 3. Tumor Site: Patients must have invasive cancer in the breast. Multifocal disease i.e. confined to a single quadrant in the same breast is allowed. Multicentric disease i.e. disease in multiple breast quadrants is not allowed. Determination of multifocal and multicentric disease status will be made by the evaluating surgeon; ambiguous cases will be reviewed by the principal investigator. Patients with synchronous contralateral invasive breast cancers are not eligible; prior contralateral breast cancer allowed as long as patient has not received prior chemotherapy or radiation therapy in the past 5 years. 