Combination Chemotherapy and Trastuzumab in Treating Women With Stage I, Stage II, or Stage III HER2-Positive Breast Cancer

DISEASE CHARACTERISTICS:

• Diagnosis of infiltrating primary breast cancer

  • Stage I-IIIA disease

  • Resected tumor with free margins (i.e., no neoplastic cells on the resected margin)

    • Must have node-negative sentinel node or complete axillary clearance

      • Axillary clearance required for micrometastasis (between 0.2 and 2 mm) in the sentinel node but not for isolated tumor cells

    • Treatment is scheduled to begin within 10 weeks from the date of surgery

      • Date of the last surgery will be taken into account for patients undergoing re-excision of positive margins or axillary lymph node dissection after positive sentinel node biopsy

• Node positivity or node negativity AND ≥ 1 of the following:

  • T > 2 cm
  • Grade 3
  • Presence of lymphovascular invasion
  • Ki 67 > 20%
  • Age 35 years
  • Hormone receptor negativity (<10%)
• HER2-positive tumor (3+ by IHC or FISH+ according to the American Society of Clinical Oncology guidelines [i.e., > 2.2; in case of polysomy, with ≥ 6 gene copies])
• Estrogen receptor-positive and/or progesterone receptor-positive disease

PATIENT CHARACTERISTICS:

• Female

• Pre- or postmenopausal status

  • Postmenopausal status defined by ≥ 1 of the following:

    • At least 60 years of age
    • Less than 60 years of age and amenorrheic for ≥ 12 months prior to day 1
    • Less than 60 years of age and amenorrheic for < 12 months prior to day 1 with luteinizing hormone and follicle-stimulating hormone values within postmenopausal range OR without a uterus
    • Prior bilateral oophorectomy
    • Prior radiation castration with amenorrhea for ≥ 6 months
• ECOG performance status 0-1
• Suitable for adjuvant chemotherapy
• WBC > 3,000/mcL
• ANC > 1,500/mcL
• Platelet count >100,000/mcL
• Total bilirubin normal
• AST and ALT 2.5 times upper limit of normal
• Creatinine normal
• Cardiac ejection fraction normal as measured by ECHO or MUGA scan
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during and for ≥ 3 months after completion of study therapy
• No contraindication to anthracycline, cyclophosphamide, fluorouracil, paclitaxel, or trastuzumab (Herceptin®) treatment

• No uncontrolled intercurrent illness including, but not limited to, the following:

  • Ongoing or active infection
  • Symptomatic congestive heart failure
  • Unstable angina pectoris
  • Cardiac arrhythmia
  • Psychiatric illness/social situations that would limit compliance with study requirements

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• See Patient Characteristics
• No prior chemotherapy, endocrine therapy, or radiotherapy
• No other concurrent investigational agents