PROJECT SUMMARY/ABSTRACT Advances in anti-retroviral therapy have transformed HIV into a chronic disease. As death from HIV has decreased for people living with HIV (PLWH), mortality from other chronic diseases of aging, particularly non- AIDS defining cancers (NADC), has significantly increased. Winship Cancer Institute’s P30 cancer center support grant and its Community Outreach and Engagement component have identified PLWH as a “Special Population”, experiencing significant cancer disparities in our catchment area of Georgia. Multiple retrospective database analyses have reported worse cancer outcomes, including survival, between PLWH vs HIV- populations, but underlying reasons to explain significant differences in cancer care and survival outcomes more fully remain to be elucidated. We propose two Specific Aims for this exploratory supplement: 1) generate a population-based cohort of age- and stage-matched HIV+ and HIV- NHL patients derived from the Georgia cancer registry; and 2) contact this cohort using established registry protocols and evaluate feasibility and acceptability of validated tools and methods to investigate social determinants of health and multi-level factors (patient, clinical, facility, provider, system) that might impact diagnosis, treatment and outcomes for both HIV+ and HIV- cancer cases through a mixed methods study design. These Aims are in alignment with the NIH OAR research priorities related to HIV-Associated Comorbidities, Coinfections, and Complications that contributes to increasing understanding of the causes, frequency, and clinical outcomes of HIV-related malignancies, as well as research to reduce Health Disparities … in treatment outcomes of PLWH. Completion of these Aims will lead to an extramural grant application to expand preliminary data to other NADC.