Gemcitabine versus gemcitabine plus dalteparin thromboprophylaxis in pancreatic cancer

[Haemostatic aspects in clinical oncology]

The clinical link between cancer and thrombosis has been recognized by Armand Trousseau in 1865. It has become clear that activation of coagulation and fibrinolysis plays an important role not only in the pathophysiology of Trousseau's syndrome, but also in the progression of solid malignancies. In particular, tissue factor is critical for both primary tumour growth and haematogenous metastasis. Haemostatic perturbations in cancer patients are, at least in part, controlled by defined genetic events in molecular tumourigenesis, including activating and inactivating mutations of oncogenes and tumour suppressor genes, respectively. While long-term treatment with low-molecular-weight heparin (LMWH) is considered standard therapy for established venous thromboembolism (VTE), pharmacological VTE prophylaxis in ambulatory cancer patients and the management of complex systemic coagulopathies remain a challenge and have to be decided on an individual basis and in a risk-adapted manner. Experimental and preclinical studies further suggest that LMWH may be beneficial in cancer therapy, but this innovative concept has not yet been proven beyond doubt in rigorously designed clinical trials.

Phase Ib Study of PEGylated Recombinant Human Hyaluronidase and Gemcitabine in Patients with Advanced Pancreatic Cancer

PURPOSE

This phase Ib study evaluated the safety and tolerability of PEGylated human recombinant hyaluronidase (PEGPH20) in combination with gemcitabine (Gem), and established a phase II dose for patients with untreated stage IV metastatic pancreatic ductal adenocarcinoma (PDA). Objective response rate and treatment efficacy using biomarker and imaging measurements were also evaluated.

EXPERIMENTAL DESIGN

Patients received escalating intravenous doses of PEGPH20 in combination with Gem using a standard 3+3 dose-escalation design. In cycle 1 (8 weeks), PEGPH20 was administrated twice weekly for 4 weeks, then once weekly for 3 weeks; Gem was administrated once weekly for 7 weeks, followed by 1 week off treatment. In each subsequent 4-week cycle, PEGPH20 and Gem were administered once weekly for 3 weeks, followed by 1 week off. Dexamethasone (8 mg) was given pre- and post-PEGPH20 administration. Several safety parameters were evaluated.

RESULTS

Twenty-eight patients were enrolled and received PEGPH20 at 1.0 (n = 4), 1.6 (n = 4), or 3.0 μg/kg (n = 20), respectively. The most common PEGPH20-related adverse events were musculoskeletal and extremity pain, peripheral edema, and fatigue. The incidence of thromboembolic events was 29%. Median progression-free survival (PFS) and overall survival (OS) rates were 5.0 and 6.6 months, respectively. In 17 patients evaluated for pretreatment tissue hyaluronan (HA) levels, median PFS and OS rates were 7.2 and 13.0 months for "high"-HA patients (n = 6), and 3.5 and 5.7 months for "low"-HA patients (n = 11), respectively.

CONCLUSIONS

PEGPH20 in combination with Gem was well tolerated and may have therapeutic benefit in patients with advanced PDA, especially in those with high HA tumors. Clin Cancer Res; 22(12); 2848-54. ©2016 AACR.

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.

Factors influencing the use of thromboprophylaxis in cancer outpatients in clinical practice: A prospective study

INTRODUCTION

Current clinical practice guidelines do not recommend routine pharmacological thromboprophylaxis in cancer outpatients receiving chemotherapy. However, a high proportion of cancer-associated venous thromboembolism (VTE) events occur in this setting. There are scarce data on the use of thromboprophylaxis in ambulatory cancer patients in real clinical practice.

MATERIAL AND METHODS

We conducted a single-center prospective study aimed to evaluate the use and factors influencing pharmacological prophylaxis in consecutive cancer patients receiving ambulatory chemotherapy. Patients were followed for 90 days after inclusion.

RESULTS

A total of 1108 patients were included. According to the Khorana score, 45.8% patients were classified as low-risk, 47.4% intermediate-risk and 6.8% as high-risk. Outpatient pharmacological prophylaxis was administered at any time during follow-up to 157 patients (14.2%) with a median duration of 42 days (range 1-90). Main factors influencing thromboprophylaxis were: previous history of VTE (odds ratio [OR], 19.11; 95% CI, 9.61-37.98), intercurrent hospitalization (OR, 5.40; 95% CI, 3.57-8.16), and gastrointestinal or gynecologic cancer (OR, 1.76; 95% CI, 1.11-2.80 and OR, 2.34; 95% CI, 1.05-5.26, respectively). During follow-up 58 (5.2%) VTE events were observed. Independent predictors of VTE were the site of malignancy (OR, 3.04; 95%CI, 1.20-7.71 and OR, 2.47; 95%CI, 1.21-5.01 for pancreas and lung cancer, respectively) and previous VTE (OR, 4.23; 95%CI, 1.26-14.27). Outpatient prophylaxis was associated with a lower risk of VTE during follow-up (OR, 0.30; 95%CI, 0.10-0.95).

CONCLUSIONS

Although the type of malignancy appears as the most relevant variable for decision-making, additional efforts are required to identify patients at particular high thrombosis risk.

Pancreatic cancer and thromboembolic disease, 150 years after Trousseau

The connection between pancreatic cancer and venous thrombosis has been discussed for almost 150 years. The exact pathophysiological mechanisms are still partly understood, but it is known that pancreatic cancer induces a prothrombotic and hypercoagulable state and genetic events involved in neoplastic transformation (e.g., KRAS, c-MET, p53), procoagulant factors [e.g., tissue factor (TF), platelet factor 4 (PF4), plasminogen activator inhibitor type 1 (PAI-1)], mucin production (e.g., through activation of P- and L-selectin) and pro-inflammatory factors [e.g., cytokines, cyclooxygenase-2 (COX-2)] may be implicated. Also pancreatitis, both acute and chronic, is associated with increased risk of venous thrombosis, but in this circumstance a direct inflammatory process may be more important. This article discusses the incidence, treatment and outcome of venous thromboembolism (VTE) complicating pancreatic disease, with special emphasis on new knowledge obtained during the last fifteen years.

