Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed non-hematologic malignancy

- Brain metastases or primary brain tumors are eligible provided patient is not
receiving steroids or antiepileptic medications

PATIENT CHARACTERISTICS:

Age:

- 18 to 55 or 70 and over

Performance status:

- CTC 0-2

Life expectancy:

- Not specified

Hematopoietic:

- Granulocyte count at least 1,500/mm^3

- Platelet count at least 100,000/mm^3

Hepatic:

- Bilirubin no greater than upper limit of normal (ULN)

- SGOT no greater than ULN

Renal:

- Creatinine no greater than ULN

Other:

- Not pregnant or nursing

- Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- Not specified

Chemotherapy:

- At least 4 weeks since prior chemotherapy (6 weeks for nitrosourea)

- No more than 1 prior chemotherapy regimen for metastatic disease (no limit if
administered in the adjuvant setting)

- No prior camptothecin

Endocrine therapy:

- See Disease Characteristics

Radiotherapy:

- At least 4 weeks since prior radiotherapy

- No concurrent radiotherapy, including for palliation

Surgery:

- At least 4 weeks since prior major surgery