MicroRNA from pancreatic duct aspirate differentiates cystic lesions of the pancreas.

INTRODUCTION

Prognostication for cystic neoplasms of the pancreas continues to evolve. Beyond simple size and cystic fluid CEA determination, microRNA (miRNA) detection holds great promise as molecular diagnostics for cancer risk. In this study, we sought to identify miRNAs that could predict malignant potential of pancreatic cystic lesions.

METHODS

RNA was harvested from the pancreatic duct aspirate of 72 cystic neoplasms of the pancreas. Samples with adequate RNA concentration (≥ 3 ng/μL) were selected for qRTPCR profiling using assays to 379 of the most common miRNAs. miRNA profiles were correlated with histopathology from resected specimens and grouped by benign (serous cystadenomas), premalignant (intraductal papillary mucinous neoplasms and mucinous cystadenomas), or malignant lesions (adenocarcinoma).

RESULTS

Adequate RNA for analysis was obtained from 42 (58.3 %) of the samples. Malignant lesions were more likely to have adequate RNA (n = 17, 81 %) than either benign (n = 6, 33 %) or premalignant lesions (n = 19, 59 %; p = 0.011). Nine miRNA were identified as differentially expressed between benign and premalignant/malignant lesions (p < 0.05). A significant correlation was found between the number of differentially expressed miRNA and the likelihood of a premalignant/malignant lesion. All premalignant or malignant lesions expressed at least one miRNA surpassing the threshold of mean miRNA expression, whereas no benign lesions had more than one miRNA surpassing the threshold.

CONCLUSIONS

The presence of RNA in the duct aspirate from patients with pancreatic cystic neoplasms may be a predictor of premalignancy or malignancy. miRNA may be utilized to further differentiate between benign, premalignant, and malignant cystic lesions of the pancreas.