Kimberly Cullen, MD

The IBIS-I randomized control trial included women of ages 35-70 from 37 health centers in eight countries from April, 1992, until March, 2001 that were deemed to be at increased risk of developing breast cancer (by virtue of family history of breast cancer or abnormal benign breast disease), and randomized to treatment with oral tamoxifen or placebo for 5 years.