MicroRNA Expression Aids the Preoperative Diagnosis of Pancreatic Ductal Adenocarcinoma

Objectives: This study aimed to evaluate microRNA (miRNA) expression in pancreatic resection specimens and fine needle aspiration biopsies and determine which, if any, miRNAs aid the distinction between benign and malignant pancreatic tumors in limited cytology material. Methods: Resection specimens containing adenocarcinoma (n = 17), intraductal papillary mucinous neoplasms (n = 11), and nonneoplastic tissues (n = 15) were evaluated for miR-21, miR-221, miR-100, miR-155, and miR-181b expression by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), and a subset of carcinomas and intraductal papillary mucinous neoplasms was analyzed with miRNA microarrays. Cellblocks containing carcinoma (n = 26) or benign pancreatic lesions (n = 11) from fine needle aspiration biopsies were subjected to qRT-PCR for miR-21, miR-221, miR-181b, miR-196a, and miR-217. Results: Carcinomas showed higher expression of miR-21, miR-221, miR-155, miR-100, and miR-181b than benign lesions by qRT-PCR, and overexpression of miR-21, miR-221, and miR-181b was confirmed by microarray analysis. Cellblocks containing carcinoma showed higher expression of miR-21, miR-221, and miR-196a than those from benign lesions (P < 0.001, P = 0.009, and P < 0.001, respectively). Conclusions: Pancreatic ductal adenocarcinomas show differential expression of miRNAs compared to benign pancreatic lesions. A select panel of miRNAs aids the distinction between pancreatic lesions in cytology specimens.