3. Have biopsy-proven ER/PR-positive (defined as ER ≥1 percent and PR ≥1 percent by IHC) and HER2-negative advanced or metastatic LBC starting new standard of care endocrine therapy
4. Adequate organ function as indicated by standard laboratory tests (CBC, liver function tests or CMP) allowing for systemic breast cancer treatment per treating oncologist
5. Patients with evaluable bone-only disease that is lytic or mixed lytic-sclerotic are eligible
6. Willing to comply with all study procedures and be available for the duration of the study
You may not be if
1. Patients with active brain metastases
3. Unable to lie flat during or tolerate PET/CT
4. Patients with a history of allergic reaction attributable to compounds of similar chemical or biologic composition to FFNP
5. Presence of liver failure as judged by patient's treating physician
6. Individuals who are pregnant, lactating, or planning on becoming pregnant during the study
7. Not suitable for study participation due to other reasons at the discretion of the investigators
8. Patients with progesterone-receptor negative disease defined as PR \<1 percent by IHC
Clareo Health | Biomarkers to Detect Endocrine Therapy Resistance