The humanistic and economic burden of venous thromboembolism in cancer patients: a systematic review

The objective of this study was to present evidence on the epidemiology, health outcomes and economic burden of cancer-related venous thromboembolism (VTE). Medline, Cochrane Central Register of Controlled Trials, Econlit, Science Direct, JSTOR, Oxford Journals and Cambridge Journals were searched. The systematic literature search was limited to manuscripts published from January 2000 to December 2012. On the basis of the literature, cancer patients experience between two-fold and 20-fold higher risk of developing VTE than noncancer patients. They are more likely to experience a VTE event during the first 3-6 months after cancer diagnosis. In addition, an increased risk of VTE in patients with distant metastases and certain types of cancer (i.e. pancreatic or lung) was revealed. VTE was found to be a leading cause of mortality in cancer patients. The annual average total cost for cancer patients with VTE was found to be almost 50% higher than that of cancer patients without VTE. Inpatient care costs accounted for more than 60% of total cost. The existing evidence assessed in the present review demonstrated the significant health and economic consequences of cancer-related VTE, which make a strong case for the importance of its proper and efficient prevention and management.

Venous thrombosis and cancer: from mouse models to clinical trials

Cancer patients have a ~4 fold increased risk of venous thromboembolism (VTE) compared with the general population and this is associated with significant morbidity and mortality. This review summarizes our current knowledge of VTE and cancer, from mouse models to clinical studies. Notably, the risk of VTE varies depending on the type and stage of cancer. For instance, pancreatic and brain cancer patients have a higher risk of VTE than breast and prostate cancer patients. Moreover, patients with metastatic disease have a higher risk than those with localized tumors. Tumor-derived procoagulant factors and growth factors may directly and indirectly enhance VTE. For example, increased levels of circulating tumor-derived, tissue factor-positive microvesicles may trigger VTE. In a mouse model of ovarian cancer, tumor-derived IL-6 and hepatic thrombopoietin have been linked to increased platelet production and thrombosis. In addition, mouse models of mammary and lung cancer showed that tumor-derived granulocyte colony-stimulating factor causes neutrophilia and activation of neutrophils. Activated neutrophils can release neutrophil extracellular traps (NETs) that enhance thrombosis. Cell-free DNA in the blood derived from cancer cells, NETs and treatment with cytotoxic drugs can activate the clotting cascade. These studies suggest that there are multiple mechanisms for VTE in patients with different types of cancer. Preventing and treating VTE in cancer patients is challenging; the current recommendations are to use low-molecular-weight heparin. Understanding the underlying mechanisms may allow the development of new therapies to safely prevent VTE in cancer patients.

Impact of venous thromboembolism on the natural history of pancreatic adenocarcinoma

BACKGROUND

Few studies have analyzed the effect of venous thromboembolism (VTE) events on the prognosis of pancreatic cancer, but their results were conflicting. The present study was undertaken to determine the effect of VTE on pancreatic adenocarcinoma (PA) outcomes.

METHODS

All consecutive patients diagnosed with PA from May 2004 to January 2012 in a single oncology center were retrospectively studied. Clinical, radiological and histological data at time of diagnosis or within the first 3 months after surgery, including the presence (+) or absence (-) of VTE were collected. VTE was defined as radiological evidence of either pulmonary embolism (PE), deep venous thrombosis without infection or catheter-related thrombosis. PA with and without PE was compared for survival using the Kaplan-Meier method to estimate overall survival.

RESULTS

Among 162 PA patients with a median follow-up of 15 (3-92) months after diagnosis, 28 demonstrated VTE (+). PA patients with and without PE were similar for age, American Society of Anesthesiologist score, body mass index, and history of treatment. The distribution of cancer stages was similar between the two groups VTE (+) and VTE (-). The median duration of survival was significantly worse in the VTE (+) group vs VTE (-) (12 vs 18 months, P=0.010). In multivariate analysis, the presence of VTE and surgical treatment were independent prognostic factors for overall survival.

CONCLUSION

VTE (+) at time of diagnosis or within the first 3 months after surgery during treatment is an independent factor of poor prognosis in PA.

The prothrombotic activity of cancer cells in the circulation

The hemostatic system is often subverted in patients with cancer, resulting in life-threatening venous thrombotic events. Despite the multifactorial and complex etiology of cancer-associated thrombosis, changes in the expression and activity of cancer-derived tissue factor (TF) - the principle initiator of the coagulation cascade - are considered key to malignant hypercoagulopathy and to the pathophysiology of thrombosis. However, many of the molecular and cellular mechanisms coupling the hemostatic degeneration to malignancy remain largely uncharacterized. In this review we discuss some of the tumor-intrinsic and tumor-extrinsic mechanisms that may contribute to the prothrombotic state of cancer, and we bring into focus the potential for circulating tumor cells (CTCs) in advancing our understanding of the field. We also summarize the current status of anti-coagulant therapy for the treatment of thrombosis in patients with cancer.

Efficacy of Prophylactic Low–Molecular Weight Heparin for Ambulatory Patients With Advanced Pancreatic Cancer: Outcomes From the CONKO-004 Trial

Purpose

Advanced pancreatic cancer (APC), in addition to its high mortality, accounts for the highest rates of venous thromboembolic events (VTEs). Enoxaparin, a low–molecular weight heparin, is effective in prevention and treatment of VTEs. Some small studies have indicated that this benefit might extend to patients with cancer.

Patients and Methods

Patients with histologically proven APC were randomly assigned to ambulant first-line chemotherapy and prophylactic use of enoxaparin or chemotherapy alone to investigate the probable reduction in symptomatic VTEs and the impact on survival.

Results

A total of 312 patients were recruited as one of the protocol end points was reached. Within the first 3 months, the numbers of symptomatic VTEs were as follows: 15 of 152 patients in the observation group and two of 160 patients in the enoxaparin group (hazard ratio [HR], 0.12; 95% CI, 0.03 to 0.52; χ2 P = .001). The numbers of major bleeding events were as follows: five of 152 patients in the observation arm and seven of 160 patients in the enoxaparin arm (HR, 1.4; 95% CI, 0.35 to 3.72; χ2 P = 1.0). Overall cumulative incidence rates of symptomatic VTEs were 15.1% (observation) and 6.4% (enoxaparin; HR, 0.40; 95% CI, 0.19 to 0.83; P = .01). Progression-free (HR, 1.06; 95% CI, 0.84 to 1.32; P = .64) and overall survival (HR, 1.01; 95% CI, 0.87 to 1.38; P = .44) did not differ between groups.

