The sTRA Plasma Biomarker: Blinded Validation of Improved Accuracy Over CA19-9 in Pancreatic Cancer Diagnosis.


The CA19-9 biomarker is elevated in a substantial group of patients with pancreatic ductal adenocarcinoma (PDAC), but not enough to be reliable for the detection or diagnosis of the disease. We hypothesized that a glycan called sTRA (sialylated tumor-related antigen) is a biomarker for PDAC that improves upon CA19-9.

We examined sTRA and CA19-9 expression and secretion in panels of cell lines, patient-derived xenografts, and primary tumors. We developed candidate biomarkers from sTRA and CA19-9 in a training set of 147 plasma samples and used the panels to make case-control calls, based on predetermined thresholds, in a 50-sample validation set and a blinded, 147-sample test set.

The sTRA glycan was produced and secreted by pancreatic tumors and models that did not produce and secrete CA19-9. Two biomarker panels improved upon CA19-9 in the training set, one optimized for specificity, which included CA19-9 and 2 versions of the sTRA assay, and another optimized for sensitivity, which included 2 sTRA assays. Both panels achieved statistical improvement (<i>P</i> < 0.001) over CA19-9 in the validation set, and the specificity-optimized panel achieved statistical improvement (<i>P</i> < 0.001) in the blinded set: 95% specificity and 54% sensitivity (75% accuracy), compared with 97%/30% (65% accuracy). Unblinding produced further improvements and revealed independent, complementary contributions from each marker.

sTRA is a validated serological biomarker of PDAC that yields improved performance over CA19-9. The new panels may enable surveillance for PDAC among people with elevated risk, or improved differential diagnosis among patients with suspected pancreatic cancer.

  • Barnett D
  • Brand RE
  • Drake RR
  • Gao C
  • Haab BB
  • He Z
  • Hsueh P
  • Huang Y
  • Hurd MW
  • Liu Y
  • Maitra A
  • Partyka K
  • Singhi AD
  • Staal B
PubMed ID
Appears In
Clin Cancer Res, 2019, 25 (9)