Anticoagulation therapy in cancer associated thromboembolism - new studies, new guidelines

Low molecular weight heparin (LMWH) has become a standard of treatment of cancer-associated thromboembolism (CAT). Until recently, direct oral anticoagulants (DOAC) have not had data about efficacy and safety in cancer patients. However, in the last two years, four randomized open-label studies comparing DOAC and LMWH in the treatment of CAT have been published. The first one was a large trial with edoxaban, followed by two smaller studies with rivaroxaban and apixaban, and, recently, by another large trial with apixaban. There are some differences among the studies concerning design, inclusion and exclusion criteria, length of treatment. In summary, DOAC are associated with a trend to the reduction of the risk of recurrence of venous thromboembolism; however, this is at the expense of some increase in bleeding risk. This risk is differential; the prevailing site of bleeding is the upper part of gastrointestinal tract, and, to a lesser extent, genitourinary tract. The updated guidelines for the treatment of CAT suggest DOAC as an alternative, however with careful consideration of the risk of bleeding and the risk of drug interactions. So far, the guidelines have mentioned edoxaban and rivaroxaban. With emerging evidence, apixaban is expected to play a role as well.