SADA-03 PREOPERATIVE ALBUMIN OUTPERFORMS ALBUMIN-BILIRUBIN AND ALBUMIN-HEMOGLOBIN INDICES IN PREDICTING 30-DAY OUTCOMES FOLLOWING METASTATIC SPINAL TUMOR SURGERY: A NATIONAL DATABASE ANALYSIS

Abstract

Accurate preoperative risk stratification remains challenging in patients undergoing metastatic spinal tumor surgery (MSTS). While albumin-based indices have demonstrated prognostic utility across various surgical specialties, their performance following MSTSremains unexplored. The purpose of this study was to evaluate and compare the predictive utility of preoperative albumin level, albumin-bilirubin index (ALBI) score, and albumin-hemoglobin index (AHI) in for 30-day outcomes following MSTS. This retrospective analysis utilized the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database (2018 – 2023) to identify patients with disseminated cancer undergoing MSTS. The primary endpoint was 30-day mortality and the secondary endpoint was 30-day major complications (Clavien-Dindo Grade III or IV). Univariable and multivariable logistic regression analyses assessed associations between biomarkers and outcomes. Receiver operating characteristic (ROC) curves were generated to evaluate discriminative ability, with area under the curve (AUROC) values compared using DeLong’s test. Among 2,097 patients (mean age 63 years, 60% male), 30-day mortality and major complication rates were 8% and 20%, respectively. In multivariable analysis, only preoperative albumin maintained independent predictive value for 30-day mortality (OR 0.53 [95% CI 0.28 to 0.99]; p = 0.048) and major complications (OR 0.58 [95% CI 0.35 to 0.95]; p = 0.031). None of the biomarkers achieved good discrimination (AUROC ≥ 0.7), with albumin demonstrating the strongest performance for mortality (AUROC 0.68) and complications (AUROC 0.61). Pairwise comparisons showed albumin significantly outperformed both composite indices for 30-day major complications. Preoperative albumin level demonstrated superior discriminative ability compared to ALBI and AHI indices for predicting 30-day outcomes in spine metastases surgery, though overall predictive performance remained modest. These findings support continued use of simple albumin measurement while highlighting the need for more sophisticated risk stratification approaches incorporating cancer-specific variables in this complex patient population.