Venous thromboembolic events in glioblastoma patients: An epidemiological study

BACKGROUND AND PURPOSE: Venous thromboembolic events (VTEs) are a major complication in cancer patients, and therefore, also in brain cancer patients, anticoagulants are considered appropriate in the treatment of VTEs. METHODS: Frequency, risk factors, and treatment of VTEs, as well as associated complications, were assessed in a population‐based cohort of glioblastoma patients in the Canton of Zurich, Switzerland. Correlations between clinical data and survival were retrospectively analyzed using the log‐rank test and Cox regression models. RESULTS: Four hundred fourteen glioblastoma patients with isocitrate dehydrogenase wild‐type status were identified. VTEs were documented in 65 patients (15.7%). Median time from tumor diagnosis to the occurrence of a VTE was 1.8 months, and 27 patients were diagnosed with VTEs postoperatively (within 35 days; 42.2%). History of a prior VTE was more common in patients who developed VTEs than in those who did not (p = 0.004). Bevacizumab treatment at any time during the disease course was not associated with occurrence of VTEs (p = 0.593). Most patients with VTEs (n = 61, 93.8%) were treated with therapeutic anticoagulation. Complications occurred in 14 patients (23.0%), mainly intracranial hemorrhages (n = 7, 11.5%). Overall survival did not differ between patients diagnosed with VTEs and those who had no VTE (p = 0.139). Tumor progression was the major cause of death (n = 283, 90.7%), and only three patients (1.0%) died in association with acute VTEs. CONCLUSIONS: Venous thromboembolic events occurred early in the disease course, suggesting that the implementation of primary venous thromboembolism prophylaxis during first‐line chemoradiotherapy could be explored in a randomized setting.