Assessment of Functional Status of Estrogen Receptors in Breast Cancer by Positron Emission Tomography

Summary

The purpose of this study is to evaluate the uptake of a radioactive tracer 21-18F-fluoro-16α,17α-\[(R)-(1'-α-furylmethylidene)dioxy\]-19-norpregn-4-ene-3,20-dione (FFNP) uptake, which binds to breast cancer progesterone receptors (PgRs) on a PET/CT scan before and after administration of estradiol for one day (estrogen challenge) to determine if the change in uptake is a predictor of response to endocrine therapy (ET) in patients with hormone-sensitive estrogen receptor positive (ER+), human epidermal growth factor receptor 2-negative (HER2-) breast cancer. Estradiol is the most potent of the naturally occurring estrogens, and can be administered to treat menopausal symptoms and also sometimes to treat metastatic breast cancer. The investigators propose to study patients with biopsy-proven newly diagnosed, locally advanced, metastatic, or recurrent breast cancer who are going to be treated with endocrine therapy (ET) (tamoxifen,aromatase inhibitors or fulvestrant as standard of care therapy. Subjects will undergo a total of two FFNP-PET/CT scans; one before and a second one immediately following the one day estradiol challenge before the start of standard of care ET. The estradiol challenge will consist of administering a total of 6 mg of estradiol orally (three doses of 2 mg each) given at approximately 8 hour intervals and over a 24 hour period.

Timeline

Start

2015-04-28

Primary completion

2019-01-03

Completion

2019-01-03

Publications

• Dehdashti F, Wu N, Ma CX, Naughton MJ, Katzenellenbogen JA, Siegel BA. Association of PET-based estradiol-challenge test for breast cancer progesterone receptors with response to endocrine therapy. Nat Commun. 2021 Feb 2;12(1):733. doi: 10.1038/s41467-020-20814-9.

Drugs

Indications