Conclusion

This study demonstrates the high efficacy and feasibility of primary pharmacologic prevention of symptomatic VTEs in outpatients with APC. Treatment efficacy was not affected by simultaneous treatment with enoxaparin in this trial setting.

Anticoagulant therapy of cancer patients: Will patient selection increase overall survival?

Already since the early 1800s, it has been recognised that malignancies may provoke thromboembolic complications, and indeed cancer patients are at increased risk of developing venous thrombosis. Interestingly, case control studies of deep-vein thrombosis suggested that low-molecular-weight heparin (LMWH) improved survival of cancer patients. This led to the hypothesis that cancer cells might 'take advantage' of a hypercoagulable state to more efficiently metastasise. Initial randomised placebo control trials showed that LMWH improve overall survival of cancer patients, especially in those patients with a relatively good prognosis. The failure of recent phase III trials, however, tempers enthusiasm for anticoagulant treatment in cancer patients despite an overwhelming body of literature showing beneficial effects of anticoagulants in preclinical models. Instead of discarding LMWH as potential (co)treatment modality in cancer patients, these disappointing recent trials should guide future preclinical research on anticoagulants in cancer biology. Most and for all, the underlying mechanisms by which coagulation drives tumour progression need to be elucidated. This could ultimately allow selection of cancer patients most likely to benefit from anticoagulant treatment and/or from targeted therapy downstream of coagulation factor signalling.

A phase I dose-escalation study of lenalidomide in combination with gemcitabine in patients with advanced pancreatic cancer

Purpose

Lenalidomide have both immunomodulatory and anti-angiogenic properties which could confer anti-cancer effects. The aim of this study was to assess the feasibility of combining lenalidomide with the standard treatment gemcitabine in pancreatic cancer patients with advanced disease.

Patients and Methods

Eligible patients had locally advanced or metastatic adenocarcinoma of the pancreas. Patients received lenalidomide days 1–21 orally and gemcitabine 1000 mg/m2 intravenously (days 1, 8 and 15), each 28 day cycle. Three cohorts of lenalidomide were examined (Cohort I = 15 mg, Cohort II = 20 mg and Cohort III = 25 mg daily). The maximum tolerated dose (MTD) of lenalidomide given in combination with gemcitabine was defined as the highest dose level at which no more than one out of four (25%) subjects experiences a dose-limiting toxicity (DLT). Patients should also be able to receive daily low molecular weight heparin (LMWH) (e.g. dalteparin 5000 IU s.c. daily) as a prophylactic anticoagulant for venous thromboembolic events (VTEs). Twelve patients (n = 4, n = 3 and n = 5 in cohort I, II and III, respectively) were enrolled in this study.

Results

Median duration of treatment was 11 weeks (range 1–66), and median number of treatment cycles were three (range 1–14). The only DLT was a cardiac failure grade 3 in cohort III. Frequent treatment-related adverse events (AEs) (all grades) included neutropenia, leucopenia and fatigue (83% each, but there was no febrile neutropenia); thrombocytopenia (75%); dermatological toxicity (75%); diarrhea and nausea (42% each); and neuropathy (42%).

Discussion

This phase I study demonstrates the feasibility of the combination of lenalidomide and gemcitabine as first-line treatment in patients with advanced pancreatic cancer. The tolerability profile demonstrated in the dose escalation schedule of lenalidomide suggests the dosing of lenalidomide to be 25 mg daily on days 1–21 with standard dosing of gemcitabine and merits further evaluation in a phase II trial.

Trial Registration

ClinicalTrials.gov NCT01547260

Canadian consensus recommendations on the management of venous thromboembolism in patients with cancer. Part 1: prophylaxis

Patients with cancer are at increased risk of venous thromboembolism (vte). Anticoagulation therapy has been shown to prevent vte; however, unique clinical circumstances in patients with cancer can often complicate the decisions surrounding the administration of prophylactic anticoagulation. No national Canadian guidelines on the prevention of cancer-associated thrombosis have been published. We therefore aimed to develop a consensus-based, evidence-informed guideline on the topic. PubMed was searched for clinical trials and meta-analyses published between 2002 and 2013. Reference lists of key articles were hand-searched for additional publications. Content experts from across Canada were assembled to review the evidence and make recommendations. Low molecular weight heparin can be used prophylactically in cancer patients at high risk of developing vte. Direct oral anticoagulants are not recommended for vte prophylaxis at this time. Specific clinical scenarios, including renal insufficiency, thrombocytopenia, liver disease, and obesity can warrant modifications in the administration of prophylactic anticoagulant therapy. There is no evidence to support the monitoring of anti-factor Xa levels in clinically stable cancer patients receiving prophylactic anticoagulation; however, factor Xa levels could be checked at baseline and periodically in patients with renal insufficiency. The use of anticoagulation therapy to prolong survival in cancer patients without the presence of risk factors for vte is not recommended.

Venous thrombosis in pancreaticobiliary tract cancer: outcome and prognostic factors

BACKGROUND

The differences in outcome among cancer patients with incidental vs. symptomatic venous thromboembolism (VTE) are unknown. In this study, patients with extrahepatic pancreaticobiliary tract cancer (PBC) were selected for a prospective cohort study between February 2008 and February 2011.

METHODS

At the time of cancer diagnosis, all patients were examined for deep vein thrombosis with bilateral compression ultrasonography (biCUS). Computed tomography pulmonary angiography was also performed to diagnose pulmonary embolisms. After inclusion, the patients were followed up with clinical examinations, blood collections, and biCUS.

RESULTS

A total of 121 PBC patients were enrolled. At the time of cancer diagnosis, 15 patients had experienced a VTE (12.4%, 95% confidence interval [CI] 7.1-19.6), including six symptomatic and nine incidental cases. A total of 25 first-time VTE events were identified (20.7%; 95% CI 13.8-29.0). Patients with a VTE had reduced survival, with a median overall survival (OS) of 4.4 months (95% CI 2.2-11.5). The median OS of the patients with incidental VTE was 3.0 months (95% CI 0.1-15.0), which was not different from the median OS of the patients with symptomatic VTE (5.0 months; 95% CI 2.1-14.5). The median OS was 11.9 months (95% CI 8.1-14.7) in the PBC patients with no VTEs.

