DISEASE CHARACTERISTICS:

• Histologically proven solid tumor or lymphoma

  • Responded to irinotecan OR no existing curative therapy
• No leukemia
• Measurable or evaluable disease

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• Karnofsky 70-100%

Life expectancy:

• Not specified

Hematopoietic:

• WBC at least 3500/mm^3
• Absolute neutrophil count at least 1500/mm^3
• Platelet count at least 100,000/mm^3

Hepatic:

• Bilirubin normal
• SGOT/SGPT less than 5 times upper limit of normal (unless due to disease)

Renal:

• Creatinine no greater than 1.5 mg/dL OR
• Creatinine clearance at least 60 mL/min

Other:

• Not pregnant or nursing
• Fertile patients must use effective contraception
• No inflammatory bowel disease requiring therapy
• No chronic diarrhea syndrome or paralytic ileus

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• At least 2 weeks since prior colony stimulating factor
• At least 4 weeks since prior biologic therapy
• No concurrent biologic therapy

Chemotherapy:

• See Disease Characteristics
• At least 4 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin)
• No other concurrent chemotherapy

Endocrine therapy:

• Not specified

Radiotherapy:

• At least 4 weeks since prior radiotherapy to greater than 25% of bone marrow
• No concurrent palliative radiotherapy

Surgery:

• No prior transplant

Other:

• No concurrent substrates of UGT1A1 enzyme
• No concurrent inducers or inhibitors of UGT1A1 enzyme activity