Abstract Purpose: The goal of this analysis was to provide insight into differences in perceived symptom burden and general health status between young adults (YA; 18-39 years of age) and older adults (OA; ≥ 40 years of age) with primary central nervous system (PCNS) tumors. Determining differences in characteristics that impact symptom burden and general health status in YA will allow for tailored survivorship programs that meet the unique needs of this population. Methods: Data were retrospectively analyzed from the National Cancer Institute Neuro-Oncology Branch’s Natural History Study (NCT02851706 PI: T.S. Armstrong), which is an observational prospective cohort study designed to follow and collect PROs and clinical information on patients diagnosed with PCNS tumors throughout their disease trajectory. Differences in patient-reported outcomes (general health status [EQ-5D-3L], symptom burden [MDASI-BT and MDASI-SP], anxiety/depression [PROMIS], and perceived cognition [Neuro-QOL]) and demographic and clinical data were assessed using chi-square tests, one-way ANOVAs, and Students’ t-tests. Linear regression with backward elimination determined which characteristics impacted perceived symptom burden and general health status as evidenced by MDASI-BT and EQ-5D-3L, respectively. Results: The sample included 271 YA (82% with a primary brain tumor [PBT]; median age 31 [range, 18-39]) and 516 OA (88% with a PBT; median age 54 [range, 40-85]). YA were more likely to be single (P<0.001), employed (P<0.001), and make < $50,000 per year (P=0.014). More YA reported pain (P=0.008), nausea (P<0.001), drowsiness (P=0.043), and vomiting (P=0.001) than OA. More YA presented with vision problems (25% of YA, 16% of OA), whereas more OA presented with cognitive deficits (17% of YA, 25% of OA). Compared to YA, 7% more OA with PBTs and 19% more OA with primary spinal tumors (PST) were diagnosed in outpatient clinics, whereas the majority of YA with PBTs (47%) were diagnosed in an emergency room. Among demographic and clinical characteristics, only Karnofsky Performance Scale score was a predictor of general health status (P<0.001) in YA with PCNS tumors and symptom interference (P=0.014) in YA with PBTs. YA reported more affective, cognitive, neurologic, treatment-related, generalized disease, and gastrointestinal symptom burden than OA, with the affective factor being the most severe among the symptom factors reported. Among individuals with PSTs, 20% more YA reported moderate-severe anxiety (P=0.050) and 32% more YA reported moderate-severe perceived cognitive deficits (P=0.023) than OA. Conclusion: YA patients were more likely to be single, employed, have a lower income, and report more symptom burden than OA. These findings underscore the need for tailored survivorship programs providing additional psychosocial support and resources to address symptom presentation in YA. Citation Format: Kimberly Reinhart, Tricia Kunst, Jennifer Reyes, Alvina Acquaye-Mallory, Ewa Grajkowska, Byram H. Ozer, Marta Penas-Prado, Jing Wu, Eric Burton, Lisa Boris, Marissa Panzer, Tina Pillai, Lily Polskin, Mark R. Gilbert, Elizabeth Vera, Terri S. Armstrong. Impact of sociodemographic and clinical factors on symptom burden in the young adult primary central nervous system tumor population [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2231.