DISP-30. Impact of distance traveled for clinical trial participation on clinical outcomes in patients with glioblastoma

BACKGROUND Patients with glioblastoma (GBM) often face limited access to clinical trials, particularly those living in rural or underserved regions. We investigated whether travel distance for trial participation is associated with survival among these patients. METHODS We conducted a retrospective cohort study of adults with recurrent or progressive high-grade glioma enrolled in clinical trials at Dana-Farber Cancer Institute between 1999 and 2018. Travel distance from residence to Dana-Farber was estimated using ZIP codes, yielding the median distance per visit. Overall survival (OS) from trial enrollment was assessed using Kaplan-Meier analysis. Log-rank tests were used to evaluate survival differences, and Cox regression models were applied to examine the independent association between travel distance and OS, adjusting for age, income, education, and Karnofsky Performance Status (KPS). RESULTS At the time of submission, 92 patients were included, most of whom were white (98%) with a median KPS of 90 at enrollment. Median travel distance per visit was 85 miles. Travel distance was not significantly associated with OS in univariable (p = 0.14) or multivariable models (HR 1.0004, p = 0.12). In the univariable analysis, older age at progression (p = 0.00484), lower KPS at enrollment (p = 0.04641), and at the end of trial participation (p < 0.0001) were associated with worse OS. In multivariable analysis, distance per visit was not associated with OS (HR 1.0004, p = 0.12). Lower KPS at end of trial participation (HR 0.96, p < 0.0001) remained a strong predictor of worse OS. Education (HR 0.94, p = 0.058) showed borderline significance. CONCLUSION In this interim analysis, travel distance for clinical trial participation was not associated with survival in GBM. Additional data from recent years are being incorporated to strengthen our analysis.