Cancer and venous thromboembolism

Drug Repurposing: A New Hope in Drug Discovery for Prostate Cancer

Prostate cancer (PCA), the most common cancer in men, accounted for 1.3 million new incidences in 2018. An increase in incidences is an issue of concern that should be addressed. Of all the reported prostate cancers, 85% were detected in stages III and IV, making them difficult to treat. Conventional drugs gradually lose their efficacy due to the developed resistance against them, thus requiring newer therapeutic agents to be used as monotherapy or combination. Recent research regarding treatment options has attained remarkable speed and development. Therefore, in this context, drug repurposing comes into the picture, which is defined as the "investigation of the off-patent, approved and marketed drugs for a novel therapeutic indication" which saves at least 30% of the time and cost, reducing the cost of treatment for patients, which usually runs high in cancer patients. The anticancer property of cardiac glycosides in cancers was tested in the early 1980s. The trend then shifts toward treating prostate cancer by repurposing other cardiovascular drugs. The current review mainly emphasizes the advantageous antiprostate cancer profile of conventional CVS drugs like cardiac glycosides, RAAS inhibitors, statins, heparin, and beta-blockers with underlying mechanisms.

Incidence and Risk Factors for Venous Thromboembolism in Female Patients Undergoing Breast Surgery

Albeit it does not have the highest venous thromboembolism (VTE) incidence compared to other neoplasms, breast cancer contributes to many VTE events because it is the most diagnosed tumor in women. We aim to analyze the occurrence and timing of VTE during the follow-up of patients who underwent breast surgery, the possible correlated factors, and the overall survival. This retrospective study included all female patients diagnosed with mammary pathology and surgically treated in our clinic between January 2002 and January 2012. Of 5039 women who underwent breast surgery, 1056 were found to have no evidence of malignancy, whereas 3983 were diagnosed with breast cancer. VTE rate resulted significantly higher in patients with invasive breast cancer than in women with benign breast disease or carcinoma in situ. Invasive cancers other than lobular or ductal were associated with a higher VTE rate. In addition, chronic hypertension, high BMI, cancer type, and evidence of metastasis turned out to be the most significant risk factors for VTE in women who underwent breast surgery. Moreover, VTE occurrence significantly impacted survival in invasive breast cancer patients. Compared to women with benign mammary pathology, VTE prevalence in women with breast cancer is significantly higher. The knowledge about the risk factors of VTE could be helpful as prognostic information, but also to eventually target preventive treatment strategies for VTE, as far as the co-existence of invasive breast cancer and VTE has a significantly negative impact on survival.

Risk factors for venous thromboembolism in metastatic colorectal cancer with contemporary treatment: A SEER-Medicare analysis

Background

The relationship between metastatic colorectal cancer (mCRC) and venous thromboembolism (VTE) is poorly defined in the modern era. Our objective was to examine impact of putative risk factors including newer treatments and anti‐angiogenic therapy on VTE incidence and survival in a modern older mCRC cohort.

Methods

This is a SEER‐Medicare cohort analysis of mCRC patients diagnosed in 2004–2009. Risk factor analysis was conducted using Cox models adjusted for sex, diagnosis age, race, primary tumor location, comorbidity, and prior VTE history, with cancer treatments as time‐varying covariates. Main outcomes were VTE incidence and overall survival.

Results

Ten thousand nine hundred and seventy six mCRC cases with mean age 77.9 years (range 65–107), 49.7% women, 83.5% white. There were 1306 VTE cases corresponding to 13.7% incidence at 1 year and 20.3% at 3 years. Independent VTE predictors included female sex (HR 1.27; 95% CI 1.14–1.42), African American race (HR 1.49; 1.27–1.73), prior VTE history (HR 16.3; 12.1–22.1), and right sided cancers (HR 1.16; 1.04–1.29). After adjustment, any therapy and bevacizumab (HR 0.68, 0.58–0.78) in particular were protective. Overall survival was 40.1% (39.4–41.3) at 1 year but improved significantly with any treatment. VTE following diagnosis of mCRC was associated with inferior OS (HR 1.09; 1.02–1.15).

Conclusions

In this large contemporary mCRC cohort, effective systemic therapy including anti‐angiogenic treatment was associated with lower VTE risk. Overall survival was poor, and modestly worse if a patient had a VTE at any time during treatment.

Venous Thromboembolism and Risk of Cancer in Patients with Diverticular Disease: A Danish Population-Based Cohort Study

Purpose

Venous thromboembolism may be a harbinger of cancer. Patients with diverticular disease are suggested to have an increased risk of developing venous thromboembolism compared with the general population, but it remains unclear whether venous thromboembolism is also a marker of occult cancer in these patients. We investigated the risk of cancer after venous thromboembolism among patients with diverticular disease.

Patients and Methods

We used Danish health registries to conduct a nationwide, population-based cohort study during 1996–2017. We identified all venous thromboembolism patients with a diagnosis of diverticular disease and calculated absolute risks of cancer and standardized incidence ratios (SIRs) by comparing observed and expected cancer incidence based on national cancer incidence in the Danish population.

Results

We followed 3406 patients with venous thromboembolism and diverticular disease for a median of 3.0 years (interquartile range: 1.0–6.0). During the first year of follow-up, we observed 212 cancer cases. The corresponding one-year risk of cancer was 6.2% (95% confidence interval [CI]: 5.5–7.1) with a SIR of 2.9 (95% CI: 2.5–3.3). The SIRs were particularly elevated for cancers of the stomach, pancreas, ovary, and kidney. During the second and subsequent years of follow-up, 337 cancers were diagnosed with a SIR of 1.1 (95% CI: 1.0–1.3).

Conclusion

Venous thromboembolism is a harbinger of occult cancer in patients with diverticular disease.

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Effects of a 1-Year Physical Activity Intervention on Markers of Hemostasis among Breast Cancer Survivors: A Randomized Controlled Trial

Introduction  Physical activity may reduce the development of breast cancer. Whereas hypercoagulability has been linked to adverse outcomes in breast cancer patients, the effects of physical activity on their hemostatic factors are unknown. The study aimed to assess whether long-term (1 year) physical activity can affect hemostatic factors in breast cancer patients. Methods  Fifty-five women (35-75 years) with invasive breast cancer stage I/II were randomized to a physical activity intervention ( n  = 29) lasting 1 year or to a control group ( n  = 26), and analyzed as intention to treat. Fibrinogen, factor VII antigen, tissue factor pathway inhibitor, and von Willebrand factor (VWF) antigen as well as prothrombin fragment 1 + 2, the endogenous thrombin potential and D-dimer, were measured in plasma before intervention (baseline), and then after 6 and 12 months. Results  Maximal oxygen uptake (measure of cardiorespiratory fitness) decreased the first 6 months among the controls, but remained stable in the intervention group. We found no significant differences between the two study groups regarding any of the hemostatic factors, except a significantly higher increase in factor VII antigen in the intervention group. The effect of the intervention on VWF was, however, significantly affected by menopausal stage, and a significant effect of the intervention was found on VWF among postmenopausal women, even after adjustment for dietary intake. Conclusion  Long-term physical activity had no effect on the majority of the hemostatic factors measured, but led to increased plasma concentrations of factor VII antigen and prevented an increase in VWF concentration after breast cancer treatment in postmenopausal women. The clinical impact of these findings for risk of vascular thrombosis warrants further studies.

