Malnutrition and cachexia as drivers of failure-to-rescue in gynecologic cancer hospitalizations, 2016–2023.

11053 Background: Malnutrition and cancer cachexia are underrecognized in administrative data yet may identify hospitalized oncology patients with limited physiologic reserve. Rather than acting solely as baseline comorbidities, these conditions may amplify the lethality of inpatient complications. The prevalence, temporal trends, and outcome-modifying role of malnutrition were evaluated among U.S. gynecologic oncology hospitalizations using a failure-to-rescue framework. Methods: A retrospective, survey-weighted analysis of the National Inpatient Sample (NIS), 2016–2023, was conducted. Adult hospitalizations with gynecologic malignancies (ICD-10-CM C51–C58) were included; palliative encounters (Z51.5) were excluded. Malnutrition was defined using a narrow phenotype (E43, E44.*, E46) and a broader definition including cachexia (R64). Outcomes included in-hospital mortality, ICU escalation (mechanical ventilation and/or shock), major complications (sepsis, bleeding/transfusion, venous thromboembolism, acute kidney injury, bowel injury/peritonitis, respiratory failure), length of stay (LOS), hospitalization cost, and failure-to-rescue (death following ≥1 complication among surgical admissions). Survey-weighted estimates with 95% confidence intervals (CI) were reported. Results: The cohort included 1,019,030 weighted hospitalizations. Malnutrition prevalence was 12.75% (95% CI, 12.53–12.98) using the narrow definition and increased from 9.61% in 2016 to 15.32% in 2023. In-hospital mortality was higher among malnourished admissions (4.36% [95% CI, 4.11–4.63] vs 1.55% [95% CI, 1.48–1.61]). Malnutrition was associated with greater ICU escalation (5.63% [95% CI, 5.35–5.92] vs 2.48% [95% CI, 2.41–2.56]), AKI (31.53% [95% CI, 30.93–32.13] vs 17.54% [95% CI, 17.33–17.76]), and any major complication (64.97% [95% CI, 64.35–65.60] vs 44.07% [95% CI, 43.74–44.40]). Resource utilization was higher with malnutrition (LOS 8.98 vs 4.71 days; cost $28,155 vs $18,740). Among admissions with complications, mortality was higher with malnutrition (6.27% [95% CI, 5.90–6.65] vs 3.16% [95% CI, 3.03–3.29]). In the surgical subcohort, failure-to-rescue mortality was 2.55% (95% CI, 1.98–3.28) with malnutrition versus 0.82% (95% CI, 0.70–0.95). Conclusions: In U.S. gynecologic oncology hospitalizations, malnutrition and cachexia identify a high-risk inpatient phenotype with disproportionate complication burden and post-complication mortality. These findings support malnutrition as a modifier of failure-to-rescue rather than an isolated baseline risk factor and highlight inpatient nutritional vulnerability as a target for early risk stratification and supportive intervention.