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