ABSTRACT In 2020, an estimated 77,240 people in the US will be diagnosed with non-Hodgkin lymphoma (NHL), and 19,940 will die from this cancer. NHL incidence rates increased over the last half of the 20th century and only recently stabilized. In parallel, NHL survival rates began improving in the mid-1990s with the advent of improved treatment strategies, leading to the current 5-year survival rate of 74%. These trends have led to a growth in the number of NHL survivors, estimated at over 757,000 in 2019. To address the unmet health needs of this patient population, we established the Lymphoma Epidemiology of Outcomes (LEO) cohort study, which by June 2020 will have enrolled over 13,000 NHL patients and have <1% lost to follow-up. The LEO cohort supports multiple grants and has generated novel and high impact findings on NHL prognosis and survivorship. To continue and expand the key contributions of LEO, in this renewal we propose to: 1) Extend recruitment at all 8 LEO centers, with a goal of recruiting 3400 newly diagnosed NHL patients focused on Hispanic (N=900), African American (N=580), and Asian (N=200) participants (doubling the current sample size for these groups) and adolescent and young adult (AYA) participants age 18-39 years (N=870; 87% increase), and non-metro and rural patients of all ages and race/ethnicities (N=1,208, 72% increase), for a total cohort of 16,500 patients; 2) Review all pathology diagnoses and maintain a NHL tumor bank that includes an H&E slide, formalin-fixed, paraffin- embedded tissue samples in a tissue microarray, and extracted tumor DNA and RNA; 3) Collect a peripheral blood sample and maintain a central biorepository of DNA, serum, plasma and buffy coat; 4) Annotate and harmonize all cases with clinical, epidemiologic, pathology and treatment data, including development of new informatics enhancements to capture clinical data from electronic health records, digital pathology images and linkage to public databases to enhance data on environmental exposures and socioeconomic factors; 5) Prospectively follow patients in the cohort to ascertain disease progression/relapse, retreatment, transformation, second cancers, survival (including cause of death), updated exposures, patient- reported outcomes (PROs), and other long-term health outcomes; and 6) Facilitate research projects that use this infrastructure, promote interactions with NCI-supported clinical trials networks, patient advocacy groups, and other collaborators. The goal of this Research Supplement is to gain a better understanding of how Hispanic patients with lymphoma perceive lymphoma clinical trials, the barriers and/or facilitators to clinical trial enrollment and various factors that influence ability or desire to participate in a clinical trial. We will achieve these aims through close coordination of the participating centers. The LEO cohort is an exceptional resource that supports a broad research agenda aimed at identifying novel clinical, epid...