CONCLUSION

The occurrence of a VTE event in a PBC patient within the first months of the disease is associated with significantly increased mortality.

VTE risk assessment in cancer. Who needs prophylaxis and who does not?

Venous thromboembolism (VTE) in patients with cancer is associated with an increased morbidity and mortality, and its prevention is of major clinical importance. However, the VTE rates in the cancer population vary between 0.5% - 20%, depending on cancer-, treatment- and patient-related factors. The most important contributors to VTE risk are the tumor entity, stage and certain anti-cancer treatments. Cancer surgery represents a strong risk factor for VTE, and medical oncology patients are at increased risk of developing VTE, especially when receiving chemotherapy or immunomodulatory drugs. Also biomarkers have been investigated for their usefulness to predict risk of VTE (e.g. elevated leukocyte and platelet counts, soluble P-selectin, D-dimer, etc.). In order to identify cancer patients at high risk of VTE and to improve risk stratification, risk assessment models have been developed, which contain both clinical parameters and biomarkers. While primary thromboprophylaxis with low-molecular-weight-heparin (LMWH) is recommended postoperatively for a period of up to 4 weeks after major cancer surgery, the evidence is less clear for medical oncology patients. Thromboprophylaxis in hospitalized medical oncology patients is advocated, and is based on results of randomized controlled trials which evaluated the efficacy and safety of LMWH for prevention of VTE in hospitalized medically ill patients. In recent trials the benefit of primary thromboprophylaxis in cancer patients receiving chemotherapy in the ambulatory setting has been investigated. However, at the present stage primary thromboprophylaxis for prevention of VTE in these patients is still a matter of debate and cannot be recommended for all cancer outpatients.

Low-molecular-weight heparins and cancer: focus on antitumoral effect

A close relationship between cancer and thrombosis does exist, documented by the fact that an overall 7-fold increased risk of venous thromboembolism (VTE) has been reported in patients with malignancy compared to non-malignancy. The potential impact of antithrombotic agents in cancer-associated VTE has long been recognized, and, in particular, several clinical trials in the last 20 years have reported the safety and efficacy of low-molecular-weight heparins (LMWHs) for treatment and prophylaxis of VTE in patients with various types of cancer. More recently, a number of preclinical and clinical studies have suggested that LMWHs may improve survival in cancer patients with mechanisms that are different from its antithrombotic effect but are linked to the ability of influencing directly the tumor biology. This paper reviews the evidence around the potential survival benefits of LMWHs by analyzing the suggested mechanisms and the available clinical data.

Prophylaxis and treatment of venous thromboembolism in patients with cancer: the Saudi clinical practice guideline

BACKGROUND AND OBJECTIVES

Venous thromboembolism (VTE) is commonly encountered in the daily clinical practice. Cancer is an important VTE risk factor. Proper thromboprophylaxis is key to prevent VTE in patients with cancer, and proper treatment is essential to reduce VTE complications and adverse events associated with the therapy.

DESIGN AND SETTINGS

As a result of an initiative of the Ministry of Health of Saudi Arabia, an expert panel led by the Saudi Association for Venous Thrombo-Embolism (a subsidiary of the Saudi Thoracic Society) and the Saudi Scientific Hematology Society with the methodological support of the McMaster University working group produced this clinical practice guideline to assist health care providers in evidence-based clinical decision-making for VTE prophylaxis and treatment in patients with cancer.

METHODS

Six questions related to thromboprophylaxis and antithrombotic therapy were identified and the corresponding recommendations were made following the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach.

RESULTS

Question 1. Should heparin versus no heparin be used in outpatients with cancer who have no other therapeutic or prophylactic indication for anticoagulation?

RECOMMENDATION

For outpatients with cancer, the Saudi Expert Panel suggests against routine thromboprophylaxis with heparin (weak recommendation; moderate quality evidence).Question 2. Should oral anticoagulation versus no oral anticoagulation be used in outpatients with cancer who have no other therapeutic or prophylactic indication for anticoagulation?

RECOMMENDATION

For outpatients with cancer, the Saudi Expert Panel recommends against thromboprophylaxis with oral anticoagulation (strong recommendation; moderate quality evidence).Question 3. Should parenteral anticoagulation versus no anticoagulation be used in patients with cancer and central venous catheters?

RECOMMENDATION

For outpatients with cancer and central venous catheters, the Saudi Expert Panel suggests thromboprophylaxis with parenteral anticoagulation (weak recommendation; moderate quality evidence).Question 4. Should oral anticoagulation versus no anticoagulation be used in patients with cancer and central venous catheters?

RECOMMENDATION

For outpatients with cancer and central venous catheters, the Saudi Expert Panel suggests against thromboprophylaxis with oral anticoagulation (weak recommendation; low quality evidence).Question 5. Should low-molecular-weight heparin versus unfractionated heparin be used in patients with cancer being initiated on treatment for venous thromboembolism?

RECOMMENDATION

In patients with cancer being initiated on treatment for venous thromboembolism, the Saudi Expert Panel suggests low-molecular-weight heparin over intravenous unfractionated heparin (weak; very low quality evidence).Question 6. Should heparin versus oral anticoagulation be used in patients with cancer requiring long-term treatment of VTE?

RECOMMENDATION

In patients with metastatic cancer requiring long-term treatment of VTE, the Saudi Expert Panel recommends low-molecular-weight heparin (LMWH) over vitamin K antagonists (VKAs) (strong recommendation; moderate quality evidence). In patients with non-metastatic cancer requiring long-term treatment of venous thromboembolism, the Saudi Expert Panel suggests LMWH over VKA (weak recommendation; moderate quality evidence).

