Trastuzumab or Observation After Combination Chemotherapy and Trastuzumab in Treating Patients Undergoing Surgery for Stage II or Stage III Breast Cancer

RATIONALE: Drugs used in chemotherapy work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Monoclonal antibodies, such as trastuzumab, can block tumor growth in different ways. Some block the ability of tumor cells to grow and spread. Others find tumor cells and help kill them or carry tumor-killing substances to them. Giving combination chemotherapy together with trastuzumab before surgery may make the tumor smaller and reduce the amount of normal tissue that needs to be removed. Giving trastuzumab after surgery may kill any tumor cells that remain after surgery. Sometimes, after surgery, the tumor may not need more treatment until it progresses. In this case, observation may be sufficient. It is not yet known whether trastuzumab is more effective than observation when given after combination chemotherapy and trastuzumab in treating patients with breast cancer. PURPOSE: This randomized phase II trial is studying trastuzumab to see how well it works compared with observation when given after combination chemotherapy and trastuzumab in treating patients undergoing surgery for stage II or stage III breast cancer.

Sex

All

Minimum age

18 Years

Maximum age

65 Years

DISEASE CHARACTERISTICS:

* Histologically confirmed invasive breast cancer by needle biopsy

  * Diagnosed within the past 4 weeks
  * Clinical stage IIB, IIIA, IIIB, or IIIC disease
* Palpable adenopathies present
* HER2/neu-positive disease, as evidenced by either of the following:

  * HER2/neu overexpression (3+) by immunohistochemistry (IHC)
  * HER2/neu amplification by fluorescence in situ hybridization (FISH)
* No metastatic disease by chest radiography, hepatic ultrasound, and bone scan (metastatic bone series if no nuclear medicine is available)
* Hormone receptor status:

  * Estrogen receptor and/or progesterone receptor status known

PATIENT CHARACTERISTICS:

* Premenopausal or postmenopausal
* WHO performance status 0-2
* Not pregnant or nursing
* Normal hepatic, renal, and hematological function
* LVEF ≥ 55% by nuclear medicine study or echocardiogram
* No prior history of cancer, except carcinoma in situ of the cervix
* No allergic reaction or hypersensitivity to paclitaxel and/or trastuzumab (Herceptin®)

PRIOR CONCURRENT THERAPY:

* No prior cancer therapy