A multi-stage prospective study evaluates serum metabolomic signatures for the differential diagnosis and prognostic stratification of PDAC

Serum metabolomics identifies novel biomarkers for PDAC diagnosis and prognosis. • A specific 4-metabolite panel distinguishes PDAC from chronic pancreatitis. • Combining these four metabolites with CA19-9 achieves a diagnostic AUC of 0.999. • The metabolic signature offers prognostic value independent of clinical stage. Background Pancreatic ductal adenocarcinoma (PDAC) lacks biomarkers for accurate diagnosis and prognostic stratification. The standard, CA19-9, has suboptimal specificity in differentiating PDAC from mimics like chronic pancreatitis (CP). We investigated serum metabolomic signatures to address these challenges. Methods We conducted a prospective, multi-cohort (n = 221) untargeted metabolomics study, analyzing PDAC (n = 66), healthy control (n = 92), other cancer (n = 40), and CP (n = 23) groups. Machine learning and survival analysis were employed to build diagnostic and prognostic models from serum samples collected at diagnosis. Results A two-metabolite panel distinguished PDAC from other cancers (AUC=0.894), and a five-metabolite signature showed high discrimination between PDAC and CP (AUC=0.998; 95% CI, 0.993–1.000). A leakage-resistant nested cross-validation sensitivity analysis yielded a mean AUC of 0.955 (SD, 0.020). The exploratory 18-metabolite risk score separated high- and low-risk groups and remained associated with overall survival after adjustment for stage, age, sex, and CA19-9 (adjusted HR, 3.94; 95% CI, 2.05–7.58; P < 0.001), with a C-index of 0.601. Conclusions Serum metabolomic profiles identified compact candidate panels that provided information complementary to CA19-9 for PDAC differential diagnosis, while the 18-metabolite risk score was associated with overall survival. These findings support targeted assay development and prospective multicenter evaluation of serum metabolomics for the clinical characterization of PDAC. Schematic: overview of the study design and analytical workflow. The study was conducted in three sequential phases. Phase 1 (Establishing a Baseline Metabolic Profile): the PC-a cohort (n = 33) was compared with healthy controls (HC, n = 92), identifying 17 annotated differential metabolites. Phase 2 (Exploratory Diagnostic Specificity): a separately enrolled single-center PC-b cohort (n = 33) was compared with other cancers (OC, n = 40) and chronic pancreatitis (CP, n = 23), yielding a two-metabolite candidate panel for PDAC versus OC and a five-metabolite candidate panel for PDAC versus CP. Phase 3 (Exploratory Prognostic Association): PC-a and PC-b were combined (n = 66; 59 deaths) to examine metabolic heterogeneity and an exploratory 18-metabolite risk score. Collectively, these sequential single-center cohorts supported discovery and internal evaluation. Download: Download high-res image (389KB) Download: Download full-size image