- Patients must be post-menopausal women with a confirmed diagnosis of metastatic breast cancer (M1). Pathologic confirmation of histology is preferable. In the case of bone metastases only, biopsy-proven metastatic disease of solitary site, or multiple sites of involvement are required. Post-menopausal is defined by one of the following criteria as per National Comprehensive Cancer Network (NCCN) guidelines Version 3. 2013: