3.1 Patient Population: Pre and post menopausal women with clinical T1-3 N0 breast cancer are eligible. All will have biopsy proven breast carcinoma. Positive core or fine needle aspiration biopsies will be obtained in all patients. Core biopsies are preferred. Excisional biopsies are not allowed. Patients must not be pregnant or lactating and must not have had prior malignancy. Diabetic patients are ineligible. An informal survey of 8 patients from Calgary indicates that all 8 would be willing to travel to Edmonton for their PET scan. (Personal communication from Dr. Mews).