Impact of malnutrition on clinical outcomes and healthcare resource utilization among hospitalized patients with breast cancer: A nationwide analysis.

247 Background: Protein-energy malnutrition (PEM) is a common yet underrecognized comorbidity in oncology that contributes to adverse outcomes and increased healthcare costs. We evaluated the association between PEM and clinical outcomes, as well as underlying demographic disparities, in hospitalized patients (pts) with breast cancer. Methods: We conducted a retrospective cohort study using the 2016–2020 Nationwide Inpatient Sample of adult patients (≥18 years) hospitalized with a diagnosis of breast cancer (N = 208,920). Pts were stratified by nutritional status: no malnutrition (n = 198,702), mild-moderate malnutrition (n = 3,633), and severe malnutrition (n = 6,585). Demographics, comorbidity burden, and hospital characteristics were compared across groups. Outcomes included in-hospital mortality, organ dysfunction, ICU (intensive care unit) use, length of stay, total hospitalization charges (THC), and discharge disposition. Multivariable logistic regression calculated adjusted odds ratios (aORs), controlling for age, comorbidities, and socioeconomic factors. Results: Pts with severe malnutrition were older (mean age 67.1 vs. 64.8 years; p < 0.001), had higher comorbidity burden (Charlson Index ≥3: 14.4% vs. 10.8%; p < 0.01), were more likely to be insured through Medicare (60.6% vs. 54.9%; p < 0.001), and more frequently resided in low-income ZIP codes (20.6% vs. 18.1%; p < 0.05). Compared to non-malnourished pts, those with severe malnutrition had significantly worse outcomes: higher odds of in-hospital mortality (aOR 7.75; 95% CI 6.51–9.23), acute respiratory failure (aOR 4.38; 95% CI 3.89–4.94), septic shock (aOR 10.91; 95% CI 7.72–15.43), ICU admission (aOR 2.98; 95% CI 2.21–4.00), and mechanical ventilation (aOR 4.47; 95% CI 3.47–5.76). Severe malnutrition was also associated with prolonged hospitalization (+5.80 days; 95% CI 5.33–6.27), higher THC (+$14,499; 95% CI $9,720–$19,277), and greater odds of discharge to rehabilitation (aOR 4.07; 95% CI 3.60–4.60). Mild-moderate malnutrition was also associated with adverse outcomes, including increased mortality (aOR 3.94; 95% CI 3.16–4.92) and ICU use (aOR 2.50; 95% CI 1.77–3.53). Conclusions: PEM independently predicts markedly worse clinical outcomes and greater resource utilization in hospitalized breast cancer pts, particularly among older adults with high comorbidity burden. These findings highlight the importance of routine inpatient nutritional screening and early intervention as high-impact, cost-effective quality improvement strategies to improve outcomes and reduce disparities in this vulnerable population.