RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die.

PURPOSE: Phase II trial to study the effectiveness of ecteinascidin 743 in treating patients who have advanced soft tissue sarcoma.

OBJECTIVES: I. Determine the therapeutic activity of ecteinascidin 743 in patients with advanced soft tissue sarcomas. II. Determine the duration of response in these patients. III. Determine the acute side effects in these patients.

OUTLINE: This is a multicenter study. Patients receive ecteinascidin 743 (ET-743) IV over 24 hours every 3 weeks. Treatment continues for at least 2-6 courses in the absence of disease progression or unacceptable toxicity. Patients are followed every 6 weeks until disease progression and every 12 weeks after disease progression.

PROJECTED ACCRUAL: Approximately 28-44 patients will be accrued for this study.

DISEASE CHARACTERISTICS: Histologically proven soft tissue sarcoma, including the following cell types: Malignant fibrous histiocytoma Liposarcoma Rhabdomyosarcoma Synovial sarcoma Malignant paraganglioma Fibrosarcoma Leiomyosarcoma Angiosarcoma including hemangiopericytoma Neurogenic sarcoma Unclassified sarcoma Miscellaneous sarcoma including mixed mesodermal tumors of the uterus Cell types NOT allowed: Malignant mesothelioma Chondrosarcoma Neuroblastoma Osteosarcoma Ewing's sarcoma Embryonal rhabdomyosarcoma Measurable lesion with evidence of progression within 6 weeks prior to study (osseous lesions, hepatomegaly, lymphedema, ascites, and pleural lesions are not considered measurable) No symptomatic or known CNS metastases

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: WHO 0-1 Life expectancy: Not specified Hematopoietic: Neutrophil count at least 2,000/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater than 1.75 mg/dL Albumin at least 2.5 g/dL AST and ALT less than 1.5 times upper limit of normal (ULN) (2.5 times ULN if liver metastasis present) Alkaline phosphatase less than 2.5 times ULN No other significant hepatic disease (e.g., active hepatitis, cirrhosis, etc.) Renal: Creatinine no greater than 1.36 mg/dL OR Creatinine clearance at least 60 mL/min Cardiovascular: No prior cardiovascular disease Other: No other severe medical illness No psychosis No prior or concurrent second primary malignant tumors, except adequately treated carcinoma in situ of the cervix or basal cell carcinoma Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: At least 4 weeks since prior chemotherapy No more than 1 prior regimen of combination chemotherapy OR No more than 2 prior single agent regimens No other concurrent chemotherapy Endocrine therapy: Not specified Radiotherapy: No prior radiotherapy to sole index lesion No concurrent radiotherapy Surgery: Not specified Other: No other concurrent investigational drugs