FLT PET in Measuring Treatment Response in Patients With Newly Diagnosed Estrogen Receptor-Positive, HER2-Negative Stage I-III Breast Cancer

PRIMARY OBJECTIVES:

I. Measure the effect of a short course of endocrine therapy on primary breast cancer
metabolism and proliferation by measuring changes in serial FLT PET measures pre and post a
short course of endocrine therapy.

SECONDARY OBJECTIVES:

I. Compare changes in imaging measures to tissue measures of response, in particular antigen
identified by proliferation-related Ki-67 antigen (Ki-67), in the pre-therapy biopsy versus
the post-therapy surgical specimen.

II. Correlate imaging measures to measures of gene expression from pre and post therapy
assays to determine if there are molecular changes associated with early response to therapy.

OUTLINE:

Patients undergo FLT PET at baseline and 1-6 weeks after the start of treatment.

Inclusion Criteria:

- A new diagnosis of invasive breast cancer > 1.0 cm in size, ER+ clinical stage I-III

- Patient must have surgical resection followed by systemic adjuvant therapy with an
aromatase inhibitor (AIs) as part of planned treatment; any approved AI at standard
clinical dosing may be used; in pre-menopausal patients, ovarian suppression with a
gonadotropin-releasing hormone (GnRH) agonist will be started prior to initiation of
the AI on a separate clinical trial in parallel with the imaging study

- Have tissue block available from core biopsy for correlative biomarkers and genomic
assay

- Have menopausal status determined prior to study enrollment; for study purposes,
postmenopausal is defined as

- A prior documented bilateral oophorectomy, or

- A history of at least 12 months without spontaneous menstrual bleeding, or

- Age 60 or older with a prior hysterectomy without oophorectomy, or

- Age less than 60 with a prior hysterectomy without oophorectomy (or in whom the
status of the ovaries is unknown) with a documented follicle-stimulating hormone
(FSH) level demonstrating confirmatory elevation in the postmenopausal range for
the lab

- Negative pregnancy test within 7 days of baseline positron emission tomography (PET)
scan for pre-menopausal patients

- Tumor HER2/neu expression must be determined (as part of standard clinical care) prior
to study enrollment; HER2 may be tested by any Food and Drug Administration (FDA)
approved HER2 testing method; if determination is intermediate by immunohistochemistry
(IHC), fluorescent in situ hybridization (FISH) or another alternate HER2 test must be
performed

- Be a candidate for [18F]FLT PET imaging

- Be informed of the investigational nature of this study and provide written informed
consent in accordance with institutional and federal guidelines prior to
study-specific screening procedures

- Be willing and able to comply with scheduled visits and other trial procedures

Exclusion Criteria:

- Current use of aromatase inhibitor as prevention or treatment for breast cancer

- Life expectancy of less than two months

- HER2/neu positive by IHC and/or another FDA approved HER2 testing method

- Inability to tolerate scanning (e.g. - claustrophobia, severe pain)

- Weight exceeding capacity of imaging table