Background
- Endocrine therapy (ET) resistance is common in estrogen receptor-positive (ER+) metastatic breast cancer (BC), where bone metastases (BMET) are usually the first sign of spread.
- ER signaling and ET effects can be influenced by other steroid hormone receptors (SHRs), such as progesterone receptor (PR) and androgen receptor (AR).
- The roles of these receptors in ER+ BC BMET are underexplored.
- PURPOSE: PR and AR protein expression was assessed by immunohistochemistry (IHC) in HER2-/ER+ BMET, and associations with overall survival (OS) were examined to address this gap.