Arora, Harshit

e19094 Background: WM/LPL is an indolent B-cell Non-Hodgkin Lymphoma with prolonged survival and predisposition to secondary malignancies (SM) influencing clinical outcomes and survivorship care. We evaluated the incidence, demography, treatment utilization, and outcomes of SM in patients with WM/LPL using population-based data. Methods: SEER-22 database was used to identify patients with LPL/WM diagnosed between 2000–2022 and stratified by SM. Overall survival (OS) was analyzed using Kaplan–Meier survival analysis and propensity score matched Cox regression was used to assess mortality risk. Hazard ratios were reported, with p<0.05 deemed significant. Results: 22,170 patients with WM/LPL were identified, with a median age of 71 years (IQR 16); the cohort was predominantly male (59.0%), White (84.0%), had a median household income of $50,000–$75,000 (48.9%), and resided primarily in urban areas (89.5%). Among all WM/LPL patients, 20.8% (n=4,615) developed a SM. Patients who developed SM were older than those without (median age 75 vs 70 years, p<0.0001) with 45.2% alive at predefined follow-up. The most common solid organ SM were gastrointestinal adenocarcinoma (16%), prostate cancer (14%), and lung adenocarcinoma (9%), while the leading hematologic SM were plasma cell myeloma (6%), diffuse large B-cell lymphoma (5%), and myelodysplastic syndrome (2%). 35.3% of the cohort received chemotherapy, while 0.1% received cancer-related surgery or radiation. On multivariable analysis, older age (OR 0.82, 95% CI 0.81–0.83), male sex (OR 0.59, 95% CI 0.44–0.80), urban residence (OR 1.99, 95% CI 1.24–3.18), and higher income (OR 2.16, 95% CI 1.13–4.15) were significantly associated with SM diagnosis. Kaplan–Meier analysis demonstrated inferior survival among patients with SM (54.8% vs 45.2%, p<0.0001), with shorter median OS (9 vs 14 years, log-rank p<0.001). Similarly, Propensity-matched analysis revealed worse OS in patients with SM (HR 1.15, 95% CI 1.09–1.22, p<0.001). Median OS varied substantially by SM site (see Table). Conclusions: Our study demonstrates a substantial burden of SMs among patients with WM/LPL and are associated with substantially inferior survival despite the indolent nature of the disease. The marked heterogeneity in SM types and outcomes highlights the need for risk-adapted surveillance, survivorship-focused care, and equitable strategies to address disparities and improve long-term outcomes in this population. SM Site Median OS (years) IQR p-value Hepatopancreatobiliary 1 0 <0.05 CNS 3.5 9 <0.05 Breast 3 6 <0.05 Colorectal 4 3.5 <0.05 Lymph Node 5 8 <0.05 Blood 6 7 <0.05 Lung 7 9 <0.05 Head & Neck 6.5 8.5 <0.05 Melanoma 9 10 <0.05 Urogenital 10.5 7 <0.05

e15708 Background: AFTT is characterized by physical, nutritional, and psychosocial decline. In GIC, AFTT arises from malnutrition, disease progression, or treatment-related toxicity resulting in poor quality of life. We evaluated the association between AFTT and IM, length of stay (LOS), and hospital charges (HC) in hospitalized GIC patients. Methods: The National Inpatient Sample (2016-21) was used to identify adult hospitalizations with GIC using ICD-10 codes, which were stratified as primary or secondary diagnoses by AFTT. Clinical characteristics and primary outcomes including IM, LOS, and HC were extracted. Multivariable regression models adjusting for demographics, insurance, comorbidity burden, census tract income, and hospital teaching status were evaluated. Results: Among 2,732,505 GIC hospitalizations, colorectal (46.9%) and pancreatic (20.4%) cancer predominated; 121,035 (4.4%) had AFTT. Patients with AFTT vs non-AFTT, were older (mean = 69.3 vs 66.5 yrs), more often male (58.1% vs 57%), and from the lowest income quartile (27.7% vs 26%). AFTT cohort had higher comorbidity burden (mean CCI = 7.24 vs 6.26), more Black patients (19.1% vs 12.8%), higher Medicare use (62.7% vs 56.0%), increased palliative care consultation (37.4% vs 13.6%), risk of malnutrition, AKI, and dementia (all p< 0.001). AFTT was associated with higher IM, longer LOS, and lower HC. Higher age, males, and self-pay were associated with increased IM and HC, but shorter LOS. Lower CCI was associated with reduced IM, LOS, HC, whereas urban hospitals showed lower IM but higher LOS and HC. Black patients had higher IM and LOS but lower HC, contrary to Hispanic patients. Conclusions: The grave impact of AFTT and variability in survival and practice patterns is driven multifactorially, raising concerns about inequitable care access and differences in healthcare utilization. Standardized guidelines and multidisciplinary interventions are urgently needed to combat AFTT in GIC. Predictor IM aOR (95% CI) LOS Adj. Ratio (95% CI) HC Adj. Ratio (95% CI) AFTT Status (vs. Non-AFTT) 1.96 (1.93-2.00) 1.13 (1.12-1.14) 0.86 (0.85-0.86) Age (/year increase) 1.02 (1.02-1.02) 1.00 (1.00-1.00) 1.00 (1.00-1.00) Sex (vs. Female) Male 1.18 (1.17-1.19) 0.99 (0.98-0.99) 1.05 (1.05-1.06) CCI Score (vs. High, ≥5) Low (≤2) Mid (3-4) 0.33 (0.32-0.33) 0.48 (0.47 - 0.48) 0.87 (0.87 - 0.88) 0.93 (0.93 - 0.94) 0.93 (0.93 - 0.94) 1.02 (1.02 - 1.02) Insurance (vs. Medicare) Private Medicaid Self-Pay 1.03 (1.01 - 1.05) Ref in model 1.29 (1.24 - 1.33) 0.92 (0.91 - 0.92) 0.96 (0.95 - 0.97) 0.98 (0.97 - 1.00) 1.03 (1.02 - 1.03) 1.06 (1.05 - 1.06) 0.96 (0.95 - 0.97) Race (vs. White) Black 1.03 (1.00 - 1.06) 1.07 (1.06 - 1.08) 0.95 (0.94 - 0.96) Facility Status (vs. Rural) Urban Non-Teaching Urban Teaching 0.87 (0.85 - 0.89) 0.78 (0.77 - 0.80) 1.10 (1.09 - 1.11) 1.18 (1.17 - 1.19) 1.64 (1.63 - 1.65) 1.86 (1.84 - 1.87)

