Introduction: Anticoagulants are often used in cancer patients with acute ischemic stroke (AIS) because of concerns for hypercoagulability. However, cancer patients are also prone to bleeding. No prospective study has compared different antithrombotic strategies in this population. We aimed to perform the first randomized trial comparing anticoagulation to antiplatelet therapy in cancer patients with AIS.
Methods: We conducted a pilot multicenter randomized trial in adult patients with active systemic cancer and MRI-confirmed AIS. Patients were randomized to subcutaneous enoxaparin (1 mg/kg twice daily) or oral aspirin (81 mg daily) for 6 months. Antithrombotic therapy beyond 6 months was dictated by treating clinicians. Exclusion criteria included clear indications for anticoagulant (e.g., DVT) or antiplatelet (e.g., recent stents) therapy, high-risk conditions for bleeding, symptomatic carotid stenosis, and severe hematologic derangements. Patients were followed at clinical visits at 1, 3, and 6 months and by chart review from 6 months to 1 year. The primary outcome was feasibility, defined as an enrollment rate among eligible patients for which the lower bound of the 95% confidence interval (CI) exceeds 30%. Secondary feasibility outcomes included patient dropout and crossover rates.
Results: In this interim analysis, 469 patients with cancer and stroke were screened from January 2013 to April 2016 and 49 (10.4%) were eligible. Frequent exclusionary reasons were clear indications for anticoagulation (n=128) and inactive cancer (n=83). We enrolled 20 of the 49 eligible patients, equating to an enrollment rate of 41% (95% CI 27-55%). Enrollment failures primarily occurred because of patient aversion to injections (n=11), patient or physician preference for anticoagulation (n=9), and patient aversion to trial participation (n=7). Thus far, there have been no dropouts but 6 patients crossed over from the enoxaparin arm to the aspirin arm. Major bleeding occurred in 3 patients in the aspirin arm and 1 in the enoxaparin arm; no patients had intracranial hemorrhage.
Conclusion: A randomized trial comparing anticoagulation to antiplatelet therapy in cancer patients with AIS may be feasible and safe, particularly with an oral anticoagulant.