Immunohistochemical Evaluation of GATA-3 Expression in ER-Negative Breast Carcinomas

AJCP / Original Article Immunohistochemical Evaluation of GATA-3 Expression in ER-Negative Breast Carcinomas Haiyan Liu, MD,1 Jianhui Shi, MD, PhD,1 Jeffrey W. Prichard, DO,1 Yun Gong, MD, PhD,2 and Fan Lin, MD, PhD1 From 1Geisinger Medical Center, Danville, PA; and 2The University of Texas M.D. Anderson Cancer Center, Houston. CME/SAM Key Words: ER negative; Breast carcinoma; GATA-3; GCDFP-15; Mammaglobin Am J Clin Pathol May 2014;141:648-655 DOI: 10.1309/AJCP0Q9UQTEESLHN ABSTRACT Objectives: Estrogen receptor (ER), gross cystic disease fluid protein 15 (GCDFP-15), and mammaglobin (MGB) are commonly used breast-specific immunomarkers; however, about half of metastatic breast carcinomas are negative for all three. GATA-binding protein 3 (GATA-3) has emerged recently as a sensitive and relatively specific immunomarker for breast and urothelial carcinomas, but the data documenting its expression in ER-negative breast carcinomas are limited; this often poses a dilemma in the setting of metastases. The purpose of this study is to investigate expression of GATA-3 in ER-negative breast carcinomas. Methods: Immunohistochemical evaluation of GATA-3, GCDFP-15, and MGB on 96 ER-negative breast carcinomas was performed. Results: Overall, 69% (66/96), 15% (14/96), and 35% (34/96) of ER-negative breast carcinomas expressed GATA-3, GCDFP-15, and MGB, respectively. Conclusions: Our data suggest that GATA-3 is, so far, the best breast-specific immunomarker, especially when encountering ER-negative metastatic breast carcinomas. GATA-3 should be included in the panel of immunomarkers in the workup of tumors of unknown primary. 648 Am J Clin Pathol 2014;141:648-655 Downloaded 648 from https://academic.oup.com/ajcp/article-abstract/141/5/648/1760868 DOI: 10.1309/AJCP0Q9UQTEESLHN by guest on 23 April 2018 Upon completion of this activity you will be able to: • list the immunomarkers commonly used to identify breast primary. • discuss the sensitivity and specificity of each of those immunomarkers. • apply those immunomarkers in their daily practice. The ASCP is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The ASCP designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 Credit ™ per article. Physicians should claim only the credit commensurate with the extent of their participation in the activity. This activity qualifies as an American Board of Pathology Maintenance of Certification Part II Self-Assessment Module. The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose. Questions appear on p 753. Exam is located at www.ascp.org/ajcpcme. In current practice, estrogen receptor (ER), gross cystic disease fluid protein 15 (GCDFP-15), and mammaglobin A (MGB) serve as breast-specific immunomarkers in the workup of tumors of unknown primary.1-5 However, the sensitivities for GCDFP-15 and MGB are reported in the ranges of 35% to 55% and 65% to 70%, respectively. Our unpublished data on tissue microarray (TMA) sections of 250 cases of invasive breast carcinomas, including ductal, lobular, and other special types, is even lower: 30% for GCDFP-15 and 50% for MGB, which is similar to the reports by Bhargava et al,2 who found GCDFP-15 expression in 23.1% and MGB expression in 55.4% of breast carcinomas, and by Lewis et al,5 who reported GCDFP-15 labeling of 37% and MGB labeling of 54% in breast carcinomas. The rate of ER-negative metastatic breast carcinoma is reported in the range of 40% to 52%.6-13 Given the frequent absence of expression of currently available breast-specific immunomarkers (such as ER, © American Society for Clinical Pathology AJCP / Original Article GCDFP-15, and MGB) in metastatic breast carcinomas, studies to discover newer breast-specific immunomarkers were undertaken. NY-BR-1 and GATA-binding protein 3 (GATA3) are among the most promising immunomarkers. NY-BR-1 is a mammary differentiation antigen expressed in normal mammary tissue and its malignant counterpart, with a predominantly cytoplasmic staining pattern. Its mRNA expression on reverse transcriptase polymerase chain reaction is restricted to carcinomas of the breast, testis, and prostate.14-16 Its expression in breast carcinomas was reported as 58.4% by Woodard et al17 and 46.6% by Balafoutas et al18; however, NY-BR-1 expression is strongly associated with ER expression in both studies. Its expression in ER-negative breast carcinomas was reported as much lower, 18% and 28.4%, respectively. GATA-3 is one of six members of a subfamily of zinc finger transcription factors, plays an important role in cell-fate specification, and has recently emerged as a critical determinant of luminal epithelial cell differentiation in the adult mammary gland. GATA-3 is highly expressed in luminal A breast carcinomas.19,20 Previously, we had studied GATA-3 expression in 1,110 cases of various human carcinomas and 310 cases of normal tissues using immunohistochemical analysis of TMA sections. We concluded that GATA-3 is a sensitive and specific marker for breast and urothelial carcinomas.21 In the current study, we used immunohistochemical analysis to further investigate the expression of GATA-3 in 96 ER-negative breast carcinomas, including 49 TMA cases and 47 consecutive core needle biopsy (CNB) specimens. In addition, immunoassays of GCDFP-15 and MGB were also performed for comparison. The aims of this study are to investigate the expression of GATA-3 in ER-negative breast carcinomas, to compare it with other breast-specific markers, and ultimately to evaluate its diagnostic usefulness as a breast-specific immunomarker in the workup of tumors of unknown primary. previously described.22,23 The ER-negative status is defined by ER immunostaining on TMA sections using the current guideline (<1%). The tumor grading is based on the Nottingham combined histologic grade (Elston-Ellis modification of Scarff-Bloom-Richardson grading system). CNB Cases Forty-seven consecutive ER-negative CNB cases were retrieved from the archives of the Department of Laboratory Medicine at Geisinger Medical Center from 2010 to 2011, including IDC grade 2 (n = 8), IDC grade 3 (n = 30), metaplastic carcinomas (n = 4), carcinoma with medullary features (n = 1), and carcinoma with apocrine features (n = 4). Thirty-seven cases were Her2/neu negative and 10 were Her2/neu positive. Immunohistochemical Analysis Immunohistochemical analysis was performed to study GATA-3 (Biocare Medical, Concord, CA), GCDFP-15 (Cell Marque Corp, Rocklin, CA), and MGB (Ventana Medical Systems, Tucson, AZ) expression in 49 TMA and 47 CNB specimens of ER-negative breast carcinomas. The Dako staining system (1:25 dilution, ethylenediaminetetraacetic acid antigen retrieval, and 45-minute incubation for primary antibody; Dako, Carpinteria, CA) was used as described previously.24,25 T (...truncated)