Inpatient characteristics and outcomes of diffuse large B-cell lymphoma in adolescents and young adults.

e19042 Background: Diffuse large B-cell lymphoma (DLBCL) is the most commonly aggressive non-Hodgkin’s lymphoma known to also affect adolescents and young adults (AYA). This population faces unique challenges such as financial toxicity, physical and emotional concerns. We examined the inpatient characteristics and outcomes of AYA patients with a diagnosis of DLBCL. Methods: A retrospective cohort analysis using the Nationwide Inpatient Sample database from 2008 to 2021, DLBCL patients with non-elective hospitalizations were identified using ICD-9 and ICD-10 codes. Descriptive analyses were conducted using STATA version 17.0 to compare sociodemographic and clinical characteristics between AYA and older populations. Multivariable logistic and linear regression models were used to examine the association between the age groups and inpatient mortality, prolonged (>5 days) length of stay (LOS), and total hospital charges. Results: There were 346,185 non-elective hospitalizations with DLBCL within the 14-year study period. Of these, 23,163 (6.7%) were in the AYA cohort.The mean age was 30 years in the AYA group and 68.4 years in the older group (P=0.001). There was a higher proportion of males in the AYA group compared to the older group (59.2% vs 56.4%, P = 0.001) but a lower distribution of non-Hispanic Whites (48.6% vs 71.7%, P < 0.001). Regarding clinical characteristics, AYA-DLBCL patients had a higher frequency of febrile neutropenia (19.5 vs 13.6%, P<0.001), bone marrow transplant (4.7 vs 3.8%, P<0.004), HIV (14.5 vs 2.6%, P<0.001), superior vena cava syndrome (3.8 vs 0.9%, P<0.001) and cardiac tamponade (1 vs 0.2%, P<0.001). AYA-DLBCL patients had a lower frequency of severe sepsis (6.3 vs 8.1%, P<0.001), AKI (12.8 vs 23.6%, P<0.001), and acute respiratory failure (6.4 vs 10.5%, P<0.001). On multivariable logistic regression, the AYA group had 50% lower odds of mortality relative to the older adult group (adjusted odds ratio [aOR]: 0.51, 95% confidence interval [CI]: 0.43-0.60, P < 0.001).There was a lower odd of prolonged hospital stay in the AYA group (aOR: 0.88, 95% CI: 0.82-0.93, P < 0.001).TheAYA cohort had higher odds of increased hospital expenditure (β-Coefficient: 11,260, 95% CI: 3,794–18,728, P = 0.003) . Conclusions: This represents the largest epidemiological study to date on DLBCL hospitalizations in AYA . The AYA cohort had lower inpatient mortality, increased hospital costs, and higher rates of febrile neutropenia and HIV. Higher hospital charges may be due to more febrile neutropenia rates, bone marrow transplants and other aggressive interventions performed in younger patients. Additional studies are needed to understand and improve long-term treatment-related toxicities in this population. Inpatient characteristics and outcomes of DLBCL in adolescent and young adults. AYA (15 - 39 years) Older Adult (≥ 40 years) P-value Total DLBCL: 346,185 Total: 23,163 (6.7%) Total: 323,022 (93.3%) Mortality 3.6% 6.6% <0.001 Prolonged (> 5 days) Hospital Stay 55.6% 57.7% <0.001 Mean Total Hospital Charge $116,430 $99,857 0.003 Febrile Neutropenia 19.5% 13.6% <0.001 Bone Marrow Transplant 4.7% 3.8% <0.004 HIV 14.5% 2.6% <0.001 Severe Sepsis 6.3% 8.1% <0.001 Acute Kidney Injury 12.8 23.6% <0.001