Novel Biomarker Panels Discriminating between Pancreatic Ductal Adenocarcinoma and Extrahepatic Bile Duct Carcinoma.

OBJECTIVE: Pancreatic ductal adenocarcinoma (PDAC) and extrahepatic bile duct carcinoma (EBDC) are distinct entities with different clinicopathological implications. Therefore, research to differentiate between the two diseases is compulsory. In this study, four biomarkers were selected (Hippocalcin-like 1 (HPCAL1); annexin A10 (ANXA10); MUC5AC; sodium/potassium-transporting ATPase subunit beta-1 (ATP1B1)) and focus was placed on clarifying the diagnostic performance of each biomarker and pioneering novel-combined biomarker panels to discriminate between PDAC and EBDC. PROCEDURES: An immunohistochemical microarray analysis of HPCAL1, ANXA10, MUC5AC, and ATP1B1 was conducted for surgically resected 55 PDACs and 77 EBDCs. The diagnostic performance discriminating between PDAC and EBDC was evaluated using four biomarkers and the combined biomarker panels. RESULTS: PDACs exhibited more positive expressions for HPCAL1, ANXA10, and MUC5AC, whereas EBDCs exhibited more ATP1B1-positive expressions. The PDAC panel with the best diagnostic performance was the profile of (+ in ≥ 2 among HPCAL1, ANXA10, MUC5AC)/ATP1B1-. The immunophenotype pattern of (- in ≥ 1 among HPCAL1, ANXA10, MUC5AC)/ATP1B1+ is the EBDC panel with the most excellent discriminating power. CONCLUSION: The suggested combined biomarker panels demonstrate the distinguishing diagnostic ability between PDAC and EBDC is better than previous studies. Therefore, for differentiation between PDAC and EBDC, these panels are expected to help unravel the clinicopathological enigma as promising biomarker panels in the future.