Management of recurrent venous thromboembolism during anticoagulant treatment in patients with cancer: a prospective cohort study.

Background: Recurrent venous thromboembolism (VTE) is a common complication in patients with cancer-associated VTE. Limited data are available on treatment, particularly in patients receiving direct oral anticoagulants (DOACs).

Objectives: We aimed to evaluate current management strategies and outcomes in patients with cancer and recurrent VTE during treatment with low-molecular-weight heparin (LMWH) or DOACs.

Methods: This was an international, prospective, observational cohort study. Patients were treated according to local practice, although the study protocol encouraged the use of a dose-escalation strategy in accordance with current clinical guidelines. Primary outcomes were second recurrent VTE and clinically relevant bleeding.

Results: Between June 2020 and November 2024, 94 patients were enrolled, of whom 81 were included in the final analysis. At the time of recurrent VTE, 55% of patients were treated with a DOAC, 41% with therapeutic-dose LMWH, and 4% with maintenance-dose LMWH. Of DOAC-treated patients, 51% switched to supratherapeutic-dose LMWH, 42% to therapeutic-dose LMWH, and 7% received other treatments. Of LMWH-treated patients, 70% received dose escalation, 18% maintained the same dose, and 12% received other treatments. At the 3-month follow-up, 10% had developed a second recurrence, 12% clinically relevant bleeding, and 20% died. VTE incidence was similar between patients receiving dose escalation and those maintained on therapeutic doses, while clinically relevant bleeding was more frequent in the latter (6% vs 25%).

Conclusion: The risk of second recurrent VTE was substantial despite two-thirds of patients receiving dose escalation. Bleeding was common regardless of treatment intensity, underscoring the challenges in this patient population.