Increased risk of cancer in patients with retinal vein occlusion: a 12-year nationwide cohort study

Aims

To investigate the association between incident retinal vein occlusion (RVO) and the subsequent development of cancer.

Methods

In this nationwide population-based retrospective study using 2002–2013 National Health Insurance Service database which covers the entire South Korean population, 186 701 incident RVO patients and their 1:1 propensity-score matched controls were included. We defined the fixed cohort from January 1st, 2004 to December 31st, 2013; the cohort included patients who suffered incident RVO after entering the cohort and their matched controls, and excluded patients having any cancer history before entering the cohort. The association of RVO and cancer was assessed by time-varying covariate Cox regression models; Model 1 included RVO as a time-varying covariate, Model 2 included Model 1 plus demographic information and Model 3 included Model 2 and comorbidities.

Results

RVO was associated with an increased risk of subsequent cancer (HR=1.29; 95% CI, 1.26–1.31 in Model 1), which was consistent in Models 2 and 3. The incidence rate of overall cancer during the study period was 25.55 (95% CI, 25.19–25.91) per 1000 person-years in the RVO group and 18.62 (95% CI, 18.46–18.79) per 1000 person-years in the control group. In the subgroup analysis, haematological malignancies showed the highest association with RVO (HR=1.65; 95% CI, 1.49–1.83).

Conclusion

Patients with RVO have an increased risk of subsequent cancer development even after adjusting for demographic factors and comorbidities. Further study is warranted to elucidate these associations to provide proper recommendations for RVO patients regarding the cancer screening.

Management of recurrent venous thromboembolism in cancer patients

Cancer is one the most prevalent risk factors in patients diagnosed with deep vein thrombosis or pulmonary embolism. Patients with cancer and venous thromboembolism have a higher risk of mortality when compared to patients with cancer without venous thromboembolism and a higher risk of recurrent thrombosis when compared with patients with venous thromboembolism without cancer. This increased risk of recurrence is not only observed after anticoagulant treatment is stopped, but also during anticoagulant treatment. Clinical trials have shown that the use of low molecular weight heparin during the first three to six months after venous thrombosis in patients with cancer is associated with a significantly lower risk of recurrence than the use of vitamin K antagonists and, thus, low molecular weight heparin is currently recommended as the treatment of choice by international guidelines. Unfortunately, the optimal management of recurrent venous thromboembolism during anticoagulant treatment remains poorly defined. In general, patients should firstly be assessed for treatment compliance, for the occurrence of heparin-induced thrombocytopenia, and for the presence of mechanical compression from tumour masses. Possible strategies include switching to a different anticoagulant drug, in particular from vitamin K antagonists to low molecular weight heparin; increasing the dose of the anticoagulant drug; or inserting an inferior vena cava filter. The results of recent registries show that the current approach to cancer patients with recurrent venous thromboembolism in routine clinical practice is highly heterogeneous.

Recurrent Venous Thromboembolism in Two Patients With Cancer Taking Rivaroxaban

Pharmacologic agents for the treatment and prevention of venous thromboembolism in the cancer patient population are limited. Currently, low-molecular-weight heparin is recommended by national consensus guidelines for this indication. Rivaroxaban, an oral factor Xa inhibitor, is Food and Drug Administration (FDA) approved for the treatment and prevention of venous thromboembolism and offers the convenience of oral fixed-dose regimens, no routine laboratory monitoring, and has few drug and dietary interactions; however, its use in patients with cancer has not been largely studied. We report 2 cases of recurrent venous thromboembolism in patients with active cancer on rivaroxaban therapy. The first case is a 64-year-old female admitted for recurrent pulmonary embolism, and the second case is a 70-year-old female admitted for recurrent deep vein thrombosis. Both patients were receiving rivaroxaban at the time of thromboembolic recurrence. These cases serve as a reminder to health-care providers that more safety and efficacy data in the cancer patient population are needed prior to using rivaroxaban for venous thromboembolism treatment.

Characteristics and Risk Factors of Cancer Associated Venous Thromboembolism

INTRODUCTION

The objective of this study was to examine the differences in commonly associated characteristics and risk factors of venous thromboembolism (VTE) between patients with and without cancer in a VTE population.

MATERIALS AND METHODS

Uniform data were collected for patients with a diagnosis of VTE obtaining care at CDC funded Thrombosis Network Centers. Patient characteristics and risk factors were compared in VTE patients with and without cancer. Logistic regression was used to calculate the unadjusted and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) to assess patient characteristics and thrombotic risk factors more frequently identified among VTE patients with cancer compared to those without cancer.

RESULTS

Between August 2003 and April 2011, 3,115 adult patients with a diagnosis of VTE including 189 (6.1%) patients with active cancer participated in the multi-site thrombosis registry. VTE patients with cancer had a higher prevalence of PE and DVT in unusual sites compared to those without cancer. Thrombophilia was more common among VTE patients without cancer than those with cancer (25.1% vs 10.6%, p<0.001). In adjusted analysis, age group≥45years (OR =5.20, 95% CI, 3.30, 8.18), surgery (OR =1.86, 95% CI, 1.19, 2.91), and hypertension (OR =1.66, 95% CI, 1.15, 2.40) were the VTE risk factors more commonly found among VTE patients with cancer.

CONCLUSION

The study identified several thrombotic risk factors more likely to be found with cancer associated VTE, which may help to characterize at risk cancer patients and to develop prevention and management strategies in this population.

Adjuvant therapy in breast cancer and venous thromboembolism

Breast cancer patients are considered to be at relatively low risk of developing a TEE. The highest incidence of VTE events occurs in metastatic breast cancer patients likely due to extension of disease, immobility for pathologic bone fractures, cancer cachexia and venous compression by the tumour mass. Although thrombosis is less common in patients with early stage cancer compared to those with more advanced disease, it does occur and is clinically challenging. The adjuvant setting is of particular interest in order to assess the specific thrombogenic potential of systemic chemotherapy, because of the low tumor burden with only microscopic tumor foci at the time of treatment administration. This review summarizes risk factors, incidence and strategies to avoid VTE in breast cancer patients receiving adjuvant therapy.

Limb necrosis in a lung cancer case presenting with widespread thrombosis

The malignancies are commonly associated with enhanced thrombotic vascular events. The thrombotic events are also increased in lung cancer subtypes. Even, the systemic mortal thrombotic disorders were reported in the literature. We report a case of a nonsmall-cell carcinoma patient who progressed with widespread thrombosis.

