GATA3 is a protein that pathologists stain for in tissue samples, using a test called immunohistochemistry. It is best known as a marker of breast and bladder (urothelial) cancers, but it also helps tell sarcomatoid mesothelioma apart from sarcomatoid lung carcinoma and other spindle-cell cancers.
Origin
GATA3 is a transcription factor, a protein that switches genes on, named for the DNA sequence G-A-T-A that it binds. Antibodies to it entered routine pathology as a marker for breast and urothelial carcinomas, and studies in the 2010s reported that it is often positive in sarcomatoid mesothelioma.
Significance in Asbestos Context
Sarcomatoid mesothelioma is the hardest subtype to diagnose: its spindle-shaped cells look like many other tumors, and they often lose the usual mesothelial markers such as calretinin and WT1. Pathologists therefore use a panel of stains. Keratin staining helps show the tumor is a mesothelioma or carcinoma rather than a true sarcoma, and GATA3 positivity, together with other findings, favors mesothelioma over sarcomatoid lung carcinoma, which is usually GATA3-negative. No single stain is decisive: GATA3 is also positive in breast and urothelial cancers, so a positive result must be read in context, and some sarcomatoid mesotheliomas are negative. In a case, the stain panel listed on the pathology report is often what a defense pathologist challenges when arguing that a tumor is not mesothelioma, so it matters that the panel was complete and reviewed by a pathologist experienced with mesothelioma.
Example Sentence
The tumor was keratin-positive with diffuse GATA3 staining, which, along with loss of BAP1, supported sarcomatoid mesothelioma over sarcomatoid lung carcinoma.
Related Terms
Immunohistochemistry, Sarcomatoid, Calretinin, Wilms Tumor 1 (WT-1), Broad-spectrum Cytokeratin, Podoplanin (D2-40), Pathology Review, HEG1
Notes
- Ask for the full pathology report, including the list of stains and results, not just the final diagnosis.
- In difficult cases, a second review by a pathologist experienced with mesothelioma is common.
- Tell the pathologist about any past breast or bladder cancer; it affects how GATA3 is read.
In the research library
15 studies in our medical research library mention GATA3 in the title or abstract. Among the most cited:
- GATA3: a multispecific but potentially useful marker in surgical pathology: a systematic analysis of 2500 epithelial and nonepithelial tumorsM. Miettinen, P.A. McCue, M. Sarlomo-Rikala, et al, 2014 · The American Journal of Surgical Pathology · cited 542 times
- GATA3 Immunohistochemistry for Distinguishing Sarcomatoid and Desmoplastic Mesothelioma From Sarcomatoid Carcinoma of the LungK.B. Berg, A. Churg, 2017 · The American Journal of Surgical Pathology · cited 54 times
- The potential utility of GATA binding protein 3 for diagnosis of malignant pleural mesotheliomasS. Prabhakaran, A. Hocking, C. Kim, et al, 2020 · Human Pathology · cited 24 times
- Evaluation of androgen receptor and GATA binding protein 3 as immunohistochemical markers in the diagnosis of metastatic breast carcinoma to the lungY. Hattori, A. Yoshida, M. Yoshida, et al, 2015 · Pathology International · cited 21 times
- GATA3 is a useful immunohistochemical marker for distinguishing sarcomatoid malignant mesothelioma from lung sarcomatoid carcinoma and organizing pleuritisZ.H. Piao, X.C. Zhou, J.Y. Chen, 2021 · Virchows Archiv · cited 12 times
The journals that publish most on it: Human Pathology (2), The American Journal of Surgical Pathology (2), Journal of Surgical Case Reports (1).
Category: Diagnostic Tools & Biomarkers · All Lexicon terms A–Z
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