This phase I trial studies how well fluciclovine positron emission tomography (PET)/computed tomography (CT) and PSMA PET/CT work in helping doctors understand and classify invasive lobular breast cancer in patients with invasive lobular breast cancer that is suspicious for or has spread to other places in the body (metastasized). Fluciclovine and PSMA are radiotracers used in PET/CT imaging scans that emit radiation. The PET/CT scan than picks up the radiation being released to create a picture from within the body. Information learned from this study may help researchers learn how to better identify metastatic disease in invasive lobular breast cancer patients which will impact appropriate staging.

PRIMARY OBJECTIVES:

I. Improve detection of metastasis with fluciclovine F18 (fluciclovine) and gallium Ga 68-labeled PSMA-11 (PSMA) PET versus best standard of care conventional imaging, as confirmed with histology.

II. Determine concordance and discordance of invasive lobular breast cancer (ILC) detection with PSMA versus fluciclovine PET, as confirmed with histology.

EXPLORATORY OBJECTIVE:

I. Establish the role of circulating tumor deoxyribonucleic acid (DNA) (ctDNA) directed to ESR1 and PI3K DNA in characterizing the degree of tumor burden as identified by metabolic amino acid transport and tumor neovasculature receptor imaging.

OUTLINE:

Patients receive gallium Ga 68-labeled PSMA-11 intravenously (IV) and undergo a PET/computed tomography (CT) scan over 30 minutes. On a separate day, patients receive fluciclovine F18 IV and undergo a PET/CT scan over 30 minutes.

After completion of study, patients are followed up in 5-10 business days, and then up to 5 years.

Inclusion Criteria:

• Treatment naive biopsy proven ILC patients with ILC
• Either: a) clinical or imaging suspicion of metastatic disease; or b) proven metastatic disease but in whom there is suspicion of an even greater tumor burden that could change therapy approach
• Ability and willingness to undergo biopsy if needed per standard of care for possible metastasis which could change therapy approach

Exclusion Criteria:

• Pregnancy. Qualitative or quantitative serum or urine pregnancy test will be done in women of childbearing potential within 24 hours before PET

  • A female of childbearing potential (FCBP) is a sexually mature woman who: 1) has not undergone a hysterectomy or bilateral oophorectomy; or 2) has not been naturally postmenopausal for at least 12 consecutive months (if age > 55 years); if the female subject is < 55 years and she has been naturally postmenopausal for > 1 year her reproductive status has to be verified by additional lab tests (< 20 estradiol OR estradiol < 40 with follicle-stimulating hormone [FSH] > 40 in women not on estrogen replacement therapy)