A survey of thrombosis experts evaluating practices and opinions regarding venous thromboprophylaxis in patients with active cancer hospitalized with an acute medical illness

Background

Current clinical practice guidelines recommend the use of prophylactic doses of low molecular weight heparins for cancer patients requiring hospitalization for acute medical illness. However, a recently published meta-analysis suggested that the risk-benefit ratio of current thromboprophylaxis regimens administered to all cancer patients admitted for medical illness is unclear. We sought to assess the clinical equipoise in using thromboprophylaxis for hospitalized medically ill cancer patients.

Methods

An electronic survey was conducted. The target sample included Thrombosis experts and members of Thrombosis Canada or the VECTOR research group.

Results

The survey was distributed 54 participants. The final response rate was 67% (36/54). The majority (75%; 95% CI: 60.3 to 85%) of responders indicated that the benefits of pharmacological parenteral thromboprophylaxis outweigh the risks. However, 63.9% (95% CI: 50.6 to 77.3%) believe that there is still clinical equipoise around the use of thromboprophylaxis in this patient population, and 88.9% (95% CI: 77.3 to 95.8%) would consider participating in a randomized trial—30.6% and 58.3% in a placebo-controlled or comparison of different agents/dosing-controlled randomized trial, respectively. For participants who would consider a randomized-controlled trial comparing different doses of thromboprophylaxis agents, the MCID was 2% between the two arms. The most common drug to be compared was enoxaparin (26%), and the two suggested doses were 30 mg and 40 mg SC twice daily.

Conclusions

Our clinical survey of thrombosis experts confirms that there is equipoise regarding the use of current regimens of parenteral pharmacological thromboprophylaxis in medically ill cancer patients. A majority of physicians would participate in a randomized-controlled trial comparing different dose of LMWH. The MCID in the risk of VTE identified was 2%.

The coagulopathy of cancer

PURPOSE OF REVIEW

To provide an updated overview of the complex coagulopathy associated with malignancy, together with the advances in our knowledge of the interactions of cancer with the hemostatic system. Also, to offer an update of the recent progresses in the risk assessment, prevention, and treatment of thrombohemorrhagic complications in cancer patients.

RECENT FINDINGS

Mechanisms underlying the hemostatic derangement caused by cancer include many prothrombotic properties of tumor tissues. Of extreme interest are the most recent findings that the regulation of tumor cell hemostatic protein expression is driven by oncogenes, the tumor-derived tissue factor-positive microparticles are an important player in thrombosis, and the changes in the tumor microenvironment in the presence of tissue factor affect 'dormant' cells to shift to a malignant phenotype.On the clinical side, risk assessment models, based on clinical and biological risk factors, are becoming very attractive to identify categories of cancer patients at different thrombotic risk. Unsuspected pulmonary embolism, incidentally discovered, is also opening an intensive area of research. Finally, new updates of the guidelines to help clinicians in the management of venous thromboembolism in cancer patient have been recently released.

SUMMARY

The coagulopathy of cancer is complex. Thrombotic and bleeding complications significantly contribute to morbidity and mortality in this disease. The accrued knowledge of the underlying mechanisms is helping establish more accurate and appropriate interventions for the management of the thrombotic risk in these patients.

Guidelines for treatment and prevention of venous thromboembolism among patients with cancer

The association between cancer and thrombosis has been recognized for more than 150 years. Not only are patients with cancer at a substantially increased risk of developing venous thromboembolism (VTE), the link between several coagulation factors and tumor growth, invasion, and the development of metastases has been established. Reported rates of VTE in patients with cancer have increased in recent years likely reflecting, in part, improved diagnosis with sophisticated imaging techniques as well as the impact of more aggressive cancer diagnosis, staging, and treatment. Various therapeutic interventions, such as surgery, chemotherapy, hormonal therapy, targeted therapeutic strategies as well as the frequent use of indwelling catheters and other invasive procedures also place cancer patients at increased risk of VTE. The increasing risk of VTE, the multitude of risk factors, and the greater risk of VTE recurrence and death among patients with cancer represent considerable challenges in modern clinical oncology. The American Society of Clinical Oncology (ASCO) originally developed guidelines for VTE in patients with cancer in 2007. ASCO recently updated clinical practice guidelines on the treatment and prevention of VTE in patients with cancer following an extensive systematic review of the literature. Revised 2013 guidelines have now been presented and will be discussed in this review. Although several new studies were identified and considered, many important questions remain regarding the relationship between thrombosis and cancer and the optimal care of patients at risk for VTE.

Risk stratification strategies for cancer-associated thrombosis: an update

Rates of venous thromboembolism (VTE) vary substantially between cancer patients. Multiple clinical risk factors including primary site of cancer and systemic therapy, and biomarkers including leukocyte and platelet counts and tissue factor are associated with increased risk of VTE. However, risk cannot be reliably predicted based on single risk factors or biomarkers. New American Society of Clinical Guidelines recommend that patients with cancer be assessed for VTE risk at the time of chemotherapy initiation and periodically thereafter. This narrative review provides an update on risk stratification approaches including a validated Risk Score. Potential applications of risk assessment including targeted thromboprophylaxis are outlined. © 2014 Elsevier Ltd. All rights reserved.

New strategies of VTE prevention in cancer patients

Venous thromboembolism (VTE) is a common complication in patients with cancer. VTE is a main cause of morbidity and mortality in patients with cancer and has a significant impact on their quality of life. Preventing VTE in cancer patients reduces both morbidity and mortality. The level of evidence for antithrombotic prophylaxis of VTE in patients with cancer varies for hospitalized and ambulatory patients. Hospitalized patients with active cancer (for both medical or surgical indication) and reduced mobility should receive thromboprophylaxis throughout hospital stay. Prophylaxis of VTE is not routinely recommended for outpatients with cancer on chemotherapy. For these patients, current guidelines suggest that clinicians should consider antithrombotic prophylaxis on a case-by-case basis in highly selected outpatients. Different strategies for identification of high-risk outpatients with cancer who could benefit of thromboprophylaxis are under consideration. The new oral anticoagulants could have a role for VTE prevention in ambulatory patients with cancer who are on chemotherapy, as they are administered at a fixed dose without routine laboratory monitoring and may have fewer drug interactions with anticancer agents.

Parenteral anticoagulation in ambulatory patients with cancer

BACKGROUND

Anticoagulation may improve survival in patients with cancer through an antitumor effect in addition to the perceived antithrombotic effect.

