Treatment of venous thromboembolism in patients with cancer: from clinical trials to real life.

Approximately one-fifth of all cases of venous thromboembolism (VTE) are related to cancer. VTE complications may have a substantial impact on prognosis, quality of life and care in patients with cancer. Patients with cancer-related VTE are at increased risk of developing recurrent VTE compared to patients without cancer, but also have a higher risk of major bleeding. In the last years, direct oral anticoagulants (DOACs) have been evaluated in a head-to-head comparison with low molecular weight heparin (LMWH) in two randomized trials for the long-term treatment of VTE in patients with advanced cancer. The results of these trials show that DOACs have a similar efficacy profile, but probably higher risk of bleeding, compared to LMWH dalteparin. Because DOACs offer a simple oral treatment regimen without the need for anticoagulation monitoring, they could be attractive alternatives to LMWHs in these setting. The American Society of Clinical Oncology guidelines, published in August 2019, recommend LMWH, edoxaban and rivaroxaban as first-choice therapies for long-term anticoagulation in cancer patients with VTE. However, several practical issues should be considered concerning the long-term use of DOAC treatment in patients with cancer. Major concerns have been highlighted about the gastrointestinal bleeding risk in patients with gastrointestinal cancers and the potential drug-drug interactions in combination for some specific anticancer therapies. Several studies comparing DOACs with LMWH are currently ongoing to refine our knowledge concerning treatment with DOACs in patients with cancer-associated VTE.