PGE₂ in Pancreatic Cyst Fluid Helps Differentiate IPMN from MCN and Predict IPMN Dysplasia

Current management of intraductal papillary mucinous neoplasm (IPMN) according to recently published International Consensus Guidelines depends upon distinguishing it from mucinous cystic neoplasms (MCNs). We have previously shown that prostaglandin E₂ (PGE₂) is increased in pancreatic cancer tissue over normal controls. Thus, we hypothesized that PGE₂ level in pancreatic fluid differentiates IPMN and MCN and is a biomarker of IPMN dysplasia. Pancreatic fluid was collected in 65 patients at the time of endoscopy (EUS or ERCP) or operation (OR) and analyzed by PGE₂ enzyme-linked immunosorbent assay (ELISA). PGE₂ level was correlated with surgical pathologic diagnosis and dysplastic stage. Mean PGE₂ level (pg/μl) in IPMNs (2.2 ± 0.6) was greater than in MCNs (0.2 ± 0.1) (p < 0.05). Mean PGE₂ level of IPMN by dysplastic stage was 0.1 ± 0.01 (low grade), 1.2 ± 0.6 (medium grade), 4.4 ± 0.9 (high grade), and 5.0 ± 2.3 (invasive). Among invasive IPMN, PGE₂ level dropped in advanced cases with pancreatic ductal obstruction by tumor (0.3 ± 0) vs non-obstructed (8.6 ± 2.9). PGE₂ level may help in distinguishing IPMN from MCN in patients with known mucinous lesions. PGE₂ level may also be an indicator of malignant progression of IPMN before ductal obstruction by tumor. Prospective evaluation will be necessary to evaluate the clinical role of PGE₂ level in pancreatic fluid.