Inclusion Criteria

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