[1613] Reevaluation and Identification of the Best Immunohistochemical Panel for Adenocarcinoma of the Pancreas

F Lin, J Shi, HL Wang, H Liu. Geisinger Medical Center, Danville, PA; Cedard-Sinai Medical Center, Los Angeles, CA

Background: Differentiation of adenocarcinoma of the pancreas from non-neoplastic pancreatic tissues can be challenging, especially in small core biopsies, pancreatic surgical margins and fine needle aspiration specimens on cell blocks. Many tumor-associated markers have been reported in this regard; however, the reproducibility of these markers has not been tested and confirmed in one system. This study investigates the utility of 26 different immunohistochemical markers in the diagnosis of adenocarcinoma of the pancreas.
Design: We immunohistochemically evaluated the expression of 1) epithelial markers (CAM5.2, CK7, CK20, CK17, CK19), 2) mucin gene products (MUC1, MUC2, MUC4, MUC5AC, MUC6), 3) tumor suppressor genes and transcription factors (p53, Dpc4/SMAD4, CDX2, pVHL), and 4) tumor-associated proteins (S100P, KOC, maspin, mesothelin, claudin 4, claudin 18, annexin 8A, fascin, PSCA, MOC31, CEA, CA19-9), on 70 cases of pancreatic adenocarcinoma (20 conventional tissue sections and 50 tissue microarray sections). Non-neoplastic pancreatic tissue was present in 40 cases. The staining intensity was graded as weak or strong. The distribution was recorded as negative (<5% of tumor cells stained), 1+ (5-25%), 2+ (26-50%), 3+ (51-75%), or 4+ (>75%).
Results: The results demonstrated 1) over 90% of cases are positive for maspin, S100P and KOC; 2) all cases show loss of expression of pVHL in adenocarcinoma, whereas non-neoplastic ducts and acini are strongly positive for pVHL in all cases; 3) normal/reactive pancreatic ducts are frequently positive for CAM 5.2, CK7, CK19, MUC1, MUC6, CEA, MOC31, PSCA, mesothelin, annexin 8A, and claudin 4, claudin 18; 4) normal pancreatic ducts are usually negative for KOC, maspin, S100P, MUC2, MUC4, and MUC5AC; 5) 60% of cases show loss of expression of Dpc4/SMAD4; and 6) a strong staining background is frequently seen in fascin, PSCA, and annexin 8A.
Conclusions: Our data demonstrate that pVHL, maspin, S100P and KOC are the best diagnostic panel of markers for confirming the diagnosis of adenocarcinoma of the pancreas.
Category: Liver & Pancreas

Tuesday, March 23, 2010 1:00 PM

Poster Session IV # 204, Tuesday Afternoon


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