Active cancer is a strong risk factor for venous thromboembolism (VTE) events and recurrent events following discontinuation of anticoagulation therapy, and cancer patients are also at a heightened risk for bleeding complications related to anticoagulation treatment.^1,2 Despite the clinical relevance, there is a lack of data from randomized clinical trials (RCT) to guide the optimal duration of anticoagulation therapy in cancer patients with concomitant distal deep vein thrombosis (DVT).³

The Optimal Duration of Anticoagulation Therapy for Isolated Distal Deep Vein Thrombosis in Patients With Cancer (ONCO DVT) study was a multicenter and open-label RCT conducted in Japan.⁴ In this trial, Yamashita et al. compared the efficacy and safety of 12 months versus 3 months of anticoagulation therapy with edoxaban 30 mg or 60 mg once daily in 601 patients with active cancer who had isolated distal DVT. The primary endpoint was the composite of symptomatic recurrent VTE or VTE-related death at 12 months while the major secondary endpoint was International Society on Thrombosis and Hemostasis (ISTH) major bleeding at 12 months. The primary endpoint occurred in 1.0% of patients in the 12-month group and 7.2% of patients in the 3-month group (odds ratio [OR] 0.13; 95% confidence interval [CI], 0.03 - 0.44). ISTH major bleeding occurred in 9.5% and 7.2% in 12 months versus 3 months of edoxaban treatment, respectively (OR 1.34; 95% CI, 0.75 - 2.41).

The ONCO DVT trial suggests that patients with active cancer and isolated distal DVT may benefit from 12 months of anticoagulation therapy with edoxaban compared with 3 months in terms of recurrent VTE or VTE-related death with higher rates of major bleeding. It is important to note that only 20% of patients had symptomatic DVT at diagnosis, and that more than half of the recurrent VTE events were of distal DVT. Further studies are needed to confirm these results and to identify the optimal duration of anticoagulation therapy in different subgroups of patients according to cancer types, DVT sites, DVT symptoms, and personalized benefit-risk.

References

1. Brown C, Brandt W, Wang T-F, Delluc A, Carrier M. Incidence of recurrent venous thromboembolism and bleeding complications in patients with cancer and isolated distal deep vein thrombosis. Thromb Res 2023;228:81-4.
2. Galanaud J-P, Trujillo-Santos J, Bikdeli B, et al. Clinical presentation and outcomes of patients with cancer-associated isolated distal deep vein thrombosis. J Clin Oncol 2023;Jul 20:[EPub ahead of print].
3. Stevens SM, Woller SC, Kreuziger LB, et al. Antithrombotic therapy for VTE disease: second update of the CHEST guideline and expert Panel Report. Chest 2021;160:e545-e608.
4. Yamashita Y, Morimoto M, Muraoka N, et al.; ONCO DVT Study Investigators. Edoxaban for 12 months versus 3 months in cancer patients with isolated distal deep vein thrombosis (ONCO DVT study): an open-label, multicenter, randomized clinical trial. Circulation 2023;148:1665-76.