Racial/ethnic disparities in healthcare utilization, post-operative outcomes, and overall survival for IDH-wildtype glioblastoma stratifying by MGMT promoter methylation status.

2081 Background: Glioblastoma is the most common malignant primary brain tumor and molecular profiles such as IDH1/2 and MGMT promoter methylation status have significant influence on survival outcomes. There is no "real-world" study has investigated the racial/ethnic disparities in healthcare utilization and outcomes for IDH-wildtype glioblastoma patients with MGMT promoter methylation status. Methods: A total of 21971 IDH-wildtype glioblastoma patients ( MGMT promoter-methylated: 41.5%, 9110/21971) were derived from the National Cancer Database (NCDB, 2018-2021). Race/Ethnicity was grouped into Non-Hispanic White (NHW), Non-Hispanic Black (NHB), Asian/Pacific Islander (API), American Indian/Alaska Native (AIAN), Hispanic, and Others. Overall survival (OS) was set as primary outcome. Healthcare utilization and post-operative outcomes are secondary endpoints. Multivariable logistic regression models, Kaplan-Meier methods, and Cox proportional hazards models were performed for post-operative outcomes, healthcare utilization, and overall survival. Results: Compared to NHW, AIAN were 78% more likely to have MGMT promoter methylation after adjusting age and gender (aOR=1.78, p=0.030). API and Hispanic were significantly less likely to undergo GTR over STR comparing to NHW. The odds of receiving chemotherapy and RT for race/ethnicity minorities patients were significantly lower than NHW (Chemotherapy: NHB: aOR=0.79, AIAN: aOR=0.57, Hispanic: aOR=0.83; RT: NHB: aOR=0.88, Hispanic: aOR=0.80). The median OSs by race/ethnicity (NHW, NHB, API, AIAN, Hispanic, and Others, respectively) were: 11.5, 12.3, 14.5, 9.2, 13.6, and 15.6, months ( MGMT promoter-unmethylated, p<0.001), 15.9, 18.8, 23.7, 14.8, 19.6, and 15.5, months ( MGMT promoter-methylated, p<0.001). After adjusting the covariates, NHB, API, and Hispanic experienced significantly lower risk of death comparing to NHW (aHR=0.82, 0.66, and 0.75, all p<0.001). Similar results were validated in stratification analysis by MGMT promoter methylation status, except MGMT promoter-unmethylated AIAN experienced 70% higher risk of death than NHW (aHR=1.70, p=0.021). Conclusions: Our findings suggests that racial/ethnic disparities exist in healthcare utilization, postoperative outcomes, and overall survival in IDH-wildtype glioblastoma population.