What is the relationship of her2 and p53 with hormone receptors in breast cancer?

Complicated: Her-2 is an oncogene usually (not always) associated with er- tumors. We know that it is in general associated with a worse prognosis, but women with her 2+ tumors may respond dramatically to Herceptin (trastuzumab) - a monoclonal antibody. P53 is a tumor suppressor gene. The relationship between p53 and er is currently under study - it may be that p53 mutations may play a role in tamoxifen responsiveness.

Unclear: Hormone receptors are present in 65-70 % of breast cancers. Her2 is present in 20%. Most her2 postive patients have hormone receptor negative tumors but about one third of them do contain hormone receptors. No clear relationship to p53.