Radiologic Evaluation and Breast Density (READ)

A Population-Based Randomized Trial to Assess the Effects of Short-Term Cessation of Hormone Replacement Therapy (HRT) on Mammography Assessments and Breast Density

The purpose of this study is to determine whether cessation of hormone replacement therapy for one or two months before a screening mammogram will improve its performance by decreasing breast density.

This randomized, controlled trial is designed to test whether short-term (1-2 months) HRT cessation will sufficiently lower breast density to decrease the proportion of women who receive a recommendation for additional evaluation following a screening mammogram, and to examine whether there is a trend by duration of cessation. The study is being conducted at Group Health Cooperative, a managed health care organization in western Washington State with an organized breast cancer screening program. We are recruiting 1,500 women and will randomize women to one of three HRT arms: 1) cessation two months before the screening mammogram; 2) cessation one month before; and 3) continued HRT use. We are using a computer-assisted method to measure mammographic breast density continuously. Mammography recall rates are being determined from an expert radiologist review of the mammograms, blinded to HRT status.

Inclusion Criteria:

• 1 or more prior screening mammograms at Group Health Cooperative within the past 2 years
• Currently taking HRT
• Taking HRT at prior screening mammogram
• Due for a screening mammogram

Exclusion Criteria:

• BI-RADS breast density of 1 (entirely fat)
• Previous cardiovascular events (heart surgery, catheterization, stent bypass, angioplasty, stroke, DVT)
• Previous breast cancer
• History of breast implants
• Breast reduction since last mammogram
• Mastectomy
• History of using Tamoxifen or Raloxifene
• Declined contact or use of data for research