Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed synovial sarcoma meeting 1 of the following stage criteria:

- Locally advanced disease, defined as 1 of the following:

- Incurable by conventional multidisciplinary therapy, including surgery

- Surgically resectable only with significant morbidity

- Metastatic disease

- Tumor HER2/neu positive (2+ or 3+) by immunohistochemistry

- Tumor tissue must be available AND patient must be willing to allow specimen
submission

- Measurable disease

- No known CNS metastases

PATIENT CHARACTERISTICS:

Age

- 18 and over

Performance status

- Zubrod 0-2

Life expectancy

- Not specified

Hematopoietic

- Absolute neutrophil count > 1,000/mm^3

- Hemoglobin > 8 g/dL

- Platelet count > 100,000/mm^3

Hepatic

- Bilirubin < 1.5 times upper limit of normal (ULN)

- SGOT and/or SGPT < 1.5 times ULN (5 times ULN if liver metastases are present)

Renal

- Creatinine < 1.5 times ULN OR

- Creatinine clearance > 60 mL/min

Cardiovascular

- LVEF > 45% by MUGA

Gastrointestinal

- No active peptic ulcer disease

- No active gastrointestinal bleeding

- No active inflammatory bowel disease

Other

- Not pregnant or nursing

- Fertile patients must use effective contraception

- No known HIV positivity

- No other malignancy within the past 5 years except adequately treated basal cell or
squamous cell skin cancer, carcinoma in situ of the cervix, or adequately treated
stage I or II cancer in complete remission

PRIOR CONCURRENT THERAPY:

Biologic therapy

- No concurrent filgrastim (G-CSF)

Chemotherapy

- At least 3 weeks since prior chemotherapy

Endocrine therapy

- Not specified

Radiotherapy

- At least 60 days since prior radiotherapy to the target lesion*

- No concurrent radiotherapy NOTE: *Lesion must have demonstrated disease progression
after completion of therapy

Surgery

- At least 21 days since prior major surgery and recovered

Other

- At least 60 days since prior embolization or radiofrequency ablation to the target
lesion* NOTE: *Lesion must have demonstrated disease progression after completion of
therapy