DISEASE CHARACTERISTICS:

• Histologically confirmed adenocarcinoma of the breast

  • Metastatic disease
• HER-2/neu overexpression (3+ by immunohistochemistry OR 2+ by fluorescence in situ hybridization)
• Measurable or evaluable disease

• Hormone receptor status:

  • Not specified

PATIENT CHARACTERISTICS:

Age

• 18 and over

Sex

• Male or female

Menopausal status

• Not specified

Performance status

• ECOG 0-2

Life expectancy

• Not specified

Hematopoietic

• Absolute granulocyte count ≥ 1,500/mm^3
• Platelet count ≥ 100,000/mm^3

Hepatic

• AST and ALT < 2.5 times upper limit of normal (ULN) (5.0 times ULN in the presence of liver metastases)
• Bilirubin < 1.5 times ULN
• No unstable or uncompensated hepatic disease

Renal

• Creatinine < 1.6 mg/dL
• No unstable or uncompensated renal disease

Cardiovascular

• LVEF > 45% by echocardiogram or MUGA
• No prior New York Heart Association class I-IV heart disease
• No prolonged PR interval or atrioventricular block on ECG
• No unstable or uncompensated cardiac disease

Pulmonary

• No unstable or uncompensated respiratory disease

• No clinically active interstitial lung disease

  • Patients who are asymptomatic and have chronic stable radiographic changes are allowed

Immunologic

• No autoimmune disorders
• No conditions of immunosuppression
• No severe hypersensitivity to taxane or gefitinib or any of its excipients

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• No other prior or concurrent malignancy within the past 5 years except basal cell carcinoma or carcinoma in situ of the cervix
• No other severe or uncontrolled systemic disease
• No other acute or chronic medical condition that would preclude study participation
• No other significant clinical disorder or laboratory finding that would preclude study participation
• No psychiatric illness that would preclude study compliance

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Prior adjuvant trastuzumab (Herceptin®) allowed if > 6 months elapsed before disease recurrence
• No prior trastuzumab for metastatic breast cancer
• No prior monoclonal antibodies directed at the epidermal growth factor receptor (EGFR)

Chemotherapy

• Prior adjuvant chemotherapy (or as first-line therapy for metastatic breast cancer) allowed
• Prior adjuvant taxane allowed if completed > 6 months before diagnosis of metastatic breast cancer
• No prior docetaxel for metastatic breast cancer

Endocrine therapy

• Prior adjuvant hormonal therapy (or as first-line therapy for metastatic breast cancer) allowed

• No concurrent hormonal therapy

  • Concurrent steroids allowed provided dose is stable

Radiotherapy

• Not specified

Surgery

• Fully recovered from prior oncologic or other major surgery
• No concurrent surgery within 7 days of gefitinib administration

Other

• Recovered from prior anticancer therapy (alopecia allowed)
• More than 30 days since prior nonapproved drug or investigational agent
• No other prior EGFR-directed therapy (i.e., tyrosine kinase inhibitors)

• No concurrent use of any of the following medications:

  • Phenytoin
  • Carbamazepine
  • Barbiturates
  • Rifampin
  • Hypericum perforatum (St. John's wort)
• No other concurrent anticancer therapy
• No concurrent cardioprotective drugs
• No concurrent oral retinoids
• Concurrent participation in the City of Hope indium-labeled trastuzumab imaging study allowed