Management of venous thromboembolism in patients with cancer.

Patients with cancer are at increased risk of venous thromboembolism (VTE). In these patients VTE is associated with substantial morbidity and complicates the clinical management of cancer. Emerging research indicates a probable detrimental effect of VTE on cancer survival. Although VTE may develop at any stage of cancer disease, the risk of VTE is particularly high in association with three clinical settings including surgery for cancer, use of a central vein catheter (CVC) and chemotherapy. Guidelines recommend post-operative prophylaxis (for at least 7-10 days) for patients undergoing elective cancer surgery. A prolonged prophylaxis (for upto four post-operative weeks) is recommended in cancer patients at high risk for VTE. The role of antithrombotic prophylaxis in the prevention of CVC-related thrombosis remains controversial. The PROTECHT study has recently evaluated the benefit of antithrombotic prophylaxis in cancer patients receiving chemotherapy, showing a statistically significant 50% relative risk reduction in symptomatic thromboembolic events. The international guidelines currently agree in non-recommending routine prophylaxis in ambulatory patients who receive anticancer chemotherapy but suggest an individual risk-based evaluation. To better identify cancer patients at high risk for VTE, simple predictive models have been validated. Further intervention studies are currently on-going to explore the benefit of antithrombotic prophylaxis in individual high-risk groups of patients. The long-term treatment of cancer-related VTE is based on therapeutic doses of LMWH in preference to warfarin. The optimal duration of antithrombotic treatment in cancer patients remains to be fully defined.