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.