Venous Thromboembolism (VTE) Increases the Healthcare Burden in Patients with Malignant Glioma (MG)

Background: The cumulative incidence of symptomatic venous thromboembolism (VTE) among patients with malignant glioma (MG) is high, with estimates ranging from 20-35% during the course of therapy. VTE is the second leading cause of death among ambulatory patients receiving cancer chemotherapy, with a 2-fold or greater increase in mortality compared to those without VTE, even after adjusting for stage. Specific to MG patients, Semrad et al. reported a higher likelihood of death at 2-year follow up (hazard ratio 1.3). The development of VTE is associated with increased mortality, an increased risk of hospitalization, delays in cancer treatment and an increased risk of complications including pain, bleeding, and bruising from high dose therapeutic anticoagulation. As a result, the economic burden of VTE in cancer patients is substantial and is associated with a nearly 2 fold increase in cost. Data regarding VTE burden encompasses all cancer types and additional data is needed to characterize VTE burden in specific cancer types, particularly rarer cancers. The aim of this study was to assess the healthcare burden associated with the development of VTE in MG patients.

Methods: A retrospective chart review of patients with MG at an academic medical center was conducted from 2009-2016. Patients 18 years and older with a histologic diagnosis of malignant glioma, WHO grade 3-4 were assessed. A total of 31 patients were identified and information was collected with respect to their healthcare consumption as related to their oncologic care. Specifically, the number of office visits, emergency room visits, inpatient hospitalizations with the associated costs of VTE management and it's complications were collected. Using SPSS, linear regression models and descriptive statistics were used to determine the relationship between the development of VTE and healthcare consumption.

Results: Of the 31 patients in the study, 10 developed VTE (32%). All patients who developed a VTE were placed on therapeutic anticoagulation as part of VTE management. Fifty percent of patients developed complications related to anticoagulation, including gastrointestinal, retroperitoneal and intracranial bleeding events. One patient required placement of an IVC filter after experiencing a bleeding complication. Patients that developed VTE had an increase in inpatients days (21.3 inpatients days) as compared to their non-VTE counterparts (10 inpatient days), (p=.04). There was a trend towards increased utilization of the emergency room with an average of 5.1 visits in those patients with VTE as compared to those without (2.89), (p=0.244). A limited cost analysis found that anticoagulation management alone generated an additional $84,335 in healthcare costs with an average of $8,433 per patient. A full cost analysis is currently underway.

Discussion: The development of VTE in patients with malignant glioma increases inpatient admissions days and pharmaceutical costs related to anticoagulation. While limited in patient number, this represents the first assessment of health care burden associated with VTE specific to this cancer patient population. Given the significant number of MG patients who develop VTE (approximately 1/3 in this study), increases in health care burden are magnified in this patient population and studies are needed to prevent VTE in this particular group of patients.