Utility of the modified Ottawa score for identification of more preferable candidates of extended anticoagulation therapy in cancer-associated isolated distal deep vein thrombosis: insight from the ONCO DVT Study

Abstract

Background: The ONCO DVT study (Edoxaban for 12 Months Versus 3 Months in Patients With Cancer With Isolated Distal Deep Vein Thrombosis) revealed superiority of 12-month relative to 3-month edoxaban treatment for the thrombotic risk in cancer-associated isolated distal deep vein thrombosis. However, it is unknown whether the superiority could be common in different modified Ottawa score subgroups.

Objectives: To identify more preferable candidates for extended anticoagulation in patients with cancer-associated isolated distal deep vein thrombosis using the modified Ottawa score.

Methods: In this post-hoc subgroup analysis of the ONCO DVT study, we stratified 601 patients into the low (≤-1, N = 126), intermediate (0, N = 323), and high (≥1, N = 152) modified Ottawa score subgroups and compared clinical outcomes between the 12-month and 3-month edoxaban treatment groups.

Results: The cumulative incidence of symptomatic recurrent venous thromboembolism or venous thromboembolism-related death was not different between the 12-month and 3-month edoxaban treatment groups in the low score subgroup (0.0% vs 2.2%), whereas it was lower in the 12-month than in the 3-month edoxaban treatment group in the intermediate (0.8% vs 7.6%) and high (3.1% vs 15.6%) score subgroups. There were no significant differences in the cumulative incidences of the major bleeding between the 12-month and 3-month edoxaban treatment groups in the low (10.1% vs 7.6%), intermediate (8.8% vs 5.0%), and high (13.9% vs 12.6%) score subgroups.

Conclusion: A 12-month compared with 3-month edoxaban treatment showed a lower risk of thrombotic events in patients with cancer-associated isolated distal deep vein thrombosis in the intermediate and high modified Ottawa score subgroups but not in the low score subgroup, suggesting a limited benefit of extended anticoagulation therapy beyond 3 months in patients with low modified Ottawa score.

Keywords: cancer; deep vein thrombosis; edoxaban; modified Ottawa score; recurrence.