This study is being done to answer the following question: Will the chance of your breast cancer returning be less if chemotherapy is added to hormonal therapy with an aromatase inhibitor and ovarian suppression? We are doing this study because we want to find out if this approach is better or worse as the other usual approach for your early-stage breast cancer that is sensitive to hormones, is HER2-negative, and is at higher risk for cancer returning. The usual approach for patients who are not in a study is treatment with surgery, radiation therapy, hormonal therapy, ovarian suppression,...