P16.02.B DISPARITIES IN TRIAL ACCESS FOR GLIOMA PATIENTS: COMPARISON ACROSS SELECTED EUROPEAN COUNTRIES

Abstract BACKGROUND Gliomas are rare and aggressive CNS tumors with limited survival, making clinical trial (CT) participation indispensable, particularly in progressive cases. Cross-national disparities in glioma CT access remain underexplored. This study investigates temporal trends and socioeconomic correlates of glioma CT activity across eight European countries, using lung cancer trials as a benchmark. MATERIAL AND METHODS Glioma CTs registered after 2004 and conducted in France, Germany, Italy, Denmark, Poland, Hungary, Greece, or Turkey were extracted from ClinicalTrials.gov. A comparable lung cancer dataset was created. National-level data on population, gross national income (GNI) per capita, human development index (HDI), and cancer incidence were obtained from public sources. Trial access was defined as active CTs per estimated annual new cases. RESULTS Of 3,292 glioma CTs globally, 640 involved at least one target country. France (n=287), Germany (n=192), Italy (n=151), and Denmark (n=61) hosted the most; Turkey (n=5), Hungary (n=13), Greece (n=10), and Poland (n=26) contributed minimally. Over time, France, Germany and Italy showed significant upward trends in glioma CT activity (p < 0.05). Denmark, despite lower absolute numbers, showed strong growth relative to population. Turkey remained the least active participant, with no significant increase in glioma trial activity. When adjusted for estimated glioma cases, Denmark had the highest trial access, followed by France and Germany. Trial access positively correlated with GNI per capita (ρ = 0.76, p = 0.028) and moderately with HDI (ρ = 0.69, p = 0.058). In contrast, lung cancer trials were more abundant and equitably distributed (p = 0.0078), without significant correlation with national socioeconomic indicators (ρ =0.14, p=0.7 gor GNI per capita and ρ =0.19 p=0.7 for HDI). Despite having similar or lower GDP per capita compared to other countries in the analysis, Poland and Hungary showed substantially higher lung cancer trial access than glioma trial access, highlighting the underrepresentation of glioma research in resource-limited settings. Notably, Turkey exhibited the lowest glioma CT access (0.0010 per patient), despite a moderate volume of lung cancer trials. CONCLUSION Glioma CT access varies widely across Europe and is closely tied to GNI and HDI, unlike lung cancer trials, which are more equitably distributed. These disparities may relate to differences in the availability of trained neuro-oncology professionals and structured care systems, warranting further study. Targeted policy efforts are needed to improve access and inclusion in glioma research across all regions.