Position paper of the Italian Society of Internal Medicine (SIMI) on prophylaxis and treatment of venous thromboembolism in patients with cancer.

Cancer patients are at high risk of developing thrombotic events, including venous thromboembolism (VTE) [deep venous thrombosis (DVT) and pulmonary embolism (PE)], and arterial thrombosis. DVT and PE represent the second leading cause of death in cancer patients; moreover, the development of thromboembolic events in cancer patients is linked to a greater need of hospitalization and frequency of side effects during treatment, in particular bleeding, and to an increased risk of recurrence during and following antithrombotic therapy. The thromboembolic risk may be different in different subgroups of cancer population, being highest in patients with metastatic disease, patients with pancreas, stomach, kidney or primary brain cancer, or during therapeutic interventions or surgery. This document focuses on several relevant topics including the epidemiology and pathogenesis of cancer-associated VTE, the current and future strategies of primary prevention and anticoagulant treatment, and the management of bleeding complications. The main literature data are discussed in detail, including, when available, evidence from randomized clinical trials and meta-analyses, international guidelines statements, the results of recently published trials comparing direct oral anticoagulants to low molecular weight heparin, and the design and aims of ongoing trials on prevention/treatment of cancer-associated VTE.