Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically or cytologically confirmed breast cancer

- Clinical evidence of metastatic disease

- Candidate for first- or second-line chemotherapy for metastatic disease

- Must have received prior anthracycline or taxane therapy (may have had both in the
neoadjuvant, adjuvant, or metastatic setting)

- At least 1 measurable lesion at least 20 mm by CT scan or MRI OR at least 10 mm by
spiral CT scan

- The following are not considered measurable disease:

- Small lesions less than 20 mm by CT scan or MRI

- Bone lesions

- Ascites

- Pleural/pericardial effusion

- Inflammatory breast disease

- Lymphangitis cutis/pulmonis

- Abdominal masses not confirmed and followed by imaging techniques

- Cystic lesions

- No active CNS metastases (treated CNS metastases stable for more than 8 weeks are
allowed)

- 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

- At least 3 months

Hematopoietic

- Absolute neutrophil count at least 1,500/mm^3

- Platelet count at least 100,000/mm^3

- Hemoglobin at least 8.5 g/dL

Hepatic

- Bilirubin no greater than 1.5 times upper limit of normal (ULN)

- AST no greater than 3 times ULN

- Alkaline phosphatase no greater than 3 times ULN

Renal

- Creatinine no greater than 1.5 times ULN

Cardiovascular

- No symptomatic congestive heart failure

- No unstable angina pectoris

- No cardiac arrhythmia

Gastrointestinal

- No inability to take oral or nasogastric medication

- No requirement for IV alimentation

- No active peptic ulcer disease

Ophthalmic

- No abnormalities of the cornea based on history (e.g., dry eye syndrome or Sjögren's
syndrome)

- No congenital abnormality (e.g., Fuch's dystrophy)

- No abnormal slit-lamp examination using a vital dye (e.g., fluorescein or
Bengal-Rose)

- No abnormal corneal sensitivity test (Schirmer test or similar tear production test)

Other

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- Sub-dermal implants and condoms are not considered acceptable forms of
contraception

- No other invasive non-breast malignancy within the past 5 years except adequately
treated basal cell or squamous cell skin cancer

- No ongoing or active infection

- No psychiatric illness or social situation that would preclude study compliance

- No other concurrent uncontrolled illness

PRIOR CONCURRENT THERAPY:

Biologic therapy

- At least 2 weeks since prior immunotherapy

- No prior cetuximab

Chemotherapy

- At least 2 weeks since prior chemotherapy and recovered

- No more than 1 prior chemotherapy regimen for metastatic disease

- No more than 2 prior chemotherapy regimens total, including adjuvant therapy

Endocrine therapy

- Prior hormonal therapy allowed in metastatic and/or adjuvant setting

Radiotherapy

- At least 2 weeks since prior radiotherapy

- No prior radiotherapy to more than 25% of bone marrow

- No prior strontium chloride Sr 89

Surgery

- More than 4 weeks since prior major surgery

- No prior surgical procedures affecting absorption

Other

- No prior epidermal growth factor receptor-targeting therapies (e.g., gefitinib or
EKB-569)

- No concurrent combination antiretroviral therapy for HIV-positive patients

- No other concurrent antitumor therapy