Risk of cancer in patients with inflammatory bowel disease and venous thromboembolism: a nationwide cohort study

BACKGROUND

Venous thromboembolism (VTE) may be a harbinger of cancer. Inflammatory bowel disease (IBD) is known to increase the risk of VTE, but it is unclear whether VTE in IBD patients is also a marker for occult cancer. We assessed the risk of cancer after VTE in IBD patients.

METHODS

We conducted a population-based cohort study by linking Danish medical registries during 1978-2008. We calculated standardized incidence ratios (SIRs) by comparing observed cancer incidence after VTE in IBD patients with that expected based on national cancer incidence in the Danish population.

RESULTS

A total of 895 IBD patients with VTE were followed for a total of 5290 person-years. During the first year of follow-up, 28 (3.1%) patients were diagnosed with cancer, corresponding to an SIR of 3.2 (95% confidence interval [CI]: 2.2, 4.7). Patients with ulcerative colitis or Crohn's disease had similar relative risks (SIR = 3.1 [95% CI: 1.9, 4.9] and SIR = 3.5 [95% CI: 1.7, 6.3], respectively). In IBD patients <55 years the SIR was 5.7 (95% CI: 2.3, 11.8) and in patients ≥55 years the SIR was 2.8 (95% CI: 1.8, 4.3). During the second and subsequent years of follow-up 61 cancers were diagnosed (SIR = 1.2 [95% CI: 0.92, 1.6]).

CONCLUSIONS

In patients with IBD a VTE event is not only a consequence of their disease, but might also be a marker of occult cancer. We suggest that IBD patients with VTE should follow the same diagnostic work-up guidelines as non-IBD VTE patients.

Basic mechanisms and pathogenesis of venous thrombosis

In 1856 Virchow proposed a triad of causes for venous thrombosis, postulating that stasis, changes in the vessel wall or changes in the blood could lead to thrombosis. We now know that abnormally high levels of some coagulation factors and defects in the natural anticoagulants contribute to thrombotic risk. Among these, factor V Leiden, which renders factor Va resistant to activated protein C, is the most prevalent with approximately 5% of the Caucasian population having this genetic alteration. These genetically controlled variants in coagulation factors work in concert with other risk factors, such as oral contraceptive use, to dramatically increase thrombotic risk. While these abnormalities in the blood coagulation proteins are associated with thrombotic disease propensity, they are less frequent contributors to thrombosis than age or cancer. Cancer increases thrombotic risk by producing tissue factor to initiate coagulation, by shedding procoagulant lipid microparticles or by impairing blood flow. Age is the strongest risk factor for thrombosis. Among possible reasons are fragility of the vessels potentially contributing to stasis, increased coagulation factor levels, impaired function of the venous valves, decreases in the efficacy of natural anticoagulants associated with the vessel wall, increased risk of immobilization and increased risk of severe infection.

The use of inferior vena caval filters prior to major surgery in women with gynaecological cancer

OBJECTIVE

To evaluate the use of inferior vena caval filters (IVCF) prior to surgery in women with gynaecological cancer and venous thromboembolism (VTE).

DESIGN

Retrospective review of medical notes and electronic records.

SETTING

Gynaecological oncology cancer centre.

POPULATION

Women with gynaecological cancer and VTE requiring major surgery.

METHODS

A retrospective analysis was performed on women treated for gynaecological malignancies who had had VTE, and an IVCF placed before major abdominal surgery were reviewed during the period 1996-2006.

MAIN OUTCOME MEASURES

Safety of IVCF placement and retrieval, peri-operative morbidity and incidence of further VTE.

RESULTS

The median age was 66 years (range 30-84 years). Of the 39 women, 35 (90%) women had a primary cancer diagnosis and 4 (10%) had recurrent disease. Twenty-two women had ovarian cancer, 2 had borderline ovarian tumours, 9 had uterine cancer, 5 had cervical cancer and 1 woman had concurrent ovarian and endometrial cancers. The recurrent cancers were two cervical, one ovarian and one uterine. The IVCF used were either of the permanent or retrievable type, the latter being more commonly used in younger women. All filters were placed without morbidity, and none of these women who then underwent major abdominal surgery had VTE complications. In 43.6% of women (n = 17), surgery was performed within 6 weeks of the diagnosis of VTE. All women received perioperative anticoagulation in the form of subcutaneous low-molecular-weight heparin. Three retrievable filters were uneventfully removed postoperatively. No filter-related problems occurred.

CONCLUSIONS

Surgery in women with gynaecological cancer and life-threatening VTE is feasible with preoperative IVCF placement. The use of IVCF was safe with no worsening of the VTE, and without surgical or filter-related problems. A short interval between the diagnosis of VTE and surgery was not associated with increased perioperative morbidity.

Risk factors associated with venous thromboembolic events in patients with malignancy

Malignancy is a major risk factor for venous thromboembolic events, but not all patients with malignancy develop such events. This study attempts to identify risk factors in patients with malignancy who develop venous thromboembolic events. In the current study, 566 consecutive patients without venous thromboembolic events and 416 patients with, admitted to University of Michigan with malignancy between 1992 and 2000, were identified using International Classification of Diseases-9 Clinical Modification codes. Data on potential risk factors was obtained from the University of Michigan Cancer Registry and the medical record. Univariate and multivariate analysis was used to identify factors associated with venous thromboembolic events and mortality. The mean patient age was 45.6 years with a mean survival of 7.8 years from cancer diagnosis. Venous thromboembolic events were associated with solid tumors (odds ratio 5.0; 95% confidence interval 1.7-14.9; P = 0.004), infection (4.9; 1.2-19.8; P = 0.03), and increasing age (1.05; 1.03-1.08; P < 0.001). While leukopenia (4.2; 1.2-14.6; P = 0.02) was associated with an increased incidence of venous thromboembolic events, neutropenia was not. Sex, type of therapy, and cancer stage were not independently associated with venous thromboembolic events. Survival was decreased in patients with venous thromboembolic events (5.9 versus 9.2 years, P < 0.0001). Solid tumors (3.9; 1.8-8.4; P = 0.001), infection (3.3; 1.1-9.9; P = 0.03), advanced stage (1.6; 1.2-2.1; P = 0.001), and increasing age (1.02; 1.0-1.04; P = 0.01) were associated with decreased survival. Patients with malignancy who have solid tumors, advanced age, infection, and leukopenia have a significantly increased risk of venous thromboembolic events.

Low-dose aspirin for the prevention of venous thromboembolism in breast cancer patients treated with infusional chemotherapy after insertion of central vein catheter

BACKGROUND

We previously demonstrated a high incidence (7.7%) of venous thromboembolism (VTE) in breast cancer patients treated with infusional chemotherapy after insertion of central vein catheters (CVC). The aim of this study was to evaluate the efficacy and safety of low-dose aspirin for the prevention of VTE.

