[Thromboprophylaxis in ambulatory patients with cancer].

Ambulatory cancer patients receiving systemic cancer therapy are at varying risk for venous thromboembolism (VTE). The VTE risk depends on different cancer types, cancer stage, anti-cancer treatment and individual patient risk factors. Whereas pharmacologic thromboprophylaxis is recommended in most hospitalized cancer patients with an acute medical condition and in patients undergoing major cancer surgery, the role of primary thromboprophylaxis in the ambulatory setting is not clear. A VTE risk stratification using specific scoring systems, e. g. the Khorana score or the recently published CAT-score should be performed. Recently, two large randomized controlled studies using rivaroxaban (CASSINI trial) and apixaban (AVERT trial) versus placebo as primary VTE prevention in high-risk ambulatory cancer patients were published. When considered together, the two trials showed a significant benefit for the prevention of VTE with a low incidence of major bleeding. The DOAC had no effect on mortality. Primary thromboprophylaxis may be offered to high-risk outpatients with cancer, e. g. patients with advanced pancreatic carcinoma, provided there are no risk factors for bleeding and no drug-interactions. The patient's preference should also be respected. Current guidelines differ in their recommendations concerning the choice of anticoagulation. Whereas LMWH is still preferred to DOAC in the current German guideline, the ISTH guidance suggest to use DOAC in high-risk ambulatory cancer patients with no drug-drug interactions and not at high risk for bleeding. Of note, DOAC are currently not approved in this indication.