Risk of recurrent venous thromboembolism in cancer patients after discontinuation of anticoagulant therapy

Abstract

Anticoagulant therapy is recommended for cancer-related venous thromboembolism (VTE). Recurrent VTE prevention is the main goal of this treatment. The majority of evidence-based practice guidelines recommend anticoagulant treatment for at least 6 months. Based on individual assessment of potential benefits and risks, tolerability, drug availability, patient preference, and cancer activity, active cancer patients should continue anticoagulant treatment beyond the 6-month course. When cancer is no longer active or the risk outweighs the benefit, anticoagulant therapy is usually stopped after 3-6 months. Until recently, there was little data on the risk of recurrent VTE in cancer-associated VTE patients after stopping anticoagulants. New results and evidence synthesis have emerged in the last 3 years. Recurring VTE occurs in over 30% in the 5 years after treatment discontinuation. In the first six months, recurrence rates are 10-15%. Recurrences reach 31% at 2 years and stabilize between 2 and 5. Duration of prior anticoagulation does not affect cumulative recurrence. The high risk of recurrent VTE after discontinuing treatment supports guidelines to continue anticoagulant treatment if cancer is active. Stopping anticoagulants after 3-6 months may not be ideal, so randomized clinical trials should be conducted quickly. This review highlights the need to improve cancer patients' primary VTE prevention efforts.

Keywords

• Cancer-associated thrombosis
• venous thromboembolism
• recurrent thromboembolism
• anticoagulant therapy