PATIENTS AND METHODS

In a monocentric prospective study, patients with stage II-IV breast cancer, who underwent CVC insertion for continuous infusional chemotherapy, were assigned to receive low-dose aspirin (100 mg daily). Treatment was started after CVC implantation and continued until the last day of chemotherapy. Patients were assessed for safety and for the incidence of symptomatic deep venous thrombosis (DVT) confirmed by color-Doppler ultrasonography.

RESULTS

Between April 2000 and March 2004, 188 consecutive patients were included in the study. Median age was 48 years (range 22-83), 31 patients (16%) had concomitant hypertension, and 14 patients (7.4%) were smokers. Median duration of treatment with aspirin was 3.6 months (range 0.4-5.7). A DVT confirmed by color-Doppler ultrasonography was observed in four patients (2.1%; 95% confidence interval, 0.58-5.35%). Side effects included mild epistaxis (three patients, 1.5%) and mild gastric pain (two patients, 1%). No major bleeding complication or International Normal Ratio alteration occurred.

CONCLUSIONS

Administration of low-dose aspirin is safe and seems to correlate with a low risk of DVT in breast cancer patients treated with infusional chemotherapy. Further randomized studies comparing low-dose aspirin with other anticoagulative agents are warranted.

Thromboembolic Disorders in Cancer

Complex factors, including substances in cancer cells, cancer treatment effects, and venous stasis associated with chronic illness, blood vessel wall injury, and immobility, interact to place patients with cancer at risk for thrombosis. This article describes the etiology, clinical manifestations, diagnostic tests, and treatments for venous and pulmonary emboli associated with cancer. It explores the nurse's role in assessing patients who are at risk, managing symptomatic thrombosis and primary and secondary prevention of emboli, and administering anticoagulant therapy. As growing numbers of patients are treated in outpatient settings, oncology nurses play a critical role in the coordination of care for patients at risk for thrombosis. A nursing care plan summarizes key nursing strategies for assessment and intervention.

Primary thromboprophylaxis for cancer patients with central venous catheters--a reappraisal of the evidence

Venous thromboembolism (VTE) is responsible for an estimated 25 000 deaths per annum in UK hospital practice. It is well established that many of these deaths could be prevented through the use of appropriate thromboprophylaxis. This issue is of particular relevance in oncology practice, where the risks of VTE and bleeding are both significantly higher than those observed in general medical patients. Cancer patients with in-dwelling central venous catheters (CVCs) are at particularly high risk of developing thrombotic complications. However, the literature has produced conflicting conclusions regarding the efficacy of using routine primary thromboprophylaxis in these patients. Indeed such is the level of confusion around this topic, that the most recent version of the American College of Chest Physicians (ACCP) guidelines published in 2004 actually reversed their previous recommendation (published in 2001). Nevertheless, minidose warfarin continues to be routinely used in many oncology centres in the UK. In this article, we have performed a systematic review of the published literature regarding the efficacy and the risks, associated with using thromboprophylaxis (either minidose warfarin or low-dose LMWH) in cancer patients with CVC. On the basis of this evidence, we conclude that there is no proven role for using such thromboprophylaxis. However, asymptomatic CVC-related venous thrombosis remains common, and further more highly powered studies of better design are needed in order to define whether specific subgroups of cancer patients might benefit from receiving thromboprophylaxis.

[Venous thromboembolism and cancer]

OBJECTIVES

The risk of venous thrombosis during cancer is largely increased especially in case of chemotherapy, surgery, advanced stage disease, coagulation abnormalities. Survival of patients with cancer experiencing venous thrombosis seems to be worse. Although thrombosis may be a presenting feature of occult malignancy, there are insufficient data to support a more extensive screening than comprehensive medical history, physical examination, routine laboratory tests and chest radiography.

CURRENT KNOWLEDGE AND KEY POINTS

Pathophysiology of venous thrombosis during cancer is unspecific: venous stasis, vessel wall damage, hypercoagulability). Other factors like platelet abnormalities or the direct responsibility of chemotherapy or hormonotherapy have recently been though to play a causative role. Treatment of cancer-associated thrombosis usually requires at least 6 months of low-molecular-weight heparin therapy rather than oral anticoagulant. Inferior vena cava filters are not indicated. Primary prophylaxis of thrombosis during cancer could safely been achieved with low-molecular-weight heparin. Central venous catheters can be associated with thrombotic complications. Many risks factors have been identified: catheter's type, modalities of catheter's implantation, type of perfusion, bulky mediastinal mass... Prophylactic anticoagulation is not routinely recommended.

FUTURE PROSPECTS AND PROJECTS

Knew oral anticoagulants could facilitate the treatment of venous thrombosis occurring during cancer in the next years.

Abnormal Clotting in Cancer: An Overview of Pathophysiology and Etiology

OBJECTIVE

To help oncology nurses become more cognizant of the increased risk cancer patients have for venous thromboembolism due to such factors as chemotherapy and hypercoagulability stemming from the neoplasm itself.

DATA SOURCES

Primary and tertiary literature and the author's clinical experience.

CONCLUSION

Establishing the optimal treatment of cancer-associated thrombosis in the future will depend in part on a better understanding of clotting aberrations. Oncology nurses must be cognizant of the various risk factors for thrombosis and bleeding and how they relate to cancer treatments and interventions.

IMPLICATIONS FOR NURSING PRACTICE

Oncology nurses are in a unique position to recognize conditions that predispose cancer patients to the development of venous thromboembolism as well as its signs and symptoms. This enhanced understanding will ensure that patients receive appropriate and timely intervention.

The risk of a second cancer after hospitalisation for venous thromboembolism

Although venous thromboembolism (VTE) is common in patients with cancer, it is not known if it is associated with risk of a second malignancy. Using the Danish Cancer Registry and National Registry of Patients, we studied a population-based cohort of 6285 patients with cancer who had an episode of VTE. The risk of a second cancer was compared with that among 30 713 cancer patients without VTE, matched for age, sex, cancer site and year of diagnosis. Overall, the relative risk for a second cancer diagnosis was 1.3 (95% confidence interval (CI) 1.1–1.4). However, the excess risk varied with the time from the initial cancer diagnosis to the thrombotic event. If the thrombotic episode occurred within the first year, the relative risk for a second cancer was 1.0 (95% CI 0.9–1.3), but if the VTE occurred more than 1 year after the initial cancer, the overall relative risk for a second cancer was 1.4 (95% CI 1.2–1.7), with strong associations for cancers of the digestive organs, ovary and prostate. The association between VTE and subsequent incident cancer extends to patients who already have had a cancer diagnosis.

