DISEASE CHARACTERISTICS: Incurable, solid tumors in patients who are not candidates for effective systemic therapy Progressive disease defined as a 25% increase in diameter of measurable lesions or appearance of new lesions

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Zubrod 0-2 Life expectancy: Greater than 16 weeks

Hematopoietic: WBC at least 4000/mm3 Platelet count at least 125,000/mm3 Hemoglobin at least 8 g/dL Hepatic:

Bilirubin within normal limits SGOT no greater than 1.5 times normal (2.5 times normal with disease involvement) Alkaline phosphatase no greater than 2.5 times normal PT or PTT less than 1.5 times normal Renal: Creatinine no greater than 1.5 times normal Creatinine clearance at least 60 mL/min Cardiovascular: No history of congestive heart failure, active ischemic heart disease, or uncontrolled hypertension No myocardial infarction within the past 6 months Other: Not pregnant or nursing (negative pregnancy test required) Fertile patients must use effective contraception No weight loss of 10% or more in the past 3 months No frequent vomiting No severe anorexia

PRIOR CONCURRENT THERAPY: Biologic therapy: Prior biologic therapy allowed No concurrent immunotherapy Chemotherapy: At least 4 weeks since prior chemotherapy (6 weeks for mitomycin or nitrosoureas) and recovered No greater than 300 mg/m2 cumulative dose of doxorubicin No concurrent chemotherapy Endocrine therapy: At least 4 weeks since prior hormone therapy No concurrent anticancer hormone therapy Concurrent corticosteroids allowed Radiotherapy: At least 4 weeks since prior radiotherapy and recovered No concurrent radiotherapy Surgery: Not specified Other: At least 4 weeks since prior investigational drug therapy No other concurrent investigational therapy