 Purpose: The purpose of this research is to find out if premenopausal women with breast cancer that has spread to other parts of the body live longer if their ovaries are removed during the second half of the menstrual cycle. This study will compare how long women live if they have their ovaries removed during the first half of their menstrual cycle follicular phase to how long women live if they have their ovaries removed during the second half of their menstrual cycle luteal phase. Tamoxifen will also be given to study participants. 