Cancer and venous thromboembolism

Venous thromboembolism occurs commonly in patients with cancer. The pathogenetic mechanisms of thrombosis involve a complex interaction between tumour cells, the haemostatic system, and characteristics of the patient. Among risk factors for thromboembolism are long-term immobilisation, especially in hospital, surgery, and chemotherapy with or without adjuvant hormone therapy. Although prophylaxis and treatment of thromboembolism in patients with cancer draw on the agents that are commonly used in those without cancer, there are many special features of patients with cancer that make use of these drugs more challenging. Low-molecular-weight heparins are the cornerstone of prophylaxis and treatment of venous thromboembolism in patients with cancer. These drugs have the potential to increase survival, at least in patients with more favourable outlook. About 10% of patients with idiopathic venous thromboembolism have an underlying malignant disorder that can be detected by extensive diagnostic investigation. However, the issue of whether screening for occult malignant disease ultimately improves prognosis and survival remains to be resolved.

Thromboembolic events in patients treated with definitive chemotherapy and radiation therapy for invasive cervical cancer

OBJECTIVES

Determine the incidence of and risk factors for thromboembolic events (TE) in patients treated with definitive chemoradiation for cervical cancer at our institution.

METHODS

A retrospective chart review was performed of all patients with a diagnosis of invasive carcinoma of the cervix (FIGO Stage IB-IVA) treated with definitive chemoradiation at University of Iowa Hospitals and Clinics (UIHC) from July 2002 to December 2003. Forty-eight patients met these criteria. All but one patient received 45 Gy to the pelvis followed by brachytherapy, IMRT, or conformal boost. One patient received 39.6 Gy to the pelvis. Cisplatin chemotherapy, 40 mg/m squared, was given weekly for 6 weeks. Data were collected for FIGO stage, age, body mass index (BMI), and smoking history. TE were confirmed by Doppler ultrasound or pulmonary imaging. Log-rank tests were used to examine the association between time to TE and the variables FIGO stage and smoking status. The association between time to TE and the continuous variables age and BMI was examined with Cox proportional hazards regression. All tests were two-sided and carried out to the 5% level of significance using the SAS statistical software package.

RESULTS

Minimum follow-up was 8 months. Eight patients (16.7%) developed a TE. The associations were not statistically significant for stage (P = 0.72), smoking status (P = 0.72), age (P = 0.63) or BMI (P = 0.86). Risk factors were similar in both groups. Data review suggests that the entire group had risk factors for TE.

CONCLUSIONS

We noted a high incidence of TE (16.7%) in patients treated at UIHC with chemoradiation for invasive cervical cancer. We did not find a statistical association between age, stage, smoking history, or BMI and risk of TE in this group. Patients with and without TE had multiple risk factors for TE.

Cancer and thrombosis: mechanisms and treatment

Standard venous thromboembolic event (VTE) treatment practices including the use of intravenous unfractionated heparin (UFH) for initial anticoagulation, oral warfarin for chronic anticoagulation, and the prescription of only 3 to 6 months total therapy may not be optimal in the setting of active cancer and ongoing anti-cancer therapy. Challenges of VTE management in cancer patients include heparin resistance due to excess circulating acute-phase proteins, increased recurrence rates during and following standard-intensity warfarin therapy, limited venous access to support therapeutic monitoring, and anticoagulation intensity-independent increased bleeding rates during anticoagulation. Bleeding during anticoagulation is of particular concern in the treatment of cancer patients with disease- or chemotherapy-related thrombocytopenia, central nervous system involvement, or recent invasive procedures. Low-molecular weight heparins (LMWH) have been shown to be at least as effective and safe for initial anticoagulation compared with UFH in persons with acute VTE and have gained popularity in the setting of VTE in cancer. LMWHs have the advantage of less non-specific protein binding, subcutaneous weight-based dosing without the need for monitoring in most cases, and probably less heparin-induced thrombocytopenia. Recent trials have demonstrated efficacy superiority of select LMWHs in place of oral warfarin for long-term anticoagulation in the cancer patient. The potential for anti-tumor effects and a survival advantage associated with select classes of anticoagulant agents is actively being investigated.

Excess risk of cancer in patients with primary venous thromboembolism: a national, population-based cohort study

We conducted a nationwide, retrospective cohort study assessing the risk of cancer in VTE patients diagnosed in Scotland in 1982-2000. Significantly elevated risks of cancer were sustained for 2 years after VTE diagnosis, most notably for ovarian tumours and lymphomas. Younger patients were at an increased relative risk from this association.

Factor V Leiden and G20210A prothrombin mutation and the risk of subclavian vein thrombosis in patients with breast cancer and a central venous catheter

BACKGROUND

To analyze the influence of the prothrombotic gene mutation factor V G1691A (factor V Leiden) and prothrombin G20210A on the risk of a first episode of catheter-related deep venous thrombosis (DVT) in a group of patients with breast cancer treated with chemotherapy.

PATIENTS AND METHODS

Between January 1999 and February 2001, the occurrence of a first symptomatic DVT was investigated in a cohort of 300 consecutive patients with locally advanced or metastatic breast cancer treated at a single institution with fluorouracil-based chemotherapy, administered continuously through a totally implanted access port. A nested case-control study included 25 women (cases) with catheter-related DVT and 50 controls without DVT matched with cases for age, identical chemotherapy, stage of disease and prognostic features. The G1691A factor V and G20210A prothrombin mutation genotypes were analyzed.

RESULTS

Five cases [20%; 95% confidence interval (CI) 9% to 39%)] and two controls (4%; 95% CI 1% to 14%) were heterozygous carriers of G1691A factor V (P = 0.04). The age-adjusted odds ratio for catheter-related DVT was 6.1 (95% CI 1.1-34.3). Only one patient (case) had the G20210A prothrombin gene mutation. Time from start of chemotherapy infusion to DVT was not significantly different between patients with (median 31 days) and without (median 43 days) G1691A factor V mutation (P = 0.6).

CONCLUSIONS

Factor V Leiden carriers with locally advanced or metastatic breast cancer have an increased risk of developing catheter-related DVT during chemotherapy.

