Sex-based differences in in-hospital outcomes among hospitalized patients with lung cancer receiving immunotherapy: A National Inpatient Sample study.

Abstract

e23073 Background: Lung cancer is the second most common malignancy and the leading cause of cancer-related mortality in the United States. Immune checkpoint inhibitors (ICI) are increasingly used within first-line therapy strategies and have improved survival. Despite these advances, inpatient hospitalizations due to ICI complications remain common during treatment. Limited data exist on sex-based differences in clinical outcomes among hospitalized patients receiving ICI. This study aims to examine sex-based differences in inpatient outcomes in this population. Methods: We conducted a retrospective cohort study using the National Inpatient Sample database from 2015 to 2022. Patients with lung cancer across all stages treated with ICI and are hospitalized for ICI-related complications were identified. Patients were stratified by sex and compared for inpatient outcomes. Multivariable logistic regression adjusted for demographics, hospital characteristics, and comorbidity burden using the Elixhauser Comorbidity Index. The primary outcome was in-hospital mortality. Secondary outcomes included ICI-related complications and intensive care unit (ICU)-level interventions. Statistical significance was defined as p < 0.001. Results: A total of 5,574 hospitalizations were studied. After multivariable adjustment, female patients had significantly higher in-hospital mortality compared with males (OR 1.83, CI 1.7 - 2.0). Female sex was associated with increased odds of hospitalizations due to ICI complications, including pneumonitis (OR 2.2, CI 2.0 - 2.04), colitis (OR 1.8, CI 1.6 - 2.0), carditis (OR 2.5, CI 2.2 - 2.8), transaminitis (OR 1.8, CI 1.7 - 2.0), anemia (OR 1.8, CI 1.7 - 1.8), acute kidney injury (OR 1.6, CI 1.5 - 1.7), and arrhythmias (OR 1.6, CI 1.8 - 1.7). Females were also more likely to experience ICU-level complications, including shock (OR 1.80, CI 1.6 - 2.1), vasopressors (OR 1.78, CI 1.6 - 2.0), mechanical ventilation (OR 1.7, CI 1.5 - 1.9), and continuous renal replacement therapy (CRRT) (OR 1.5, CI 1.3 - 1.7) (all p < 0.001). Conclusions: In this nationwide cohort, among patients with lung cancer treated with ICI, the female sex was associated with higher in-hospital mortality, and increased ICI-related complications causing hospital admissions and ICU-level care. These findings highlight clinically meaningful sex-based differences in patient outcomes. This study aims to shed light and underscore the need for further investigation into mechanisms that contribute to such differences. Future studies are warranted to guide sex-informed clinical management, from biological factors to treatment practices across hospitals.