Effect of Aromatase Inhibitors on Breast Magnetic Resonance Imaging (MRI)

Phase 2

Completed

Brief Summary: This study is a primary investigation to determine the usefulness and safety of a short course of a relatively high dose of letrozole (a medication used to decrease the female hormone estrogen which is produced locally inside the breast after menopause) in improving the performance of of breast MRI (Magnetic Resonance Imaging). The inhibition of estrogen in the breast by letrozole might help better identifying of suspicious areas in the breast and could assist radiologists in distinguishing between benign breast areas and cancer tissue. This might help reducing the rate of call backs and unnecessary biopsies for patients. We expect to enroll 20 healthy postmenopausal women in this study.

Detailed Description: A breast MRI will be performed in the standard way for diagnosis and to serve as a baseline. A second MRI will be performed within a month and following administration of letrozole 12.5 mg daily for three days to reduce breast estrogen levels and in anticipation of lowering breast gadolinium dye uptake.

Recruitment & Eligibility

Inclusion Criteria

Women are eligible to participate if they are 40 years or older and have been menopausal (had no menstrual bleeding during the past 12 months)

Exclusion Criteria

Arm && Interventions

Group	Intervention	Description
Letrozole, Breast enhancement, Safety	letrozole	Single arm of healthy postmenopausal women who received baseline diagnostic MRI will receive letrozole of 12.5 mg/day orally for three successive days. A second post treatment breast MRI is done right after receiving the three days of letrozole treatment and within one month after the first MRI .

Primary Outcome Measures

Name	Time	Method
Number of Women With Reduced Breast Parenchymal Enhancement	One month MRI study after letrozole compared to baseline MRI study, both with gadolinium enhancement	Image analysis was done using the e-film workstation. A region of interest was selected in all images. The signal intensity of enhancement was recorded and the relative enhancement (percentage of increase in signal intensity) was calculated as (SIc - SI)/SI × 100, where SI and SIc are the precontrast and the postcontrast signal intensities, respectively. Relative enhancement was compared at the baseline MRI study and the after one month MRI study for all participants.

Secondary Outcome Measures

Name	Time	Method
Number of Participants Developed Adverse Effects of 12.5 mg of Letrozole	Three days plus One Week following medication	The number of participants who developed short term hypoestrogenic side effects or other adverse effects of letrozole during the intake of the medication or in the following week.