Deep venous thrombosis

Venous thromboembolism (VTE), manifested as either deep venous thrombosis (DVT) or pulmonary embolism (PE), is an extremely common medical problem, occurring either in isolation or as a complication of other diseases or procedures. Yet, despite its frequency, much remains to be learned regarding the pathogenic mechanisms that initiate VTE, about tailoring its treatment to the individual with her/his specific set of risk factors for recurrence, and about its medical management when associated with specific disease entities, such as cancer. These three topics are addressed in this chapter. In Section I, Drs. López and Conde discuss the mechanisms by which venous thrombi may be initiated on the vessel wall in the absence of anatomically overt vessel wall injury. The authors propose a model whereby tissue factor (TF)-bearing microvesicles that arise from cells of monocyte/macrophage lineage can fuse with activated endothelial cells in regions of vessel activation or inflammation and initiate blood coagulation. Key components of this model include docking of the microvesicles to the stimulated endothelium through P-selectin glycoprotein ligand-1 on their surfaces binding to either P-selectin or E-selectin on the endothelium, and the role of hypoxia during blood stasis in initiating local endothelial activation. Elevations in the levels of TF-bearing microvesicles associated with inflammatory conditions would help to explain the increased risk of thrombosis associated with infections and inflammatory states such as inflammatory bowel disease. In Section II, Dr. Clive Kearon discusses the risk factors for recurrent thrombosis and strategies for determining length of therapy and tailoring specific therapies through risk stratification. Those patients who experience VTE in association with a major reversible risk factor such as surgery are much less likely to experience a recurrence when anticoagulation is discontinued than are patients with a persistent risk factor, such as thrombophilia or cancer unresponsive to therapy. Those with a minor reversible risk factor, such as prolonged air travel, have an intermediate risk of recurrence after discontinuance of anticoagulant therapy. The author provides an algorithm for using risk assessment as a means of determining the length and type of therapy to be used to minimize the rate of recurrence while simultaneously diminishing the risk of bleeding associated with anticoagulation. In Section III, Dr. Agnes Lee updates the topic of VTE associated with malignancy. Patients with cancer make up approximately 20% of those presenting with first time VTE, and the presence of VTE forebodes a much poorer prognosis for patients with cancer, likely because of the morbidity associated with VTE itself and because VTE may herald a more aggressive cancer. Recent evidence indicates that low-molecular weight heparins (LMWHs) improve survival in patients with advanced cancer through mechanisms beyond their effect as anticoagulants. Because of their improved efficacy and safety and potential anti-neoplastic effect, the LMWHs have become the anticoagulants of choice for treating VTE associated with cancer.

Hypercoagulable state testing and malignancy screening following venous thromboembolic events

Mounting interest in hypercoagulability, increased availability of hypercoagulable state test 'panels' and enhanced ability to identify abnormalities in tested patients have prompted widespread testing. Testing for acquired and inherited hypercoagulable states uncovers an abnormality in over 50% of patients presenting with an initial venous thromboembolic event (VTE) but may have minimal actual impact on management in most of these patients. Such laboratory screening should be reserved for patients in whom the results of individual tests will significantly impact the choice of anticoagulant agent, intensity of anticoagulant therapy, therapeutic monitoring, family screening, family planning, prognosis determination, and most of all duration of therapy. Testing 'just to know' is neither cost-effective nor clinically appropriate. The most important testing in patients following acute VTE may be age- and gender-specific cancer screening. Cancer screening following VTE seems most prudent in older individuals and in those with idiopathic VTE and no laboratory evidence for an inherited hypercoagulable state. Cancer screening should focus on identification of treatable cancers and those where diagnosis in an early stage favorably impacts patient survival. Extensive searches for occult malignancy employing whole-body computed tomography and serum tumor markers may identify more cancers but without affecting patient outcome. We advocate that physicians should focus their attention more on VTE prophylaxis and proper treatment and less on costly and, at times, invasive testing of questionable value.

Thromboembolic Events in the Cancer Patient

Thromboembolic events are a major cause of morbidity in cancer patients and may be harbingers of occult malignancy. Trousseau's syndrome (TS) is probably the best known thromboembolic syndrome in the cancer patient, encompassing a variety of paraneoplastic thromboembolic disorders. These include spontaneous recurrent or migratory venous thromboses and arterial emboli caused by nonbacterial thrombotic endocarditis in a patient with malignancy. Although linked to almost all cancers, venous thromboembolism (VTE) is a terminal event in many cancers occurring in women, such as breast, uterine, and lung cancers (Monreal et al. Thrombosis and Haemostasis 1997;78:1316). Appropriate recognition of the syndrome is paramount because TS often requires careful medical surveillance and management. Significant complications of thromboembolic events in the cancer patient include limb ischemia and deep venous thrombosis/pulmonary embolism, which can cause devastating and permanent consequences. The rehabilitation management of these complications is reviewed, with an emphasis on diagnostic and therapeutic approaches in this patient population.

Factors associated with recurrent venous thromboembolism in patients with malignant disease

PURPOSE

The role of prophylactic vena cava filters (VCF) in patients with cancer is debated. Although VCF are often placed in patients with cancer after recurrence of venous thromboembolic events (VTE), identification of this subset of patients has not been well-defined. This study was undertaken to assess factors associated with increased risk for recurrent VTE.

METHODS

All patients with a history of thromboembolism or malignant disease and who required a VCF because of failure of or contraindication to anticoagulation therapy were abstracted from the Michigan Filter Registry. Univariate analysis of potential risk factors for recurrent VTE and logistic regression models were used to identify associations between these variables and recurrent VTE.

RESULTS

Ninety-nine patients (49 men, 50 women) with a mean age of 58 years were included in the study. New metastases occurred in 55% of patients, and 12% of patients had a history of VTE before cancer diagnosis. Corticosteroid agents were used during therapy in 48% of patients. Acute VTE was present in 52% of patients at cancer diagnosis, and in 34% of patients VTE was associated with new metastases. Recurrent VTE occurred in 40% of patients, and significant risk factors included presence of new metastases (odds ratio [OR], 3.3; 95% confidence interval [CI], 1.16-9.09; P =.02) and history of VTE (OR, 10.6; CI, 1.98-57.2; P =.006). Whereas a single episode of neutropenia did not reach significance (OR, 1.1; CI, 0.97-1.35; P =.11), multiple neutropenic episodes were significantly associated with recurrent VTE (P =.04). Smoking, hormone replacement therapy, decreased mobility, post-surgical state, and obesity were not independently associated with increased risk. Mean survival in this series was 30 months, and was significantly worse in patients with VTE at cancer diagnosis and with inability to tolerate anticoagulant therapy in conjunction with VCF.

CONCLUSION

Patients with malignant disease may be at increased risk for recurrent VTE after development of new metastases or multiple episodes of neutropenia, especially those patients with a history of VTE. VCF may be a reasonable alternative to long-term anticoagulation therapy in this subgroup of patients at high risk patients, provided their quality of life is reasonable.

Clinical and laboratory evaluation of thrombophilia

Thrombophilia is the predisposition to venous thromboembolism and is caused by inherited and acquired factors, alone or in combination. With the discovery of APC resistance and the prothrombin gene mutation, more than half of all patients with clinical characteristics of thrombophilia are now diagnosed with an inherited disorder. The hypercoagulable work-up of patients with venous thromboembolism is important, because the causes can influence the duration and management of anticoagulation therapy, as well as affect other decisions regarding life and health issues.

