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Immunohistochemical Labeling for the Dpc4 Gene Product Is a Specific Marker for Adenocarcinoma in Biopsy Specimens of the Pancreas and Bile Duct

Metin Tascilar MD, G. Johan A. Offerhaus MD, Renee Altink MD, Pedram Argani MD, Taylor A. Sohn MD, Charles J. Yeo MD, John L. Cameron MD, Michael Goggins MD, Ralph H. Hruban MD, Robb E. Wilentz MD
DOI: http://dx.doi.org/10.1309/WF03-NFCE-7BRH-7C26 831-837 First published online: 1 December 2001


We immunohistochemically labeled 72 biopsy specimens from the extrahepatic biliary tree and pancreas for Dpc4 protein and correlated expression with histologic diagnosis and patient follow-up. Specimens were classified histologically as follows: nonneoplastic, 35; neoplastic, 22; atypical, 15. Loss of expression of Dpc4 protein was identified in 12 specimens; 11 were histologically diagnostic of carcinoma. The 12th specimen was from a patient whose biopsy specimen initially was diagnosed as “atypical,” but clinical follow-up revealed adenocarcinoma. Of the 12 atypical biopsy specimens with intact expression for Dpc4, follow-up later revealed that 10 were adenocarcinoma. Loss of expression of Dpc4 protein was never identified in a benign specimen.

Immunohistochemical labeling for the Dpc4 gene product is a specific marker of carcinoma in biopsy specimens of the pancreas and extrahepatic bile ducts and is marginally helpful in classifying atypical specimens. The sensitivity for carcinoma is low. This latter finding is not unexpected, because the DPC4 tumor suppressor gene is inactivated in only about half of pancreatic and biliary malignant neoplasms. Importantly, loss of Dpc4 expression has been reported in in situ carcinomas, suggesting that loss of expression should not be equated with invasive carcinoma.

Key Words:
  • Pancreas
  • Bile duct
  • Adenocarcinoma
  • Dpc4
  • Immunohistochemistry
  • Tumor suppressor