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

Grant #: DOD IDEA Award
PI Name: Buist, Diana
Title: A Population-Based Randomized Trial to Assess the Effects of Short-Term Cessation of HRT on Mammography Assessments and Breast Density
Funding Started: 2003

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 will be conducted at Group Health Cooperative, a managed health care organization with an organized breast cancer screening program. The investigators will use automated to identify HRT users who are due for screening mammograms. Women will be recruited through mailed correspondence and telephone contact. A total of 1500 women will be recruited and randomized to one of three HRT arms: 1) cessation two months before the screening mammogram, 2) cessation one month before, and 3) continued HRT use. Breast density will be measured using a computer assisted method and recall rates will be determined from an expert radiologist review of the mammograms, blinded to HRT status. The investigators will test whether: 1) HRT cessation I or 2 months before a screening mammogram reduces the likelihood of receiving a recommendation for additional evaluation compared to women who continue using HRT; 2) HRT cessation for I versus 2 months affects the likelihood of receiving a recommendation for additional evaluation; and 3) there is a greater change in breast density (to lower breast density) among women who stop HRT I or 2 months before a screening mammogram to those who do not stop HRT. Change in breast density will be measured as the difference between breast density on the screening mammogram before the trial (while on HRT) and during the trial.