We think that lapatinib will help to shrink your tumor when given prior to the main or primary therapy for the kind of breast cancer you have been diagnosed with. When treatment is given before the main or primary therapy, it is called neoadjuvant therapy. We will compare lapatinib with lapatinib plus trastuzumab (herceptin) for 12 weeks. If your tumor is estrogen receptor positive (ER positive), estrogen deprivation will also be given to you. Tumors that are ER positive have a lot of estrogen receptors found in them. This is also called "over expression" or amplification of estrogen receptors.