit from anticoagulant prophylaxis. In this review, we will discuss the evidence in support of CTC induced hypercoagulability, and highlight areas where CTC-detection platforms may provide prognostic insight into the risk of developing thrombosis for patients with cancer.

Recombinant human soluble thrombomodulin safely and effectively rescues acute promyelocytic leukemia patients from disseminated intravascular coagulation

We treated individuals for disseminated intravascular coagulation (DIC) caused by acute promyelocytic leukemia (APL) (n=9) using human soluble thrombomodulin (rTM) in combination with all-trans retinoic acid (ATRA) and chemotherapy, and compared the clinical outcomes with historical control patients (n=8) treated with ATRA and/or chemotherapy. Two control patients developed intracranial vascular incidents. On the other hand, no bleeding related mortality was noted in rTM-treated patients. Notably, treatment with rTM rescued patients from DIC earlier than historical controls (log rank test, p=0.019). These results suggest that administration of rTM should be considered for the treatment of individuals with DIC associated with APL.

Thrombosis and acute leukemia

Thrombosis is a common complication in patients with acute leukemia. While the presence of central venous lines, concomitant steroids, the use of Escherichia coli asparaginase and hereditary thrombophilic abnormalities are known risk factors for thrombosis in children, information on the pathogenesis, risk factors, and clinical outcome of thrombosis in adult patients with acute lymphoid leukemia (ALL) or acute myeloid leukemia (AML) is still scarce. Expert consensus and guidelines regarding leukemia-specific risk factors, thrombosis prevention, and treatment strategies, as well as optimal type of central venous catheter in acute leukemia patients are required. It is likely that each subtype of acute leukemia represents a different setting for the development of thrombosis and the risk of bleeding. This is perhaps due to a combination of different disease-specific pathogenic mechanisms of thrombosis, including the type of chemotherapy protocol chosen, the underlying patients health, associated risk factors, as well as the biology of the disease itself. The risk of thrombosis may also vary according to ethnicity and prevalence of hereditary risk factors for thrombosis; thus, it is advisable for Latin American, Asian, and African countries to report on their specific patient population.

Bleeding and thrombosis in acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) has evolved from being a deadly to a highly curable disease, due to targeted molecular therapy with all-trans retinoic acid (ATRA). As a result, the incidence of early hemorrhagic deaths for which APL is notorious has reduced to 5-10% as reported in clinical trials. These results are not replicated outside of clinical trials as is evident from recent population-based registries. High incidence of early hemorrhagic deaths remains the greatest contributor to treatment failure in this otherwise curable leukemia. Additionally, thrombosis is now being increasingly recognized in APL patients and may be associated with ATRA usage.

Risk of venous thromboembolism in patients with cancer: a systematic review and meta-analysis

BACKGROUND

People with cancer are known to be at increased risk of venous thromboembolism (VTE), and this risk is believed to vary according to cancer type, stage of disease, and treatment modality. Our purpose was to summarise the existing literature to determine precisely and accurately the absolute risk of VTE in cancer patients, stratified by malignancy site and background risk of VTE.

METHODS AND FINDINGS

We searched the Medline and Embase databases from 1 January 1966 to 14 July 2011 to identify cohort studies comprising people diagnosed with one of eight specified cancer types or where participants were judged to be representative of all people with cancer. For each included study, the number of patients who developed clinically apparent VTE, and the total person-years of follow-up were extracted. Incidence rates of VTE were pooled across studies using the generic inverse variance method. In total, data from 38 individual studies were included. Among average-risk patients, the overall risk of VTE was estimated to be 13 per 1,000 person-years (95% CI, 7 to 23), with the highest risk among patients with cancers of the pancreas, brain, and lung. Among patients judged to be at high risk (due to metastatic disease or receipt of high-risk treatments), the risk of VTE was 68 per 1,000 person-years (95% CI, 48 to 96), with the highest risk among patients with brain cancer (200 per 1,000 person-years; 95% CI, 162 to 247). Our results need to be considered in light of high levels of heterogeneity, which exist due to differences in study population, outcome definition, and average duration of follow-up between studies.

CONCLUSIONS

VTE occurs in greater than 1% of cancer patients each year, but this varies widely by cancer type and time since diagnosis. The absolute VTE risks obtained from this review can aid in clinical decision-making about which people with cancer should receive anticoagulant prophylaxis and at what times.