OBJECTIVES

To evaluate the efficacy and safety of parenteral anticoagulants in ambulatory patients with cancer who, typically, are undergoing chemotherapy, hormonal therapy or radiotherapy, but otherwise have no standard therapeutic or prophylactic indication for anticoagulation.

SEARCH METHODS

A comprehensive search included (1) an electronic search (February 2013) of the following databases: Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 1), MEDLINE (1966 to February 2013; accessed via OVID) and EMBASE(1980 to February 2013; accessed via OVID); (2) handsearching of conference proceedings; (3) checking of references of included studies; (4) use of the 'related citation' feature in PubMed and (5) a search for ongoing studies.

SELECTION CRITERIA

Randomized controlled trials (RCTs) assessing the benefits and harms of parenteral anticoagulation in ambulatory patients with cancer. Typically, these patients are undergoing chemotherapy, hormonal therapy or radiotherapy, but otherwise have no standard therapeutic or prophylactic indication for anticoagulation.

DATA COLLECTION AND ANALYSIS

Using a standardized form we extracted data in duplicate on methodological quality, participants, interventions and outcomes of interest including all-cause mortality, symptomatic venous thromboembolism (VTE), symptomatic deep vein thrombosis (DVT), symptomatic pulmonary embolism (PE), arterial thrombosis (e.g. stroke, myocardial infarction), major bleeding, minor bleeding and quality of life.

MAIN RESULTS

Of 9559 identified citations, 15 RCTs fulfilled the eligibility criteria. These trials enrolled 7622 participants for whom follow-up data were available. In all included RCTs the intervention consisted of heparin (either unfractionated heparin or low molecular weight heparin). Overall, heparin may have a small effect on mortality at 12 months and 24 months (risk ratio (RR) 0.97; 95% confidence interval (CI) 0.92 to 1.01 and RR 0.95; 95% CI 0.90 to 1.00, respectively). Heparin therapy was associated with a statistically and clinically important reduction in venous thromboembolism (RR 0.56; 95% CI 0.42 to 0.74) and a clinically important increase in the risk of minor bleeding (RR 1.32; 95% 1.02 to 1.71). Results failed to show or to exclude a beneficial or detrimental effect of heparin on major bleeding (RR 1.14; 95% CI 0.70 to 1.85) or quality of life. Our confidence in the effect estimates (i.e. quality of evidence) was high for symptomatic venous thromboembolism, moderate for mortality, major bleeding and minor bleeding, and low for quality of life.

AUTHORS' CONCLUSIONS

Heparin may have a small effect on mortality at 12 months and 24 months. It is associated with a reduction in venous thromboembolism and a likely increase in minor bleeding. Future research should further investigate the survival benefit of different types of anticoagulants in patients with different types and stages of cancer. The decision for a patient with cancer to start heparin therapy for survival benefit should balance the benefits and downsides, and should integrate the patient's values and preferences.

Prevention and treatment of venous thromboembolism in patients with cancer

Robust evidence remains scarce in guiding best practice in the prevention and treatment of venous thromboembolism in patients living with cancer. Recommendations from major consensus guidelines are largely based on extrapolated data from trials performed mostly in noncancer patients, observational studies and registries, studies using surrogate outcomes, and underpowered randomized controlled trials. Nonetheless, a personalized approach based on individual risk assessment is uniformly recommended for inpatient and outpatient thromboprophylaxis and there is consensus that anticoagulant prophylaxis is warranted in selected patients with a high risk of thrombosis. Prediction tools for estimating the risk of thrombosis in the hospital setting have not been validated, but the use of prophylaxis in the ambulatory setting in those with a high Khorana score is under active investigation. Symptomatic and incidental thrombosis should be treated with anticoagulant therapy, but little is known about the optimal duration. Pharmacologic options for prophylaxis and treatment are still restricted to unfractionated heparin, low molecular weight heparin, and vitamin K antagonists because there is currently insufficient evidence to support the use of target-specific, non-vitamin K-antagonist oral anticoagulants. Although these agents offer practical advantages over traditional anticoagulants, potential drug interaction with chemotherapeutic agents, gastrointestinal problems, hepatic and renal impairment, and the lack of rapid reversal agents are important limitations that may reduce the efficacy and safety of these drugs in patients with active cancer. Clinicians and patients are encouraged to participate in clinical trials to advance the care of patients with cancer-associated thrombosis.

Venous thromboembolism in cancer patients

OBJECTIVE

Venous thromboembolism (VTE) is a common complication in cancer patients. This review summarizes some of the most current knowledge of the epidemiology, risk factors, risk models, prophylaxis, and treatment of VTE in cancer patients.

METHODS

A literature search was conducted using PubMed; the search terms were venous thromboembolism, anticoagulation, and cancer. The bibliographies of pertinent studies and review articles were reviewed for additional references.

RESULTS

Venous thromboembolism is the second leading cause of death in patients with cancer. Cancer patients with VTE have poorer outcomes compared with noncancer patients with VTE. Many risk factors have been identified for VTE in patients with cancer that are patient-related, cancer-related, or treatment-related. Several biomarkers have been identified as potentially predictive of VTE risk. Risk assessment models such as the Khorana Risk Score stratify cancer patients with low, intermediate, and high risk of developing VTE based on baseline clinical and laboratory variables. Currently, enoxaparin is the preferred anticoagulant for initial VTE treatment in cancer patients. Low molecular weight heparin (LMWH) is recommended for both initial and long-term management of cancer-related VTE. Because the optimal duration of anticoagulation in cancer patients with VTE is unknown, the decision to extend anticoagulation requires weighing the risk of recurrent thrombosis against the risk of major bleeding. Patients with recurrent VTE can be bridged with LMWH, transitioned to full-dose LMWH or treated with LMWH dose escalation. While there is insufficient data to determine whether anticoagulation should be held in the setting of thrombocytopenia, full-dose anticoagulation is typically considered unsafe when platelets are < 50 000/μL. Inferior vena cava filters are currently recommended only for patients with acute VTE and contraindications to anticoagulation. Although management of catheter-associated thrombosis has not been well studied in cancer patients, it is recommended that cancer patients with catheter-associated thrombosis be treated with therapeutic anticoagulation for ≥ 3 months. Venous thromboembolism prophylaxis with UFH, LMWH, or fondaparinux is recommended in all hospitalized nonsurgical cancer patients and cancer patients undergoing major cancer surgery. Primary thromboprophylaxis is only currently recommended in high-risk ambulatory cancer patients such as multiple myeloma patients receiving thalidomide- or lenalidomide- based therapy.

