Antithrombotic Therapy in Cancer Patients

Abstract number: SYM29

Lee AYY

Cancer patients have a high risk of venous thromboembolism (VTE). This complication can be difficult to treat and can also interfere with their cancer treatment. Low molecular weight heparins (LMWH) are now established as the initial treatment of choice for outpatient therapy in patients with VTE. This advance is particularly important for cancer patients, in whom quality of life is an important issue. For the long-term treatment of VTE, vitamin K antagonists (VKA) have been the mainstay of therapy. However, the narrow therapeutic window and inconvenience of laboratory monitoring make these agents particularly problematic in cancer patients. Furthermore, patients with cancer have a 2- to 3-fold risk of recurrent VTE and a 3- to 6-fold risk of major bleeding compared with patients without cancer while on treatment. Recently, a multinational randomized controlled trial demonstrated that in cancer patients, a LMWH reduced the risk of recurrent VTE by 52% compared with VKA therapy, without increasing the risk of bleeding. In addition to its superior efficacy over VKA, LMWH eliminates the need for laboratory monitoring, has few drug interactions, and easily accommodates thrombocytopenia and invasive procedures. These properties make LMWH an attractive option in cancer patients who have difficult venous access, limited mobility, a high risk of bleeding, or are receiving chemotherapy and other drugs. Despite this important advance, the management of VTE in cancer patients remains challenging. Further studies are still needed to determine the optimal duration of therapy, tailor therapy in patients who have a high risk of bleeding, identify those who would benefit the most from LMWH, and manage patients who develop recurrent VTE despite LMWH. Regardless of the chosen course of therapy, the treatment of VTE in cancer patients should always be guided by the individual patient's quality of life and life expectancy.