Cancer and Venous Thromboembolism: Scope of the Problem

Venous thromboembolism (VTE) in patients with cancer: epidemiology and risk factors

Although cancer is recognized as a major risk factor for venous thromboembolism, the exact magnitude of the problem and specific risk factors most strongly associated with the development of VTE is not well defined. Several recent studies have shown that the incidence of VTE is highest in patients who present with metastatic cancer, particularly cancers associated with a high one-year mortality rate, such as pancreatic cancer. The incidence rate of VTE is highest in the first few months after the diagnosis of cancer, and it decreases over time thereafter. For most cancers, it is not clear to what extent undergoing major surgery adds to the already high risk of VTE associated with the presence of the cancer. However, patients with glioma clearly have a very high incidence of VTE soon after they undergo any invasive neurosurgical procedure. Active chemotherapy, the use of erythropoetin agents, and the use of certain anti-cancer therapies such as thalidomide, high-dose steroids, and anti-angiogenic therapy also increase the risk of thrombosis. Similar to patients without cancer, the risk of VTE is higher in patients with coexisting chronic medical illnesses. Development of VTE is clearly associated with decreased survival and this effect is greater among patients initially diagnosed with local or regional stage cancer compared to patients with metastatic cancer.

Audit of anticoagulant thromboprophylaxis in hospitalized oncology patients

BACKGROUND

Venous thromboembolism (VTE) is a significant problem in oncology patients. VTE prophylaxis is underutilized in hospitalized medical patients, but there are few data for the appropriateness and frequency of its use in the oncology subgroup. We aimed to document local practice.

METHODS

A cross-sectional chart review of all hospitalized patients cared for by the Christchurch Hospital Oncology Service was carried out during two defined 4-week periods. Assessment for indications and contraindications to prophylactic anticoagulation was based on the 2004 American College of Chest Physicians evidence-based consensus guidelines.

RESULTS

Of 113 admissions to the oncology service, 38 (33.6%) had indications for prophylactic anticoagulation. However, 23 of these also had contraindications, leaving only 15 (13%) admissions where prophylactic anticoagulation was deemed appropriate. Only one was appropriately given prophylactic anticoagulation.

CONCLUSION

Only a minority of hospitalized oncology patients are appropriate for prophylactic anticoagulation. Where it is suitable, however, it is poorly utilized locally. Local promotion of VTE prophylaxis and further study of this subgroup of hospitalized medical patients may improve uptake of this practice and attenuate morbidity from VTE.

[Venous thromboembolism and cancer]

Cancer and venous thromboembolism (VTE), VTE and cancer: there is a close bond between these two diseases. On the one hand, a cancer patient runs a high risk of developing VTE. Certain cancer-specific factors, such as its metastatic nature increase this risk. The means involved in the care of cancer (insertion of a venous catheter, chemotherapy, etc.) also increase the probability of a thromboembolism. On the other hand, VTE, especially if it is idiopathic, may be the harbinger of a neoplasm. The present paper involves the dual nature of this relationship, first dealing with several points specific to the occurrence of VTE in a cancer patient, before dealing with the specific care in a curative and prophylactic situation. VTE is then considered as a clinical manifestation prior to a cancer. Several characteristics evoking an underlying neoplasm are known. However, the benefits of the screening for cancer when confronted with an episode of VTE remains to be debated.

Targeting patients for anticoagulant prophylaxis trials in patients with cancer: who is at highest risk?

INTRODUCTION

It is not clear which cancer patients are at highest risk for developing venous thromboembolism (VTE).

MATERIALS AND METHODS

The epidemiology of VTE in cancer patients was investigated by linking the California Cancer Registry database to the discharge records of all patients hospitalized in California public hospitals between 1993-1999. Nineteen types of cancer were studied, four in detail.

