Trends in mortality associated with tumor lysis syndrome in the United States, 2011-2023.

215 Background: Tumor lysis syndrome (TLS) is a life-threatening condition that occurs during cancer chemotherapy. The resulting metabolic derangements can lead to delays in chemotherapy, which increases the risk of death. However, there is a paucity of population-based studies on TLS-associated deaths in the United States (US). We analyzed the trends in age-adjusted mortality rate (AAMR) for TLS-related deaths among persons with neoplasms in the US from 2011-2023, overall and stratified by age, gender, race, and census region. Methods: We conducted a retrospective, repeated cross-sectional analysis of US national death certificate data from the CDC WONDER database for the years 2011 to 2023. Adults aged 35 years and older with neoplasms (ICD-10 codes C00-D49) listed as the underlying cause of death were included. TLS-related deaths were identified using ICD-10 code E88.3 from the multiple cause-of-death dataset. We calculated AAMR for TLS per 100,000 population. The main outcome was the temporal trends in TLS-related AAMR, overall, and stratified by age, gender, race/ethnicity, urbanicity, and census region. Differences in the groups were assessed with the Mann-Whitney U test and ANOVA, as appropriate. Temporal trends were evaluated using Joinpoint regression and expressed as average annual percentage change (AAPC) with corresponding 95% confidence intervals (CIs). The trend was significant if the CI did not include 0. A p-value of < 0.05 was considered statistically significant for group comparisons. Results: Among 2.28 billion individuals aged 35 years and older with neoplasms, 7,024 had TLS listed as a contributing cause of death (AAMR 0.3). The AAMR increased significantly with age (35-54: 0.05; 55-74: 0.3; 75 years and older: 0.76; P < 0.001). Males had a higher AAMR compared to females (0.37 vs. 0.18 per 100,000; P < 0.001). The AAMR did not significantly differ by rural-urban status, race, or census region. From 2011 to 2023, the overall AAMR increased from 0.1 to 0.4 (AAPC 12.4%; CI: 7.2–17.9; P < 0.001). Similarly, the AAMR increased significantly in males (AAPC 11.7%; CI: 9.2–14.3), females (AAPC 12.0%; CI: 8.9–16.0), Hispanic persons (AAPC 9.5%; CI: 3.2–16.4), non-Hispanic Black race (AAPC 13.3%; CI: 8.9–17.9), non-Hispanic White race (AAPC 13.3%; CI: 8.9–17.7), and across all four US census regions. The AAMR increased significantly in rural (AAPC 16.1%; CI: 6.8–25.9) and urban/metropolitan (AAPC 15.2%; CI: 8.1–22.7) areas and in those aged 55–74 years (AAPC 12.4%; CI: 9.7–15.2), and ≥75 years (AAPC 13.3%; CI: 11.1–15.6). Conclusions: The occurrence of TLS-related mortality was low, but the AAMR increased significantly in the US between 2011 and 2023. This worrying observation, against the backdrop of advances in medical care and cancer therapy, requires further inquiry to determine the factors driving this trend.