DISEASE CHARACTERISTICS: Histologically proven advanced solid tumor for which no curative therapy exists No prior or concurrent primary brain tumor or brain metastasis

PATIENT CHARACTERISTICS: Age: Over 18 Performance status: ECOG 0-1 Life expectancy: At least 12 weeks Hematopoietic: Granulocyte count at least 1,500/mm3 Platelet count at least 100,000/mm3 No inherited predisposition to hypercoagulation Hepatic: Bilirubin normal SGOT no greater than 2.5 times upper limit of normal Renal: Creatinine no greater than 1.5 mg/dL Cardiovascular: No uncompensated coronary artery disease on electrocardiogram or physical examination No myocardial infarction or severe unstable angina within the past 6 months No severe peripheral vascular disease related to diabetes mellitus No deep venous or arterial thrombosis within the past 3 months No inherited predisposition to thrombosis Pulmonary: No pulmonary embolism within the past 3 months Other: No other malignancies within the past 5 years except basal or squamous cell skin cancer or carcinoma in situ of the cervix No other significant medical illness No serious active infections Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY: Biologic therapy: At least 4 weeks since prior biologic therapy and recovered No concurrent biologic therapy Chemotherapy: At least 4 weeks since prior chemotherapy and recovered No other concurrent chemotherapy No prior cisplatin or irinotecan Endocrine therapy: At least 4 weeks since prior hormonal therapy and recovered No concurrent hormonal therapy Radiotherapy: At least 4 weeks since prior radiotherapy to less than 25% bone marrow and recovered No concurrent radiotherapy Surgery: At least 4 weeks since prior surgery and recovered No concurrent surgery Other: No other concurrent investigational drugs