NCOG-41. COMPARATIVE ANALYSIS OF MORTALITY AND SHORT-TERM SIDE EFFECTS IN PATIENTS WITH GLIOBLASTOMA MULTIFORME TREATED WITH TEMOZOLOMIDE VERSUS TEMOZOLOMIDE PLUS BEVACIZUMAB CHEMOTHERAPY

Abstract INTRODUCTION Glioblastoma multiforme (GBM) is a highly aggressive primary brain tumor in adults with limited treatment options and poor prognosis. Temozolomide (TMZ) chemotherapy is the standard treatment for GBM, but alternative therapies have shown limited success. Bevacizumab (BEV), a monoclonal antibody targeting vascular endothelial growth factor (VEGF), is used to restrict GBM growth and spread. This study evaluates the efficacy of combining TMZ with BEV compared to TMZ alone in managing GBM. METHODS A retrospective cohort study was conducted using TriNetX database data, focusing on patients diagnosed with GBM and receiving chemotherapy. Cohorts were defined by treatment: TMZ plus BEV versus TMZ alone. Propensity-score matching balanced baseline characteristics, including demographics and health conditions. Primary outcomes included mortality rates and short-term side effects within the first year of treatment, such as cognitive communication deficits, headache, dizziness, insomnia, and nausea/vomiting. RESULTS After matching, 922 patients were included in each cohort. There were no significant demographic differences post-matching. The mortality rate was higher in the TMZ plus BEV group compared to TMZ alone (51.30% vs. 36.98%, RR: 1.387, 95% CI: 1.249-1.541). However, TMZ plus BEV was associated with a lower incidence of cognitive communication deficits (1.95% vs. 4.34%, RR: 0.45, 95% CI: 0.26-0.779) and dizziness (7.27% vs. 10.52%, RR: 0.691, 95% CI: 0.513-0.93). No significant differences were found in headache, insomnia, or nausea/vomiting rates between the groups. CONCLUSION This study indicates that combining bevacizumab with temozolomide may increase mortality in GBM patients but reduce certain side effects such as cognitive deficits and dizziness. These findings emphasize the need to carefully consider the benefits and risks of different chemotherapy regimens for GBM and highlight the necessity for further research to optimize treatment strategies and improve patient outcomes.