Combination Chemotherapy Plus Trastuzumab in Treating Patients With Advanced, Recurrent, or Metastatic Colorectal Cancer

DISEASE CHARACTERISTICS: * Histologically confirmed advanced, recurrent, or metastatic colorectal adenocarcinoma * Resected CNS metastases stable greater than 1 month after completion of radiotherapy for CNS metastases eligible * No existing CNS metastases allowed * Measurable disease * At least 1 dimension as at least 20 mm with conventional techniques OR * At least 10 mm with spiral CT scan * No truly nonmeasurable lesions: * Bone lesions * Leptomeningeal disease * Lymphangitis cutis/pulmonis * Abdominal masses not confirmed and followed by imaging techniques * Cystic lesions * Must have progressed on at least 1 prior, but no more than 2 prior, fluorouracil and/or irinotecan containing treatment regimens for metastatic colorectal cancer * Must have documented HER-2/neu overexpression by immunohistochemistry staining * Staining score at least 2+ PATIENT CHARACTERISTICS: Age: * 18 and over Performance status: * ECOG 0-2 Life expectancy: * Not specified Hematopoietic: * Granulocyte count at least 1,500/mm3 * Platelet count at least 100,000/mm3 Hepatic: * Bilirubin no greater than 2.0 mg/dL * AST no greater than 2.5 times upper limit of normal Renal: * Creatinine normal OR * Creatinine clearance at least 60 mL/min Cardiovascular: * No history of cardiac ischemia or congestive heart failure * LVEF at least 50% by ECG or MUGA Other: * Not pregnant or nursing * Fertile patients must use effective contraception * No concurrent second malignancy except nonmelanoma skin cancers or carcinoma in situ of the cervix unless completed therapy and considered to be at less than 30% risk of relapse PRIOR CONCURRENT THERAPY: Biologic therapy: * Not specified Chemotherapy: * See Disease Characteristics * No prior platinum containing chemotherapy * At least 3 weeks since prior chemotherapy and recovered * No other concurrent chemotherapy Endocrine therapy: * Not specified Radiotherapy: * At least 3 weeks since prior radiotherapy and recovered Surgery: * Not specified