RMTD-03 SOCIOECONOMIC DISPARITIES IN CLINICAL TRIAL ENROLLMENT AMONG PATIENTS WITH BRAIN METASTASES: A CENTRAL PENNSYLVANIA CROSS-SECTIONAL ANALYSIS IN NEIGHBORHOOD-DISADVANTAGE METRICS

Abstract Socioeconomic disparities significantly influence health outcomes in patients with brain metastases (BM), yet their influence on clinical trial enrolment remain understudied. This cross-sectional analysis evaluated 1,802 patients (non-small cell lung cancer [NSCLC]: n=1,536; melanoma: n=182; HER2-positive breast cancer: n=84) treated at Penn State Cancer Institute (2006–2022) to assess associations between neighborhood disadvantage metrics, education, and clinical trial enrollment. Neighborhood disadvantage was measured via the Area Deprivation Index (ADI; national/state percentiles/deciles) and Community Human Development Index (CHDI). Logistic regression and Kaplan-Meier analyses examined predictors of enrollment and survival outcomes. An improved overall survival was noted in clinical trial enrollees versus non-enrollees across all patients (p=0.0043), without a significant association between ADI and survival. Subgroup analyses (NSCLC, melanoma, HER2+ breast cancer) showed no survival benefit linked to trial participation, likely related to the limited sample size in each cohort. Higher education (OR: 1.02, 95% CI: 1.00–1.03; p=0.02) significantly predicted increased trial enrollment in the combined cohort. Conversely, elevated national ADI (NADI; OR: 0.97, 95% CI: 0.96–0.99; p=0.007) and state ADI (SADI; OR: 0.85, 95% CI: 0.74–0.97; p=0.02) were associated with reduced enrollment, suggesting that residing in disadvantaged neighborhoods decreased access. Trends toward increased enrollment with higher life expectancy (p=0.072) and CHDI (p=0.068) were also observed. In melanoma patients, lower income was independently associated with enrollment (p=0.04). These findings underscore socioeconomic inequities in trial access, driven by education and neighborhood disadvantage, and highlight survival advantages for enrollees. Targeted interventions addressing structural barriers in disadvantaged communities are critical to improving equity in cancer care and research participation.