Evaluation of PSMA in HER2- AR+ Metastatic Breast Cancer

The purpose of this research is to determine the expression of prostate specific membrane antigen (PSMA) in human epidermal growth factor receptor 2 (HER2)-negative, androgen receptor (AR)-positive metastatic breast cancer, and to determine its role in resistance to the anti-androgen, bicalutamide. The investigators hypothesize that PSMA expression will correlate with resistance to anti-androgen therapies, as has been documented in prostate cancer, and this can be used to select patients most likely to benefit from these therapies in future clinical trials. 15 people with HER2-negative, AR-positive metastatic breast cancer will be enrolled and be on study for about 3 days.

Inclusion Criteria: * Patients diagnosed with metastatic HER2-negative breast cancer AR expression of ≥ 10% Exclusion Criteria: * Other (non-breast) known active malignancy. Participants with previously treated cancers which are in remission or have no evidence of disease are eligible. * Unable to lie flat during or tolerate PET/CT * Participants with any medical condition or other circumstances that, in the opinion of the investigator, compromise the safety or compliance of the subject to produce reliable data or completing the study * Women of childbearing potential must not be pregnant or breast feeding (pregnancy test negative within 7 days prior to PET/CT