[201] Identification of an Effective Immunohistochemical Panel in Distinction of Breast Carcinoma from Endometrial Adenocarcinoma

Haiyan Liu, Jeffrey Prichard, Fan Lin. Geisinger Medical Center, Danville, PA

Background: When working on a tumor of unknown origin, breast carcinoma (BCA) versus endometrial adenocarcinoma (EDAC) may present a diagnostic challenge because of the overlapping morphological features and immunostaining profile. In this study, we re-evaluate the expression of an extensive panel of biomarkers including recently described markers GATA3, Trefoil factor 1 (TFF1), Trefoil factor 3 (TFF3) and PAX8 using a single immunostaining system (Dako).
Design: We immunohistochemically evaluated the expression of 1) epithelial markers (AE1/3, CAM5.2, CK7, CK20, CK17, CK19, CK903, EMA); 2) mucin gene products (MUC1, MUC2, MUC4, MUC5AC, MUC6); 3) tumor suppressor genes and transcription factors (ER, PR, p53, beta-catenin, WT-1, CDX2, pVHL); and 4) tumor-associated proteins (TTF-1, napsin A, GATA3 [Santa Cruz; Sc-268], TFF1 [Epitomics; AC-0045], TFF3, FOXA1, ERG, HepPar1, glypican 3, SALL4, OCT4, PAX2, PAX8, RCC GCDFP-15, mammaglobin, S100P, IMP3, maspin, MOC31, CEA, CA19-9, CA125, CD10, CD15, villin, and P504S) on 146 cases of breast carcinoma (98 ductal carcinomas and 48 lobular carcinomas) and 58 cases of endometrial adenocarcinoma on tissue microarray sections. 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 positive staining results from selected antibodies, which demonstrated diagnostic value, are summarized in Table 1. When combining ductal and lobular carcinomas, the positive staining results for GATA3 and TFF1 were 95% and 77%, respectively, with a strong and diffuse staining (3+ or 4+) in 131 cases (90%) and 79 cases (56%), respectively. For endometrial adenocarcinomas, 50 cases (88%) were strongly and diffusely (3+ or 4+) positive for PAX 8, and 36 cases (69%) were strongly and diffusely (3+ or 4+) positive for vimentin.

Table 1. Summary of immunostaining results on selected antibodies
AntibodyBreast DCABreast LCAEDAC
GATA390/98 (92%)48/48 (100%)2/58 (3%)
TFF168/95 (72%)41/47 (87%)4/58 (7%)
PAX80058/58 (100%)
p1614/98 (14%)057/58 (98%)
Vimentin3/97 (3%)2/48 (4%)52/58 (90%)
DCA-ductal carcinoma; LCA-lobular carcinoma; EDAC-endometrial adenocarcinoma

Conclusions: These data demonstrate that GATA3, TFF1, PAX8, p16 and vimentin are the most effective diagnostic panel for distinguishing breast carcinoma from endometrial adenocarcinoma.
Category: Breast

Monday, March 19, 2012 1:00 PM

Poster Session II # 54, Monday Afternoon


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