RESULTS AND CONCLUSIONS

The incidence of VTE was highest in patients who presented with metastatic cancer, particularly clinically aggressive cancers associate with a high one-year mortality rate, such as pancreatic cancer. The incidence of VTE increased as the number of chronic medical co-morbid conditions increased. The incidence of VTE was highest in the first few months after diagnosis, and decreased over time, even when the death rate due to cancer remained constant. Patients with glioma had a very high incidence of VTE after invasive neurosurgery, whereas patients with solid cancers who underwent major surgery had a lower risk of developing VTE compared to patients who did not undergo major surgery. Development of VTE was associated with significantly shortened survival compared to cancer patients without VTE matched for age, race, sex, initial cancer stage and time after cancer diagnosis. This effect of VTE on survival was greatest in patients initially diagnosed with local or regional stage solid cancer as VTE was associated with emergence of metastatic disease. If primary thromboprophylaxis of cancer patients is considered, treatment should begin immediately after cancer diagnosis, and it should be targeted toward patients who have a biologically aggressive cancer that is initially metastatic and/or toward patients who have several chronic co-morbid conditions. Secondary thromboprophylaxis should be targeted toward patients who have evidence of an ongoing active malignancy. Glioma patients are at very high risk in the 3 month period immediately after invasive neurosurgery.

Thromboprophylaxis during chemotherapy after advanced cancer

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

Tissue factor activity is increased in a combined platelet and microparticle sample from cancer patients

BACKGROUND

Cancer patients have an increased risk of thrombosis. Tissue factor (TF) antigen and TF activity associated with microparticles in plasma are elevated in patients with various types of cancer. Of these two measurements, TF activity is considered superior to TF antigen levels because the activity more closely reflects the ability of TF to initiate coagulation. Recent studies showed that platelets also express TF.

OBJECTIVE

To determine the level of TF activity associated with a combined platelet and microparticle sample from cancer patients (n = 20) and healthy individuals (n = 23).

METHODS

TF activity was measured using a two step chromogenic assay and soluble P-selectin was measured by ELISA in healthy controls and metastatic cancer patients.

RESULTS

We determined the composition of a combined platelet and microparticle sample. The sample consisted of platelets, large microparticles (30-200 nm) and membrane debris. We compared the TF activity of a combined platelet and microparticle sample from cancer patients with that from healthy individuals. We found that TF activity in a combined platelet and microparticle sample from cancer patients was higher than in samples from healthy individuals (21.5+/-12.3 pM (n = 20) versus 8.6+/-6.8 pM (n = 23), mean+/-SD, p < 0.001). Cancer patients also had a higher level of soluble P-selectin compared with controls (18.9+/-5.5 ng/mL versus 13.2+/-2.3 ng/mL, p < 0.001).

CONCLUSION

This study indicates that measurement of TF activity in a combined platelet and microparticle sample can be used as a simple assay to determine the level of circulating TF.

Supportive management of patients with brain tumors

Management issues for patients with brain tumors include peritumoral edema, symptomatic seizures, venous thromboembolism, headache, pain, fatigue and neuropsychological complaints. Vasogenic edema is typically ameliorated with the lowest dose possible of corticosteroid. Seizures are managed with attention to additional or complicated side effects of antiepileptic drugs and their interactions with chemotherapy, and primary prevention with antiepileptic medications is not recommended. Appropriate treatments for headache, pain, fatigue and neuropsychological complaints are important, but are not yet well standardized. Above all, patients' personal goals regarding their priorities at the end of life have the most importance.

Venous thromboembolism prevention in cancer patients: the search for common antecedents

Venous thromboembolism (VTE) is a well-recognized concomitant of cancer. Although treatment with warfarin is often difficult and tedious, the heparins, and particularly the low molecular weight heparins, have afforded improved care of the patient with cancer-associated VTE, but with increased cost and the need for self-injection. Development by the pharmaceutical industry of inhibitors of specific activated coagulation factors and P-selectin holds promise for improved control of thrombosis with reduced toxicity. Increasing understanding of the interplay between the coagulation mechanism and neoplasia has yielded clues to the upstream origins of both, which may lead to experimental intervention potentially capable of preventing both.

Cancer and thrombosis: from molecular mechanisms to clinical presentations

Although the bidirectional association between cancer and venous thromboembolism (VTE) has been known for almost two centuries, recent advances in our understanding of the clinical, laboratory, and epidemiologic aspects of this association have created a renewed interest in this topic. This review consists of two parts. The first part discusses the occurrence, determinants and significance of VTE in those with cancer, as well as the risk of developing and the possible need to detect cancer in those presenting with VTE. The second part reviews the role of hemostatic constituents (coagulation and fibrinolytic proteins and platelets) in promoting growth and progression of cancer, as well as the effects and possible mechanisms of the low molecular weight heparins (LMWH) in this process.

Thromboembolic disease after total hip arthroplasty: who is at risk?

