Pancreatic juice collection is performed by intravenous injection of FDA approved synthetic human secretin (ChiRhoClin Inc., Burtonsville, MD) at a dose of 0.2 µg/kg will be administered while the endoscope is positioned in the second portion of the duodenum. From within the duodenum and without cannulation of the papilla of Vater, a 2.3-mm plastic aspiration catheter (Olympus, Tokyo, Japan) will be passed through the biopsy channel of the endoscope until visible on screen in the endoscopic monitor. Once active visible secretion via the papilla has begun, the first 10 ml of pancreatic juice will be collected via suctioning. This entire process from secretin injection to sample collection takes an average of 5 minutes. The sample is then aliquoted into 2 ml ampules, which are snap-frozen in liquid nitrogen (or portable rapid-freeze freezer) and freezer-stored until the assays are performed. The top 10 candidate markers from discovery and validation on tissue (AUCs \>0.95) and from pilot pancreatic-juice testing (AUCs \>0.9) will be evaluated in this study. Following extraction from an equivalent of 0.4 ml pancreatic juice, DNA will be bisulfite treated using optimized methods. Then, an assay of aberrant methylation on target genes will be conducted using the QuARTS technique. Results will be normalized to either a human DNA marker (eg, beta-actin) or a methylated DNA marker identified for normal pancreatic epithelium.
