Evaluation of acute thrombus regression effect of edoxaban for deep vein thrombosis in patients with cancer: a single-center prospective observational study.

Background: Although there are reports on the recurrence prevention in the chronic phase using direct oral anticoagulants (DOACs) for deep vein thrombosis (DVT) in patients with cancer, acute thrombus regression effect using DOACs has not been assessed. This study aimed to assess the thrombus regression effect of initial treatment using edoxaban for acute lower-extremity DVT in patients with active cancer.

Methods and results: In this observational study, among the inpatients with cancer and lower-extremity DVT who underwent initial treatment with edoxaban at our hospital from November 2019 to December 2021, 34 consenting patients were recruited in this study. The quantitative ultrasound thrombus (QUT) score of thrombus volume was calculated at baseline (before administration) and 7-14 days after the start of edoxaban administration, using lower-extremity venous ultrasound to evaluate changes in thrombus volume. The primary and secondary endpoints were the acute thrombus regression effect of edoxaban and the impact of patients' clinical frailty on the thrombus regression effect, respectively. Anticoagulant therapy with edoxaban significantly reduced QUT score (p < 0.001). In addition, regardless of the Clinical Frailty Scale scores, QUT score decreased significantly.

Conclusion: Initial treatment with edoxaban was effective for lower-extremity DVT in patients with cancer. In addition, the effect was the same independent of the degree of frailty.