IMMUNOHISTOCHEMISTRY, GATA-3

What this test checks

Detects GATA-3 protein, expressed in breast and bladder cancers. A useful marker for identifying breast or urothelial (bladder) origin in metastatic tumours of unknown primary.

Why do people get this test?

When cancer has spread and the site of origin is unclear, GATA-3 positivity strongly suggests breast or bladder cancer — changing the chemotherapy regimen and treatment approach entirely.

When you should consider this test

• When investigating cancer of unknown primary site
• When classifying a metastatic tumour to determine if it originated in the breast or bladder
• As part of breast cancer or bladder cancer diagnostic panels

How to prepare

No preparation needed — performed on biopsy or surgical tissue.