Approach to venous thromboembolism in the cancer patient

Venous thromboembolism (VTE) is frequently encountered in cancer patients, acts as an important cause of morbidity and mortality, and may be a predictor of worse prognosis. In cancer patient who have a poor life expectancy, preventing death from pulmonary embolism is the mainstay of treatment. Patients who present with severe hypotension or other clinical manifestations suggestive of critical pulmonary embolism and do not have contraindications to thrombolysis should promptly be administered thrombolytic drugs. Except for selected cases requiring aggressive therapy, treatment of VTE in patients with cancer should not differ from that of patients without malignancy; the initial treatment should be conducted with adjusted dose of unfractionated heparin (UH), fixed dose of low-molecular-weight heparins (LMWH), or fondaparinux. LMWHs and fondaparinux have the potential to greatly simplify the initial treatment of VTE, making the management of the pathology feasible in an outpatient setting for selected patients. Traditionally, in cancer as well as in non-cancer patients, UH or LMWH or fondaparinux are overlapped by oral anticoagulation, targeted to reach an International Normalized Ratio (INR) between 2.0 and 3.0, and then followed by oral anticoagulants. However, during oral anticoagulant therapy, cancer patients exhibit a two- to fourfold higher risk of recurrent VTE and major bleeding complications when compared to non-cancer patients. Studies performed during the current decade have demonstrated that LMWHs offer several advantages in terms of efficacy in preventing VTE recurrences without increasing the bleeding risk. According to International Guidelines, the long-term administration of LMWH should be considered an alternative to anti-vitamin K drugs in patients with advanced disease and in those with conditions limiting the use of oral anticoagulants. The targeted policy is to administer LMWH at full therapeutic doses for the first month of treatment and then 75% of the initial dose for at least the following 5 months of therapy. Prolongation of anticoagulation should be considered for as long as the malignant disorder is active. In patients with acute deep venous thrombosis and contraindications to anticoagulation, vena cava filters should be considered. If anticoagulation is temporarily contraindicated, retrievable filters should be considered. Only patients who are actively bleeding or who are at extremely high risk for bleeding should receive a filter without anticoagulation coverage.