Diagnosis and treatment of pulmonary embolism in the elderly

Pulmonary embolism (PE) is a difficult diagnosis in patients of all ages, but more so in the elderly. Nonspecific symptoms and laboratory results are often misattributed to common diseases or to age itself, and can delay or even deter the diagnosis and treatment of PE. Advanced age is sometimes mistakenly seen as a contraindication to anticoagulation and thrombolysis. Together, these factors contribute to the higher morbidity and mortality associated with PE in the elderly than in younger patients. This article reviews the risk factors, diagnosis, and treatment of PE as it applies to the elderly.

Thromboembolism preceding cancer: a correlation study

Thromboembolic (TE) events preceding cancer have been observed. Some studies failed to find this correlation. We retrospectively examined the cancer incidence following thromboembolic events in patients at our medical center. Medical records of 183 patients with established thromboembolic events documented in their records were selected and reviewed. Time interval between primary, secondary, and recurrent TE events preceding cancer diagnosis was analyzed. Two hundred age- and sex-matched controls seen during the same period and without any evidence of TE were randomly selected and charts reviewed for malignancy. Cancer occurred after TE in 48 of 183 patients (26.2%). In controls, cancer was diagnosed in 23 (11.5%). This was statistically significant with an odds ratio of 2.736 (1.586, 4.720). In the 64 primary TE patients, the cancer incidence was 37.5%. The 63 patients with recurrent TE had an incidence of 35.4%, and 56 secondary TE patients had an incidence of 27.1%. Time between initial TE and cancer diagnosis was <6 months in 27 (56.3%) patients, between 6 months and 1 year in 12 (25.0%), 1-5 years in 5 (10.4%), and >5 years in 4 (8.3%). Fourteen (31.1%) TE patients presented with metastatic cancer. This study indicates that thromboembolic events are important predictors of cancer. Cancer in this population occurs within a year in the majority of patients. Cancer screening in patients without identifiable risk factors for thrombosis could be helpful for early detection, diagnosis, and management of cancer.

The effects of chemotherapeutic agents on the regulation of thrombin on cell surfaces

Thromboembolic disorders are common in cancer patients. Two major contributing factors are central venous catheters for drug delivery and the use of l-aparaginase, which decreases the plasma antithrombin level, but the causes of the hypercoagulable state in these patients are not fully understood. In this study, the T24/83 cell line was used as a model to investigate the effects of chemotherapeutic agents on cell surface thrombin regulation. Plasma thrombin generation and prothrombin consumption was increased in most of the treated cells, particularly vincristine- and adriamycin-treated cells (P < 0.05), compared with controls. However, no free thrombin generation or prothrombin consumption was observed in factor VII (FVII)-depleted plasma. No significant differences in the levels of thrombin-alpha2-macroglobulin (IIa-alpha2M) and thrombin-anti-thrombin (TAT) were observed between controls and any of the treatments, except for vincristine- and adriamycin-treated cells, which showed a significant difference in TAT production (P < 0.05). Also, there was an upregulation in tissue factor (TF) mRNA expression in etoposide-, methotrexate- and vincristine-treated monolayers compared with controls, as well as an upregulation in TF protein production in vincristine-treated cells. The data suggests that thrombin generation occurs via the extrinsic (TF-dependent) coagulation pathway on cell surfaces and that some chemotherapeutic agents are able to upregulate TF mRNA and protein expression in T24/83 cells.

Recurrent venous thromboembolism and bleeding complications during anticoagulant treatment in patients with cancer and venous thrombosis

A small proportion of patients with deep vein thrombosis develop recurrent venous thromboembolic complications or bleeding during anticoagulant treatment. These complications may occur more frequently if these patients have concomitant cancer. This prospective follow-up study sought to determine whether in thrombosis patients those with cancer have a higher risk for recurrent venous thromboembolism or bleeding during anticoagulant treatment than those without cancer. Of the 842 included patients, 181 had known cancer at entry. The 12-month cumulative incidence of recurrent thromboembolism in cancer patients was 20.7% (95% CI, 15.6%-25.8%) versus 6.8% (95% CI, 3.9%- 9.7%) in patients without cancer, for a hazard ratio of 3.2 (95% CI, 1.9-5.4) The 12-month cumulative incidence of major bleeding was 12.4% (95% CI, 6.5%-18.2%) in patients with cancer and 4.9% (95% CI, 2.5%-7.4%) in patients without cancer, for a hazard ratio of 2.2 (95% CI, 1.2-4.1). Recurrence and bleeding were both related to cancer severity and occurred predominantly during the first month of anticoagulant therapy but could not be explained by sub- or overanticoagulation. Cancer patients with venous thrombosis are more likely to develop recurrent thromboembolic complications and major bleeding during anticoagulant treatment than those without malignancy. These risks correlate with the extent of cancer. Possibilities for improvement using the current paradigms of anticoagulation seem limited and new treatment strategies should be developed.

Venous thromboembolism as first manifestation of cancer

Since Trousseau's time numerous studies have addressed the relationship between cancer and venous thromboembolism (VTE) providing firm evidence of the increased risk of subsequent clinically overt malignancy during the follow-up of patients with idiopathic VTE. These malignancies are not limited to certain subtypes, but involve virtually all body systems. This knowledge has led to a long-standing debate on the need to screen for occult malignancies patients with idiopathic VTE with no clinical evidence of cancer at the time of the index thrombotic event. In fact the high incidence of newly discovered cancers does not automatically imply that screening is indicated in these patients since it is unknown whether a substantial proportion of cancers can be diagnosed, whether the diagnosed cancers are treatable and what the impact on cancer-related mortality is. Proper clinical trials are being conducted to find an answer to these questions.

Thalomid (Thalidomide) capsules: a review of the first 18 months of spontaneous postmarketing adverse event surveillance, including off-label prescribing

The sedative/hypnotic thalidomide was withdrawn from the worldwide market nearly 40 years ago, because of its teratogenic and neurotoxic effects. Thalidomide was later found to very effectively suppress erythema nodosum leprosum (ENL). The US Food and Drug Administration (FDA) has approved Thalomid (thalidomide) capsules for the acute treatment of the cutaneous manifestations of moderate to severe ENL. Thalidomide is currently under investigation for the treatment of a wide variety of diseases, including conditions thought to have an inflammatory or immune basis, malignancies and complications of infection with HIV. Interest in the potential anti-inflammatory, immunomodulatory and anti- angiogenic effects of thalidomide has resulted in off-label use of prescription thalidomide. During the first 18 months of spontaneous postmarketing adverse event surveillance for Thalomid, 1210 spontaneous postmarketing adverse event reports were received for patients treated with prescription thalidomide for all therapeutic indications, including off-label use. The most common adverse events spontaneously reported would have been expected on the basis of the current Thalomid labelling/product information. The current labelling/product information reflects what was known about the risks associated with thalidomide therapy in limited patient populations at the time of the approval of Thalomid. With the postmarketing use of thalidomide in populations other than patients with ENL, it becomes increasingly important to identify patient groups that may be particularly susceptible to specific adverse drug effects and to identify conditions under which specific adverse events may be more likely to occur. Oncology patients may represent a patient population with increased susceptibility to thalidomide-associated adverse effects, including thromboembolic events. Consideration of the spontaneous postmarketing safety surveillance data may help to identify and characterise factors associated with increased risk in this and other patient groups. Serious unexpected adverse events reported with sufficient frequency to signal previously undetected product-event associations for which there may potentially be plausible evidence to suggest a causal relationship have included seizures and Stevens-Johnson syndrome. The potential effects of thalidomide on wound healing are also being closely monitored. Premarketing human clinical trials of drug products are inherently limited in their ability to detect adverse events. Broader postmarketing experience with thalidomide in more varied patient populations and more experience in the setting of long term thalidomide use will increase our ability to detect rare adverse events and to identify signals that may need to be evaluated in more controlled settings.

