DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed advanced solid tumor refractory to standard therapy or for which no standard therapy exists

• Renal function as defined by the following parameters:

  • Normal (creatinine clearance (CrCl) greater than 80 mL/min)
  • Mild dysfunction (CrCl 50-80 mL/min)
  • Moderate dysfunction (CrCl 30-50 mL/min)
  • Severe dysfunction (CrCl less than 30 mL/min)
  • End-stage renal disease (requiring dialysis)
• No symptomatic or active brain metastases (e.g., edema or progression on CT scan or MRI)

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• ECOG 0-2

Life expectancy

• At least 12 weeks

Hematopoietic

• Absolute neutrophil count at least 1,500/mm3
• Platelet count at least 100,000/mm3
• Hemoglobin at least 9.0 g/dL

Hepatic

• Bilirubin normal
• AST or ALT no greater than 2 times upper limit of normal
• Albumin at least 2.8 g/dL

Renal

• See Disease Characteristics

Cardiovascular

• No active congestive heart failure
• No uncontrolled angina
• No myocardial infarction within the past 6 months

Other

• No concurrent serious infection
• No other life-threatening illness
• No overt psychosis or mental disability or other incompetency that would preclude informed consent
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy

• No concurrent anticancer biologic therapy

Chemotherapy

• At least 4 weeks since prior chemotherapy (6 weeks for mitomycin or nitrosourea) and recovered
• No prior exatecan mesylate
• No other concurrent anticancer chemotherapy

Endocrine therapy

• No concurrent anticancer hormonal therapy
• Concurrent megestrol for appetite stimulation allowed

Radiotherapy

• At least 4 weeks since prior radiotherapy and recovered
• No concurrent anticancer radiotherapy

Surgery

• At least 4 weeks since prior major surgery and recovered
• No concurrent anticancer surgery

Other

• At least 4 weeks since prior investigational drugs including analgesics or antiemetics
• At least 1 week since prior grapefruit juice
• No other concurrent anticancer therapy
• No other investigational drugs during and for 4 weeks after study
• No concurrent grapefruit juice
• No other concurrent anticancer cytotoxic therapy
• Concurrent chronic hemodialysis or ambulatory peritoneal dialysis allowed