Inclusion Criteria:

- Female patients 18 years of age or older

- Biopsy-proven breast cancer

- Tumor estrogen-receptor and progesterone-receptor status already determined or
scheduled to be determined at time of surgery without intervening therapy.

- Primary lesion size ≥ 1.5 cm as determined by imaging studies (ultrasonography,
mammography, CT or MRI) or physical examination

- Able to give informed consent

- Not currently pregnant or nursing: Subject must be surgically sterile (has had a
documented bilateral oophorectomy and / or documented hysterectomy), post menopausal
(cessation of menses for more than 1 year), non lactating, or of childbearing
potential for whom a urine pregnancy test (with the test performed within the 24 hour
period immediately prior to administration of FFNP) is negative.

Exclusion Criteria:

- No previous history of hormone therapy; NOTE - subjects who were treated with hormone
therapy for reasons other than breast cancer or breast cancer prevention may be
allowed to participate after review of history by the primary investigator

- Patients with other invasive malignancies, with the exception of non-melanoma skin
cancer, who had (or have) any evidence of the other cancer present within the last 5
years

- Unable to tolerate 60-90 minutes of PET imaging per imaging session