EPID-29. Impact of Multicenter Treatment on Molecular Biomarker Testing, Stand-of-Care Delivery, and Outcomes for Patients with Glioblastoma: Findings from a Nationwide Dataset

Abstract BACKGROUND The associations between receiving treatment at multiple facilities and access to molecular testing, delivery of stand-of-care (SOC) treatment, and outcomes in glioblastoma patients remain poorly understood. METHODS A total of 41,142 glioblastoma patients were queried from the National Cancer Database (NCDB, 2018-2022), with a subset of 21,683 IDH-wildtype (IDH-wt) patients having available MGMT-m status (52.7%). Patients who received treatments at multiple facilities were identified (N=8,009, 19.5%). Multivariable logistic regression, the Kaplan-Meier method, and Cox proportional hazards models were performed to assess the impact of treatments at multiple facilities on IDH/MGMT testing, SOC treatment, post-operative outcomes, and overall survival (OS). RESULTS Patients with younger age, private insurance, higher income, longer travel distance to hospital, urban residence, and no comorbidity were significantly more likely to undergo treatment at multiple facilities. In multivariable analyses, compared to patients underwent treatment at single facility, those were treated at multiple hospitals had significantly higher odds of receiving IDH mutation test (aOR=1.28, p<0.001), MGMT-m test (aOR=1.26, p<0.001), gross total resection (aOR=1.17, p<0.001), and concurrent CRT (aOR=1.52, p<0.001). Further, patients received treatments at multiple facilities experienced significantly reduced odds of unplanned readmission (aOR=0.72, p<0.001), 30-day mortality (aOR=0.22, p<0.001), 90-day mortality (aOR=0.40, p<0.001), and decreased hazards of death [median OS (months): total cohort - 15.0 vs. 11.2; IDH-wt+MGMT-um - 13.6 vs. 10.9; IDH-wt+MGMT-m - 19.7 vs. 14.9; all log-rank test p<0.001; aHR=0.85, p<0.001, after accounting for MGMT-m status and other covariates]. CONCLUSIONS Our findings suggest that receiving treatment at multiple facilities may improve access to molecular biomarker testing and clinical treatment modalities, leading to better post-operative outcomes and overall survival. Future studies will be conducted to investigate the underlying mechanisms of this favorable effect using other datasets with more granular information.