Antithrombotic therapy for prophylaxis and treatment of venous thromboembolism in patients with cancer: review of the literature on current practice and emerging options

The treatment of cancer-associated venous thromboembolism (VTE) is difficult because cancer patients with VTE on anticoagulation are at an increased risk of bleeding compared with patients without VTE. This review summarises the evidence supporting the current standard of care and emerging treatment options. In difficult-to-treat subpopulations, where clinical data are often lacking, this review also provides the best clinical practice strategies based on the available data. The use of therapeutic doses of parenteral anticoagulants in patients with cancer-associated VTE for at least 3 to 6 months is supported by the current clinical data. After major cancer surgery, extended thromboprophylaxis for approximately 1 month following hospital discharge is also supported. In select populations of ambulatory cancer patients with solid tumours, or in patients with myeloma receiving immunomodulatory agents in combination with chemotherapy and/or corticosteroids, pharmacological prophylaxis could be considered. Although parenteral anticoagulants may not be tolerated by some patients, the data pertaining to the use of direct oral anticoagulants (DOACs) in cancer patients with VTE at this point can only be considered hypothesis generating. Clarity of the use of DOACs is awaiting the results of head-to-head trials between DOACs and parenteral anticoagulants. In addition, because of the lack of clinical trials, there are still unanswered questions on the optimal treatment regimens in subpopulations at increased risk of bleeding, including cancer patients with thrombocytopenia and those with brain metastases. For clinicians to balance the risk of recurrent thrombosis with the chance of bleeding, they need to assess the relevant clinical data. Current data support the use of parenteral anticoagulants in cancer patients with VTE, but many unanswered questions pertaining to the optimal regimens in special subpopulations and regarding the efficacy and safety of DOACs remain. To address this need, there are currently several clinical trials under way.