Global 
Deutschland Pancreas
Gastroenterology. 2026;170(2):375-384
Validation of a serum-based biomarker signature for detection of early-stage pancreatic ductal adenocarcinoma
Background and aims: This study’s goal was to clinically validate the performance of a serum biomarker signature composed of tissue inhibitor of metalloproteinase 1, intercellular adhesion molecule 1, cathepsin D, thrombospondin 1, and carbohydrate antigen 19-9 for detection of early-stage pancreatic ductal adenocarcinoma (PDAC) in an independent cohort.
Methods: Signature analytes were retrospectively measured in serum samples from a blinded cohort of stage I and stage II PDAC cases and genetic and/or familial high-risk controls. A predictive signal for PDAC was generated from a predefined cutoff established in a previous model development study optimized at 98% specificity. Diagnostic sensitivity and specificity were evaluated on the full cohort. McNemar or 2-proportion z tests were used to compare test performance between stage I and stage II cases, and between controls with and without a germline mutation and/or familial susceptibility to PDAC. Diagnostic certainty of test results was evaluated using a Monte Carlo simulation.
Results: Biomarker signature distinguished early-stage PDAC (n = 202) from high-risk controls (n = 864) with 78.5% sensitivity (95% CI: 72.5–83.9%) and 93.5% specificity (95% CI: 91.9–95.2%), significantly outperforming carbohydrate antigen 19-9 alone (p < 0.001). The test performed consistently between stage I and II PDAC and between controls with and without genetic or familial susceptibility. In addition, 93.7% of all samples were classified as PDAC-positive or PDAC-negative with 100% certainty. Only 1.8% of all samples were classified with < 80% certainty.
Conclusions: These findings indicate that this biomarker signature is a high-performing biomarker test to aid in the detection of early-stage PDAC. Overall, this work represents an important step toward improving early-stage diagnostic success.