This randomized phase IIB trial studies how well tamoxifen or afimoxifene works in treating
patients with estrogen receptor positive breast cancer. Estrogen can cause the growth of
breast cancer cells. Hormone therapy using tamoxifen citrate or afimoxifene may fight breast
cancer by blocking the use of estrogen by the tumor cells.
Ductal Breast Carcinoma In Situ, Estrogen Receptor Positive