e14111 Background: Primary CNSL (PCNSL) is a rare, aggressive B-cell non-Hodgkin lymphoma limited to the CNS, while secondary CNSL (SCNSL) represents CNS involvement from systemic lymphoma. Previous observations focused on CNSL have limited data clinically comparing PSNSL and SCNSL. We aimed to evaluate overall survival and associated factors in patients with PCNSL vs SCNSL using a large population database. Methods: We conducted a retrospective cohort study using the SEER-22 database to identify patients diagnosed with CNSL between 2020-2022. Group comparisons used t-tests or ANOVA for continuous variables, chi-square tests for categorical variables, and Kaplan–Meier survival analysis, with all analyses performed in RStudio 4.1.1 and significance deemed as p<0.05. Results: 14,964 patients with CNS lymphoma were identified, with 84.6% PCNSL and 15.4% SCNSL cases. The overall median age was 65 years (IQR 20), with 52% male, 66% White patients, residing in urban areas (90%) and median household income of $50,000–$75,000 (52%). Compared with PCNSL, patients with SCNSL were significantly older (72 vs 64 years, p<0.0001). SCNSL more frequently involved the cerebrum (39% vs 34%) and cerebellum (5.5% vs 4.5%), but less commonly affected the nerves (12.0% vs 12.5%) and spinal cord (4.2% vs 5.1%) (p<0.05). Disease was predominantly unilateral (95.8%) in both groups. Chemotherapy (55% vs 56%) and radiotherapy (19% vs 18%) utilization did not differ significantly, with external beam radiation comprising 94.3% of radiated cases. PCNSL patients were more likely to undergo surgical intervention than SCNSL patients (31.8% vs 28.7%; p=0.0027). Diffuse large B-cell lymphoma was the most common histologic subtype in both PCNSL (70.1%) and SCNSL (74.3%). Median overall survival was shorter in SCNSL (1.64 years) than PCNSL (1.99 years). Survival improved significantly across diagnostic eras (2000–2005 to 2016–2020; log-rank p<0.001), while lower income (<$50,000) and rural residence were associated with inferior outcomes (p=0.028 and p=0.033). Conclusions: Survival in CNS lymphoma remains poor, with SCNSL associated with worse outcomes compared with PCNSL. Greater understanding of treatment variation and disease differences is needed to optimize therapy and improve patient outcomes. Characteristic PCNSL SCNSL Total p-Value N 12667 2297 14964 Population Distribution 0.033 Urban 11426 2038 13464 Rural 1241 259 1500 Surgery 0.0027 Yes 3630 730 4360 No 9037 1567 10604 Months from Diagnosis to Rx(Mean, SD) 0.31 (0.86) 0.27 (0.65) 0.30 (0.83) 0.0077 Death Status <0.0001 Dead 8603 1772 10375 Alive 4064 525 4589 Overall Survival (in years, Mean, SD) 1.99 (2.85) 1.64 (2.31) 1.93 (2.77) <0.0001