This will be a phase II clinical trial to assess the clinical value of FES for staging and detection of disease recurrence in patients with ER-positive breast cancer, in direct comparison to the National Comprehensive Cancer Network's (NCCN) recommended standard-of-care using CT of the chest/abdomen/pelvis and bone scan [2].~Two cohorts will be evaluated:~Patients with advanced local breast cancer that will undergo standard of care imaging (CT + bone scan) to evaluate for unsuspected distant metastases.~Patients with suspicion for breast cancer recurrence that will undergo standard of care imaging (CT + bone scan) to evaluate for disease recurrence.~In both cohorts, FES PET/CT will be obtained, and compared with standard of care imaging. Whether on standard of care imaging or the research FES PET/CT, lesions suspicious for unsuspected distant metastases (cohort 1) or the site of disease recurrence (cohort 2) will be selected for biopsy, as is clinically standard of care to confirm disease that would alter patient management. Pathology will be used as the reference standard for confirming malignancy.
The standard of care imaging of breast cancer metastases recommended by the National Comprehensive Cancer Network (NCCN), CT of the chest/abdomen/pelvis and bone scan, may be suboptimal. 18F-fluoroestradiol (FES) is a novel PET tracer designed to detect estrogen receptors, which are often expressed in breast cancers. FES PET/CT may provide improved evaluation of metastases in patients with ER-positive breast cancer.