Anticoagulant Treatment in Patients with Cancer and Venous Thrombosis Recurrent Venous Thromboembolism and Bleeding Complications During

Abstract Rationale: A small proportion of patients with deep-vein thrombosis develop recurrent venous thromboembolic complications or bleeding during anticoagulant treatment. These complications may occur more frequently if such patients have concomitant cancer. Objective: To determine in a prospective follow-up study whether in thrombosis patients those with cancer have a higher risk for recurrent venous thromboembolism or bleeding during anticoagulant treatment than those without cancer. Findings: Of the 842 included patients, 181 had known cancer at entry. The 12-month cumulative incidence of recurrent thromboembolism in cancer patients was 20.7 percent (95 percent CI, 15.6 to 25.8 percent) versus 6.8 percent (95 percent CI, 3.9 to 9.7 percent) in patients without cancer, for a hazard ratio of 3.2 (95 percent CI, 1.9 to 5.4). The 12-month cumulative incidence of major bleeding was 12.4 percent (95 percent CI, 6.5 to 18.2 percent) in patients with cancer and 4.9 percent (95 percent CI, 2.5 to 7.4 percent) in patients without cancer, for a hazard ratio of 2.2 (95 percent CI, 1.2 to 4.1). Recurrence and bleeding were both related to cancer severity, occurred predominantly during the first month of anticoagulant therapy but could not be explained by sub- or overanticoagulation. Conclusions:Cancer patients with venous thrombosis are more likely to develop recurrent thromboembolic complications and major bleeding during anticoagulant treatment than those without malignancy. These risks correlate with the extent of cancer. Possibilities for improvement using the current paradigms of anticoagulation seem limited and new treatment strategies should be developed.From bloodjournal.hematologylibrary.org by guest on June 12, 2013. For personal use only.