Key Message
Six evidence-based guidelines were identified regarding the long-term (6 months or longer) use of pharmacological thromboprophylaxis for the management of cancer-associated thrombosis. The guidelines used rigorous methodology, systematically searched for evidence, and were clearly reported. Anticoagulation therapy for 6 months or longer is recommended by 5 guidelines for patients with active cancer and venous thromboembolism to prevent recurrences of venous thromboembolism. However, the recommendations are weak and made based on low-quality evidence or expert consensus. Two guidelines recommend a low-molecular-weight heparin or direct oral anticoagulant for long-term use (6 months or longer) in patients with cancer. This recommendation is based on low- to high-certainty evidence. Two guidelines strongly recommend direct oral anticoagulants in patients with cancers in locations other than gastrointestinal or genitourinary cancers. This recommendation is based on high-quality evidence. No guidelines were identified regarding arterial thrombosis or chronic disseminated intravascular coagulation associated with cancer.