EASIX Score as an Independent Prognostic Marker in De Novo Metastatic Pancreatic Cancer.

: Metastatic pancreatic ductal adenocarcinoma carries a dismal prognosis and there is an unmet need for simple, widely available prognostic biomarkers to guide risk stratification and treatment planning. This study aimed to evaluate whether baseline EASIX score, calculated from routine laboratory parameters (LDH, creatinine, platelet count), predicts overall survival (OS) in patients with de novo metastatic pancreatic cancer. : We performed a retrospective cohort study at a single tertiary center (Medical Oncology Department, Kocaeli University Faculty of Medicine) including 332 patients diagnosed with de novo metastatic pancreatic ductal adenocarcinoma between January 2019 and October 2025. Baseline EASIX was calculated using LDH, creatinine, and platelet count. Statistical analyses included ROC analysis with Youden index to determine exploratory cut-off, Kaplan-Meier survival estimation with log-rank test, and univariate and multivariate Cox proportional hazards regression to identify independent prognostic factors. The primary endpoint was OS, defined as time from initiation of first-line therapy to death from any cause. : A total of 332 patients were included. Median OS was 8.0 months overall. Patients with high EASIX (>2.505) had significantly shorter median OS compared with low EASIX patients (8.4 vs. 27.6 months, < 0.001). ROC analysis was considered exploratory for overall survival; therefore, an additional fixed-time (12-month mortality) ROC analysis was performed to provide a discrimination estimate accounting for censoring. The AUC for EASIX was 0.887 (95% CI: 0.816-0.958), and the exploratory cut-off determined was 2.505 (sensitivity 96.95%, specificity 72.97%). In multivariate Cox regression, high EASIX remained an independent predictor of worse OS (HR 4.124; 95% CI: 2.011-8.457; < 0.001) after adjustment for relevant covariates. : Baseline EASIX score is an independent prognostic marker for overall survival in de novo metastatic pancreatic cancer, based on routine laboratory tests, and may facilitate exploratory risk stratification. Prospective validation in independent cohorts is warranted before clinical implementation.