Venous thromboembolism predicts poor prognosis in irresectable pancreatic cancer patients

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

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

Pancreatic cancer: A model cancer for the study of the therapeutic effects of anticoagulants

Cancer-related thromboembolic disease is a well recognized syndrome since first described by Armand Trousseau in 1865. Preventing the morbidity and mortality related to thromboembolism in these patients is becoming a priority research area with the advent of new anti-coagulants. It is only recently that randomized trials of improved quality are been undertaken to study this question. Many of these trials however are still not accounting for the heterogeneity of “cancer” in terms of anatomical site, histology, stage and treatment. This editorial review highlights why pancreatic cancer may serve as a model malignancy to study this question.

Assessing risk of venous thromboembolism in the patient with cancer

PURPOSE

Patients with cancer are increasingly at risk for venous thromboembolism (VTE). Rates of VTE, however, vary markedly among patients with cancer.

DESIGN

This review focuses on recent data derived from population-based, hospital-based, and outpatient cohort studies of patients with cancer that have identified multiple clinical risk factors as well as candidate laboratory biomarkers predictive of VTE.

RESULTS

Clinical risk factors for cancer-associated VTE include primary tumor site, stage, initial period after diagnosis, presence and number of comorbidities, and treatment modalities including systemic chemotherapy, antiangiogenic therapy, and hospitalization. Candidate predictive biomarkers include elevated platelet or leukocyte counts, tissue factor, soluble P-selectin, and D-dimer. A recently validated risk model, incorporating some of these factors, can help differentiate patients at high or low risk for developing VTE while receiving chemotherapy.

CONCLUSION

Identifying patients with cancer who are most at risk for VTE is essential to better target thromboprophylaxis, with the eventual goal of reducing the burden as well as the consequences of VTE for patients with cancer.

Does clinical method mask significant VTE-related mortality and morbidity in malignant disease?

After more than 150 years of a recognised link between cancer and vascular thromboembolic events (VTE), and despite a greatly improved understanding of its pathophysiology, epidemiology and treatment, the management of patients with cancer and VTE is still limited. Limitations can be related to the thromboembolism itself, the underlying cancer, or to the management process. There is significant literature that deals with the first two, but very little regarding the systems we use, or how the inadequacies in documentation, identification and classification of VTE affect the cancer patients themselves. This review aims to raise awareness of this neglected area and stimulate research that may lead to improvements in patient care.

Dose escalation of low molecular weight heparin to manage recurrent venous thromboembolic events despite systemic anticoagulation in cancer patients

SUMMARY BACKGROUND

Cancer patients with venous thromboembolism (VTE) are at high risk of recurrent VTE despite standard anticoagulation. To date, very little published literature is available to guide the treatment of cancer patients with recurrent VTE.

OBJECTIVES

To evaluate the benefit and risk of low molecular weight heparin (LMWH) dose escalation in cancer patients with recurrent VTE.

PATIENTS AND METHODS

This was a retrospective cohort study of consecutive cancer outpatients referred for management of a symptomatic, recurrent VTE while receiving an anticoagulant. Confirmed episodes of recurrent VTE were treated with either dose escalation of LMWH in patients already anticoagulated with LMWH, or initiation of therapeutic dose LMWH in patients who were taking a vitamin K antagonist (VKA). All patients were followed for a minimum of 3 months after the index recurrent VTE unless they died during this period.

RESULTS

Seventy cancer patients with a recurrent VTE despite ongoing anticoagulation were included. At the time of the recurrence, 67% of patients were receiving LMWH, and 33% were receiving a VKA. A total of six patients [8.6%; 95% confidence interval (CI) 4.0-17.5%] had a second recurrent VTE during the 3-month follow-up period, at an event rate of 9.9 per 100 patient-years (95% CI 2.0-17.8%). Three patients (4.3%; 95% CI 1.5-11.9%), or 4.8 per 100 patient-years (95% CI 0.0-10.3%) of follow-up, had bleeding complications. The median time between the index recurrent VTE to death was 11.4 months (range, 0-83.9 months).

CONCLUSIONS

Cancer patients with recurrent VTE have a short median survival. Escalating the dose of LMWH can be effective for treating cases that are resistant to standard, weight-adjusted doses of LMWH or a VKA.

Treatment with low-molecular-weight heparin for deep venous thrombosis complicated with digestive tract cancer: an analysis of 63 cases

AIM: To compare therapeutic efficacy of long-term low-molecular-weigh heparin treatment with routine Warfarin treatment for digestive tract cancer complicated with deep venous thrombosis.

METHODS: Sixty three digestive tract cancer patients complicated with deep venous thrombosis were retrospectively allotted from February 2005 to December 2006 either into long-term low-molecular-weight heparin treatment group (LMWH group) or into warfarin treatment group (routine care group). The bleeding rate, the rates of recurrent venous thromboembolism and the platelet counts of patients of both groups were analyzed.

RESULTS: In long-term LMWH group, bleeding occurred in 6 patients (18.8%) and the platelet count of 1 patient (3.1%) decreased below normal level, which did not show significant difference compared with routine care group (25.8% and 6.5%, respectively). However, at 12 months, recurrent venous thromboembolism occurred in 3 of 32 cases (9.4%), which showed significant difference compared with routine care group (29.0%, P < 0.05).

CONCLUSION: Long-term low-molecular-weight heparin, more convenient and more effective than routine warfarin therapy, is considered to be more effective for digestive tract cancer complicated with deep venous thrombosis.

Coagulation, anticoagulation and pancreatic carcinoma

An increase in coagulation in patients with pancreatic carcinoma has long been documented. In this Review, we present what is known about the pathophysiology of increased coagulation in cancer and how it applies to pancreatic carcinoma. The relationship between the activation of coagulation or symptomatic thromboembolic disease and the development of pancreatic carcinoma is explored. Data on the relationship between thromboembolic disease and the behavior of pancreatic cancer before, during or after a diagnosis is made are also reviewed. Finally, the rationale and evidence for the use of oral anticoagulants or heparin in patients with pancreatic carcinoma is presented. This Review is a critical appraisal of what is known, and when the evidence is acceptable, on the subject of thromboembolism, anticoagulation, and treatment with anticoagulants in patients with pancreatic carcinoma.