There are several diagnostic immunohistochemistry markers used in breast cancer staging and diagnosis. Some of the commonly used markers include:

There are several diagnostic immunohistochemistry markers used in breast cancer staging and diagnosis. Some of the commonly used markers include:

1. Estrogen receptor (ER) and progesterone receptor (PR): These markers are used to determine the hormone receptor status of the cancer cells. Breast cancers that are positive for ER and/or PR are more likely to respond to hormone therapy.

2. Human epidermal growth factor receptor 2 (HER2): This marker is used to determine the HER2 status of the cancer cells. HER2-positive breast cancers tend to be more aggressive and may require targeted therapy with drugs like trastuzumab.

3. Ki-67: This marker is used to determine the proliferation rate of the cancer cells. High levels of Ki-67 expression may indicate a more aggressive tumor.

4. Cytokeratins (CKs): These markers are used to identify epithelial cells, which are the cells that make up most breast cancers.

5. CD44 and CD24: These markers are used to identify cancer stem cells, which are thought to be the cells that drive tumor growth and recurrence.

The choice of markers used in a specific case may depend on various factors, including the type and stage of the cancer, as well as the treatment plan.