TMIC-29. BEVACIZUMAB IS ASSOCIATED WITH INCREASED RATE OF RECURRENCE IN GLIOBLASTOMA

Abstract

Abstract BACKGROUND The primary cause of Glioblastoma’s (GBM) dismal outcomes is the high rate of tumor recurrence, which is closely related to its resistance to standard therapies. Bevacizumab has increasingly been used in the treatment of recurrent GBM. However, the data on Bevacizumab has been mixed regarding its efficacy in improving patient survival. Moreover, there is no conclusive evidence in the literature regarding Bevacizumab treatment and its association with increased incidence of distant or diffuse recurrence. Objective: To provide conclusive evidence on the recurrence rate associated with Bevacizumab treatment in GBM patients METHODS UCLA GBM patients were reviewed for recurrence pre-and post-Bevacizumab treatment. Patients whose Bevacizumab treatment was not flanked by surgeries and patients with only one surgery were excluded. After exclusion criteria were applied, 94 patients were included in the results. The number of recurrences preceding and following Bevacizumab was recorded. RESULTS In a cohort of 94 patients, the average recurrence rate pre-Bevacizumab treatment was 0.29 ± 0.88, whereas the average recurrence rate post-Bevacizumab treatment was 2.51 ± 1.64. Overall, the recurrence rate was significantly higher in GBM patients post-Bevacizumab treatment (95% CI [1.83, 2.59]; p< 0.0001). CONCLUSION Our results suggest that Bevacizumab treatment is associated with an increased rate of recurrence. This finding is indicative of tumor transition to a more aggressive phenotype that is associated with Bevacizumab treatment.