Statistically compare PCNSL trial demographics with population demographics to determine how well US trials reflect population demographics. Geographically analyze the distribution and level of urbanization of trials across the US.

Primary Central Nervous System Lymphoma (PCNSL) is a rare and aggressive malignant brain cancer affecting, on average, 1,500 people in the US annually. Currently, there is limited demographic data showing which patients have enrolled nationally in PCNSL clinical trials

Data was collected on median age, gender, ethnicity, and race in US PCNSL trials from ClinicalTrials.gov dating from 1995-present and compared to US population demographics obtained from the CBTRUS Statistical Report: Primary Brain and Other Central Nervous System Tumors Diagnosed in the United States in 2013–2017. Zip codes were gathered for trial locations and their level of urbanization was determined using the Rural-Urban Commuting Area Codes.

88.8% of trials were in metropolitan areas and 2.24% in small towns or rural areas. The trial median age was 60.5 compared to the population median age of 67. The trial distribution of males and females was 52.42% and 47.58%, compared to the population distribution of 50.54% and 49.46%. The trial proportion of Black/African Americans was 3.48% compared to the population proportion of 7.99%. The trial proportion of Hispanics was 3.73% compared to the population proportion of 11.68%.

US PCNSL trials were located primarily in metropolitan areas. The trial median age was lower than the population median age and Black/African Americans and Hispanics were underrepresented in trials compared to the US population. Due to disparities between PCNSL trials and the population, data gathered from these trials may be biased towards treating a certain demographic and not accurately represent the entire US population demographic.