P08.26 Venous thromboembolism and survival in patients with glioblastoma multiforme

Abstract

Introduction: The most aggressive form of primary brain tumors is glioblastoma multi forme (GBM). Despite the improvement of overall survival by combined treatment with radiotherapy and temozolomide, median survival remains only 14.6 months. During their short life time patients suffer from comorbidity such as venous thromboembolism (VTE). The prevalence of VTE in patients with GBM varies between 7.2 and 30 percent and is high as compared to patients with other malignancies. Previous studies showed no significant difference in survival between GBM patients with or without VTE. In this study we investigated the prevalence of VTE and correlation with survival in a large cohort of patients with GBM. Methods: This study included 263 patients with histological proven GBM treated in the Elisabeth-Tweesteden Hospital, The Netherlands, between 1th of January 2009 and 31 th of December 2011. We investigated retrospectively the prevalence rate of symptomatic deep venous thrombosis (DVT) and pulmonary embolism (PE) diagnosed by ultrasound or CT-scan. Furthermore, we investigated the type of surgery and adjuvant treatment. The Kaplan-Meier method was used to estimate overall survival (OS). Results: One hundred forty-six patients received chemoradiation (CRT). Fifty-two patients were treated with radiotherapy only. The median follow-up time was 69 months (49-109 months). The median OS after the diagnosis of GBM was 9 months. In patient that received CRT, the OS was 16 months. Twenty-eight patients (10.65%) developed a VTE of which 12 DVT's (4.6%) and 17 PE's (6.5%). One patient was diagnosed with both DVT and PE. Among patients whom developed VTE 28.6% underwent biopsy only, 14.3% partial resection and 57.1% gross total resection. Out of the patients without VTE 36.2% underwent biopsy only, 10.2% partial resection and 53.6% gross total resection. Eighty-two point one percent of the VTE patients underwent CRT vs. 52.3% of the patients without VTE. The median OS in the VTE group was 13 months vs. 9 months in the non- VTE group, although the difference was not significant (p 0.203). The survival after the different types of surgery was significantly different (p < 0.05) with a median OS after biopsy of 4 months, 9 months after subtotal resection and 15 months after gross total resection. The dissimilarity in OS with respect to surgery was present in both VTE and non-VTE group and was not significantly different between the two groups. Conclusion: The prevalence of venous thromboembolism in patients with glioblastoma multi forme is high. In our study population the median OS was 9 months and the OS differed significantly according to the type of surgery patients underwent. Although not significant, we found a trend towards better median overall survival in GBM patients that developed a VTE during the course of their disease versus no VTE.