Paclitaxel With or Without Trastuzumab in Treating Patients With or Without HER-2/Neu Breast Cancer That is Inoperable, Recurrent, or Metastatic

PRIMARY OBJECTIVES: I. To determine whether "dose dense" (DD) treatment with paclitaxel via weekly 1-hour infusion has a significantly higher response rate than "standard" (S) paclitaxel treatment, regardless of human epidermal growth factor receptor 2 (HER-2/neu) status and assignment to Herceptin (trastuzumab). II. To determine if the addition of Herceptin to DD or S paclitaxel significantly improves the response rate as compared to DD or S paclitaxel alone for HER-2/neu non-overexpressing metastatic breast cancer (e.g., 0 or 1+). III. To determine whether the addition of Herceptin to chemotherapy treatment modifies the quality of life experienced by patients with HER-2/neu non-overexpressing metastatic breast cancer. IV. To determine whether the quality of life experienced by patients with metastatic breast cancer who have been treated with "standard" paclitaxel treatment differ from that of patients treated with "dose dense" paclitaxel treatment. V. To correlate amplification and overexpression of the growth factor receptor ErbB2 by immunohistochemistry and fluorescent in-situ hybridization (FISH) with response rate, time to progression, and overall survival of patients with metastatic breast cancer treated with paclitaxel chemotherapy and paclitaxel + Herceptin. VI. To correlate ErbB2 shed extracellular domain (ECD) with response rate, time to progression, and overall survival of patients with metastatic breast cancer treated with different doses and schedules of paclitaxel and paclitaxel + Herceptin. In addition, to follow patterns of ErbB2/ECD after treatment and upon relapse. SECONDARY OBJECTIVES: I. To evaluate time to progression and survival of patients with HER-2 overexpressing metastatic breast cancer treated with either DD or S paclitaxel plus weekly Herceptin. II. To evaluate time to progression and survival of patients with HER-2 non-overexpressing metastatic breast cancer treated with either DD or S paclitaxel alone or DD or S paclitaxel plus weekly Herceptin. III. To evaluate cardiac toxicity as measured by changes in LVEF from baseline to follow-up measurements. OUTLINE; Patients are assigned to 1 of 2 treatment groups. GROUP I (HER2/neu non-overexpressors): Patients are randomized to 1 of 4 treatment arms. ARM A: Patients receive paclitaxel intravenously (IV) over 3 hours every 3 weeks. ARM B: Patients receive paclitaxel IV over 1 hour weekly. ARM C: Patients receive paclitaxel as in Arm A. Patients also receive trastuzumab IV weekly. ARM D: Patients receive paclitaxel as in Arm B and trastuzumab as in Arm C. GROUP II (HER2/neu overexpression): Patients are assigned to 1 of 2 treatment arms. ARM E: Patients receive paclitaxel and trastuzumab as in Arm C. ARM F: Patients receive paclitaxel and trastuzumab as in Arm D. In all arms, courses repeat every 3 weeks in the absence of disease progression or unacceptable toxicity. After the completion of study treatment, patients are followed up periodically for up to 5 years.