DISEASE CHARACTERISTICS:

• Histologically proven recurrent or metastatic solid tumor that is not amenable to curative surgery, radiotherapy, or conventional chemotherapy of proven value
• Must have disease that can be safely and readily biopsied under local anesthesia (including, but not limited to, subcutaneous metastases, superficial lymph node metastases, or ascites)

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• ECOG 0-2

Life expectancy:

• At least 3 months

Hematopoietic:

• WBC at least 4,000/mm^3
• Platelet count at least 100,000/mm^3

Hepatic:

• Bilirubin no greater than 1.5 times upper limit of normal (ULN)
• AST less than 2 times ULN
• Alkaline phosphatase less than 2 times ULN
• Lactic dehydrogenase less than 2 times ULN

Renal:

• Creatinine no greater than 1.5 times ULN

Other:

• HIV negative
• No active uncontrolled bacterial, viral, or fungal infection
• No nonmalignant systemic disease that would preclude study participation
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• See Disease Characteristics
• At least 3 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin)
• No prior irinotecan

Endocrine therapy:

• Not specified

Radiotherapy:

• See Disease Characteristics
• At least 4 weeks since prior radiotherapy except small-port radiotherapy for local control
• No concurrent radiotherapy except small-port radiotherapy for local disease control (e.g., pain relief or impending fracture)

Surgery:

• See Disease Characteristics
• At least 2 weeks since prior major surgery

Other:

• No concurrent anticoagulants except warfarin or subcutaneous heparin