Please note - GATA3 is not as specific as originally reported (see below). Also, the staining can be variable, ranging from 5% to 100%. In breast cancers, the degree of staining should parallel the ER staining. Thus, if a possible breast cancer is strongly positive for GATA3 but negative or only focally/weakly positive for ER, consider additional stains to evaluate for possible ovary or endometrial cancers.
- GATA3 staining is found in urothelial tumors (76- 100% of urothelial cancers are GATA3 positive, per reports in literature); GATA3 is less specific but is more sensitive than uroplakin III
- GATA3 can be used to identify urothelial carcinoma, in particular when metastatic, with a higher sensitivity and specificity than either p63 or uroplakin III. This antibody is useful in a panel with PSA and PSAP to discriminate bladder from prostate cancer
- Signet ring cell adenocarcinomas / plasmacytoid carcinomas of the bladder will also stain for GATA3 (57-100%)
- GATA3 will also stain urothelial cells in Brenner tumors of the ovary, and cystic Walthard rests of the fallopian tube.
- GATA3 staining is found in >90% of breast cancers; the staining is in luminal epithelium, not in myoepithelial cells
- GATA3 has comparable specificity but is more sensitive as a breast cancer marker than GCDFP-15 and mammaglobin, and can be used to discriminate lung cancers from breast cancers
- GATA3 will stain T lymphocytes
- Recent articles are showing that other cancers can show more than 30% staining for GATA3, including squamous cell carcinomas and malignant mesotheliomas
- Approximately 37% of pancreatic adenocarcinomas will show positive staining for GATA3, and some renal cell carcinomas will also show positive staining (51% of chromophobe carcinomas)
- Lung adenocarcinomas can rarely show GATA3 staining (8%), as can carcinomas of the endometrium, stomach and ovary
- GATA3 staining has been reported in normal, hyperplastic and neoplastic parathyroid tissue
- Salivary gland tumors have been reported to stain for GATA3
- Some cervical and anal squamous cell carcinomas can show focal weak staining
- GATA3 has also been identified in >90% of trophoblastic and endodermal sinus tumors
- GATA3 has also been described as expressed in paragangliomas, which can be found near the bladder
- GATA3 is highly sensitive and specific for identifying mesonephric lesions in the lower genital tract.
- This marker can also be seen in basal cell carcinomas, apocrine carcinomas of the skin, and skin adnexal tumors.