Interstitial lung disease as a predictor of inpatient outcomes among patients with breast cancer.

e12734 Background: Interstitial lung disease (ILD) is an important comorbidity among patients with breast cancer, influenced by prior thoracic radiation, autoimmune disease, and exposure to systemic therapies such as taxanes, CDK4/6 inhibitors, and immune checkpoint inhibitors. ILD may increase vulnerability to respiratory and systemic complications during hospitalization. Limited national-level data exist evaluating the impact of ILD on inpatient outcomes in this population. This study examines whether ILD independently predicts adverse in-hospital outcomes among hospitalized women with breast cancer. Methods: The National Inpatient Sample (2018–2022) was analyzed to identify hospitalized women ≥18 years with breast cancer using ICD-10 codes. Patients with missing data were excluded. ILD and clinical outcomes were identified using validated ICD-10 codes. Outcomes included in-hospital mortality, length of stay (LOS), and complications such as sepsis, acute kidney injury, acute myocardial infarction, acute pulmonary embolism (PE), and ARDS. Categorical variables were compared using Chi-square testing and continuous variables using Kruskal-Wallis testing. Multivariable logistic regression assessed the association between ILD and outcomes, adjusting for diabetes, COPD, chronic kidney disease, coronary artery disease, pulmonary hypertension, alcohol use, and smoking. Results: A total of 164,448 hospitalized women with breast cancer were identified. Mean age was 64.7 ± 14.2 years, and 66.7% were White. ILD was significantly associated with higher in-hospital mortality (OR 1.79; 95% CI 1.50–2.13; p < 0.01), ARDS (OR 3.71; 95% CI 2.11–6.53; p < 0.01), acute PE (OR 1.42; 95% CI 1.05–1.94; p = 0.024), and increased LOS (coef 1.13 days; 95% CI 0.81–1.46; p < 0.01). ILD was also associated with higher odds of sepsis (OR 1.14), cardiogenic shock (OR 1.18), and cardiac arrest (OR 1.44), though these did not reach statistical significance. Conclusions: ILD is an independent predictor of adverse in-patient outcomes among women hospitalized with breast cancer, including higher mortality, increased risk of ARDS and acute PE, and longer LOS. These findings highlight the need for heightened clinical vigilance and tailored inpatient management for this high-risk population.