CONCLUSION

Cancer-associated thrombosis is a common problem. As we begin to better understand the risk factors and biomarkers for cancer-associated VTE, we can further refine and develop risk-assessment models to determine those patients who would most likely benefit from anticoagulation. While LMWH products are generally preferred in cancer-related VTE, more research will continue to evolve our understanding of treatment and thrombopprophylaxis in cancer-associated VTE.

Clinical guide SEOM on venous thromboembolism in cancer patients

Venous thromboembolism (VTE) is a common event in cancer patients and one of the major causes of cancer-associated mortality and a leading cause of morbidity. In recent years, the incidence rates of VTE have notably increased; however, VTE is still commonly underestimated by oncologists. VTE is considered an adverse prognostic factor in cancer patients in all settings. In 2011 the Spanish Society of Medical Oncology (SEOM) first published a clinical guideline of prophylaxis and treatment of VTE in cancer patients. In an effort to incorporate evidence obtained since the original publication, SEOM presents an update of the guideline for thrombosis and cancer in order to improve the prevention and management of VTE.

Low molecular weight heparin (LMWH) for primary thrombo-prophylaxis in patients with solid malignancies - systematic review and meta-analysis

BACKGROUND

Patients receiving chemotherapy for cancer are at increased risk for venous thromboembolism (VTE). We performed a meta-analysis of all randomized controlled trials (RCTs) which evaluated low molecular weight heparin (LMWH) as primary prophylaxis in ambulatory patients with solid malignancies.

METHODS

A comprehensive search was conducted until October 2013. Primary outcome was symptomatic VTE. Secondary outcomes were pulmonary embolism (PE), any VTE, deep vein thrombosis (DVT), mortality and adverse events.

RESULTS

Eleven trials met the inclusion criteria, and evaluated a total of 6942 patients. Primary prophylaxis with LMWH reduced symptomatic VTE (RR 0.46, 95% CI 0.32-0.67) and the rate of PE (RR 0.49, 95% CI 0.29-0.84). In the subgroup analysis of VTE in patients with lung and pancreatic cancers LMWH further reduced VTE [RR 0.42 (95% CI 0.25-0.71); RR 0.31 (95% CI 0.18-0.55), respectively]. Meta-analysis of six trials which reported survival outcomes revealed no statistically significant benefit for LMWH in one-year mortality rates (RR 0.93, 95% CI 0.83-1.04). There was no significant increase in major bleeding events (RR 1.28, 95% CI 0.84-1.95).

CONCLUSIONS

LMWH reduces the incidence of symptomatic VTE and PE in patients receiving chemotherapy for cancer, with no apparent increase in major bleeding. The benefit is most apparent in pancreatic cancer and also lung cancer. VTE prophylaxis should be considered for these specific populations.

Primary prophylaxis for venous thromboembolism in ambulatory cancer patients receiving chemotherapy

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

For this update, the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched May 2013), CENTRAL (2013, Issue 5), and clinical trials registries (up to June 2013).

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

Data were extracted on methodological quality, patients, interventions, and outcomes including symptomatic VTE and major bleeding as the primary effectiveness and safety outcomes, respectively.

MAIN RESULTS

We identified 12 additional RCTs (6323 patients) in the updated search so that this update considered 21 trials with a total of 9861 patients, all evaluating pharmacological interventions and performed mainly in patients with advanced cancer. Overall, the risk of bias varied from low to high. One large trial of 3212 patients found a 64% (risk ratio (RR) 0.36, 95% confidence interval (CI) 0.22 to 0.60) reduction of symptomatic VTE with the ultra-low molecular weight heparin (uLMWH) semuloparin relative to placebo, with no apparent difference in major bleeding (RR 1.05, 95% CI 0.55 to 2.00). LMWH, when compared with inactive control, significantly reduced the incidence of symptomatic VTE (RR 0.53, 95% CI 0.38 to 0.75; no heterogeneity, Tau(2) = 0%) with similar rates of major bleeding events (RR 1.30, 95% CI 0.75 to 2.23). In patients with multiple myeloma, LMWH was associated with a significant reduction in symptomatic VTE when compared with the vitamin K antagonist warfarin (RR 0.33, 95% CI 0.14 to 0.83), while the difference between LMWH and aspirin was not statistically significant (RR 0.51, 95% CI 0.22 to 1.17). No major bleeding was observed in the patients treated with LMWH or warfarin and in less than 1% of those treated with aspirin. Only one study evaluated unfractionated heparin against inactive control and found an incidence of major bleeding of 1% in both study groups while not reporting on VTE. When compared with placebo, warfarin was associated with a statistically insignificant reduction of symptomatic VTE (RR 0.15, 95% CI 0.02 to 1.20). Antithrombin, evaluated in one study involving paediatric patients, had no significant effect on VTE nor major bleeding when compared with inactive control. The new oral factor Xa inhibitor apixaban was evaluated in a phase-II dose finding study that suggested a promising low rate of major bleeding (2.1% versus 3.3%) and symptomatic VTE (1.1% versus 10%) in comparison with placebo.

AUTHORS' CONCLUSIONS

In this update, we confirmed that primary thromboprophylaxis with LMWH significantly reduced the incidence of symptomatic VTE in ambulatory cancer patients treated with chemotherapy. In addition, the uLMWH semuloparin significantly reduced the incidence of symptomatic VTE. However, the broad confidence intervals around the estimates for major bleeding suggest caution in the use of anticoagulation and mandate additional studies to determine the risk to benefit ratio of anticoagulants in this setting. Despite the encouraging results of this review, routine prophylaxis in ambulatory cancer patients cannot be recommended before safety issues are adequately addressed.

