ARM I*: Patients receive doxorubicin hydrochloride intravenously (IV) and cyclophosphamide IV over 20-30 minutes on day 1. Treatment repeats every 3 weeks for 4 courses. Patients then receive paclitaxel IV over 1 hour beginning on day 1 of week 13 and continuing weekly for 12 courses in the absence of disease progression or unacceptable toxicity. NOTE: *Patients who completed paclitaxel on or after October 25, 2004 may receive trastuzumab for a maximum of 52 weeks either concurrently with paclitaxel or following completion of paclitaxel treatment.