1. ¹Department of Pathology, Min-Sheng General Hospital, Taoyuan City, Taiwan, ROC
2. ²Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan, ROC
3. ³Department of Dentistry, College of Medicine, National Taiwan University, Taipei, Taiwan, ROC
4. ⁴Department of Pathology, National Taiwan University Hospital, and Department of Pathology, College of Medicine, National Taiwan University, Taipei, Taiwan, ROC

Correspondence: Dr Y-M Jeng, MD, Department of Pathology, College of Medicine, National Taiwan University Hospital, National Taiwan University, 7, Chung-Shan South Road, Taipei, Taiwan, ROC. E-mail: mrna0912@yahoo.com.tw

Received 28 January 2008; Revised 13 May 2008; Accepted 18 May 2008; Published online 13 June 2008.

Abstract

Cadherin-17, also called liver-intestine cadherin, is a calcium-dependent transmembrane glycoprotein that mediates cell–cell adhesion in intestinal epithelium. Expression of cadherin-17 was reported in gastric, pancreatic, and colorectal adenocarcinomas but not in other tumors. Whether cadherin-17 can be used as a marker for diagnosis of cancers is still unclear. In this study, we used immunohistochemical methods to stain cadherin-17 in tissue arrays containing most normal tissues and 518 carcinomas from many anatomic sites. Among normal tissues, the expression of cadherin-17 was limited to epithelial cells of small intestine and colon. Colorectal adenocarcinomas showed staining in 96% of cases and most of them had strong and diffuse staining. Gastric, pancreatic, and biliary adenocarcinomas showed diffuse or scattered staining in about 25–50% of cases. Fewer than 1% of carcinomas outside the digestive system were positive for cadherin-17. When a two-marker, Cadherin-17/cytokeratin 7, profile was used, 37 of 38 (97%) cadherin-17(+)/cytokeratin 7(-) tumors were colorectal adenocarcinomas; 49 of 56 (86%) cadherin-17(+)/cytokeratin 7(+) tumors were gastric, pancreatic, or biliary adenocarcinomas. Our results show that cadherin-17 is a useful immunohistochemical marker for diagnosis of adenocarcinomas of the digestive system.