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.

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.