Tissue factor is the only activator of coagulation in cultured human lung cancer cells

It is a long-known principle that tumour cells tend to exploit the host's physiologic systems in order to get support in terms of, for example, nutrition, growth or metastasis. One of these physiologic systems is the blood coagulation cascade, which has been found activated in many tumour patients. The mechanisms of the activation of coagulation have been assessed in numerous animal and in vitro experiments, and the results appeared to point to several distinct activators. The present study used a large panel of different cultivated human lung cancer cell lines and experimental systems involving normal plasma, plasmas deficient of factors V, VII or X, purified coagulation factors II and X, recombinant tissue factor (TF), and specific inhibitory antibodies against factor VII and TF. The results provide strong evidence that there is no activator of coagulation besides TF in the wide array of lung cancer cells examined. However, this work reveals a striking variability of TF content among the cell lines. This might explain ambiguous results of clinical trials of anticoagulation as an adjunct to antineoplastic therapy in lung cancer. By sensitive diagnostic tools like the plasma thrombin-antithrombin complex levels it might be possible to select patients with activated coagulation, who might benefit from anticoagulation.

Pulmonary embolism in the elderly

The elderly are at increased risk for pulmonary embolism because of both the conditions common to this age group, and the immobility that often accompanies them. Whether aging alone represents a hypercoagulable state is unclear. The incidence of pulmonary embolism rises with age, however, as does pulmonary embolism mortality. The diagnosis of pulmonary embolism is difficult and frequently missed because elderly patients and their physicians may attribute nonspecific symptoms to underlying cardiopulmonary disease or to age itself. Routine laboratory examinations are also nonspecific. Lower extremity studies to diagnose DVT should always be pursued because a positive study results in identical treatment, without the need for further testing. D-dimer concentrations are useful when low, but are commonly elevated in the elderly because of other comorbid conditions. Lung scanning remains the most common initial study to diagnose pulmonary embolism, although spiral CT is as sensitive and specific. Pulmonary angiography should always be considered when the initial studies are nondiagnostic and clinical suspicion is high, and this test is well tolerated in the elderly. The role of newer diagnostic techniques, such as MR imaging, cannot be determined until well-designed outcomes trials are completed. Prophylaxis with appropriate pharmacologic agents or mechanical measures should be administered not only to patients undergoing hip or knee reconstruction surgery, but to all bed-ridden elderly medical and general surgery patients. Treatment for pulmonary embolism with anticoagulation reduces the mortality rate and should be administered in all elderly patients without contraindications. In addition, thrombolysis should be considered for all hemodynamically unstable patients with pulmonary embolism, regardless of age. Vena caval filters are warranted when anticoagulation is contraindicated, although evidence of the long-term benefit of these devices is lacking. At present, pulmonary embolism is underdiagnosed and undertreated in the elderly. By heightening awareness of this diagnosis and its appropriate management in this age group, considerable morbidity and mortality may be avoided.

Prognosis of cancers associated with venous thromboembolism

BACKGROUND

Little is known about the prognosis of cancer discovered during or after an episode of venous thromboembolism.

METHODS

We linked the Danish National Registry of Patients, the Danish Cancer Registry, and the Danish Mortality Files to obtain data on the survival of patients who received a diagnosis of cancer at the same time as or after an episode of venous thromboembolism. Their survival was compared with that of patients with cancer who did not have venous thromboembolism (control patients), who were matched in terms of type of cancer, age, sex, and year of diagnosis.

RESULTS

Of 668 patients who had cancer at the time of an episode of deep venous thromboembolism, 44.0 percent of those with data on the spread of disease (563 patients) had distant metastasis, as compared with 35.1 percent of 5371 control patients with data on spread (prevalence ratio, 1.26; 95 percent confidence interval, 1.13 to 1.40). In the group with cancer at the time of venous thromboembolism, the one-year survival rate was 12 percent, as compared with 36 percent in the control group (P<0.001), and the mortality ratio for the entire follow-up period was 2.20 (95 percent confidence interval, 2.05 to 2.40). Patients in whom cancer was diagnosed within one year after an episode of venous thromboembolism had a slightly increased risk of distant metastasis at the time of the diagnosis (prevalence ratio, 1.23 [95 percent confidence interval, 1.08 to 1.40]) and a relatively low rate of survival at one year (38 percent, vs. 47 percent in the control group; P<0.001).

CONCLUSIONS

Cancer diagnosed at the same time as or within one year after an episode of venous thromboembolism is associated with an advanced stage of cancer and a poor prognosis.

Physician compliance with warfarin prophylaxis for central venous catheters in patients with solid tumors

PURPOSE

There is an established benefit of prophylactic warfarin in cancer patients with central venous catheters. This study assessed the compliance rate of prophylactic low-dose warfarin prescription in cancer patients with central venous catheters at a single institution.

PATIENTS AND METHODS

Oncology patients with central venous catheters were identified by a retrospective chart review. Information retrieved included whether prophylactic warfarin had been prescribed and whether the patient had suffered a thrombotic or bleeding event. After the initial chart review, physicians were notified of the benefits of warfarin prophylaxis, and subsequently, a physician-independent mechanism of prescribing prophylactic warfarin was instituted. After each of these interventions, we retrospectively reviewed a further two cohorts of patients to assess compliance with warfarin prophylaxis.

RESULTS

During the baseline study, only 10% of patients were prescribed prophylactic warfarin. After physician notification, the compliance rate increased to only 20% (P =.3). After instituting the physician-independent mechanism of prescribing prophylactic warfarin, the compliance rate increased to 95% (P <.001). The rate of catheter-related thrombosis was 11% for patients who were prescribed warfarin compared with 21% in those who were not anticoagulated (P =.2).

CONCLUSION

At our institution, the rate of prescribing prophylactic warfarin was low in this patient population, and there was a reluctance of treating physicians to change their prescribing practice. Mechanisms exist to improve the rate of anticoagulant prophylaxis in this clinical setting. We recommend that institutions review their rate of compliance with prophylactic anticoagulation for patients with central venous catheters and solid tumors.