Hematologic malignancies and thrombosis

Patients with hematologic malignancies have an increased risk of venous thromboembolism (VTE), particularly at diagnosis and during the treatment with chemotherapy, asparaginase or immunomodulatory drugs (IMiDs). A disease-dependent hypercoagulable condition associated with other risk factors like drugs, central venous catheter (CVC), immobility and infections are responsible for this high VTE rate. Thrombotic complications have a significant impact on morbidity and in some cases also on mortality of patients with onco-hematologic diseases, therefore thromboprophylaxis to prevent VTE in this setting is needed. However, thrombocytopenia and hemorrhagic complications pone many difficulties in the management of an anticoagulant or antiaggregant treatment in these patients. Recommendations from current guidelines are limited to multiple myeloma patients treated with thalidomide or lenalidomide associated with dexamethasone or chemotherapy, but hematological clinical departments should implement a policy for prevention and treatment of thromboembolic complications in hematologic malignancies.

Risk of recurrent venous thromboembolism according to malignancy characteristics in patients with cancer-associated thrombosis: a systematic review of observational and intervention studies

Patients with cancer-associated venous thromboembolism (VTE) should be treated with low molecular weight heparin. The ideal duration of anticoagulation in this population is unknown. It is important to evaluate whether there is variation in susceptibility for recurrent VTE according to malignancy characteristics. In this systematic review we sought to evaluate cancer characteristics that may influence the risk for VTE recurrence and the success of anticoagulation in patients with cancer-associated VTE. A systematic literature search strategy identified potential studies on MEDLINE, Embase, the Cochrane Register of Controlled Trials, MEDLINE In-Process and other nonindexed citations using the Ovid interface. There was no restriction to study design or language. No randomized controlled trials fulfilled our inclusion criteria. We included four retrospective and six prospective studies. VTE recurrence rate according to tumour stage suggested an increased risk for patients with metastatic malignancy compared with patients with localized disease (relative risk 1.36; 95% confidence interval 1.06-1.74, P = 0.01). We were unable to pool data to evaluate VTE recurrence according to tumour site and histology. The isolated evaluation of the included studies suggested that younger patients with adenocarcinoma, lung or gastrointestinal malignancy have the highest risk. There is paucity of data regarding detailed malignancy characteristics in patients with cancer-associated VTE. It appears that metastatic malignancy, or adenocarcinoma, or lung malignancy confers a higher risk of VTE recurrence than patients with localized malignancy, nonadenocarcinoma or breast cancer.

Thromboembolic and bleeding complications in acute leukemia

The risk of both thromboembolic and bleeding complications is high in acute leukemia. This double hazard has a significant negative impact on the morbidity and mortality of patients with this disease. The clinical manifestations of both complications show special features specific to the form of acute leukemia. Recognition of these characteristics is important in the diagnosis and management of acute leukemia. In this article, several additional issues are addressed, including the features of bleeding and thrombosis in acute promyelocytic leukemia, the current understanding of the leukostasis syndrome and the iatrogenic complications including catheter-associated thrombosis, and the adverse effects of therapeutic agents used in acute leukemia. As regards the bleeding complications, thrombocytopenia is a major cause. Corrective measures, including recent guidelines on platelet transfusions, are provided.

Retrievable Inferior Vena Cava Filter and Catheter Directed Thrombolysis (CDT) for Treating a 19-year-old Man with Acute Myeloid Leukemia Complicated by Deep Vein Thrombosis (DVT): A Case Report

Here, we report a case of a 19-year-old man with acute myeloid leukemia complicated by deep vein thrombosis (DVT) in which we placed a retrievable inferior vena cava (IVC) filter during catheter directed thrombolysis (CDT). We were able to retrieve the IVC filter after a successful CDT and concluded that the use of this filter might be efficacious and better than an indwelling IVC filter that is associated with long-term risks. A retrievable filter and CDT should be considered in patients who are at transient risk for phlebemphraxis and require placement of a filter.

Peripheral arterial ischemic events in cancer patients

Thromboembolic complications are the second leading cause of death in cancer patients. In contrast to the large body of literature on venous thromboembolism (VTE), relatively few reports have focused on the pathogenesis, incidence, management and outcomes of arterial thromboembolic events in patients with malignancy. The purpose of this article is to review the current literature on the etiology, mechanisms, and prognosis of arterial thromboembolic events in cancer patients and outline appropriate screening and management guidelines that may help lower the rates of morbidity and mortality related to these events.

