Aberrant Expression of cdx2 Homeobox Gene in Intraductal Papillary- Mucinous Neoplasm of the Pancreas But Not in Pancreatic Ductal Adenocarcinoma

OBJECTIVES: The authors investigated differential expression of cdx2 in intraductal papillary mucinous neoplasm of the pancreas (IPMN) and ductal adenocarcinoma. METHODS: Patients with IPMN (n = 23) and pancreatic ductal adenocarcinoma (n = 30) were studied. Expression of cdx2 mRNA, CDX2 protein, muc2 mRNA, MUC2 apomucin, and MUC5AC apomucin were determined. RESULTS: Of 23 IPMN, expression of cdx2 was detected in 8 of 9 adenomas, 6 of 8 borderline malignancies, and 3 of 6 malignancies, respectively. Of the 3 cdx2-expressing malignant IPMN, 2 did not display CDX2 expression. The appearance of CDX2-positive neoplastic cells in IPMN coincided with that of MUC2-positive neoplastic cells. All 23 IPMN displayed a positive MUC5AC expression irrespective to the status of CDX2 expression. Of 30 ductal adenocarcinomas, none displayed cdx2, CDX2, and MUC2 expression, while 10 cases displayed positive MUC5AC expression. CONCLUSION: Aberrant expression of cdx2 homeobox gene was detected in IPMN but not in ductal adenocarcinoma, which might determine their diverse carcinogenesis.