The diagnostic and prognostic value of MRP8/MRP14 in intrahepatic cholangiocarcinoma

Myeloid-related protein 8 (MRP8) and 14 (MRP14) are abundantly expressed in several kinds of benign and malignant tumors. However, little is known about their clinicopathological significance in intrahepatic cholangiocarcinoma (ICC), biliary intraepithelial neoplasia (BilIN), intraductal papillary neoplasm of bile duct (IPNB), or inflammatory hepatic biliary ducts epithelium (IHBD). This study aimed to investigate the diagnostic and prognostic values of MRP8 and MRP14 as new biomarkers for ICC. We examined MRP8 and MRP14 expression levels by immunohistochemistry in IHBD (n = 15), BilIN (BilIN1 = 24, BilIN2 = 9, BilIN3 = 5), IPNB (n = 18) and ICC (n = 416). The differential diagnostic and prognosis values were also evaluated. The results showed that the ratio of tumor-infiltrating MRP8 and MRP14 positive immune cells, relative to biliary epithelial cells, was significantly increased in ICC tissues compared with nonmalignant tissues, including IHBD, BilIN1, BilIN2, BilIN3, and IPNB (P value < 0.05). In addition, over-expression levels of MRP8 and MRP14 were correlated with overall survival (OS) and time to recurrence (TTR) by univariate analysis; MRP8/MRP14 combination was an independent prognostic factor for OS and TTR. MRP8 and MRP14 expression might help to identify the benign bile duct diseases from ICC, as high expression of MRP8 and MRP14 suggests a poor prognosis after surgical resection.