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

Inclusion Criteria:

Histologically confirmed adenocarcinoma of the female breast which is inoperable, recurrent or metastatic
HER-2/neu status must be known at the time of protocol registration; HER-2/neu assessment will be based on FISH analysis of either the primary tumor or a metastatic site; a scoring of 0 or 1+ by immunohistochemistry (IHC) is considered negative; 2+ is considered negative unless confirmed by FISH positivity, in which case it should be considered positive; 3+ by IHC is considered positive; for centers using FISH only, a positive FISH assay by itself is sufficient to determine HER-2 positivity

Patients with the following prior therapy are eligible:

Patients with 0-1 prior chemotherapy regimens for metastatic or locally advanced breast cancer, with the following exception: no prior taxane for metastatic/locally advanced breast cancer
Patients with 0-1 prior chemotherapy regimens in the adjuvant setting; if adjuvant regimen included a taxane, patient must have been disease free for at least 12 months from completion of adjuvant therapy until relapse

Patients must be > 2 weeks from prior surgery, other than simple biopsy or placement of venous access device; patients must be > 4 weeks from prior chemotherapy; patients must be >6 weeks from nitrosoureas, melphalan, or mitomycin

Patients must be > 4 weeks from prior hormonal therapy unless tumor measurements document clear progression while on treatment; if progression is documented and toxicity from hormonal regimen has resolved, patients may be placed on study > 1 week from prior hormonal therapy
Prior Herceptin therapy is not allowed
Patients with central nervous system metastases are eligible only if the patient has completed cranial irradiation at least 6 months prior, is currently asymptomatic, and is not currently receiving corticosteroids for this condition; patients with leptomeningeal carcinoma (carcinomatous meningitis) are not eligible

MESURABLE DISEASE: Any mass reproducibly measurable in two perpendicular dimensions, examples include:

Pulmonary nodules
Hepatic lesions
Skin nodules (if two measurements can be assigned)
Lymph nodes

The following lesions do not qualify as measurable:

Central nervous system (CNS) lesions
Bone disease only; lytic lesions should be documented and followed
Lymphangitic pulmonary metastases (patients with lymphangitic metastases are eligible if there are other sites of metastatic disease which can be measured)
Lesions which have been irradiated unless there is definite documentation of progression since radiotherapy
A baseline assessment of left ventricular ejection fraction within 8 weeks of registration is required (echocardiogram or resting multi gated acquisition scan [MUGA] (radionuclide cineangiography [RNCA]) nuclear scintigraphy); patients with a left ventricular ejection fraction (LVEF) < 45% are ineligible
Granulocytes >= 1500/ul
Platelet count >= 100,000/ul
Creatinine =< 2.0 mg/dl
Bilirubin within institutional normal limits
Serum glutamic oxaloacetic transaminase (SGOT) (aspartate aminotransferase [AST])