 In this study, trastuzumab and etoposide will be given by intravenous infusion IV; through a vein on the first 3 days of every 3-week cycle. This is repeated for 6 cycles. After 6 cycles, only trastuzumab will be given until worsening of disease. In this study, a small amount of your tissue that was collected when you had surgery will be evaluated in the lab to look at genetic differences among people and how those differences may affect a response to a specific drug or medicine. This testing will look for a gene called Top2A. Previous studies suggest that people who have both the Top2A and Her2 genes respond to certain chemotherapies anti-cancer drugs differently from those who only have the Her2 gene. 