The effect of low molecular weight heparin on survival in cancer patients: an updated systematic review and meta-analysis of randomized trials

BACKGROUND

Tumors may exploit the coagulation system to enhance the survival and dissemination of cancer cells. Some studies have suggested that heparin and low molecular weight heparin (LMWH) have antitumor effects. We reported a previous meta-analysis that suggested a modest improvement in overall survival with the use of LMWH in patients with cancer. Herein, we present the results of an updated systematic review and meta-analysis.

OBJECTIVE

To evaluate the effect of LMWH as compared with placebo or no anticoagulant on the overall survival in patients with solid cancers.

METHODS

We conducted a systematic review and meta-analysis of randomized trials evaluating the use of LMWH vs. placebo or no anticoagulant in cancer patients without venous thrombosis. A meta-analysis was conducted with a random-effects model, and data were analyzed by the use of odds ratios (ORs) and relative risks (RRs) calculated for 1-year overall mortality.

RESULTS

We identified 724 potentially relevant studies, nine of which met our inclusion criteria, and reported data on 1-year overall mortality. Studies were heterogeneous regarding types of cancer and interventions, and included 5987 patients, 98.4% of whom had advanced-stage disease (III and IV). There was no discernible effect on mortality with the use of LMWH (pooled OR 0.87, 95% CI 0.70-1.08; RR 0.94, 95% CI 0.86-1.04).

CONCLUSIONS

In contrast to the previous study, these results did not show a survival benefit in cancer patients receiving LMWH. The effect of LMWH on overall survival in patients with limited-stage disease still is unknown.

Cancer and venous thromboembolic disease: from molecular mechanisms to clinical management

Venous thromboembolism (vte) represents a major challenge in the management of patients with cancer. The malignant phenotype is associated with derangements in the coagulation cascade that can manifest as thrombosis, hemorrhage, or disseminated intravascular coagulation. The risk of vte is increased by a factor of approximately 6 in patients with cancer compared with non-cancer patients, and cancer patients account for approximately 20% of all newly diagnosed cases of vte. Postmortem studies have demonstrated rates of vte in patients with cancer to be as high as 50%. Despite that prevalence, vte prophylaxis is underused in hospitalized patients with cancer. Studies have demonstrated that hospitalized patients with cancer are less likely than their non-cancer counterparts to receive vte prophylaxis. Consensus guidelines address the aforementioned issues and emerging concepts in the area, including the use of risk-assessment models, biomarkers to identify patients at highest risk of vte, and use of anticoagulants as anticancer therapy. Despite those guidelines, a gulf exists between current recommendations and clinical practice; greater efforts are thus required to ensure effective implementation of strategies to reduce the incidence of vte in patients with cancer.

In situ evaluation of gemcitabine-DNA interaction using a DNA-electrochemical biosensor

The electrochemical behaviour of the cytosine nucleoside analogue and anti-cancer drug gemcitabine (GEM) was investigated at glassy carbon electrode, using cyclic, differential pulse and square wave voltammetry, in different pH supporting electrolytes, and no electrochemical redox process was observed. The evaluation of the interaction between GEM and DNA in incubated solutions and using the DNA-electrochemical biosensor was studied. The DNA structural modifications and damage were electrochemically detected following the changes in the oxidation peaks of guanosine and adenosine residues and the occurrence of the free guanine residues electrochemical signal. The DNA-GEM interaction mechanism occurred in two sequential steps. The initial process was independent of the DNA sequence and led to the condensation/aggregation of the DNA strands, producing rigid structures, which favoured a second step, in which the guanine hydrogen atoms, participating in the C-G base pair, interacted with the GEM ribose moiety fluorine atoms.

Evidence-based guidance on venous thromboembolism in patients with solid tumours

Venous thromboembolism (vte) is a serious, life-threatening complication of cancer. Anticoagulation therapy such as low molecular weight heparin (lmwh) has been shown to treat and prevent vte. Cancer therapy is often complex and ongoing, making the management of vte less straightforward in patients with cancer. There are no published Canadian guidelines available to suggest appropriate strategies for the management of vte in patients with solid tumours. We therefore aimed to develop a clear, evidence-based guideline on this topic. A systematic review of clinical trials and meta-analyses published between 2002 and 2013 in PubMed was conducted. Reference lists were hand-searched for additional publications. The National Guidelines Clearinghouse was searched for relevant guidelines. Recommendations were developed based on the best available evidence. In patients with solid tumours, lmwh is recommended for those with established vte and for those without established vte but with a high risk for developing vte. Options for lmwh include dalteparin, enoxaparin, and tinzaparin. No one agent can be recommended over another, but in the setting of renal insufficiency, tinzaparin is preferred. Unfractionated heparin can be used under select circumstances only (that is, when rapid clearance of the anticoagulant is desired). The most common adverse event is bleeding, but major events are rare, and with appropriate follow-up care, bleeding can be monitored and appropriately managed.

Reduction of death rate due to acute myocardial infarction in subjects with cancers through systemic restoration of impaired nitric oxide

Introduction

Excessive aggregation of platelets at the site of plaque rupture on the coronary artery led to the formation of thrombus which is reported to precipitate acute myocardial infarction (AMI). Nitric oxide (NO) has been reported to inhibit platelet aggregation and induce thrombolysis through the in situ formation of plasmin. As the plasma NO level in AMI patients from two different ethnic groups was reduced to 0 µM (median) compared to 4.0 µM (median) in normal controls, the effect of restoration of the NO level to normal ranges on the rate of death due to AMI was determined.

Methods and Results

The restoration of plasma NO level was achieved by a sticking small cotton pad (10×25 mm) containing 0.28 mmol sodium nitroprusside (SNP) in 0.9% NaCl to the abdominal skin of the participants using non-toxic adhesive tape which was reported to normalize the plasma NO level. The participants (8,283) were volunteers in an independent study who had different kinds of cancers and did not wish to use any conventional therapy for their condition but opted to receive SNP “pad” for their condition for 3 years.

The use of SNP “pad” which normalized (≈4.0 µM) the plasma NO level that in consequence reduced the death rate due to AMI, among the participants, was found to be significantly reduced compared to the death due to AMI in normal population.

Conclusion

Our data suggested that the use of SNP “pad” significantly reduced the death due to AMI.

Trial Registration

www.ctri.nic.in004236