Inclusion Criteria

DISEASE CHARACTERISTICS:

- Stratum A (less than 3 months since prior therapy) closed to accrual effective
06/20/2000)

- Histologically or cytologically confirmed recurrent or refractory small cell lung
cancer

- Only 1 prior regimen allowed (an alternating regimen with
cyclophosphamide/doxorubicin/vincristine and etoposide/cisplatin is acceptable)

- No mixed histology

- Measurable or evaluable disease that has not been in the field of prior radiotherapy

- No uncontrolled CNS metastases (treated CNS metastases eligible)

PATIENT CHARACTERISTICS:

Age:

- 18 and over

Performance status:

- ECOG 0-2

Life expectancy:

- Not specified

Hematopoietic:

- Absolute neutrophil count at least 2,000/mm^3

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

Hepatic:

- Total bilirubin no greater than 1.5 times upper limit of normal (ULN) OR

- Direct bilirubin normal

Renal:

- Creatinine no greater than 1.5 times ULN

Cardiovascular:

- No unstable angina pectoris

- No uncontrolled congestive heart failure

- No myocardial infarction within the past 3 months

Other:

- No uncontrolled infections

- No other concurrent malignancy except skin cancer or localized prostate cancer

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- Not specified

Chemotherapy:

- See Disease Characteristics

- No prior topoisomerase I inhibitor (e.g., topotecan or irinotecan) or taxane (e.g.,
paclitaxel or docetaxel)

- At least 3 months since other prior chemotherapy

Endocrine therapy:

- Not specified

Radiotherapy:

- See Disease Characteristics

- At least 2 weeks since prior radiotherapy

- No concurrent radiotherapy

Surgery:

- At least 3 weeks since any prior major surgery