Prognostic value of blood urea nitrogen-to-albumin ratio in critically ill lung cancer patients

urpose: This study aimed to investigate factors influencing mortality in intensive care units (ICUs)-treated lung cancer patients, focusing on the prognostic value of the blood urea nitrogen-to-serum albumin ratio (BAR). Materials and Methods: This retrospective study included lung cancer patients treated in the ICU between 2020 and 2024. Clinical and laboratory data were collected, including demographics, reasons for ICU admission, and scores from BAR, Acute Physiology and Chronic Health Evaluation II (APACHE-II), and Sepsis-related Organ Failure Assessment (SOFA). BAR levels at admission, 24 hours, and 72 hours were analyzed for their predictive value on 30-day mortality using ROC analysis. Results: Among 110 patients, the 30-day mortality rate was 21.8%. Increasing BAR values over time were significantly associated with mortality. The 72-hour BAR had the highest predictive power (AUC=0.783), surpassing APACHE-II and SOFA scores. Cox regression identified elevated BAR and the need for invasive mechanical ventilation (IMV) as independent predictors of mortality. Conclusion: BAR is a valuable prognostic biomarker in ICU-managed lung cancer patients. Its dynamic assessment enhances predictive accuracy and may support early clinical decision-making.