Treatment of venous thromboembolism in cancer patients with dalteparin for up to 12months: the DALTECAN Study

BackgroundTreatment of venous thromboembolism (VTE) in patients with cancer has a high rate of recurrence and bleeding complications. Guidelines recommend low-molecular-weight heparin (LMWH) for at least 3-6months and possibly indefinitely for patients with active malignancy. There are, however, few data supporting treatment with LMWH beyond 6months. The primary aim of the DALTECAN study (NCT00942968) was to determine the safety of dalteparin between 6 and 12months in cancer-associated VTE. MethodsPatients with active cancer and newly diagnosed VTE were enrolled in a prospective, multicenter study and received subcutaneous dalteparin for 12months. The rates of bleeding and recurrent VTE were evaluated at months 1, 2-6 and 7-12. FindingsOf 334 patients enrolled, 185 and 109 completed 6 and 12months of therapy; 49.1% had deep vein thrombosis (DVT); 38.9% had pulmonary embolism (PE); and 12.0% had both on presentation. The overall frequency of major bleeding was 10.2% (34/334). Major bleeding occurred in 3.6% (12/334) in the first month, and 1.1% (14/1237) and 0.7% (8/1086) per patient-month during months 2-6 and 7-12, respectively. Recurrent VTE occurred in 11.1% (37/334); the incidence rate was 5.7% (19/334) for month 1, 3.4% (10/296) during months 2-6, and 4.1% (8/194) during months 7-12. One hundred and sixteen patients died, four due to recurrent VTE and two due to bleeding. ConclusionMajor bleeding was less frequent during dalteparin therapy beyond 6months. The risk of developing major bleeding complications or VTE recurrence was greatest in the first month of therapy and lower over the subsequent 11 months.