Following surgery, pathology will be performed on the excised breast tumor tissue to determine tumor cell death. For breast conservation, the breast must be of sufficient size to allow adequate tumor removal with a satisfactory cosmetic result. The objective of surgery is to obtain local control of the breast cancer with the best cosmetic result possible. A breast conservation surgery procedure requires excision of the tumor and margins without removal of more normal breast tissue than is required to achieve negative margins. Pathologic evaluation of the excised tissue will determine whether the margins are negative or positive. For subjects with involved margins following breast conservation surgery, if the breast will tolerate it, the subject may undergo one or more further segmental resections in order to achieve clear margins.