The purpose of this study is to evaluate the safety and
effectiveness of the anticancer drug eribulin when added to
standard chemotherapy given after surgery in women with early-
stage breast cancer. Eribulin is a new chemotherapy drug
approved for the treatment of advanced breast cancer that
persists despite prior treatment, but its use for early-stage
disease is considered investigational. Eribulin, which is
derived from a sea sponge, works by inhibiting microtubules
(which provide scaffolding in cancer cells), leading to cell
death. It is administered intravenously (by vein). In this
study, eribulin will be given after one standard treatment for
breast cancer with the drugs doxorubicin and cyclophosphamide.