The strong activation of the clotting cascade that occurs during total hip arthroplasty places patients at increased risk for venous thromboembolism. The risk is higher in those patients with the following predisposing factors, listed in approximate order of importance: hip fracture; malignancy, particularly if associated with chemotherapy; antiphospholipid syndrome; immobility; history of venous thromboemholism; administration of tamoxifen; raloxifene; oral contraceptives or estrogen; morbid obesity; stroke; atherosclerosis; and an American Society of Anesthesiologists physical status classification of 3 or greater. The following risk factors are weak or controversial: advanced age; diabetes mellitus; congestive heart disease; atrial fibrillation; varicose veins; and smoking. However, 50% of patients who develop thromboembolism after total hip arthroplasty have no clinical predisposing factors. In a matched, controlled study, we defined the major genetic predispositions that increase the risk of venous thromboembolism after total hip arthroplasty: deficiency of antithrombin III (< 75%) and protein C (< 70%), and prothrombin gene mutation. Preoperative genetic screening in conjunction with the recognized clinical risk factors can help categorize postoperative venous thromboembolism risk and differentiate patients who can be protected with milder and safer prophylaxis (eg, aspirin, intermittent pneumatic compression) compared with those at higher risk who need to be anticoagulated.

Acute bilateral pulmonary emboli occurring while on adjuvant aromatase inhibitor therapy with anastrozole: case report and review of the literature

Hormonal therapy is the mainstay of adjuvant treatment for women with early-stage estrogen receptor-positive breast cancer. Recently, the aromatase inhibitors have moved to the forefront of adjuvant hormonal therapy, however, the adverse effects of these agents are not yet fully understood. It is generally accepted that tamoxifen, but not the aromatase inhibitors, is associated with an increased risk of thrombosis in women with breast cancer. Studies comparing aromatase inhibitors to tamoxifen in the adjuvant setting have reported a lower rate of venous thromboembolism with the aromatase inhibitors, yet the incidence of venous thromboembolism with these new agents is higher than that expected in the general population. Here we report a case of acute bilateral pulmonary emboli occurring while on adjuvant aromatase inhibitor therapy with anastrozole, and review the literature on the incidence of venous thromboembolism during the use of aromatase inhibitors in the adjuvant setting.

Prevention of severe menorrhagia in oncology patients with treatment-induced thrombocytopenia by luteinizing hormone-releasing hormone agonist and depo-medroxyprogesterone acetate

BACKGROUND

Menorrhagia is a serious complication in young female oncology patients who suffer from severe thrombocytopenia during myelosuppressive treatment. To the authors' knowledge, little is known regarding the incidence of this complication or the effectiveness of possible therapies for its prevention.

METHODS

In this retrospective clinical study, after a thorough gynecologic evaluation, young female oncology patients with regular menstrual cycles undergoing myelosuppressive treatments received either depo-medroxyprogesterone acetate (DMPA), or D-tryptophan-6-luteinizing hormone-releasing hormone depot treatment (gonadotropin-releasing hormone agonist [GnRH-a]), or no treatment before the administration of myelosuppresive chemotherapy. Only patients who later developed severe thrombocytopenia (<25,000 platelets per muL) were included in the study. Daily blood counts, menorrhagia, nonvaginal bleeding episodes, and the need for blood products, gynecologic consultations, and other medical interventions were determined.

RESULTS

Of 101 women with cancer who met the inclusion criteria, 42 patients received DMPA, 39 patients received GnRH-a, and 20 patients remained untreated. The mean duration (+/- standard deviation) of severe thrombocytopenia was 24.76 +/- 23.6 days. Four patients were not included because of significant gynecologic pathologies. General bleeding from nongynecologic sites was similar for all groups and was not associated with vaginal bleeding. Severe or moderate menorrhagia was documented in none of the 39 women who received GnRH-a, in 9 patients (21.4%) who received DMPA, and in 9 untreated patients (40%; P = .02). Fewer calls for urgent gynecologic consultations were documented in the GnRH-a group compared with the untreated group (P < .0001).

CONCLUSIONS

Female patients undergoing myelosupressive therapy are at high risk of developing significant menorrhagia during prolonged, severe thrombocytopenia. Pretreatment gynecologic evaluation can detect significant pelvic pathologies. GnRH-a treatment effectively prevented menorrhagia, whereas DMPA administration was less effective.