Fulvestrant (FASLODEX™) as a Treatment in Postmenopausal Women With Estrogen Receptor Positive Breast Cancer

Inclusion Criteria: * Postmenopausal women defined as women who have stopped having menstrual periods * Written informed consent to participate in the trial * Biopsy confirmation of invasive breast cancer * Evidence of hormone sensitivity * Willingness to undergo biopsies Exclusion Criteria: * Any previous treatment for breast cancer * Unwillingness to stop taking any drug known to affect sex hormonal status or a patient in which it would be inappropriate to stop. * Any severe concurrent condition that would preclude surgery or that would jeopardize compliance with the study, e.g., uncontrolled cardiac disease or uncontrolled diabetes mellitus * The presence of more than one primary tumor * History of hypersensitivity to castor oil * History of known bleeding disorders