Improved Diagnosis of Pancreatic Adenocarcinoma Using Haptoglobin and Serum Amyloid A in a Panel Screen

Timely, accurate diagnosis of pancreatic adenocarcinoma (PA) is hampered by the lack of effective circulating biomarkers. No single test has emerged that improves upon the commonly used biomarker cancer antigen 19–9 (CA 19–9) to discriminate PA from benign conditions effectively. The goals of this study were to validate two acute-phase proteins, haptoglobin and serum amyloid A (SAA), as biomarkers for PA and determine if the combination of haptoglobin, SAA, and CA 19–9 would improve PA diagnosis over CA 19–9 alone. Levels of haptoglobin, SAA, and CA 19–9 were measured in pretreatment sera from 75 PA patients, 32 patients with chronic pancreatitis, 42 patients with other benign pancreatic disease or biliary stricture, and 150 healthy control subjects by enzyme-linked immunosorbent assay or colorimetric binding assay. Relative levels of haptoglobin or SAA were compared between groups using analysis of variance. The diagnostic accuracy of serum haptoglobin and SAA levels were investigated using receiver operating characteristics (ROC) analysis. Using classification tree analysis, an algorithm was developed that used haptoglobin, SAA, and CA 19–9 in a diagnostic screening panel. Both haptoglobin and SAA were significantly elevated in sera from PA patients compared to healthy control subjects (p