Emerging risk stratification approaches to cancer-associated thrombosis: risk factors, biomarkers and a risk score

Cancer patients are well-known to be at increased risk of venous thromboembolism (VTE). However, the risk varies widely between patients and over the natural history of malignancy. Recent data have identified multiple clinical risk factors as well as biomarkers predictive of VTE. Risk factors include patient-associated factors such as age, obesity and medical comorbidities, cancer-associated factors such as site and stage of cancer, and treatment-associated factors, particularly chemotherapy and anti-angiogenic therapy. Biomarkers associated with increased risk of cancer-associated VTE include leukocyte count, platelet count, and levels of tissue factor, P-selectin and D-dimer. This review focuses on the evidence for risk stratification of cancer patients, based on these risk factors and biomarkers, as well as a recently validated predictive model which can be used to identify patients at highest risk. Targeted thromboprophylaxis utilizing model-based and/or biomarker-based approaches may provide an optimal risk-benefit ratio and is currently the focus of ongoing clinical trials.

Open issues on bleeding and thrombosis in acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) is a distinct subtype of acute myeloid leukemia characterized by a specific genetic alteration, affecting the retinoic acid receptor-alpha (RAR-alpha), and leading to the accumulation of the promyelocytic blasts in the bone marrow and blood which is frequently associated with a life-threatening consumptive coagulopathy. The body of biological information on APL establishes this leukemia as a unique entity that has to be promptly recognized to counteract the coagulopathy, especially in light of its striking response to treatment with all-trans retinoic acid. In fact, the current standard for induction therapy results in extremely high antileukemic efficacy, achieving 90 to 95% complete remission rate. However, while primary leukemia resistance has virtually disappeared as a cause of remission induction failure, death due to hemorrhage remains the major problem during the early treatment phase. As a part of the clotting activation commonly present in APL, thrombosis is a less recognized and probably underestimated life-threatening manifestation in patients with this disease. In addition to reviewing the available data on the incidence, outcome and prognostic factors of bleeding and thrombosis in APL, we discuss the current consensus and controversies on the most appropriate management of these complications.

Acute promyelocytic leukemia treated with idarubicin complicated by focal segmental glomerulosclerosis

The authors report a 9-year-old boy presenting with a left cerebral ischemic infarction as the first manifestation of acute promyelocytic leukemia. During consolidation chemotherapy, the patient developed nephrotic syndrome and a renal biopsy revealed focal segmental glomerulosclerosis (FSGS). Remission in bone marrow was achieved with chemotherapy, however, new intracranial ischemic areas developed on follow-up. Acute promyelocytic leukemia complicated by FSGS has not been previously reported in children. There may be a relationship between anthracycline treatment and FSGS. Thrombosis could be related with both leukemia and nephrotic syndrome, here thrombosis was the initial symptom, before FSGS was diagnosed.

Venous thromboembolism in the hematologic malignancies

Patients with hematologic malignancies are at high risk of thrombotic or hemorrhagic complications. The incidence of these events is greatly variable and is influenced by many factors, including the type of disease, the type of chemotherapy, and the use of a central venous device. As in solid tumors, a number of clinical risk factors have been identified and contribute to the increasing thrombotic rate in hematologic malignancies. Biologic properties of the tumor cells can influence the hypercoagulable state of patients with these malignancies by several mechanisms. Of interest, oncogenes responsible for neoplastic transformation in leukemia also may be involved in clotting activation. Epidemiologic data allow an estimate of the incidence of venous thromboembolism (VTE) in acute leukemia, lymphomas, and multiple myeloma (MM). In this review, we focus on the epidemiology, pathogenesis, and VTE management in these three hematologic malignancies. No recommendation for routine thromboprophylaxis in these conditions, with the exception of MM, is available. Large, prospective, randomized clinical trials are needed to establish the best practice for thromboprophylaxis and treatment of VTE in these types of cancers.

Treatment of venous thromboembolism in patients with cancer: Guidelines of the Italian Society for Haemostasis and Thrombosis (SISET)

BACKGROUND

The treatment of venous thromboembolism (VTE) in cancer patients remains controversial.

PURPOSE

The Italian Society for Thrombosis and Haemostasis (SISET) commissioned a project to develop clinical practice guidelines for the therapy of VTE in patients with malignancies.

