Efficacy and limitations of 180-day subcutaneous heparin therapy for cancer-associated ischemic stroke.

BACKGROUND

Cancer-associated ischemic stroke has a high recurrence rate. Subcutaneous (SC) heparin therapy is used to prevent this recurrence, but its long-term efficacy remains unclear. This study evaluated the 180-day effects, safety, and sustainability of SC heparin treatment in patients with cancer-associated ischemic stroke.

METHODS

Patients with cancer-associated ischemic stroke who were treated with unfractionated heparin were retrospectively investigated. Clinical data, such as D-dimer levels, heparin dosing, and cancer-related information, were collected. Outcomes assessed over 180 days included recurrent cancer-associated thrombosis (CAT), mortality, adverse events, and treatment discontinuation.

RESULTS

Five of 100 patients treated with SC heparin experienced recurrence of CAT (ischemic stroke, four patients; pulmonary embolism, one patient). The cumulative recurrence rates of CAT were 2.4 % at 30 days and 7.7 % at 90 days, with no recurrence observed thereafter. At 180 days of follow-up, 19 patients survived without CAT recurrence and one patient was completely cured of cancer through surgery, while 29 patients died of cancer without recurrence of CAT. This finding suggested that approximately half of the patients benefited from SC heparin therapy. Adverse events such as major bleeding were observed in 16 patients, leading to the discontinuation of treatment. Additionally, treatment was discontinued for various reasons such as psychological distress in 30 patients. D-dimer levels at the time of the initial cancer-associated ischemic stroke tended to be higher in patients with recurrence than in those without recurrence, but this was not significant. No recurrence of CAT was observed in patients with pancreatic cancer, likely due to early cancer-related mortality. CAT recurrence and adverse event rates were not significantly different by cancer stage (stage IV vs. other stages) or between the fixed dose and adjusted dose heparin groups.

CONCLUSIONS

SC heparin therapy effectively maintained a low recurrence rate of CAT for 180 days, and may have contributed to preserving functionality and quality of life of the patients. Recurrence and adverse events were primarily observed within the first 90 days. However, challenges related to long-term SC heparin therapy remain. To improve treatment sustainability, comprehensive palliative care that addresses physical discomfort and psychological distress is essential. This study suggests the potential long-term benefits and limitations of SC heparin therapy and highlights the need for future long-term prospective studies comparing this therapy with alternative anticoagulation strategies.