Researchers do not have data to determine if women taking another aromataase inhibitor should switch to letrozole. On October 5, 2005, the FDA approved exemestane tablets (Aromasin®, a product of Pfizer Inc.) for adjuvant treatment of postmenopausal women with estrogen receptor positive early breast cancer who have received two to three years of tamoxifen and are switched to exemestane for completion of a total of five consecutive years of adjuvant hormonal therapy. • Should women with a family history of breast cancer consider taking this drug to help prevent breast cancer? No. At this time, researchers do not have data to show that letrozole would prevent the development of breast cancer in high-risk women who have never had breast cancer. This trial was not designed to answer this question. • Should women currently undergoing chemotherapy or radiation take letrozole? No. This study is not applicable to women with breast cancer currently undergoing chemotherapy or radiation. However,