METHODS

Key questions about the treatment of VTE in patients with malignancies were formulated by a multidisciplinary working group consisting of experts in clinical medicine and research. After a systematic review and discussion of the literature, recommendations were formulated and graded according to the supporting evidence. For those questions for which the literature search did not yield any definitive answer (absence of evidence evidence of low quality, and contradictory evidence), a formal consensus method was used to issue clinical recommendations.

RESULTS

The results of the available literature on VTE treatment in cancer patients were reviewed and clinical recommendations were drafted.

CONCLUSION

We describe the results of a systematic literature review and an explicit approach to consensus techniques which resulted in recommendations for the key therapeutic issues in cancer patients with VTE.

The coagulopathy of acute promyelocytic leukaemia revisited

Since the initial description of the disease, the life-threatening coagulopathy associated with acute promyelocytic leukaemia (APL) has been the defining clinical characteristic. Historically, this uncommon subtype of acute myeloid leukaemia has been associated with a high mortality rate during induction therapy, most frequently attributable to haemorrhage. Since the introduction of all-trans retinoic acid (ATRA) into the therapy of all patients with APL, disease-free survival and overall survival have improved dramatically, such that the disease is now highly curable. However, induction mortality remains a major problem and haemorrhage still accounts for the majority of such early deaths. Pathogenesis of the coagulopathy is complex and includes disseminated intravascular coagulation (DIC), fibrinolysis and proteolysis. As a result, while the predominant clinical manifestation of the coagulopathy is haemorrhage, thromboembolic events may occur both at presentation and during therapy. A major recent finding is the high expression of annexin II in the leukaemic cells from patients with APL. Annexin II is a protein with high affinity for plasminogen and tissue-type plasminogen activator (tPA), and also acts as a cofactor for plasminogen activation by tPA. As a result, both plasminogen and tPA are increased on the cell surface of the leukaemic cell, increasing plasmin activity. Annexin II is expressed in high amounts in cerebral microvascular endothelial cells, perhaps accounting for the relatively high incidence of intracranial haemorrhage in APL compared with other sites. Microparticles are cell-derived membrane fragments originating from normal cells or released from malignant cells involved in activating coagulation. Recent studies have found that microparticles containing tissue factor, tPA, plasminogen activator inhibitor-1 and annexin II have been found in the plasma of APL patients, suggesting a role in pathogenesis of the coagulopathy. Treatment of the coagulopathy remains primarily supportive. Aggressive transfusions of platelets and cryoprecipitate appear to be important. There is no clear role for the routine use of heparin or antifibrinolytic therapy. The most important factor may be the early introduction of ATRA at the first suspicion of a diagnosis of APL, before it is confirmed genetically.

Dexamethasone induces a heat-stress response that ameliorates the conformational consequences on antithrombin of L-asparaginase treatment

BACKGROUND

L-asparaginase (L-ASP) treatment of patients with acute lymphoblastic leukemia causes a severe antithrombin deficiency by intracellular retention of this serpin within the endoplasmic reticulum (ER) of hepatic cells, and a subsequent risk of thrombosis. Interestingly, co-administration of dexamethasone with L-ASP seems to reduce the risk of thrombosis.

OBJECTIVES

We have investigated the effect of two corticoids, dexamethasone and prednisone, on the conformational consequences of L-ASP treatment on antithrombin.

PATIENTS/METHODS

Levels, activity, conformation and immunohistological features of antithrombin were studied in patients, cell and mice models. Because of the importance of the steroid receptor-heat stress response (HSR) axis, and the role of unfolded protein response (UPR) in conformational diseases, we also evaluated Hsp27, Hsp70, Hsp90, HSF-1 and ER chaperons (Grp78 and Grp94).

RESULTS

In all models, L-ASP alone or in combination with prednisone caused the intracellular retention of antithrombin associated with a severe deficiency. In contrast, the combination of L-ASP with dexamethasone ameliorated both the deficiency and intracellular retention of the serpin, which is associated with increased expression of heat shock proteins and ER-chaperons.

CONCLUSIONS

These results suggest a protective effect of dexamethasone on the conformational consequences of L-ASP on antithrombin as a result of exacerbated HSR and UPR that help to explain the reduced risk of thrombosis reported in patients that follow this scheme of treatment.