Plectin-1 is a biomarker of malignant pancreatic intraductal papillary mucinous neoplasms.

INTRODUCTION: Pancreatic intraductal papillary mucinous neoplasms (IPMN) are now identified with increasing frequency. The detection of carcinoma in IPMN is difficult and suffers from high false-positive and false-negative rates, often resulting in inappropriate treatment decisions. Improved detection of malignancy using novel biomarkers may therefore improve diagnostic accuracy. One such promising novel biomarker is Plectin-1 (Plec-1).
METHODS: Using immunohistochemistry, Plec-1 expression was assayed in benign (low and moderate dysplasia, n = 6) as well as malignant IPMN (high-grade dysplasia and invasive carcinoma, n = 31) and lymph node metastases from carcinoma arising in IPMN (n = 12). Furthermore, cyst fluids from benign (n = 3) and malignant IPMN (n = 4) were evaluated for Plec-1 expression. RESULTS AND DISCUSSION: Twenty-six of 31 malignant IPMN and all 12 lymph node metastases were Plec-1 positive. In contrast, only one of six benign IPMN expressed Plec-1. The specificity of Plec-1 in distinguishing malignant IPMN from benign IPMN was 83% and its sensitivity 84%. Furthermore, all (four out of four) cyst fluids from malignant IPMN, but none of the three benign IPMN, were Plec-1 positive. These data support Plec-1 as an excellent biomarker for the early detection of carcinoma arising in IPMN.