miRNA Biomarkers in Cyst Fluid Augment the Diagnosis and Management of Pancreatic Cysts

Abstract

Purpose The diagnosis of pancreatic cystic lesions has increased dramatically. Most are benign, whereas some, such as intraductal papillary mucinous neoplasms (IPMN), represent precursors of pancreatic adenocarcinoma. Therapeutic stratification of IPMNs is challenging without precise information on dysplasia grade and presence of invasion. We assessed the diagnostic benefit of using miRNAs as biomarkers in pancreatic cyst fluid, focusing on IPMNs because of their frequency and malignant potential. Experimental Design RNA was extracted from 55 microdissected formalin-fixed, paraffin-embedded (FFPE) IPMN specimens, and 65 cyst fluid specimens aspirated following surgical resection. Expression of 750 miRNAs was evaluated with TaqMan miRNA Arrays using 22 FFPE and 15 cyst fluid specimens. Differential expression of selected miRNA candidates was validated in 33 FFPE and 50 cyst fluid specimens using TaqMan miRNA Assays. Results We identified 26 and 37 candidate miRNAs that distinguish low-grade from high-grade IPMNs using FFPE and cyst fluid specimens, respectively. A subset of 18 miRNAs, selected from FFPE and cyst fluid data, separated high-grade IPMNs from low-grade IPMNs, serous cystadenomas (SCA) and uncommon cysts, such as solid pseudopapillary neoplasms (SPN) and cystic pancreatic neuroendocrine tumors (PanNET). A logistic regression model using nine miRNAs allowed prediction of cyst pathology implying resection (high-grade IPMNs, PanNETs, and SPNs) versus conservative management (low-grade IPMNs, SCAs), with a sensitivity of 89%, a specificity of 100%, and area under the curve of 1. Conclusions We found candidate miRNAs that helped identify patients with high-grade IPMN and exclude nonmucinous cysts. These classifiers will require validation in a prospective setting to ultimately confirm their clinical usefulness.

Cyst Fluid Biomarkers - Diagnosis and Prediction of Malignancy for Cystic Lesions of the Pancreas

“…Several studies have found that mRNA markers have a high sensitivity and specificity (>80%) for identifying cyst type and IPMNs with high-grade dysplasia or invasive pancreatic adenocarcinoma [17,18]. However, all the studies are single-center, retrospective studies with very few markers evaluated in more than one report.…”

Diagnosis and Management of Pancreatic Cystic Neoplasms

“…Chemical analysis of cyst fluid, in particular CEA level, was suggested by some groups to predict malignancy 36,37 but has not been reproducible. 19,38 Molecular assessment of cyst fluid (eg, DNA analysis for oncogenic KRAS or GNAS mutations and/or amplifications), 38,39 Kim & Fernandez-del Castillo microRNA (miRNA) profiling, 40 cytokine measurement (eg, of interleukin [IL]-1ß 41 and prostaglandin E 2 [PGE 2 ]), 42 and mucin proteomic profiling 43 may each improve prediction of malignancy but require further investigation. Overall, EUS/FNA is promising but prone to interobserver variability and operator dependency, should be performed in centers with expertise in these techniques, and requires further validation prior to widespread use.…”

Management and Outcome of 64 Patients with Pancreatic Serous Cystic Neoplasms

“…Cyst fluid may be used to detect high-risk IPMNs employing the Das-1 monoclonal antibody raised against a reactive premalignant colonic epithelial phenotype [35] . A 9 miRNA panel may also be able to distinguish high-grade IPMNs, PNETs and pseudopapillary neoplasms from low-grade IPMNs and SCNs [36] . Most recently cyst fluid VEGF-A levels were found to be significantly upregulated in test series of SCNs compared with other pancreatic cysts and with a cutoff of 8,500 pg/ml, VEGF-A had a 100% sensitivity and 97% specificity as an SCN biomarker [37] .…”