• Loss of DPC4 expression by IHC provides evidence for the pancreaticobiliary tract as the origin of the tumor (approximately 60% of pancreatic tumors will show loss of this marker)
• Primary ovarian mucinous tumors have not been shown to exhibit loss of expression
• Retained expression of this marker neither confirms nor refutes a diagnosis of metastatic pancreaticobiliary carcinoma, since 39% of these tumors will be positive for this marker
• Loss of DPC4 has in pancreatic ductal carcinoma has been shown to be an independent and significant poor prognostic factor for overall and disease-free survival

References:

1. Meriden Z et al: Ovarian metastases of pancreaticobiliary tract adenocarcinomas: analysis of 35 cases, with emphasis on the ability of metastases to simulate primary ovarian mucinous tumors. Am J Surg Pathol 2011;35:266-288.
2. Oshima M et al: Immunohistochemically detected expression of 3 major genes (CDKN2A/p16, TP53, and SMAD4/DPC4) strongly predicts survival in patients with resectable pancreatic cancer. Ann Surg. 2013 Aug;258(2):336-46. doi: 10.1097/SLA.0b013e3182827a65.
3. Shin SH et al: Genetic alterations of K-ras, p53, c-erbB-2, and DPC4 in pancreatic ductal adenocarcinoma and their correlation with patient survival. Pancreas. 2013 Mar;42(2):216-22. doi: 10.1097/MPA.0b013e31825b6ab0.
4. Pinto PB et al: Metastatic mucinous carcinomas in the ovary: a practical approach to diagnosis related to gross aspects and to immunohistochemical evaluation. Int J Gynecol Pathol. 2012 Jul;31(4):313-8. doi: 10.1097/PGP.0b013e31823f844d.
5. Nakanishi Y et al: Expression of cell cycle-related molecules in biliary premalignant lesions: biliary intraepithelial neoplasia and biliary intraductal papillary neoplasm. Hum Pathol. 2008 Aug;39(8):1153-61. doi: 10.1016/j.humpath.2007.11.018. Epub 2008 May 20.