title: Comparative Sensitivities and Specificities of Antibodies to Breast Markers GCDFP-15, Mammaglobin A, and Different Clones of Antibodies to GATA-3: A Study of 338 Tumors Using Whole Sections.
abstract: GATA-3 is a transcription factor that has recently been identified by immunohistochemistry to be highly expressed in urothelial and breast carcinomas (CAs). We sought to determine the potential utility of GATA-3 in identifying metastatic breast CA, and to compare its utility with the standard breast markers, GCDFP-15, and mammaglobin A. We identified an archival series of 338 formalin-fixed paraffin-embedded whole-tissue sections of various CAs. Using standard immunohistochemical (IHC) techniques we used mouse monoclonal antibodies to GATA-3 (clones L50-823, HG3-31), GCDFP-15 (23A3), and mammaglobin A (31A5). Both clones of GATA-3 showed positivity in 96% of non-triple-negative breast carcinomas (TNBCs), L50-823 and HG3-31, demonstrating expression in 87% and 63% of TNBCs, respectively; GCDFP-15 and mammaglobin A were expressed in 69% and 61% of non-TNBCs, respectively, and 10% and 17%, of TNBCs, respectively. The L50-823 clone manifested a lower specificity in identifying breast CAs (84%) than did the HG3-31 clone (97%). Both monoclonal antibodies to GATA-3 are very sensitive reagents for the identification of breast CA, surpassing antibodies to GCDFP-15 and mammaglobin A, and offer a significant improvement in identifying TNBCs. However, the L50-823 clone showed a lower level of specificity, which may qualify its utility in the setting of CAs of unknown primary.
authors.affiliation: *The PhenoPath Laboratories PLLC †Pacific Pathology Partners ‡CellNetix Pathology and Laboratories, Seattle, WA.
authors.forename: Patricia L
authors.initials: PL
authors.lastname: Kandalaft
authors.forename: Rochelle A
authors.initials: RA
authors.lastname: Simon
authors.forename: Christina
authors.initials: C
authors.lastname: Isacson
authors.forename: Allen M
authors.initials: AM
authors.lastname: Gown
mesh_terms: D000918:Antibody Specificity; D014408:Biomarkers, Tumor / Q000276:immunology*; D001943:Breast Neoplasms / Q000276:immunology* / Q000473:pathology; D002352:Carrier Proteins / Q000276:immunology*; D005260:Female; D005557:Formaldehyde; D050990:GATA3 Transcription Factor / Q000276:immunology*; D006023:Glycoproteins / Q000276:immunology*; D006801:Humans; D007150:Immunohistochemistry; D060785:Mammaglobin A / Q000276:immunology*; D026901:Membrane Transport Proteins; D016612:Paraffin Embedding
chemical_list: D014408:Biomarkers, Tumor; D002352:Carrier Proteins; D050990:GATA3 Transcription Factor; C494749:GATA3 protein, human; D006023:Glycoproteins; D060785:Mammaglobin A; D026901:Membrane Transport Proteins; C488892:PIP protein, human; D005557:Formaldehyde