DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed soft tissue sarcoma

  • Metastatic or locally advanced
  • Failed at least 1 prior therapy
• Measurable disease outside prior irradiation field
• No CNS metastases

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• SWOG 0-2

Life expectancy:

• Not specified

Hematopoietic:

• Not specified

Hepatic:

• Bilirubin no greater than 2 times upper limit of normal (ULN)

Renal:

• Creatinine less than 1.5 times ULN
• Calcium less than ULN
• Potassium normal

Other:

• No other malignancy within the past 5 years except stage I or II cancer in complete remission, carcinoma in situ of the cervix, or basal cell or squamous cell skin cancer
• Not pregnant or nursing
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Prior biologic response modifier therapy allowed

Chemotherapy:

• No more than 3 prior chemotherapy regimens for advanced, recurrent, or metastatic disease
• No other concurrent chemotherapy

Endocrine therapy:

• No concurrent hormonal therapy for malignancy

Radiotherapy:

• See Disease Characteristics
• At least 3 weeks since prior radiotherapy and recovered
• No concurrent radiotherapy

Surgery:

• At least 4 weeks since prior surgery and recovered

Other:

• No other concurrent cardiac glycosides