Irinotecan and Cetuximab in Treating Patients With Metastatic Breast Cancer

DISEASE CHARACTERISTICS:

* Histologically confirmed adenocarcinoma of the breast

  * Clinical manifestations of metastatic disease
* If patient's tumor is HER2 positive (3+ by immunohistochemistry \[IHC\] or amplified by fluorescent in situ hybridization \[FISH\]), must have received at least one prior trastuzumab (Herceptin)-containing regimen unless there is a contraindication
* Measurable disease defined as at least one lesion whose longest diameter can be accurately measured

  * The only evidence of metastasis must not be bone metastases or other non-measurable disease
  * Nonmeasurable disease is defined as all other lesions, including small lesions (longest diameter \< 2 cm) and truly nonmeasurable lesions which include any of the following:

    * Bone lesions
    * Leptomeningeal disease
    * Ascites
    * Pleural/pericardial effusion
    * Inflammatory breast disease
    * Lymphangitis cutis/pulmonis
    * Cystic lesions
    * Abdominal masses that are not confirmed and followed by imaging techniques
* No known CNS metastasis unless controlled by prior surgery and/or radiotherapy

  * To be considered controlled, there must be at least 2 months of no symptoms or evidence of progression prior to study entry
* Hormone receptor status

  * Not specified

PATIENT CHARACTERISTICS:

* Men or women
* Menopausal status not specified
* ECOG performance status 0-2
* Life expectancy \> 3 months
* Hemoglobin \> 8.0 g/dL
* Absolute neutrophil count ≥ 1,500/mm³
* Platelet count ≥ 100,000/mm³
* Creatinine ≤ 1.5 times upper limit of normal (ULN)
* Bilirubin normal
* AST and ALT ≤ 5 times ULN
* Not pregnant or nursing
* Negative pregnancy test
* Fertile patients must employ adequate contraception (as determined by the treating physician) during treatment and for 30 days after treatment ends
* Disease-free for ≥ 3 years of other invasive non-breast malignancies (exception: curatively treated basal cell or squamous cell carcinoma of the skin and carcinoma in situ of the cervix)
* No history of allergy or hypersensitivity to drug product excipients, murine antibodies, or agents chemically similar to irinotecan and/or cetuximab
* No history or evidence of Gilbert's syndrome
* No active, unresolved infection
* No New York Heart Association class III or IV cardiovascular disease
* No serious concomitant medical condition that would make it undesirable for patient to participate in the trial or would jeopardize compliance with protocol treatment

PRIOR CONCURRENT THERAPY:

* See Disease Characteristics
* No more than 2 prior chemotherapy regimens in the metastatic setting (irrespective of hormonal therapy or prior trastuzumab therapy)

  * Prior treatment in the metastatic or adjuvant setting must have included an anthracycline or a taxane
* No major surgery ≤ 3 weeks prior to registration
* No chemotherapy ≤ 2 weeks prior to registration
* No radiotherapy ≤ 4 weeks prior to registration
* No prior irinotecan hydrochloride
* No prior therapy with an epidermal growth factor receptor (EGFR) antagonist (either monoclonal antibody or tyrosine kinase inhibitor), such as gefitinib or erlotinib
* No prior therapy with a dual EGFR/HER2 inhibitor (e.g., lapatinib)
* No concurrent interleukin-11(oprelvekin)
* Routine use of granulocyte colony stimulating factors (CSFs) is not permitted during course 1 of this study

  * Subsequent use of CSFs is permitted at the discretion of the treating investigator
* No other concurrent antitumor therapy