In-hospital mortality and incidence trends for tumor lysis syndrome in the United States from 2016 to 2020, a National Inpatient Sample study.

e22536 Background: Tumor lysis syndrome (TLS) is an oncologic emergency characterized by metabolic disturbances that can lead to organ failure. The largest prior analysis was a National Inpatient Sample (NIS) study examining inpatient mortality and outcomes from 2010 to 2013. However, with advancements in oncology therapies, an updated analysis is warranted. This study examines trends in TLS from 2016–2020 using NIS data. Methods: The NIS database was analyzed for patients with TLS (ICD-10 code E88.3) and associated malignancies from 2016 to 2020. Logistic and linear regression models were employed to identify predictors of mortality and length of stay (LOS), respectively. Results: We identified 14,798 TLS-related hospital discharges. The incidence rate (per 100,000 discharges) increased from 31.63 in 2016 to 54.75 in 2020 (p < .01). Inpatient mortality was 22.1% without significant improvement over the years. The mean LOS was 13.7 days. Primary malignancies associated with TLS included acute lymphoblastic leukemia (ALL) (21.1%), acute myeloid leukemia (AML) (20.9%), chronic lymphocytic leukemia (CML) (7.35%), and chronic myeloid leukemia (CML) (3.45%). Non-Hodgkin lymphoma (NHL) comprised 31.5% of cases, predominantly non-follicular subtypes (20.57%), followed by Hodgkin lymphoma (HL) (0.7%) and multiple myeloma (MM) (5.68%). Solid tumors accounted for 9.32% of cases. Complications occurred in 70.06% of patients, with acute kidney injury (AKI) present in 65.8% being the most common, 10.5% of whom required dialysis. Logistic regression analysis identified predictors of mortality, including age (odds ratio [OR] 1.01), Charlson Comorbidity Index (OR 1.12), and weekend admission (OR 1.59). Liquid malignancies were associated with lower mortality risk compared to solid tumors (table 1). No significant associations with mortality or LOS were found for race, income, gender, primary payer, hospital size, or insurance status. Dialysis (OR 21.6) and AKI (OR 3.7) were strongly associated with higher mortality. Conclusions: This study represents the largest recent analysis of TLS using NIS data. The incidence of TLS has risen compared to prior analyses, potentially reflecting an increased prevalence of acute leukemias and increased life expectancy in the United States. Liquid malignancies accounted for 90.86% of TLS cases. This increase is likely influenced by the broader use of immune checkpoint inhibitors (ICIs) as first line in solid tumors, a therapy that exhibits a low incidence of TLS. These findings emphasize the need for proactive interventions to reduce incidence of TLS, particularly in an increasingly aging population. Mortality. Mortality (%) OR P value Solid tumors 34.9 Reference NHL 31.5 0.64 0.05 AML 18.4 0.79 0.02 ALL 26.0 0.23 <0.01 CML 12.3 0.50 0.04 CLL 15.3 0.42 <0.01 MM 16.7 0.50 <0.01 HL 5.1 0.43 <0.01