 Doxorubicin has been an integral part of the treatment of women with breast cancer for many years. Since amrubicin may have more activity than doxorubicin, as well as less cardiotoxicity, evaluation of amrubicin in the treatment of advanced breast cancer should be a priority. In this Phase II study, the investigators propose an evaluation of single-agent amrubicin as second- or third-line treatment for women with metastatic breast cancer. 