Tamoxifen and Its Effects on Background Parenchymal Enhancement on Breast MRI

Background: Tamoxifen is a selective estrogen receptor modulator, which is used to decrease the likelihood of recurrence in premenopausal women diagnosed with estrogen-receptor positive breast cancer. Prior published data has suggested that hormonal changes result in variations in amount of fibroglandular tissue observed on a mammogram as well as degree of background parenchymal enhancement observed on breast MRI. Objective: To determine if tamoxifen results in detectable changes in the amount of fibroglandular tissue or background parenchymal enhancement on breast MRI. Methods: This retrospective study was performed by first mining a database to identify those patients who had an MRI of at least 1 breast before and during tamoxifen treatment over a 6-year period at one institution. All eligible patients had been receiving the standard dose of 20 mg of tamoxifen per day. Two radiologists were tasked with reviewing all of the images from the chosen studies. Readers were blinded to whe more...